Development of Helicoverpa armigera on different hybrids of sunflower (Helianthus annuus)

Abstract

An experiment was conducted during 1999-2000 to study the development of Helicoverpa armigera (Hubner) on hybrids of sunflower (Helianthus annuus L.) at Ludhiana. Incubation period varied from 2.67 ± 0.33 days on 'Jwalamukhi' to 3.50 ± 0.35 days on 'PSFH 67'. Less number of eggs hatched (87.34%), on 'PSFH'. The mean pupal survival was significantly higher on 'Jwalamukhi', (87.82%) and 'MSF 8' (82.64%) than on 'SH 3322' (78.20%) and 'PSFH 67' (72.72%). The mean pupal weight was maximum (282.75 ± 10.00 mg) on 'Jwalamukhi' and minimum (260.62 ± 7.16 mg) on 'PSFH 67'. There were significant differences in female pupal length on all the 4 hybrids during March 1999. There were no significant differences in pre-oviposition, oviposition and post-oviposition period on 4 hybrids. Pre-oviposition period varied from 2.0 ± 0.41 to 3.5 ± 0.29 days. Oviposition period was maximum (3.75 ± 0.26 days) on 'PSFH 67' and minimum on 'MSFH 8' (3.0 day) and 'SH 3322' (3.0 ± 0.58 days). Sex ratio was in the favour of males o)l'PSFH 67'. The number of eggs/laid female varied from 386.50 ± 104.47 to 749.00 ± 143.2, being maximum on 'Jwa1amukhi' and minimum on 'PSFH 67'. The insect took less number of days (32.47 ± 1.81 days) to complete its development on 'Jwalamukhi' and more number of days (35.71 ± 2.26 days) on 'PSFH 67'.