Ent 101 Entomology And Environmental Health Lecture Notes PDF

1 Ent 101 ENTOMOLOGY AND ENVIRONMENTAL HEALTH Arthropoda Characteristics Exoskeleton Chitin Segmented appendages Segmented body Bilateral symetry Dorsal tubular heart Ventral paired nerve chord Classes of Arthropods Arachnida – spiders, mites, tick...

1 Ent 101 ENTOMOLOGY AND ENVIRONMENTAL HEALTH Arthropoda Characteristics Exoskeleton Chitin Segmented appendages Segmented body Bilateral symetry Dorsal tubular heart Ventral paired nerve chord Classes of Arthropods Arachnida – spiders, mites, ticks Diplopoda – millipedes Chilopoda – centipedes Insecta – insects  Ticks Arachnida Characteristics Ticks, mites, spiders, scorpions Body divided into two parts mites Four pairs of legs No antennae spiders scorpions No wings  Chilopoda Centipedes Longer antennae than millipedes Flattened in cross section 1 pair of legs per segment Beneficial – prey on other arthropods Are fast moving Have poison glands & can inflict a painful bite  Diplopoda Millipedes Feed on fungi and decaying plants Can damage plants 2 pair of legs per segment 2 visible body parts – head and body Round in cross section Slow moving CIRCLE THE INSECTS Cuticle Insects’ exoskeleton is formed basically from an epithelial cell layer that secrets chitin (a sugar) with proteins, fats and pigments membrane seta epicuticle exocuticle pore canals endocuticle basement epithelium tormogen trichogen membrane Head of Insect Head of Insect Genae ‘Cheeks’ Head of Insect Compound eyes Head of Insect Ocelli Simple eyes Head of Insect Antennae Head of Insect Clypeus Head of Insect Frons Head of Insect Mouth Head of Insect Labrum Head of Insect Mandibles Head of Insect Maxilla Head of Insect Labium 21  Types of mouthparts Chewing m.p. Grasshoppers Piercing sucking m.p. Mosquito 22  Types of mouthparts Sponging sucking m. p. Siphoning sucking m. p. House fly Butterfly 23  Types of mouthparts Chewing lapping m. p. Honey bee 24 25 ORIENTATION OF THE HEAD Prognathous: orientated horizontally. Mouth parts are pointed forward. Hypognathous: orientated vertically. Mouth parts are pointed down. Opisthognathous: orientated obliquely. Mouthparts are pointed backward. 26 TYPES OF ANTENNAE Setaceous Filiform Moniliform Serrate Bristle-like Thread-like Bead-like Saw toothed Dragonfly Cockroaches Termites Click beetles Ground beetles TYPES OF ANTENNAE Clavate Capitate Pectinate Geniculate Gradually clubbed Abruptly clubbed Comb-like Elbowed Carrior beetles Butterflies Male glow-worms Ants Weevils TYPES OF ANTENNAE Aristate Lamellate Pulmose Pouch-like with Nested plates Feather-like lateral bristles Scarab beetles (June bugs) Mosquitoes Flies Male moths ANTENNAL STRUCTURE 30 WHY INSECTS ARE SUCCESSFUL they have a protective shell or exoskeleton (hard and light) they are small (eat a little, hide easily) most of them can fly (escape, migrate) short life cycle (multiply quickly) 31 32 THANK YOU