EFFECT OF NESOLYNX THYMUS (HYMENOPTERA: EULOPHIDAE) DENSITY ON ITS PROGENY PRODUCTION ON EXORISTA BOMBYCIS (DIPTERA : TACHINIDAE) AND MUSCA DOMESTICA (DIPTERA : MUSCIDAE)
S.H. DIVYA *
PEST MANAGEMENT LABORATORY, CENTRAL SERICULTURAL RESEARCH AND TRAINING INSTITUTE, SHRIRAMPURA, MY SORE-570 008, INDIA
A.S. ARUNA *
PEST MANAGEMENT LABORATORY, CENTRAL SERICULTURAL RESEARCH AND TRAINING INSTITUTE, SHRIRAMPURA, MY SORE-570 008, INDIA
K. SATHYA PRASAD *
PEST MANAGEMENT LABORATORY, CENTRAL SERICULTURAL RESEARCH AND TRAINING INSTITUTE, SHRIRAMPURA, MY SORE-570 008, INDIA
*Author to whom correspondence should be addressed.
Abstract
Nesolynx thymus is one among 20 hymenopteran parasitoids reported to attack the uzi fly, Exorista bombycis, which in turn infests the silkworm, Bombyx mori accounting a cocoon yield loss of 1020%. A host of factors viz., age and size of host, age and size of parasitoid, availability of host, temperature and quality of host are reported to influence the reproductive efficiency of the parasitoids. In the present study an attempt was made to record the influence of foraging parasitoid density on their reproductive performance. Two day-old uzi pupae and 2 day old Musca domestica pupae were offered to Varying numbers (1, 5, 10, 15, 20) of 2 day old Nesolynx thymus adults for parasitization. No significant variation was observed for number of pupae parasitized in different treatments comprising both uzi and Musca domestica pupae. The progeny production (59.55 – 95.5 adults when parasitoid density was 5 and 20 respectively on uzi pupa) per pupa increased significantly with increased in the number of foraging parasitoid adults. The sex ratio (M F) of the parasitoid decreased (1:5.63 – 1: 14.33 when parasitoid density was 10 and l, respectively on uzi pupa) significantly with increase in parasitoid adults.
Keywords: Nesolynx thymus, parasitoid density, Exorista bombycis, Musca domestica, reproductive performance