Wild silk moth, Circula trifenestrata
Species: Cricula trifenestrata (Helfer) (Lepidoptera: Saturniidae)
This species is found to defoliate on cashew, mango, litchi, ber, pepper, tea, avocado, okra, black cardamom, ground nut, sponge gourd etc.
It occurs in a sporadic manner, damages the leaves in isolated trees. It is considered as minor pest of cashew. But the silk obtained from its golden shiny cocoon has economic value.
In the early stage, the larvae are found congregated on the under surface of the leaves, later they get dispersed, but restrict its feeding on its neighbouring trees.
Pest appearance:
The larva has orange and blackish transverse bands on the dorsal side. The head and ventral side of the body are deep red in colour. There are numerous raised yellow spots and white hairs on the body. The cocoons are yellowish, seen within shoots or sometime in crop debris on the ground. Male moths are yellowish with two pairs of wavy black markings both on fore and hind wings. Female moths are deep yellowish-brown in colour. Three prominent transparent eye spots are present on forewings and one in the hind wing.
Source: https://www.flickr.com/photos/itchydogimages/33216384358
The utilization of Tasar silk worm and Cricula silk worm as a possible Vanya silk source will enable cashew farmers to derive additional revenue from their plantations as no adverse effect on normal growth of trees has been detected due to the feeding by these wild silk worms on cashew trees. A team of scientists at CRS, Madakkathara, Kerala found that the spun silk of Cricula trifenestrata yielded durable silk threads/ yarns and was successfully used for weaving silk clothes in power loom on an experimental basis.
Reference:
- Pal, S. and Medda, P.S. 2006. Occurrence of wild silk moth, Cricula trifenestrata (Helfer) on cashew, Anacardium occidentale L. under Terai conditions of West Bengal. The Orissa Journal of Horticulture, 34 (1) 117.
- http://www.fnbnews.com/Top-News/Silk-production-potential-of-insect-pest-of-cashew-identified-by-KAU-team