Mating disruption of Cadra cautella (Walk.) (Lepidoptera: Pyralidae) using its sex pheromone components, (Z, E)-9,12-tetradecadienyl acetate (ZETA) and (Z)-9-tetradecadien-1-yl acetate (ZTA), is successful in its population management. In addition, botanical oils have extensively been investigated in stored product pest management, but the effect of synthetic sex pheromones on the mating of C. cautella in the presence of plant volatiles is still unknown. Spinosad is used in food facilities as a contact insecticide but, if C. cautella larvae burrow into food, they may escape from spinosad. Importantly, the impact of spinosad on burrowing ability of C. cautella remains unknown. Therefore, the objectives of this study were to determine the effects of sex pheromone components ZETA and ZTA in the presence of botanical oils on the mating of C. cautella and the burrowing ability of C. cautella larvae in different types of flour treated with spinosad. In the first study, male and female moths were introduced into the cubicle having botanical oils and pheromone components. The mating status of female moths and male moth attraction to the trap was determined. The control experiments had only the botanical oils or pheromones. In the second study, burrowing ability of C. cautella larvae through different flour types was evaluated over 10 d. The flour was sprayed with spinosad (treatments) or water (controls). The mating success was higher with botanical oils alone but declined with exposure to pheromone either alone or combined with botanical oils. No differences in male attraction to traps were observed in botanical only, pheromone only or pheromone + botanical oil treatments. The burrowing of C. cautella larvae differed with flour type and spinosad altered burrowing ability. Thus, we conclude that the mating and burrowing of C. cautella is influenced by its pheromone and by exposure to botanicals and spinosad.

The Indianmeal moth, Plodia interpunctella (Hübner) (Lepidoptera: Pyralidae), is a serious insect pest of stored products, and its late-instar larvae

Substantial losses are common due to various reasons of durable crops during storage, which threatens economy, health and food security. Despite the frequent reports on post-harvest losses of paddy and other cereals throughout Sri Lanka, a comprehensive study has not been conducted in Anuradhapura district in recent past to assess storage losses of aforesaid commodities. Objectives of this study were to find out main types of durable crops stored following harvest, and their quantitative and qualitative losses incurred during storage period at the household level in Anuradhapura district of Sri Lanka. Data were collected throughout Anuradhapura district representing all 22 divisional secretariats. The main stored commodities were paddy, maize and greengram. The storage period varied from 4 to 12 months. The storage losses of Nadu and Samba rice varietal types respectively were highest in Palagala and Kekirawa, whereas losses were minimum in Rambewa and Galenbindunuwewa. The main qualitative losses were the presence of damaged seeds, grain flour/dust, grains without kernel and faecal matter. The study highlights that severe quantitative and qualitative losses occur during storage of rice, maize and greengram, and appropriate remedial measures are needed to be developed to minimize the said losses ensuring food security.