Insect Pests of Fruit, Plantation, Medicinal & Aromatic Crops (2+1)

3. Stem borer

3. Stem borer- Batocera rufomaculata Dejean. (Cerambycidae:Coleoptera )

Damage

• The grubs bore in to the branches causing drying of the branches.
Damage

• The grubs feed by tunneling through the bark of branches and main stem.
  
• The damage may also show itself by the shedding of leaves and drying of terminal shoots in early stage of attack.
  
• When the damage occurs at the main stem, the whole tree succumbs.
Bionomics

• The adult is a large longicorn beetle about 5 cm long and 1.6 cm broad and yellowish brown in colour.
  
• It has two pink dots and lateral spines on thorax.
  
• It lays eggs singly on the bark, or cracks and crevices on the tree trunk or branches hatch in about 1-2 weeks.
  
• The grub is stout with well-defined segmentation and yellow in colour.
  
• The grub makes zig - zag burrow beneath the bark.
  
• The grub feeds on the internal tissues and become full fed in about six months.
  
• It pupates inside the tunnel itself.
  
• The pupal period is. 19-36 days.





Management

1. Remove and destroy the dead trees and affected branches from the garden.
2. Swab trunk with carbaryl 20 g/1.
3. Use light trap 1 / ha to attract adult moths or beetles.
4. Locate bore holes, spike out grubs using a needle or iron wire.
5. Exclude the alternative host, silk cotton from mango orchards.
6. Grow less susceptible varieties viz., Neelam, Humayudin, and Panchavarnam.
7. Swab coal tar + Kerosene (1 :2) on the basal part of the trunk up to 3 feet high after scraping the loose bark to prevent the female from egg laying.
8. Spike out the grub if the bore holes are located, and add insecticide emulsion (monocrotophos 0.1 % at 20 ml / hole) a fumigant tablets (3 g aluminium phosphide) or petrol and seal the holes with the mud.
9. Follow padding with monocrotophos 36 WSC 10 ml per tree soaked in absorbent cotton when the trees are not in bearing stage.
10. Apply carbofurean 3 - 5 g per hole and plug with mud after removing the grub by using needle.
11. Apply carbofuran granules in the soil at 75 g / tree basin.