6. Lime/orange tree borer: Cheledonium cinctum, (Chloridolum) C. alcamene (Cerambycidae; Coleoptera)

Distribution and Status: Major and highly destructive pest in South India.

Host range: Orange

Damage symptoms

The grubs bore into stem and feed on the internal tissues, which results in drying of terminal shoots in early stages, followed by wilting of thicker branches and main stem.  Gum exudation and wood powder accumulation on ground below are symptoms of attack.

Bionomics 

Adult lays 30-50 eggs are laid on twigs and thorns covered by a resinous fluid secretion. Female lays 30-50 eggs. Egg period 11-72 days, creamy white grub with flat head, grub period 10 months, pupates in a tunnel inside the stem and pupal period three weeks. Dull metallic green to dark violet adults, with a yellow band across the middle of the elytra emerge in April-May and remain within the pupal chamber for a long time. Total life cycle is completed in one year

Management

• Prune infested branches containing grubs
• Plug fresh holes with cotton soaked in monocrotophos solution mixed at 5 ml/ 20 ml of water.
• Undertake stem padding with monocrotophos 2.5 ml+2.5 ml of water.