What is Citrus Stem Borer?
Anoplophora versteegi, commonly called stem/trunk borer, make holes for entry & exit in trees. They feed on the tissues of trunk to feed. They interrupt the normal conduction of food material to various parts of tree.
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Life Cycle of Citrus Stem Borer
Life cycle-
- Eggs– Female laid 30-50 eggs are laid on twigs and thorns covered by a resinous fluid secretion. The egg period ranges from 11-72 days
- Larva– The larvae is creamy white with flat head. The grub/larvae period is 10 months.
- Pupae– The grub pupates in a tunnel inside of the stem and pupal period three weeks.
- Adult– Adult emerges in April-May and remain within the pupal chamber for a long time. It is characterized with dull metallic green to dark violet adults, with a yellow band across the middle of the elytra. Adult completes its life cycle in 1 year.
How does it damage the plant?
- The larvae make holes into the branches and feeds on the soft tissue.
- The feeding zone held with the presence of webby mass of chewed wood particle and excreta of larvae conspicuously plastered on tree trunks.
- The adult feed on bark of twigs.
Symptoms-
- The grub of the trunk borer insect bores the tree trunk near ground level horizontally up to the pith and then tunnels vertically and again horizontally for exit.
- The attacked tree gradually dries up with leaves turning yellow and drop off prematurely due to the results in the interruption in the translocation of cell sap.
- Affected twigs break at the point of attack and severely affected plants lose its vigour and look sickly.
Prevailing season–
Post monsoon & Onset of winters.
Management-
| Mechanical & Cultural Control | Chemical Control |
| Maintaining cleanliness in the orchard is the thumb rule for any pest and disease infestationPruning should be done 4-5cm below the dried portion and pruned portion should be disposed or burned properly.Control is necessary during all the life cycle stages but the best control time is when eggs are hatching and larvae are small.A piece of wire inserted into the bored hole to kill the caterpillar inside can be quite effective in small orchards or when the infestation is low. | In case of severe infestation, a swab of cotton wool soaked in Flubendiamide @ 2ml per liter or Chlorantiniliprole 25% EC @ 0.5 ml per liter injecting the same through bored holes can effectively control the same.Injecting kerosene oil in the hole has also been reported to be effective. Always seal the hole after any treatment with cotton or mud. |
Source–
Book – High density cultivation of Nagpur Mandarin by ICAR – CCRI, (IARI)
