Suman Manjoo ¹, N. K. Bajpai ¹

Affiliations
1 Department of Entomology, Rajasthan College of Agriculture (MPUAT), Udaipur, IN

Abstract

Investigations on parasitization of different host ages (5 to 20 days old) of Chilo partellus larvae by Cotesia flavipes were carried in the laboratory conditions at 27±2°C and 75±5 per cent relative humidity. Higher parasitization and cocoon formation was recorded on the 17 and 20 day old larvae of C. partellus with 82.61 and 82.46 per cent parasitization and 43.09 and 42.70 cocoon formation, respectively while no parasitization and cocoon was recorded in 5 day old larvae. The 11 and 14 day old larvae were highly preferred recording significantly more female progeny and on par with 17 and 20 days old larvae.

Keywords

Cotesia flavipes, Host Age, Chilo partellus, Parasitism, Cocoon Formation, Sex Ratio.

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Suman Manjoo ¹, N. K. Bajpai ¹

Affiliations
1 Department of Entomology, Rajasthan College of Agriculture (MPUAT) Udaipur 313 001, Rajasthan, IN

Abstract

Investigations on larval parasitization of Chilo partellus (Swinhoe) by Cotesia flavipes Cameron in ovipositional chambers of different sizes were carried out under laboratory conditions at 27±2°C and 75±5 per cent relative humidity. Maximum parasitization (89.56 per cent) and maximum number of cocoons (37.53) was recorded in test tube when only one larva was provided in ovipositional chambers. The larval parasitization and cocoon formation were reduced with the increase in larval density from 2 to 5 larvae per chamber. The sex ratio recorded in test tube was statistically superior to pearl pet jar of 1000 and 2000 g but was on par with pearl pet jar of 500 g. The data showed that the provision of one larva to the one pair of adult of C. flavipes in test ovipositional chamber resulted in more female biased sex ratio, (80.0 per cent) in test tube followed by 78, 72 and 53 per cent sex ratio in pearl pet jar of 500, 1000 and 2000 g respectively.

Keywords

Cotesia flavipes, Larval Endoparasitoid, Chilo partellus, Maize Stem Borer, Ovipositional Chambers

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Suman Manjoo ¹, N. K. Bajpai ¹

Affiliations
1 Department of Entomology, Rajasthan College of Agriculture (MPUAT) Udaipur - 313 001, Rajasthan, IN

Abstract

Investigations on storage at 5 to 20°C for 5 to 30 days on biological parameters of Cotesia flavipes Cameron were carried in the laboratory. Adult emergence from cocoons of C. flavipes varied with storage time and temperature. The storage of cocoons for 10 and 15 days at 5, 10, 15 and 20°C did not affect adult emergence significantly and resulted in 95.96 to 97.58 per cent and 95.22 to 98.46 per cent adult emergence respectively and was at par with 5°C. Lowest temperature (5°C) significantly affected the female emergence (24 to 39 per cent) at different days of storage. Maximum female emergence (85 per cent) was observed when cocoons were stored for 10 days at 20°C followed by 82 per cent at 20°C for 15 days. The storage of cocoons at 10°C reduced female emergence, 51 to 60 per cent, while at 15°C it ranged from 68 to 76 per cent. Maximum cocoons (47.08) were formed from the adults who were emerged from the cocoons stored for 10 days at 20°C while 5°C temperature inhibited the growth and development with least number of cocoons.

Keywords

Cotesia flavipes, Endo Larval Parasitoid, Chilo partellus and Maize Stem Borer.

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