Department of Agricultural Entomology, Tamil Nadu Agricultural University, Coimbatore - 641003, Tamil Nadu, (India).
1A part of approved M.Sc. (Ag.) thesis submitted by P. Jeyakumar to Tamil Nadu Agricultural University, Coimbatore - 641003 (India).
Under insectary conditions, the most preferred age of cotton (variety MCU 5) for oviposition by the American serpentine leaf miner, Liriomyza trifolii (Burgess) was 10-day old plants, the number of eggs laid being significantly more (3.4 eggs per leaf) as compared to 45-day old plants (1.23 eggs per leaf). But, there were no significant differences in ovipositional punctures produced in plants of different ages, viz., 10, 20, 30 and 45-day old plants. The number of ovipositional punctures varied from 4.8 per leaf (10-day old plants) to 4.1 per leaf (45-day old plants). Amongst three ages, viz., 15, 30 and 45-day old cotton plants of varieties, MCU 5, LRA 5166 and hybrid TCHB 213; the per cent incidence (mining) due to leaf miner was respectively 44.0, 56.2 and 54.8, being the highest on 15-day old plants. On the other hand, biomass was higher in plants exposed to L. trifolii adults 45 days after sowing (DAS) in comparison to 15 DAS, irrespective of varieties.
