Here is the information you requested about the pests that affect cashew trees:
1. Tea mosquito bug:
- Scientific name: Helopeltis antonii
- Family: Miridae
- Order: Hemiptera
- Damaging stage: Nymphs and adults feed on the tender parts of shoots, flowers, and nuts.
- Nature of damage: Feeding causes the formation of characteristic corky spots on nuts, deformed flowers, and shoot withering.
- Oviposition: Eggs are laid in groups on the underside of leaves.
- Pupation site: Pupation occurs on the plant or in the litter beneath the tree.
- Management: Cultural practices like pruning, removing fallen debris, and early harvest can help control the population. Insecticides can be used if the infestation is severe.
2. Cashew stem borer:
- Scientific name: Plocaederus ferrugineus
- Family: Cerambycidae
- Order: Coleoptera
- Damaging stage: Larvae bore into the main stem and branches.
- Nature of damage: Infested branches and stems exhibit gummy exudation, wilting, and dieback.
- Oviposition: Eggs are laid in crevices on the stem or branch.
- Pupation site: Larvae pupate within the galleries they create in the wood.
- Management: Infested branches should be pruned and destroyed. Insecticides can be used if necessary.
3. Cashew shoot borer:
- Scientific name: Maruca vitrata
- Family: Crambidae
- Order: Lepidoptera
- Damaging stage: Larvae bore into the tender shoots and feed on the developing leaves.
- Nature of damage: Infested shoots show wilting, dieback, and defoliation.
- Oviposition: Eggs are laid on the young leaves or tender shoots.
- Pupation site: Larvae pupate within silken cocoons on the plant or in the soil.
- Management: Pruning infested shoots, applying botanical insecticides, and using pheromone traps can help control the population.
4. Cashew thrips:
- Scientific name: Scirtothrips dorsalis
- Family: Thripidae
- Order: Thysanoptera
- Damaging stage: Both nymphs and adults feed on the leaves, flowers, and fruits.
- Nature of damage: Feeding causes leaf curling, stunted growth, distorted flowers, and scarring on the nuts.
- Oviposition: Eggs are inserted into the plant tissue.
- Pupation site: Pupation occurs within the soil.
- Management: Cultural practices like removing infested plant material, pruning, and application of suitable insecticides can help manage thrips populations.
