Sources of carry-over and possibilities of cultural control of Pectinophora gossypiella (Saunders) in the Punjab, Pakistan

Mortality of PEW diapausing larvae in the soil residue was 56% due to irrig ation, 22% with moldboard plough and 16% with local cultivator. Larval mort ality was 54% in cotton stalks shredded with a rotary slasher and incorpora ted into the soil with rotavator and 23% with the disc plough. Moths emerge nce from the crop residue and gin waste kept as heaps, spread or incorporat ed into the soil was completed from March to May and remaining larvae died when temperatures were above 40 degreesC. In the left over bells of cotton stalks kept horizontally, 3.5% larvae survived in the lower part of the hea p but mortality was 100% when cotton stalks were stored in small bundles ve rtically. There was no major alternate host and very negligible infestation was found on Althaea rosea, Hibiscus mutabilis and on ratoon cotton. (C) 2 001 Elsevier Science Ltd. All rights reserved.