---

ABSTRACT

Muga silkworm, Antheraea assamensis Helfer (Lepidoptera: Saturniidae) is reared outdoor on its primary host plants, Som (Persea bombycina) and Soalu (Litsea monopetala). Due to its outdoor rearing, Muga silkworm is vulnerable to attacks from different pests and pathogens. Among various insect pests of muga silkworm, Uzi fly viz., Exorista sorbillans and Blepharipa zebina (Diptera: Tachinidae) cause considerable damage to the muga silkworm rearing, accounting for 20-40% and 80-90% loss as reported in various studies. The gravid female Uzi fly generally lay eggs on the body of the 4th & 5th instar silk worm larvae. The maggots bore into the body of the silkworm larvae and started growing by feeding silkworm fluid. As the matured worm pupates and forms the cocoon the mature maggot comes out by making a hole in the cocoon shell after killing the pupae. In case of a heavy infestation in the early 4th stage, the worms do not spin cocoons. Thus, within a short life span of 15-20 days, it not only causes severe economic loss by affecting cocoon formation and direct damage to cocoon but also hamper the next season rearing by killing the silkworm pupae within the cocoon. The short cycle and severity of infestation by the Uzi fly make it quite difficult to control as infestation starts. Also, the sensitivity of muga silkworm towards pesticides adds to the difficulty. The current practice of using nylon net to prevent the uzi fly attack is hard to afford by many muga rearers at large rearing fields given the height of the host plant and predominance of muga farmers in Assam who are small and marginal. Therefore, the high need is there to find some eco-friendly and cost-effective techniques to control the uzi fly without using chemical insecticides. Mass multiplication and release of Nesolynx thymus and other local parasitoids as biocontrol agents within a radius of 1.0 km in the farmer`s rearing field can become an alternative solution. This parasitoid doesn`t harm muga silkworm and it has high target specificity, host searching ability and parasitization ability at the pupal stage of the host which adds towards its possibility to become the most effective means of controlling Uzi fly organically.

Keywords: Uzi fly, Nesolynx thymus, Parasitoid, Biocontrol, Muga.

Download the full article bellow

---

Nesolynx thymus (Hymenoptera Eulophidae) – A promising pupal endo-parasitoid to control uzi fly infesting muga silkworm (2)-converted-1-4.pdf