TUBER VEGETABLES :: MAJOR PESTS:: LEAF FOLDER

4. Leaf folder: Brachmia convolvuli (Gelechiidae: Lepidoptera)
Distribution and status: It is regarded as a pest of several Ipomoea species.
Host range Ipomoea triloba and I. aquatic, weed Mikania cordata (Asteraceae).
Damage symptoms
Young larva scrapes the tender surface tissues of leaves remaining in thin webbings. Later on leaves folded longitudinally and green tissues eaten resulting in drying of leaves. Folds are usually single, but sometimes two folds are made, or two leaves are joined together.

Brachmia convolvuli

Bionomics
Adult is a small slender moth and grayish-brown in colour. It lays eggs in small groups at the base of radiating veins on the underside of leaves. The eggs are oval, yellowish white when newly laid and turn pinkish yellow. Egg period three days. White neonate larva feeds on leaves and becomes full grown in 14 days undergoing five instars.Full-grown larva is slightly flattened and tapering towards both ends. Head is reddish-brown, glossy and flattened; thorax and two abdominal segments are velvety black and other segments are yellowish-white with a velvety black band. It pupates within leaf fold in 7 days.

Brachmia convolvuli

IPM
Management

* Use of insect-free planting materials

* Conserve ichneumonid parasite,Macrocentrus sp.that attacks young larvae when they have not yet folded the leaf margins.

* If level of infestation warrants the use of chemicals,then contact-systemic insecticides can be applied.

*Collect and destroy  folded leaves along with egg clusters,larvae and pupae

*Spray dichlorvos 76 SC 660 ml or endosulfan 35 EC 750 ml or carbaryl 50 WP 1.0  kg or phosalone 35 EC 750 ml in 500 L water per ha to control widespread infestation