Mites and Their Characteristics

Chromosomes of Mites

• Mites have 2 to 12 chromosomes, varying from group to group (Wrensch et al, 1994)

Categories of Mites

• Divided into four main groups based on economic importance:
  • Phytophagous mites (plant feeding mites)
  • Predatory mites
  • Stored grain and stored product mites
  • Parasitic mites (mites of medical and veterinary importance)

Phytophagous Mites

• Infest and damage cultivated crops, vegetables, orchards, and wild vegetation
• Around 7500 species are known to damage plants
• Characteristics: opaque white, translucent, slow-moving, short-legged, and suck sap with stylet-like chelicerae
• Cause qualitative and quantitative losses, e.g., 10-30% losses in rice, sugarcane, eggplant, okra, and chillies, and up to 50-80% in mangoes
• Feeding results in leaf stippling, blotching, curling, and twisting, and modification of developing tissue by forming galls and injecting toxins

Gamasid Mites

• Considered as vectors of epidemic hemorrhagic fever virus
• Leptotombidiumni akamushi and L.deliense transmit scrub typhus in humans

Mites Associated with Mammals and Birds

• Usually translucent or whitish in color, changing to reddish brown after feeding on host's blood
• Life cycle includes egg, larva, two nymphal stages, and adult
• Act as causative agents for anemia, pneumonia, crustation of skin, hair loss, and death of host
• Life cycle generally requires 2 to 17 days

Mites Associated with Honeybees

• External parasites like Varroa destructor and Varroa jacobsoni, and internal parasites like Acarapis woodi
• Penetration of cells by mite stylets and injection of saliva cause mechanical damage and changes in cell cytology, physiological, and biochemical processes of non-punctured adjacent cells

Eriophyidae

• Occur on all parts of a plant, causing different types of injuries
• Classified into:
  • Gall formers, causing hypertrophy of cells and formation of galls on leaves, flower buds, and stem
  • Leaf rollers, rolling whole leaves or only edges of leaves and feeding within the rolls
  • Erineum formers, producing hair-like outgrowths on the epidermal layer of cells
  • Blister mites, causing formation of blisters on the leaf sheath and feeding within

Tenuipalpidae and Tarsonemidae

• Feed on the ventral surface of leaves near the midrib or veins, causing bronzing and rusting symptoms
• Form galls on the leaves and stems of plants
• Infest tender portions of plants and suck sap from buds, leaves, shoots, flowers, and stem sheaths

Learn about the characteristics and behavior of mites, including their association with mammals and birds, life cycle, and role as vectors of diseases. Discover how they change color after feeding on host's blood and the nature of damage they cause.