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Mungbean has potential for expansion as an opportunity crop planted on residual soil water after flood on active floodplains in Cambodia. However, mungbean production is severely affected by insect pests and excessive application of chemical insecticides has led to increased losses from secondary pests such as bean flower thrips (Megalurothrips usitatus Bagnall). In an exploratory study, we evaluated the effectiveness of blue and yellow sticky traps as part of an integrated management strategy to control bean flower thrips in mungbean at three locations in Battambang province in the early dry season 2021. The sites were situated in three different agro-ecological systems: semi-urban (Sala Balat); lowland rice (Os Tuk); and intensive mungbean (Preaek Trab). Blue sticky traps, impregnated with thrip pheromone, were six-times more effective than yellow traps for capturing thrips. Thrip numbers varied between sites but increased in a linear fashion between 15 and 35 days after sowing at Preak Trab which has a history of intensive insecticide use in mungbean. A concern with blue traps was that they were more effective than yellow traps for capturing beneficial ground beetles, rove beetles and hoverflies. Therefore, further study is required to determine potential adverse impacts of deployment of blue sticky traps. This study confirmed the potential value for blue sticky traps to monitor and potentially control bean flower thrips in mungbean in North-West Cambodia. We also put forward a range of Integrated Pest Management (IPM) options to manage bean flower thrips in mungbean and the challenge is to find a way to have them adopted. Transfer of technical information in this community is primarily through the village network, especially for information on fertilisers and pesticides. The key to an effective strategy is to engage the key influencers on insect pest management to facilitate adoption of IPM in mungbean. [ABSTRACT FROM AUTHOR]

Chinese mustard is an important leafy vegetable, which is grown in about 5% of total vegetable area in major vegetable producing provinces of Cambodia. Production of Chinese mustard is severely hampered by the insect pests especially lepidopteran caterpillars and the flea beetles. Chinese mustard producers predominantly rely on the application of chemical pesticides for management of these pests and produce blemish free produce. In order to reduce the extensive reliance on pesticides, efficacy of biopesticides (Bacillus thuringiensis and Metarhizium anisopliae formulations, and neem extract), either alone and in combination (as an IPM package) against diamondback moth, common armyworm, cabbage webworm and striped flea beetle on Chinese mustard was assessed in three different provinces of Cambodia during 2015–2018. The bio-pesticides reduced the incidence of diamondback moth, common armyworm, cabbage webworm and the damage by striped flea beetle to the levels equivalent to chemical pesticide (abamectin) during trials in 2015 and 2016. Although the yield was significantly higher in bio-pesticide treated plots than untreated plots in 2015, the yield did not differ among the treatments in 2016 trials. Multi-location trials during 2016–2018 confirmed that the performance of the bio-based IPM package was on par with farmers' practice of calendar-based pesticide application in reducing the damages by target pests, leading to significant yield gains. Hence, the bio-based IPM package can be a better alternative to chemical pesticides in managing the key insect pests on Chinese mustard in Cambodia. • Insect pests such as diamondback moth, common armyworm, cabbage webworm and flea beetles are major production constraints in Chinese mustard. • Pesticides are the main control option adopted and use of bio-pesticides is highly uncommon in Cambodia. • An integrated pest management strategy based on use of Bacillus thuringiensis , Metarhizium anisopliae and neem was developed for Chinese mustard. • Multi-locational on-station and on-farm trials confirmed the effectiveness of bio-based IPM package as an effective alternative to chemical pesticides. [ABSTRACT FROM AUTHOR]