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To explain the asymmetrical abundance of native Frankliniella intonsa (Trybom) (Thysanoptera: Thripidae) and invasive Frankliniella occidentalis (Pergande) in the fields, we examined differential susceptibility to pesticides and environmental conditions, i.e., nine combinations of temperatures and relative humidities (RHs). We found adult female F . intonsa to be more susceptible to most of the tested insecticides as compared to F . occidentalis . Chlorfenapyr was most toxic to both thrips’ species. In the evaluation of environment conditions in the adult stage, F . intonsa survived 2.5 and 2.4-fold longer as RH increased at 20 and 25 °C, respectively, whereas F . occidentalis survived 1.8 and 1.6-fold longer, respectively. In both pupal and larval stage, no significant effect of interaction of temperatures and RHs was found between the two species. In conclusion, the insecticides tested differed considerably in their species-specific toxicity, and F . intonsa was generally more susceptible to the insecticides, while at the same time survivorship was better at higher RH conditions than F . occidentalis . Thus, differences in the relative susceptibility to changing environmental conditions, especially humidity, may be an underlying mechanism for the recent dominance of F . intonsa over F . occidentalis in the strawberry plastic greenhouse in Korea.

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An experiment was conducted to assess the adequacy of distinctive management practices, viz. yellow sticky trap set at 50, 100, and 150 cm height, fruit fly bait with a mashed sweet gourd (MSG), bagging, sanitation, and Ecomec 1.8 EC at the rate of 1mL per liter of water sprayed at 7 days interval. The experiment was carried out with a randomized complete block design (RCBD) with 8 treatments and 3 replications. All the treatments significantly differed from the control. The total highest number and weight of healthy fruits were recorded in bagging (41.33 and 6.08 kg) but the lowest in control (19.00 and 2.22 kg, respectively). No infested fruits were found in bagging, meanwhile, the highest number and weight of infested fruits were counted in control (13.00 and 1.27 kg). In addition, bagging appeared to have no percent of infestation by number and weight. The highest percent of fruit infestation was found in control (40.75% and 36.48%) treatments based on number and weight. No wet reduction was found in the bagging treatment and the highest percent weight reduction per fruit was recorded in Ecomec 1.8 EC (30.17%). The highest number of larval densities were found in fruit fly bait with MSG (15.83) and the lowest in a yellow sticky trap set at 150 cm height (6.7). The highest number of fruit flies in a yellow sticky trap set at 50 cm height was captured on 21 March 2021 (4.33) and the lowest was on 29 April 2021 (1.33). The highest number of fruit flies were captured in a yellow sticky trap set at 50 cm height (43/trap) and the lowest in a bait trap with MSG (9.70/bait). The highest yield and increase of yield over control were found in bagging (12.16 tons/ha and 176.10%). J. Asiat. Soc. Bangladesh, Sci. 48(1-2): 67-82, June-December 2022

Field study was carried out at Bangladesh Agricultural Research Institute (BARI) farm during March to August 2005 to find out the most appropriate management practices against thrips of mungbean. The experiment consisted of seven treatments of various management practices. It was laid out in Randomized Complete Block Design (RCBD) with four replications. The incidence of this pest was first noticed during vegetative and flowering stage. The infestation rate was highest in reproductive stage. Application of Furadan 5G as a seed treatment gave the maximum yield (950.5 kg − ha ). On the other hand, minimum yield was found in control treatment. Two times application of Shobicron 425 EC also gave the satisfactory result but it was not economically viable. Neem oil with Trix gave the significant result in comparison with other treatments and it may be environmentally friendly.