Azuki bean beetle (ABB), Callosobruchus chinensis (L.) is a field-to-storage pest of legumes and its female produces sex pheromone with two isomeric components, 2Z-homofarnesal and 2E-homofarnesal. Two day old virgin adults were exposed to 0, 200, 300, 400, 500 & 600 Gy gamma radiation and effect on longevity, fecundity, sterility and pheromone production were studied. Longevity (female; P < 0.001, male; P < 0.001) and fecundity (P < 0.001) were dose-dependently affected by the gamma irradiation. Both adults were totally sterilized by the tested doses of gamma irradiation as depicted by the null hatchability of laid eggs. Gas chromatography-mass spectrometry for solid phase micro extraction revealed that both of the pheromone components were significantly but not completely reduced by 300 Gy. It is a pre-requisite for a successful sterile insect technology that the sterility of ABB is induced without the total disruption of calling behavior.

Azuki bean beetle (ABB), Callosobruchus chinensis (L.) is a field-to-storage pest of legumes. It is ideal to estimate its field population before it invades the stored legume stuffs. The seasonal occurrence was monitored with rocket traps supplied with synthetic female sex pheromone and with sweep netting during 2015-2016. Harvest damage was evaluated by taking purposive samples of the pods at harvest. Over-wintering stage was identified from the pod samples of left over plants. The results ascertained that October was the peak season of ABB in the azuki bean field. Grain damage and weight loss of the harvested azuki bean were 2.7% and 2.4% respectively, which could be the inoculum for storage loss. The adult emergence only from live pupae collected from pods revealed for its most probable over-wintering stage. In all, this study provides insight into some field ecological parameters of ABB that could be helpful in adopting its management strategies.

Plant essential oils (EOs) exhibit an array of biological activities against insect pests. However, their negative influences on the pheromonal activity of azuki bean beetle (ABB), Callosobruchus chinensis L., the field-to-storage pest of legumes, have not received research attentions. We evaluated the effects of three EOs and their two major components on the attractiveness of male ABBS to synthetic homofarnesal (2E- : 2Z-homofarnesal = 6:4) using Y-tube olfactometry in laboratory and rocket traps in the semi-open vinyl house. The tested EOs of Illicium verum, Croton anisatum and Gaultheria fragrantissima as well as the major components, trans-anethole and methyl salicylate ascertained significant negative effect against homofarnesal both in Y-tube olfactometry and in semi-open vinyl house tracing out a new opportunity of integrating them in ABB management programs both in field and storage.

Ethyl formate (EF) and methyl salicylate (MS) are naturally occurring and generally safe substances for use. Sub-lethaldoses of EF and MS were evaluated to find synergistic fumigation action against azuki bean beetle (ABB), Callosobruchuschinensis (L.). Susceptibility of the ABB to EF was in the order of eggs =adults >larvae >pupae. Adults was most sensitiveto MS, and followed by eggs. Larvae and pupae were highly tolerant to MS. However, in synergistic effects of EF andMS showed that all the stages of ABB were highly sensitive in the order of adults >eggs >larvae >pupae. Highest synergisticratio was found against adults when using LC10 of both EF and MS as compared to other stages. Notably, MS synergizedthe EF exposure to all stages of ABB. This finding paves the way to exploiting synergistic activity of MS and EF againstABB for the safeguard of stored azuki bean grains.

The female azuki bean beetle, Callosobruchus chinensis L., a worldwide notorious pest of azuki beans produces sex pheromone having two isomer compounds; (2Z,6E)-7-ethyl-3,11-dimethyl-2,6,10-dodecatrienals (2Z-homofarnesal) and (2E,6E)-7-ethyl-3,11-dimethyl-2,6,10-dodecatrienals (2E-homofarnesal). We synthesized and evaluated the attractiveness of different blends of the two isomeric compounds using Y-olfactometry in laboratory and rocket traps in the field. The attractiveness pattern of the tested blends in Y-olfactometry was found as 1:9≥6:4>9:1 of 2E-:2Z-homofarnesal. Under field condition also, the 6:4 blend was more attractive than 9:1 blend. The result ascertained the enhanced pheromonal activity of homofarnesal with the increased ratio of Z-component in the blend. This provides an opportunity to synthesize Z-rich homofarnresal with less sophisticated and economically feasible Z-selective method.