Occurrence of Diseases on Muga Silkworm Host Plant Species Litsea monopetala Roxb. Under Prevailing Weather Conditions during Different Seasons in District Bageshwar, Uttarakhand

Abstract

Muga silk is cultivated through rearing of the insect silkworm Antheraea assamensis Helfer on the leaves of its host plant Litsea monopetala Roxb. under open weather conditions. During the course of development, the host plants of silkworm are found prone to various diseases. The leaves of host plants because of disease infection become unpalatable for the muga silkworms which ultimately affects on quality and quantity of muga silk production. In the present study, during the year 2012 and 2013, a survey on foliar diseases on the muga silkworm primary host plant L. monopetala Roxb. was carried out in District Bageshwar of Uttarakhand, India and recorded greatest foliar damage (FD) and per cent disease index (PDI) because of the diseases that is red rust (Cephaleuros sp.) FD 19.02% and PDI 11.98, leaf spot (Phyllosticta sp.) FD 7.14% and PDI 5.28, brown blight (Colletotrichum gloeosporioides Penz.) FD 11.63% and PDI 7.31% and grey blight [Pestalotiopsis theae (Thuem.) Stey.] FD 9.30% and PDI 7.11% and others during August-October on the host plant species under open weather during respective years.