First report of fungus gnat (Lycoriella sp.) (Diptera: Sciaridae) on oyster mushroom from North East India

Abstract

A new dipteran fungus gnat (Lycoriella sp.) was recorded on oyster mushroom (Pleurotus ostreatus) during the month of April and May, 2012. A single larva could damage 20-35 % of a fruiting body within 3-4 days of infestation. In cases of severe infestations, it damaged 7080% of the fruiting bodies in mushroom beds. Hence, looking at the severity of infestation, certain aspects of its biology were studied under laboratory conditions. The female laid round, white or translucent eggs singly or in groups on the upper part as well as on the stalk of the fruit bodies. The pre-, post-oviposition and incubation periods were 5-6 days, 2-3 days and 3-4 days, respectively. Maggots were white in colour and vermiform with a conical head possessing a pair of sclerotized, black and pointed mandibles. There were four larval instars and total larval period was 10-13 days. The body length of the four instars were approximately 4.06 mm, 5.46 mm, 8.56 mm and 9.60 mm, respectively. Pupae were coacrate, brown in colour, about 9.20 mm in length and pupal period was of 3 days. Adult flies had a shiny black head, long antennae and legs and transparent, thin wings with distinct venation.