Pala RamShete, Nilesh Suresh2018-09-182018-09-182018http://krishikosh.egranth.ac.in/handle/1/5810073523Aenasius arizonensis (Girault) (=Aenasius bambawalei Hayat) (Hymenoptera: Encyrtidae) is a solitary nymphal endoparasitoid of solenopsis mealybug, Phenacoccus solenopsis (Girault), a serious pest of cotton and other vegetable crops worldwide. The present studies were carried out during 2014-17 in the laboratory, screen house and research farm of the Department of Entomology, CCS Haryana Agricultural University, Hisar. Information on this parasitoid is scanty and investigations on its bioecology and efficacy were conducted to improve the knowledge of the A. arizonensis and P. solenopsis relationship and its implication on mass rearing, cold storage, dispersal behaviour, inoculative efficacy and its abundance. Impact of mating on several fitness parameters, i.e., longevity, parasitism, fecundity and sex ratio of the parasitoid in relation to its host at 27±2oC showed that, virgin male (16.73 days) and female (27.07 days) lived longer than the mated once. Maximum parasitization (89.71%) and minimum sex ratio (F:M) (1.14:1) was obtained when one male was placed with 20 females, parasitization decreased and sex ratio increased with increasing female density. Maximum fecundity (91.65 mealybugs parasitized/female), highest sex ratio (1.37:1) and lowest longevity (17.10 days) was recorded when one mated female was placed with 5 males. Maximum male (24.37 days) and female longevity (46.65 days) was recorded at 15±10C with the provision of food (50% honey) which was higher than those tested at higher temperatures and without food. The post storage daily fecundity, longevity, oviposition period and sex ratio were found significantly higher when parasitoids were exposed to 1, 4, 7, 10 and 14 days of storage period at 15±10C as compared to 20±1oC. The impact of constant parasitoid-host ratios with varying densities of females on the progeny production of A. arizonensis revealed that, maximum parasitization was obtained at 1:10 parasitoid-host ratios at all female parasitoid densities (1, 2 and 4) but the parasitism declined with the increase in host density at each parasitoid density and parasitoid/host ratio. The study on mutual interference among varying densities of female parasitoid (1, 2, 5, 10, and 20) demonstrated that, the mean number of host parasitized per female parasitoid and sex ratio decreased significantly with the increase in the number of female densities from one to 20. Maximum host parasitization was recorded on Abutilon indicum L. among the other host plant species in both free choice (67.67%) and no choice (65.33%) conditions. The findings on searching behaviour showed that, maximum mealybug parasitism by A. arizonensis was recorded 5 days after release at 12 m distance in north direction. Maximum mealybug parasitism was recorded when parasitoid was released @10000 females/acre, indicating the effectiveness of higher inoculative rates. Upto 90 per cent mealybug parasitism by A. arizonensis was recorded on cotton and other host plants as well as association of hyperparasitoids like Myiocnema comperei Ashmead and Promuscidea unfaciativentris Girault was also recorded throughout the year except in winter season. The results of the present study provide essential information for further research and its implication in mass rearing and for a successful biocontrol programme of P. solenopsis.ennullThesis