Beneficial Organisms (PDF)

BENEFICIAL ORGANISMS (INSECTS, ARTHROPODS, NEMATODES) What is Beneficial Organism? 1. In agriculture and gardening, a beneficial organism is any organism that benefits the growing process, including insects, arachnids and other animals, plants, bacteria, fungi, viruses, and nematodes. 2....

BENEFICIAL ORGANISMS (INSECTS, ARTHROPODS, NEMATODES) What is Beneficial Organism? 1. In agriculture and gardening, a beneficial organism is any organism that benefits the growing process, including insects, arachnids and other animals, plants, bacteria, fungi, viruses, and nematodes. 2. Beneficial organisms include those that pollinate crops, produce useful products, kill harmful organisms, recycle waste, maintain soil health, etc. 3. Insects, spiders, predatory mites, and other arthropods are considered beneficial when they eat arthropods that humans consider undesirable. 4. Over 97 percent of those usually seen in the home landscape are either beneficial or are innocent bystanders. 5. Managing our yards as habitat for beneficial arthropods is a great way to minimize pest problems, often greatly reducing or eliminating the use of pesticides. Some Definition of Terms: 1. Arthropods - is an invertebrate animal that has an exoskeleton, a segmented body, and jointed appendages. 2. Insects - They are the largest group within the arthropod phylum. Insects have a chitinous exoskeleton, a three-part body (head, thorax and abdomen), three pairs of jointed legs, compound eyes and one pair of antennae 3. Arachnids - a class of chelicerate arthropods that includes spiders, scorpions, mites, and ticks. They have become adapted for a terrestrial life and possess both lungs and tracheae, and many have silk or poison glands. 4. Nematodes – A.K.A. roundworms, are multicellular animals that belong to the phylum Nematoda. CATEGORIES OF BENEFICIAL 1. Predators - capture and eat other organisms such as insects or arachnids. Predators include spiders, mites, nematodes and insects. Over 100 families of spiders, mites, nematodes and insects contain species that are predaceous, either as adults, immatures or both. a. Spiders Most spiders observed in the open during the day are not likely to bite or cause lasting harm if they do bite you. Spiders whose bites might require you to seek medical attention spend most of their time hidden. Spiders are arachnids, not insects. They have 8 legs and 2 body parts. They lack wings and antennae. Spider families vary by body shape, web type, hunting or other behavior, and the arrangement and relative size of their eyes. All spiders are predators, and most feed on insects caught in a web. Others, such as jumping spiders and wolf spiders, are active hunters relying on excellent vision to kill their prey. Crab spiders, anothercommonly encountered group, ambush their prey. Garden Spider Wolf Spider Daddy Long Leg  b. Predatory Mites Predatory mites are not insects but are related to spiders and ticks (Arachnida). They consume dozens of related spider mites daily. They look almost identical to and are about the same size as spider mites. They have a shiny, unspotted, more pear-shapedbody, and longer legs that enable them to move much faster than spider mites (can’t see all this with naked eye). They are commercially available. Thrips Predatory Mites Two-Spotted Mite Predator Predatory Mites Amblyseius cucumeri Phytoseiulus persimilis Neoseiulus californicus c. Nematodes Beneficial nematodes are microscopic round worms that feeds on over 200 kinds of soil dwelling insects. They feed on insects in their larval and pupal stage primarily in the soil; been known to attack pests above ground in all stages also. Nematodes move within moist soil and enter a suitable host through natural openings. Beneficial nematodes are microscopic round worms that feeds on over 200 kinds of soil dwelling insects. They feed on insects in their larval and pupal stage primarily in the soil; been known to attack pests above ground in all stages also. Nematodes move within moist soil and enter a suitable host through natural openings. A healthy white grub larva next to a darker one infected with the nematode Heterorhabditis bacteriophora. Heterorhabditis controls: Beet Armyworm, Cucumber Beetle, Heterorhabditis bacteriophora Leafminer, Thrips, Ticks, and more Steinernema controls: Armyworm, Cutworm, Vine Weevil, Cockroaches, Corn Earworm, Leafminers, Flea Beetles, And More Steinernema carpocapsae  d. Insects Predatory insects eat many pest insects and are an important part of a natural control program for the home garden. The most common insect predators are in the beetle (Coleoptera), true bug (Hemiptera), lacewing (Neuroptera), wasp (Hymenoptera), and dragonfly (Odonata) orders, as well as some flies such as flower fly (Diptera). Predatory insect larvae and adults feed on all stages of mites and insects. (COLEOPTERA) Lady Beetles There are many species of ladybird beetles that vary in size, color and pattern. Dome-shaped, often brightly colored adults, also known as “ladybugs” and ladybird beetles, range in size from 1/16 to 3/8 of an inch long. Colors are highly variable and include orange, black, pink, or yellow. Spots may or may not be present. Predaceous both as larvae and adults, and feed chiefly on aphids. They also eat scale insects and mealybugs. Seven-Spotted Asian Ash Grey Two-Spotted Convergent Soldier Beetles Ground Beetles Soldier beetles (Cantharis spp.) Most are shiny brown, black, or blue- black are colorful insects, often black insects ranging in size from one quarter to or brown with a red, yellow or over one inch long, with long legs and long orange head and thorax. antennae. They are elongate and flat with Ground beetles have prominent jaws used to long threadline antennae. kill caterpillars (including armyworms, cutworms, and grubs) and other insects, as well as small snails and slugs. Both adults and larvae are primarily nocturnal Golden Rod Small Black  (Neuroptera) Lacewing Common species of lacewings include two green lacewing species, Chrysoperla carnea and Chrysopa oculata, and one brown lacewing species, Hemerobius pacifus. Green lacewing larvae feed on insect pests, adults feed on pollen and nectar. Both larvae and adult brown lacewings feed on insects. Pests eaten by lacewings Lacewing Larvae include aphids, spider mites, whiteflies thrips, leafhoppers, scales, mealybugs, psyllids, small caterpillars and insect eggs. Green Lacewing Common Green Lacewing Brown Lacewing Chrysopa oculata Chrysoperla carnea Hemerobius pacifus (HEMIPTERA) Assassin Bug Big-eyed Bug Assassin bugs feed on a wide variety of Big-eyed bugs (Geocoris spp.) are aptly pests ranging from small ones like aphids named insects that are about one-eighth to larger ones like caterpillars. inch long, black and white, with silvery They may either stalk their prey, or wait wings and large, bulging eyes on the sides for an insect to come near, then suddenly of the head. attack with their dagger-like, piercing- Big-eyed bugs are important predators of sucking beak, repeatedly stabbing their chinch bugs (with which they are often prey. confused). Large species will bite humans as well as They also feed on small caterpillars, mites, their prey. insect eggs, and any other insect that they can catch and subdue. Adults are commonly found on flowers. Minute Pirate Bug Minute pirate bugs (Orius spp. & Anthocoris spp.) are tiny (one-eighth to one-quarter inch long) black and white insect. Adults and larvae feed on thrips, mites, insect eggs, and any kind of insect that they can catch.  (MANTODEA) Praying Mantis Adults are 2-4 inches long and green, brown or yellow in color. Mantids (Mantis spp.) have an elongated thorax and grasping forelegs, which they use to hold their prey while they eat. Eat virtually any insect they can catch. Egg case (DIPTERA) Hoverflies Hover Flies are also known as Syrphid Flies or Flower Flies. Adults (0.3-0.6”) may be brightly colored, and many resemble wasps and bees. Adults frequent flowers over which they hover before landing to feed on nectar and pollen (their only food source). The larvae of most species are predaceous feeding on aphids, scales, thrips and other small soft-bodied insects. Larvae  (ODONATA) Dragonflies Red Pearcher Adult Dragonfly Emerging Typically ranges from 2 to 3 inches in length Bright and vibrant colors, often with a combination of green, blue, and black markings Approximately 3 to 4 inches Found in various habitats including freshwater lakes, rivers, ponds, and rice fields Throughout the Philippines, including Luzon, Visayas, and Mindanao islands Agile fliers known for their rapid and acrobatic flight patterns Carnivorous, preying on smaller insects such as mosquitoes, flies, and smaller dragonflies Mating involves a complex aerial dance, and females lay their eggs in or near freshwater bodies Many species of dragonflies found in the Philippines exhibit striking and unique coloration, making them a popular subject for insect enthusiasts and photographer s. Damselflies Damselfy Niad Narrow-winged Damselfly Generally smaller and more delicate than dragonflies, typically ranging from 1 to 2 inches in length Diverse range of colors and patterns, often with metallic or iridescent hues Typically, less than 3 inches Found in a variety of freshwater habitats, including rivers, streams, ponds, and rice fields Throughout the Philippines, including Luzon, Visayas, and Mindanao islands Similar to dragonflies, damselflies are agile fliers known for their graceful flight patterns and are often seen perched on vegetation near water bodies. Carnivorous, feeding on smaller insects such as mosquitoes, flies, and other small aquatic invertebrates Damselflies lay their eggs in or near freshwater, and their mating rituals are intricate and often involve courtship displays. 2. Parasitoids - are insects that parasitize other insects. The immature stages of parasitoids develop on or within its host, eventually killing it. Parasitoids may attack all stages of their host (eggs, larvae, nymphs, pupae, adults). Adult parasitoids serve mainly to transport their offspring to new hosts. Two major groups of parasitoids are parasitic wasps and tachinid flies. (HYMENTOPTERA) Wasps Most insect parasitoid wasps are host-specific. There are hundreds of species of parasitoid wasps. The most commonly noticed ones are the larger Braconid and Ichneumonid wasps. Many other parasitoid wasp species are much smaller, only a few millimeters long. Braconid Wasp Ichneumonid Wasp The wasps typically have a larval stage that feeds on the inside of the host insect, and the larvae slowly devour the host, which eventually dies. Some of the wasps emerge to pupate on the outside of the host, others develop into pupae inside and emerge from the host as adults. An adult parasite can lay eggs in hundreds of host individuals. Infested Pupa Host Larvae (DIPTERA) Parasitic Flies – Tachinids The tachinids are the most important parasitoid flies. Adult tachinid flies measure anywhere from 1/3″ to 3/4″ long. Most tachinids are endoparasites - the developing larvae (maggots) feed within their hosts.  Some adult female tachinid lay eggs on leaves to be eaten by caterpillars, others insert eggs or maggots directly into the host, and still others attach eggs or maggots to the outside of the host. Eggs consumed by the host or inserted by the mother hatch into maggots inside the victim. Eggs affixed to the skin of prey hatch and the maggots bore into the body of the host. Safely inside, the maggots complete their development, consuming their host as they grow. Fly Emerged from Pupa 3. Pollinators - include honeybees, leafcutter bees, other wild bees, butterflies, moths and other insects that visit flowers to feed on nectar and pollen. Pollinators transfer pollen within and between flowers of the same species (pollination) which is essential to seed and fruit production for plants. (Hymenoptera) Bees Bees are the most important and efficient pollinators, Bees rely solely on protein and carbohydrates found in pollen and nectar. As they travel in search of food, pollen sticks to the very fine, short hairs that cover their bodies and legs and is transferred from flower to flower. North America has more than 5,000 species of native bees, 90 percent of which lead solitary lives. Bees are unique – only insects that actively gather large amounts of pollen to feed themselves. Honeybees Introduced to North America in the late 1600s. In the Philippines, the Asian honeybee (Apis cerana) has several native names which include Ligwan, Laywan and Alig. These social bees can forage up to five miles from their hive in search of nectar and pollen and are highly effective pollinators. Western Honey Bee Stingless Bee Asian Honey Bee Giant Honey Bee  Carpenter Bees Chew nesting galleries in solid wood, stumps, logs and dead branches or in soft pithy wood. Can sting but not aggressive Food is pollen and nectar Eastern Carpenter Bee (Xylocopa virginica) Southern Carpenter Bee (Xylocopa micans) Bumble Bees Size – ¾” to 1 ½” Not usually Feed on pollen and nectar aggressive but have Pollen basket (corbicula) on their hind legs a painful sting Hairy abdomen Sweat Bees Sweat bees are a large and very diverse group. Usually 0.12”- 0.40” long Usually more numerous than all other bees except honeybees. They feed on nectar and pollen and provide a store for each egg they lay. Very important pollinators for wildflowers and crops Lasioglossum nymphale Poey’s Furrow Bee Sphecodes heraclei  Leaf-cutting Bees From 5mm to 20 mm, solitary Each nest cell has 1 egg and pollen balls Use almost any cavity for a nesting site Important pollinators Cut ¼” to ½” circular pieces of leaves to construct nests of wildflowers, fruits and vegetables (Hymenoptera) Wasps In addition to being highly beneficial predators of insect pests such as caterpillars and flies, wasps are also pollinators. Many species take advantage of the quick energy nectar and pollen can provide. Because their slender bodies have fewer hairs than bees, wasps aren’t quite as effective at pollination but they can still pass pollen along from one plant to another. Mason Wasp (Zethus spp.) Potter Wasps (Eumenes spp.) Solitary, 3/8” to 3/4” long Potters use mud Masons use abandoned Insectivorous – Use lepidopteran larvae burrows or vegetable to feed their young – Beneficial matter for nests. Adults feed on pollen and nectar Potters use mud Zethus slossonae Eumenes smithii Paper Wasps (Polistes spp.) Nests are made of wood pulp and saliva Feed on caterpillars, adult insects, and nectar Red Paper Wasp European Paper Wasp (Polistes Carolina) (Polistes dominula)  (LEPIDOPTERA) Butterflies There are about 17,500 species of butterflies in the world, and around 750 species in the United States. In the Philippines it is about 903 species recorded. Butterflies have excellent vision and are thus drawn to bright colors, including reds and oranges. Butterflies especially rely on native wildflowers for nectar and as caterpillar host plants. Blooms that provide good landing areas, such as flat-topped clusters or flowers with wide petals, make feeding easier. Having long legs and a proboscis, or feeding tube, a butterfly’s body may never actually touch the flower it’s resting on. But its wings still brush against and collect pollen, especially when hanging onto down-facing blooms. Danaid Eggfly Monarch Cabbage White Pipeline Swallowtail Moths There are some 160,000 species of moths in the world, compared to 17,500 species of butterflies. When it comes to pollinating late afternoon or evening bloomers moths, are very effective. Although most moths are only active after dusk, diurnal moths feed during the daytime. Their bodies may not have direct contact with flowers but pollen does collect on a moth’s quickly beating wings as they feed, just as with butterflies. Atlas Moth Hawk Moth Silkworm Moth Tiger Moth Snout Moth  (DIPTERA) FLIES Flies can transport large amounts of pollen, which they often pick up from nectar- producing flowers. They prefer shallow, open flowers with readily accessible nectar droplets. Flies generally have sponging mouthparts, which vary in length and limit which flowers different species will visit. They are drawn to umbelliferae (carrots, celery/celeriac, parsnip, and parsley), brassicaceae (cole crops, mustards, and Asian greens), rosacea (strawberry, raspberry, and blackberry), and alliaceae (onions, leeks, and chives), many of which also happen to be unattractive to bees. Flowers that produce a putrid odor, like rotting meat , carrion, dung, humus, sap and blood are fly- pollinated. Blowfly Bee fly Tachinid Fly Syrphid Fly References: Willis, D., Dunaway, C., Timmerman, A. and Barton-Willis, D., (2022). Beneficial Insects and Pollinator Protection. [ebook] Available at: [Accessed 11 October 2022].  ARTHROPODAL PEST KINGDOM: Animalia PHYLUM: Arthropoda; Arthro = Joints, Poda = legs Subphylum: Hexapoda; Hexa = six, Poda = legs CLASS: Insecta Subclass: Pterygota = winged insects AGRICULTURALLY IMPORTANT INSECT ORDERS Insect Orders Greek meaning Examples Blattodea Blatta = cockroach Cockroaches, Termites Coleoptera Koleos = sheath; ptera = wing Beetles, Weevils, Fireflies Dermaptera Derma = skin; ptera = wing Earwigs Diptera Di = two; ptera = wing Mosquitoes, Flies Hemiptera Hemi = half; ptera = wing Aphids, Mealybugs, Scaly Insects Hymenoptera Hymen = membrane; ptera = wing Bees, Wasps Lepidoptera Lepido = scales; ptera = wing Butterflies, Moths Mantodea Mantis = prophet; eidos = form Mantis Neuroptera Neuro = nerve; ptera = wing Lacewing Odonata Odontos = tooth Dragonflies, Damselflies Orthoptera Ortho = straight; ptera = wing Grasshoppers, Crickets, Katydid Phasmatodea Phasm = phantom Walking Stick Thysanoptera Thysanos = fringe; ptera = wing Thrips KINGDOM: Animalia PHYLUM: Arthropoda; Arthro = Joints, Poda = legs Subphylum: Chelicerata; khele = claw, keras = horn CLASS: Arachnida – arakhne = spider Subclass: Acari – akari = mites, tiny, minute AGRICULTURALLY IMPORTANT ACARID ORDERS Superorders Greek meaning Examples Parasitiformes Parasitos = parasite, forma = shape Mites and Ticks Acariformes Akari = mites, forma = shape Mites The Biological World and its Balancing Mechanism Natural ecosystem - Phytophagous insects co-existed in a complex relationship with plant communities that vary in phenology, abundance, and association with other living organisms Plant life Insects are intimately associated with a number of beneficial activities including pollination, or harmful activities like damaging the plants and even cause its death. In biological warfare between plants and insects, harmful insects are suppressed either by other insects or through natural plant defense mechanism. These factors prevent the excessive population growth of harmful insect species. Crop Production Natural ecosystems are disturbed when land is cleared to plant crops. Leads to disturbance of balance between the host and insect communities Example: Kaingin, excessive use of fertilizers and pesticides (DDT) The use of DDT had given us 3 eras: a. Era of Optimism (1946-1962) b. Era of Doubt (1962-1976) c. Era of IPM (1976- present) Broad spectrum insecticides kill both the insect pests and the beneficial insects. Era of Optimism (1946-1962) DDT is a colorless, crystalline, tasteless and almost odorless organochloride known for its insecticidal properties. DDT (dichloro-diphenyl-trichloroethane) was developed in the 1940s. It was initially used with great effect to combat malaria, typhus, and the other insect-borne human diseases among both military and civilian populations and for insect control in crop and livestock production, institutions, homes, and gardens. Era of Doubt (1962-1976) Silent Spring written by Rachel Carson and published by Houghton Mifflin on September 27, 1962. It brought environmental concerns to the American public and led to a nationwide ban on DDT for agricultural uses, and inspired an environmental movement that led to the creation of the U.S. Environmental Protection Agency EPA has banned the registration and interstate sale of DDT for nearly all uses in the United States effective December 31, 1972  Harmful Effects of Pesticides: a. Insect Resistance b. Insect Resurgence c. Harm non-target Organisms 1. increase pesticide residues on crops 2. increase pesticide residues on bodies of animals d. Pollute the environment Era of IPM (1976- present) Integrated Pest Management - An ecological approach to pest control which utilizes a combination of any of the following pest control tactics: a. Host Plant Resistance (Antibiosis, Antixenosis, Tolerance) b. Cultural Control c. Biological Control d. Use of Chemicals (last resort) Review of Ecological Concepts & Principles - basis of Biological Control To reduce a pest population, one must make its environment unfavorable for the pest. Example: use of insecticides, resistant plant varieties, cultural control, etc. Biological control of insect pests is one of the methods of pest control which manipulates the biotic factors to create an environment unsuitable for insect pests to live. Biological control is safe, permanent, cheap and is environmentally friendly. Things to consider in the study of ecology a. Balance of nature – the tendency of the population densities of all species in the same general area to maintain a more or less numerical relations to each other, due to interaction with each other and the physical environment. b. Population equilibrium & equilibrium position Population equilibrium - the average species density when the population fluctuates both positively and negatively. Equilibrium position – the steady density or the average population level of species. A single species may have different average population densities in different habitats due to the following differences in: 1. food 2. shelter 3. natural enemies 4. physical factors Permanent displacement of the equilibrium position of a species classified into 2 types: 1. Disturbances resulting from a major change in habitat Example: change in food, drying of the ponds, etc. 2. Disturbances which result from transferring an insect from its native home into a new habitat where natural enemies are absent. Example: importation of new plant varieties Most insect pests are immigrants thus they are classified into the second type. These introduced species are of less importance in their native home where their population equilibrium is kept at low level by their natural enemies. Examples of Introduced Pest Effects on the Ecosystem Jumping plant lice Introduced by the typhoon in 1980. Has (Heterophylla cubana) affected almost all standing Leucaena leucocephala (ipil-ipil) plantations Leafminer (Liriomyza sp.) Accidentally introduced with the importation of chrysanthemum: major pest of potato and ornamentals. Mealy bug (Pseudococcus sp.) Affects coconut in Northern Palawan. Accidentally introduced in 1990 with the importation of hybrid coconut planting materials. Spiraling whitefly Affected vegetables (Aleurodicus dispeures) and ornamentals. Accidentally introduced with the importation of ornamental kalanchoe in the 1970s. Riceblack bug Major problem for rice in Mindanao and (Scontinophora coarctata) Leyte. Introduced through vessels plying the route between the province of Palawan and countries south of the Philippines. (Golden Apple Snail) Consumes crops like rice, taro, cassava, Pomacea canaliculate papaya, kangkong, and sweet potato was introduced in Asia, specifically in Taiwan from Argentina in 1979 as human food to be cultured indoors (Mochida, 1991). From Taiwan, it spread to Japan in 1981 and to the Philippines in 1983 (Santos, 1987) to boost food production and increase the protein intake of average Filipino families.  (Mango Pulp Weevil) Its establishment in southern Palawan is Sternochetus frigidus attributed to the shipping route and trade activities between southern Palawan and Borneo, which is a native area of the pulp weevil (Basio et al., 1994). (Mango Seed Weevil) Originating from India (Waterhouse, 1993) Sternochetus mangiferae and Myanmar (CABI, 2001), it has often been spotted by the Service of the United States Department of Agriculture (Anonymous, 1988). However, its mode of transfer to the Philippines is unknown. Review Basic Definition of Insect Pests and Their Characteristics Insect pests - injure/cause damage to human’s interest - destroy crops; compete with humans for food & shelter; transmit diseases & reduce availability, quality, and value of human resources. Terminologies: Movement of organisms to new locations is important to Biological Control Indigenous (or native) – those organisms in a specified area, that arose evolutionarily in their current taxa in that location Precinctive – are the subset of the indigenous of a given area that occur nowhere else Adventive- those species in specified location that did not evolve there but arrived there from elsewhere (opposite of native) Immigrants- are those adventive organisms in a specified location that arrived there without the deliberate, purposeful aid of man. Includes both actively dispersing organisms, ones arriving as stowaways on plants or other commodities moved by man. Introduce- those brought to a location by the conscious choice of man (food crop species, ornamentals or forage plants, pets and domestic animals, biological control animals). Biological control attempts to restore the natural balance by duplicating the conditions in the pest’s native home through the importation of its natural enemies. This successful restoration of the natural balance exemplifies the ecological basis for biological control. Insect Pest based on their Feeding Habits: a. Chewing ex. larvae of stemborers b. Rasping-sucking ex. nymph & adult thrips c. Cutting-sponging ex. adult horse fly d. Piercing-sucking ex. nymph & adult green leaf hoppers Major Orders of Insect Pest: – Hemiptera ex. Green leafhoppers – Lepidoptera ex. Rice stemborers – Diptera ex. Corn seedling maggots – Coleoptera ex. Coconut rhinoceros beetles – Thysanoptera ex Thrips – Orthoptera ex. Mole crickets – Blattodea ex. Cockroaches – Phasmatodea ex. Walking sticks – Isoptera ex. Termites – Siphonaptera ex. Fleas Factors that determine the existence of an organism in an ecosystem Ecosystem – any community of living (biotic) and non- living (abiotic) things working together. - Biotic factors include plants, animals and any other living things while abiotic factors include all non-living things in an ecosystem. - Both factors are related to each other in an ecosystem, if one is missing the entire community is affected for the survival of an individual or organisms. - Focus Interactions Host-Parasitoid Predator-Prey Interactions: 1. Single-Species Population - dynamics of populations with discreate or distinct generations - individuals in the population compete for the limiting resource e.x. ovipositional sites (adult), food (larvae) 2. Interspecific Competition -important in communities such as: social insects, insects feeding on ephemeral resources (last for a short time), parasitoids, predatory beetles 3. Interaction between single host or prey and natural enemy Host-Parasitoid Systems Prey-Predator System A. Host-Parasitoid Systems - dependent on host rate of increase Various factors affecting the overall parasitoid performance: 1. searching efficiency 2. max. rate of attack of adult females 3. spatial distribution of parasitoid 4. sex ratio 5. survival of parasitoid progeny B. Prey-Predator System Factors affecting predatory ability: 1. Intrinsic factors a) Limited time available for prey searching b) Limited stomach size c) Time needed for digestion 2. Extrinsic factors a) Competition with another predator b) Environmental disturbances Competition with another predator Resource competition/Scramble competition - when there are many predator & abundant preys available, the predators capture as many preys as quickly as possible Interference competition/Contest competition - as predation causes prey to become more limited, competing predators may interact directly, leading to injuries or limited predatory success. Environmental disturbances (ex. flooding, fire, pesticide use of farming). C. Multispecies Systems - multiple natural enemies should be used if the net impact is greater than that of a single natural enemy. 1. Natural enemy species attacking competing prey/host species 2. Competing natural enemy species sharing a common prey or host species 3. Prey species attacked by both generalist and specialist natural enemies CONCEPT OF BIOLOGICAL CONTROL OF AGRICULTURAL PESTS Definition and Concepts of Biological Control 1. Biological control - refers to the utilization of natural enemies to regulate or suppress population of insect pests. - is the use of living organisms/natural enemies to suppress the population density or impact of a specific pest organism, making it less abundant or less damaging than it would otherwise be (DeBack, 1974 and Crump et.al.,1999) - intentional (intervention) use of parasitoid, pathogen, antagonist, or competitor populations to suppress a pest population, making it less abundant and thus less damaging than it would otherwise be. 2. Natural control - is the regulation of insect pest population by any or combination of natural factors (biotic and abiotic factors). Major components of Natural Control: 1. Environmental factors (abiotic) ex. Climatic factors (light, temperature, water, etc.) Soil factors (structure of soil, minerals and salt) 2. Natural enemies (biotic) ex. Food, interspecific and intraspecific competition. Definitions of Terms: Parasite – an organism that is usually smaller than its host, and a single individual does not kill the host (e.g. tapeworms, round worms, lice and ticks) Parasitoid – are insects that kill their hosts slowly and complete their full development on a single host - immature stage derive its nourishments from its host, the adults are free-living (e.g. Trichogramma spp., Telenomus triptus, etc.) Predator – a free living organism throughout its life, kills its prey, usually larger than its prey, and requires more than 1 prey to complete its development (e.g. Rodolia cardinalis, preying mantis, etc.) Primary parasitoid – insects that develop on a non- parasitic insect. Hyperparasite – insects that develop or attack another parasitoid. Direct hyperparasite – the parasite deposits directly into the host and the developing larva kills the host before it reaches the pupal stage. Multiple parasitism – a situation wherein more than one primary parasitoid species occurs simultaneously on the single host. Superparasitism – a situation wherein several individuals of the same species attack a single host but the host could not support them up to maturity. Gregarious or polyembryonic parasitism – when an individual is attack by several individuals of the same species and allows them to develop to maturity. Autoparasitism - type of hyperparasitism wherein the female develops as a primary parasitoid but the male is a secondary parasitoid of the female of its own species. In Encarsia formosa males (larvae) exhibit a unique behavior called hyperparasitism. Female wasps lay their eggs inside whitefly nymphs, which serve as hosts for the developing larvae. Male wasps, however, parasitize other Encarsia formosa larvae (either female or male) that are already developing inside the whitefly host. This allows the male larvae to feed off their own species, instead of directly targeting the whitefly. Cleptoparasitism – type of parasitism wherein the adult parasitoid prefers to give to its progeny the previously parasitized host of another parasitoid. e.g. Craticulina seriata is a cleptoparasite of sand wasps, depositing its larvae on the food reserved for the larvae of the wasp. Unique characteristics of insect as it affects biological control strategies Character- any possible trait an individual might possess used to construct classification, identify taxa which classification recognize could be anything from shape of a particular sclerite (morphological character) to a particular kind of amino acid in the hemolymph. Taxonomic character categories: a. Morphological - These are physical traits and structures that can be observed directly and are the traditional basis for insect taxonomy e.g. body segments, wings, antennae etc. b. Physiological - These refer to the biological functions of insects and their systems. While these traits may not always be visible, they are important in understanding classification and adaptation e.g. metabolism, respiration etc. c. Molecular - These are typically invisible but provide precise classification at the species level and help in evolutionary studies e.g. DNA sequencing, Protein-coding genes etc. Biological characters categories:  a. Ecological - These refer to the roles that insects play in their ecosystems and their interactions with the environment e.g. habitat, tropic levels, adaptation to environment, interaction with other species etc. Insects are found in a wide variety of habitats, including terrestrial (soil, plants, forests, deserts), aquatic (ponds, streams), and even extreme environments (e.g., caves, high altitudes) Some insects are highly specialized, living in specific ecological niches (e.g., aquatic larvae of dragonflies). Trophic Level Herbivores - Insects that feed on plants, such as caterpillars (Lepidoptera) or aphids (Hemiptera). Carnivores - Predatory insects, such as mantises or ladybugs, that feed on other insects or small animals. Detritivores - Insects that feed on decaying organic matter, such as dung beetles or termites. Parasites - Insects that live on or inside other organisms, such as fleas, lice, and parasitic wasps. Pollinators - Insects that facilitate plant reproduction by transferring pollen, such as bees, butterflies, and hoverflies. b. reproductive - These traits describe how insects reproduce, ensuring the survival and spread of their species. Mating Systems Monogamy - Rare in insects, but some species have long-term mating pairs (e.g., some termite kings and queens) Polygyny - One male mates with multiple females (e.g., honeybee drones) Polyandry - One female mates with multiple males (e.g., queen honeybees, some butterfly species) Oviparity vs. Viviparity Oviparity - Most insects lay eggs (e.g., butterflies, grasshoppers). Viviparity - Some insects give birth to live young (rare but observed in aphids) Oviposition Behavior - Where and how insects lay their eggs can vary widely.  For example: Endoparasites (e.g., parasitic wasps) lay eggs inside a host. Plant-feeding insects may lay eggs on specific plants that their larvae will later feed on (e.g., monarch butterflies on milkweed) Some insects provide care or protection for their eggs, such as burying beetles that bury dead animals to feed their larvae. Social insects like ants, bees, and termites exhibit advanced brood care, protecting and feeding the larvae in communal nests. Developmental Strategies Holometabolous Insects undergo complete metamorphosis (e.g., butterflies, beetles), allowing distinct stages of life, such as larval feeding and adult reproduction. Hemimetabolous Insects undergo incomplete metamorphosis (e.g., grasshoppers), where juveniles resemble smaller versions of the adults and develop gradually. c. Behavioral - Behavioral characters describe how insects respond to their environment, interact with each other, and perform essential survival tasks. Social Behavior Solitary - The majority of insects live and operate independently, such as beetles, flies, or moths. Subsocial - Some insects exhibit limited parental care, such as dung beetles, which create food resources for their larvae. Eusocial - Highly organized social structures are seen in ants, bees, termites, and some wasps. These species have a division of labor, cooperative brood care, and overlapping generations within colonies. Foraging Behavior - Different species have unique strategies for finding and securing food Random Searching - Some predatory insects search for food without following a specific pattern (e.g., ladybugs hunting aphids). Trail-following - Ants use chemical pheromones to lay down trails that other members of their colony can follow to food sources. Food-hoarding - Some insects, like honeybees, collect and store food (nectar) for future use. Defensive Behavior  Camouflage - Many insects use coloration to blend into their surroundings (e.g., stick insects, leaf mimics). Aposematism - Bright warning colors, often combined with chemical defenses, signal predators to stay away (e.g., the bright orange of monarch butterflies). Mimicry - Some harmless insects mimic more dangerous species, such as hoverflies resembling bees and wasps. Communication Chemical - Insects use pheromones to communicate for mating (sex pheromones), marking territory, or signaling danger (alarm pheromones in ants and bees) Auditory - Some insects, like crickets and cicadas, produce sounds by rubbing body parts together (stridulation) to attract mates or communicate with others. Visual - Fireflies communicate using light flashes to attract mates. Other insects use body movements or color displays for mating purposes. Migration and Dispersal: Some insects undertake long-distance migrations, such as monarch butterflies, which travel thousands of kilometers during their seasonal migrations. Dispersal can be passive (e.g., wind dispersal of aphids) or active (e.g., swarming behavior in locusts). Symbiosis - relationship of 2 or more different organisms in a close association - to live together or living together in more or less intimate association or close union of two dissimilar organisms - also termed as nutritional relationship Three (3) Basic Types of Symbiosis: a) Mutualism - relationship is of mutual benefit to both species. ex. bee & flower b) Commensalism - one species benefits & the other does not but is not harmed. c) Parasitism - an individual derives nutritional benefit at the detrimental expense of another. - some larvae feed on the paralyze host and complete their development - other seek the eggs, larvae or pupae of various insects and deposit their eggs within them - parasitic mode of life is common within Hymenoptera The host plant and important component of biological control types of host plant resistance affecting the pest Resistance - vary between immunity and high susceptibility. Immune plant - is a nonhost for herbivores and usually outside the host range of insect herbivores Immunity of nonhost plants is heritable and is due to either the presence of genes that interfere with the herbivore’s ability to recognize and utilize the nonhost, or the absence of genes necessary for an herbivore to recognize and utilize the nonhost plants. Host Plant Resistance (HPR)- are crop varieties that are resistant to pest damage. Mechanisms of Resistance: a) Antixenosis (non-preference) - mechanism that affects the way an insect perceives the desirability of the host plant - Host plant either provide stimuli that are unattractive to the pest or fail to provide stimuli that are attractive to the pest. Example: Cucumber varieties with hairy leaves (trichomes) can repel aphids or whiteflies. The presence of dense trichomes makes the surface less appealing, and the insect may avoid landing or feeding on it. Glossy Brassica species are less attractive to aphids due to the absence of waxy coatings that usually attract the pest. b) Antibiosis - mechanism that operate after the insect have colonize and have started utilizing the plant. Host plant causes injury, death, reduced longevity, or reduced reproduction of the pest. Example: Bt cotton has been genetically modified to express toxins from the bacterium Bacillus thuringiensis (Bt). When cotton bollworms feed on it, the toxin disrupts their gut function, causing death before they can reproduce. Tomato plants producing higher levels of the defensive compound alpha-tomatine can reduce the growth and survival of caterpillars like Helicoverpa zea. c) Tolerance - adaptive mechanism for the survival of the host plant to yield well despite the damage caused by insect. Plants can heal wounds and fight diseases that enter through wounds. Example:  Wheat varieties tolerant to Hessian fly (Mayetiola destructor) can recover from the damage caused by larvae feeding on their stems. The plant compensates by producing new tillers, maintaining acceptable yields even after initial damage. Rice varieties tolerant to brown planthopper (Nilaparvata lugens) can withstand infestations without significant reductions in yield. The plant continues to grow and repair itself despite feeding damage. NATURE OF BIOLOGICAL CONTROL AGENTS Parasitoid - a parasitic insect that lives in or on and eventually kills a larger host insect (or other arthropods) Host - the insects attacked by the parasitoid (victim) Some Common Parasitic Orders & Families of Parasitoids Two Major Orders: 1. Hymenoptera – bees, wasps, ants 2. Diptera – flies Major Groups of Hymenoptera Trichogrammatidae Mymaridae 1. Superfamily Chalcidoidea (Chalcids) a) Mymaridae b) Trichogrammatidae Mymaridae & Trichogrammatidae - are egg parasitoids and are usually minute, some less than 0.25mm in length Encyrtidae Aphelinidae c) Encyrtidae d) Aphelinidae Metaphycus helvolus - an encyrtid Encarsia pergandiella - parasitize parasitoid of the black scale insect of citrus Bemisia tabaci, whitefly larvae 2. Superfamily Ichneumonoidea Braconidae Ichneumonidae a) Braconidae (Braconids) b) Ichneumonidae Aphidiinae Netelia sp Platygasteridae \Scelionidae 3. Superfamily Serphoidea a) Platygasteridae b) Scelionidae Allotropa sp. – Parasitoids of mealybugs, scales and whiteflies The wasps, Telenomus euproctidis are phoretic on virgin female of Orvasca (= Euproctis) taiwana Major Groups of Diptera 1. Tachinidae Sub-families of Tachinidae: a. Exoristinae (ex. Compsilura concinnata) b. Tachininae c. Dexiinae 2. Cyrtidae/Acroceridae 3. Nemestrinidae 4. Pipunculidae 5. Conopidae - family of parasitoid wasp-mimicking flies that are found worldwide. Thick-headed fly larvae are internal parasites of stinging Hymenoptera. 6. Pyrgotidae - parasitoids of adult scarabaeid beetles or Hymenoptera. They are known to land on flying beetles, and while in flight, to use their conical oviscapt (basal part of the ovipositor) to pierce the soft terga under their host’s elytra and deposit an egg. Characteristics of Insect Parasitoids Destroy their host during development Parasitoids’ host is the same taxa (Class Insecta) Parasitoids are small relative to their hosts or approximates that of hosts Parasitoid adults are free-living, only the immature stages are parasitic Parasitoid adults develop on only 1 host individual during the immature stage Parasitoid similar to predatory insects with respect to population dynamics (with a lag phase) Anatomical Features of Hymenopteran Parasitoids: Appendicular ovipositor - tubular elongated, egg-laying structure, permits precise placement of the egg in habitats that other insects cannot reach Constricted waist (petiole) - constricted between the thorax and the abdomen, 2nd abdominal segment (petiole), promotes abdominal flexibility, enables the adult to sting hosts & prey into paralysis and also permits egg deposition in confined spaces Accessory gland secretions - serve to lubricate the egg, provide substrate for fungal growth, induce gall formation, constitute venom for subduction of prey and host Provide for progeny - place their eggs in/on their host MODE OF DEVELOPMENT OF PARASITOIDS A. With respect to the host placement 1. Endoparasitoid (internal) e.g. Evania appendigaster , (host: egg of cockroach 2. Ectoparasitoid (external) e.g., Bracon brevicornis, (host: larvae of corn borer) B. With respect to numbers of immatures per individual host 1. Solitary parasitoid e.g., Jewel wasp, Ampulex compressa host: adult cockroach 2. Gregarious parasitoid e.g., Braconid wasp, Cotesia congregata (Say) host: tobacco hornworm C. With respect to host stage 1. Egg 2. Larvae 3. Pupa 4. Adult 5. Combinations of the above (i.e., egg-larval parasitoid) D. With respect to effect on host a. Idiobionts: a parasitoid paralyzes and/or arrests the development of a host at oviposition, providing its larvae with an immobilized static resource on which to feed. b. Koinobionts: a parasitoid allows its host to continue to feed and/or develop after oviposition, such that its larvae feed on an active host that is only killed at a later stage. E. With respect to other parasitoid species 1. Primary parasitoid e.g., Itoplectis conquisitor host: saw fly 2. Secondary parasitoid (Hyperparasitism) - The parasitoids develop itself in or on the host that are primary parasitoid. e.g., Aphids’ primary parasitoids (Hymenoptera: Aphelinidae, Braconidae), and associated secondary parasitoids (Hymenoptera: Charipidae, Megaspilidae, Pteromalidae) 2. Tertiary parasitoid (Hyperparasitism) - The parasitoid develops itself in or on the host which is already secondary parasitoid. e.g. Tetrastichus coerulescens F. Competition among immature parasitoid stages 1. Intraspecific competition e.g., Gregarious: Nasonia vitripennis Host: Calliphora vomitoria (pupa) Superparasitism – common in parasitic Hymenoptera - One female allocating more eggs to a host than can usually develop into maturity - Several conspecific females allocating more eggs than can usually develop into maturity 2. Interspecific competition Multiple parasitism- females of more than one species oviposit in a host individual e.g., Solitary: Hyposoter horticola and Gregarious: Cotesia melitaearum Host: Glanville fritillary butterfly, Melitaea cinxia (larva) TYPES OF HYPERPARASITISM a. Direct- when the secondary parasitoid searches out and deposit its eggs in or on the body of its host (a primary parasitoid), which may or may not be contained in the body of a living herbivore insect b. Indirect- when a secondary parasitoid searches out and deposits its egg in the body of unparasitized herbivore. The egg usuall remain underdeveloped until the herbivore is subsequently parasitized by a primary parasitoid, which then serves as the host for the secondary parasitoid c. Facultative- in which secondary parasitoid develop as primary parasitoid under the right conditions d. Obligatory- in which secondary parasitoid can only develop within or on another primary parasitoid e. Autoparasitism- male of the species develops as a hyperparasite (sometimes of the female of the same species) and the female develop as a primary parasitoid. f. Cleptoparasitism-parasitoid preferentially attacks host already parasitized by another parasitoid species and then competes with the first parasitoid for nutrients in the host. MODE OF REPRODUCTION IN PARASITIC HYMENOPTERA:  Arrhenotoky - Unfertilized eggs produce males and fertilized eggs produced females - “biparental”  Deuterotoky - Unmated females produce both male & female progeny - Males produced are biologically and ecologically nonfunctional - “uniparental”  Thelytoky - Only female progeny is produced - Males can be produced when female adults are reared under extreme temperature conditions or if female adults are feed with antibiotics to kill the endosymbionts PARASITOID ATTACK AND HOST DEFENSE Behavior in Host Selection: (5) 1. HOST HABITAT FINDING 2. HOST FINDING  Infochemicals- any chemical conveying information in an interaction between two individuals 2 kinds of infochemicals: 1. Pheromones- act intraspecifically 2. Allelochemicals- act interspecifically 3 types of allelochemicals: 1. Synomones allelochemicals in the receiver a response that is adaptively favorable to both receiver and emitter(source) 2. Kairomones- allelochemicals that evokes in the receiver a response that is adaptively favorable only to the receiver, not the emitter 3. Allomones-allelochemicals that evokes in the receiver a response that is adaptively favorable only to the emitter Sources of chemicals: The host itself (ex. From frass, during molting, during feeding, sex pheromone & aggregation pheromones) From the host’s food plant Interaction between host and food plant (ex. Feeding damage) 3. HOST ACCEPTANCE 4. HOST SUITABILITY Internal Host Defense involves: 1) Cellular Encapsulation- is the formation of a cyst by host cells around foreign objects -may occur in various tissues (epidermal, tracheal, gut muscle, nervous tissues) -hemolymphic capsules are formed by the hemocytes congregating and differentiating into two layers -cells of the inner layer form connective tissue fibers Melanization- reactions involve the deposition of pigment around a parasitoid - Associated with encapsulation and is essentially a cellular phenomenon - The melanin formed is derived from tyrosine by way of phenolase reaction  2) `Humoral Phenomena 2. Viewpoints: a) That hemocytes play primary role in causing the death of living eggs and larvae of parasitoids b) That humoral phenomena cause immunity, and hemocytes merely act as scavengers Host immune responses may be affected by: Temperature Superparasitism Multipleparasitism Parasitoids also may simply starve to death in a host that is unsuitable for its development 5. HOST REGULATION - Regulate or reduce the host population. Characteristics of Insect Predators Predators- entomophagous species whose larvae develop by consuming more than one individual or prey Prey- victim, being eaten up Types of Insect Predators (feeding mechanism): 1. Chewing- chew up and swallow their prey 2. Piercing- sucking – with sharp stylets to pierce the victim’s body then sucks up the body fluid with toxins for efficient prey handling and digestion. PREDATORS Major Characteristics of Predators: 1. Adults and immatures are most generalist than specialist 2. Generally larger than prey 3. Kill or consume many prey 4. Male, females, adults, immatures are predatory 5. Attack adult and immature prey 6. Use camouflage to “sit and wait” for prey 7. May be active hunters 8. Deposit eggs near prey 1. PREY HABITAT LOCATION - process of finding the area where the prey is likely to be found (mediated by various stimuli) Stimuli: a) physical cues (vision and touch) b) chemical cues (odor and taste) c) combination 2. PREY FINDING - successful location of prey Factors affecting prey finding: 1. Travel time between patches of prey 2. Competition between predators 3. Physiological condition of predator 3. PREY ACCEPTANCE - prey fits the physical requirement of the predator Influence by: 1. Size 2. Quality 3. Physical characters Prey defenses 4. Chemical odors Predator handling time - time from seeing the prey & exact time on feeding on it 1. Pursue (runs after) 2. Subdue (keep the prey still) 3. Consume (eaten) Prey Defense 1) Hiding – through cryptic morphology, wherein some are nearly invisible against the background (ex. stick insect) - through camouflage, resembling uniformly colored background 2) Mimicry – some mimic (resembles) dangerous species 2 Kinds: a. Batesian mimicry – a non-toxic species assuming the color pattern of toxic one b. Mullerian mimicry – group benefits from assuming distasteful species 3) Behavioral – to escape predation, they burrow into substrate death feigning (thanatosis) bright colors may flash underneath cryptic ones eyespot provokes retreat 4) Mechanical hard cuticle modified mandible spines on legs like mantids 5) Autotomy – shedding of appendages to distract predators in stick insects 6) Chemical – allomones harm receiver - aposematic (warning) patterns - reflex bleeding or autohemorrhaging Chemical Defenses: Class I: cantharidine, cyanide, alkaloid, cardenolides - Irritate, injure, poison or drug individual (immediate: upon handling, delayed: induce vomiting Class II: acid, aldehyde, aromatic ketone, quinone and terpenes - Harmless, stimulate scent and taste receptors, discourage feeding 7) Social defense – termites, soldier guards with large mandibles at entrance, blocks nest 8) Immunity - self-protection via cuticle and hemolymph with phagocytes against foreign body 9) Phenotypic plasticity – single genotype exhibits a range of phenotypes depending on the season, influenced by food eaten (seasonal change of immature) 4. PREY SUITABILITY - whether it can be utilized as prey May be affected by: 1. Nutritional condition prey 2. Stage of prey 3. Defense mechanism exhibited by prey 5. PREY REGULATION - regulate/reduce prey population FEEDING HABITS OF INSECT PREDATORS Predacious Insects vary in their dietary range a) Monophagous- feeds on only 1 species of prey; highly specific Ex. vedalia beetle feeds on cottony cushion scale insect b) Stenophagous/Oligophagous- restrict feeding to a range of related taxa Ex. Hippodomia convergens feeds on aphid’s species c) Polyphagous - a range of species accepted as prey Ex. praying mantis feeds on small insects Determining Prey Range: 1. Observation 2. Gut Analysis - through dissection 3. Feces Analysis - examine undigested part 4. Serological Techniques - for identifying which predators feed on target pests Adaptations: 1. Have grasping & holding forelegs, large eyes & movable head (preying mantis) 2. Have specialized mouthparts to capture aquatic prey (nymphs of dragonflies) 3. Excellent fliers (adult dragonflies) 4. Use enlarged legs to grab and subdue prey (adult carabid beetles) 5. Have specially constructed pits (antlion larvae) 6. Assist each other in capturing and moving their prey to their nests (ants) 7. Paralyze their prey with a venomous sting (wasps) 8. Deposit their eggs directly among the prey (syrphid fly adults) 9. Body shape and slow movements (coccinellid beetle adults) Attributes of an Effective Natural Enemy 1. High Searching ability a) Its power of locomotion b) Its power of perception c) Its power of survival d) Its aggressiveness & persistence 2. Limited host specificity - High degree of host specificity indicates good bio-physiological adaptation to the host and fairly direct dependence on changes in the host’s population 3. High reproductive potential - Short developmental period and relatively high fecundity (number of offspring) 4. Wide environmental tolerance - Well adapted to a broad range of climatic conditions 5. Restriction of oviposition to suitable hosts - Oviposition in previously parasitized hosts or unhealthy hosts would limit the effectiveness of the parasitoid 6. Amenability to insectary rearing - This would facilitate the breeding of material for colonization and distribution, thus make early control of pest more probable 7. Density-dependent performer - Only those natural enemies that increase mortality levels in their host or prey populations. The cause of mortality alone does not mean that a natural enemy will “regulate” a host or prey population. 8. Good competitive ability - Many natural enemy species may compete for the same host. A good natural enemy may be outcompeted resulting in inefficient control 9. Synchronization with the host and its habitat - Some natural enemies may not appear in sufficient numbers at crucial times (spring) - Allow hosts to reproduce first