Influence of abiotic factors on seasonal incidence of pests of tasar Silkworm Antheraea mylitta D.

Abstract

Rearing of tropical tasar silkworm, Antheraea mylitta Drury is mainly conducted in outdoor on Terminalia tomentosa W. & A. a nature grown primary host plant available in forest and also on raised primary host plant Terminalia arjuna Bedd. Temperature, relative humidity and rainfall are the main environmental factors for occurrence of pests (parasites and predators) of tasar silkworm during I, II and III crop rearing in the tropical tasar producing zones. The present study was aimed to study the influence of abiotic factors on prevalence of tasar silkworm pests. The study was conducted at different agro-climatic regions viz., Central Tasar Research &Training Institute, Ranchi, Jharkhand, Regional Extension Centre, Katghora, Chattisgarh and Regional Extension Centre, Hatgamaria during 2010-13 covering 3 seed crop and 6 commercial crops. Data on incidence of tropical tasar silkworm endo-parasitoids like Uzi Fly, Blepharipa zebina Walker and Ichneumon fly (Yellow Fly), Xathopimpla pedator, Fabricius and Predators such as Stink bug (Eocanthecona furcellata Wolf), Reduviid bug (Sycanus collaris Fabricius) and Wasp (Vespa orientalis Linnaeus) was recorded Weekly. The meteorological data was collected daily. Data was collected from 4 different agro-climatic zones of tasar growing areas. Analysis of the data revealed a significant negative correlation between abiotic factors and incidence of ichneumon fly and uzi fly. Based on the 3 years data on prevalence of pests region-wise pest calendars and prediction models were developed.

Influence of abiotic factors on seasonal and non-seasonal emergence of Tasar silkworm, Antheraea mylitta Drury

“…The influence of bioclimatic conditions on the emergence of insects is a well-known fact. Erratic and non-seasonal emergence was strongly correlated with humidity and rainfall (Siddaiah et al, 2014). Influence of bioclimatic condition on the emergence of insects (including silkworm) has been reported (Messenger, 1958).…”

Mechanism of adult emergence in Xanthopimpla pedator (Fabricius)- a major pupal parasitoid of Tasar silkworm

“…Xanthopimpla predator is a noted parasitoid of Anthereae mylitta with a crop loss of 35-40 th %. X. pedator begins its life cycle in late 5 instar spinning larva of A. mylitta from the time of hammock formation to early cocooning stage and uses its long ovipositor to drill through silky envelope of spinning larva and deposits single egg in the abdominal segment th th preferably 5 to 7 day of cocoon spinning (Marepally, 2016;Aruna et al, 2014;Bhatia and Yousuf, 2013;Gadad et al, 2022).…”