Mustard (Brassica juncea) variety BARI Shorisha-11 was cultivated during September 2016 to March 2017 in Gazipur, Bangladesh to find out the population dynamics of aphid and its infestation level on mustard. The aphid Lipaphis erysimi (Homoptera: Aphididae) was abundant in the field and caused infestation. The population of aphid in the mustard field showed fluctuation and reached to the peak at 22 December which was 289 per plant. Inflorescence had significantly higher level of infestation compared to individual siliqua and leaf. The daily mean temperature had significant negative, light intensity had insignificant negative and relative humidity had insignificant positive correlation with the abundance of aphid. The multiple linear regression analysis showed that the weather parameters namely temperature, light intensity and relative humidity individually as well as combindly contributed on the abundance of aphid, but the temperature had greater effect than other factors.Bangladesh J. Agril. Res. 43(4): 611-618, December 2018

A field experiment was carried out in Gazipur, Bangladesh to find out the abundance and behavior of native insect pollinators and their impact on the yield and seed quality of mustard (Brassica juncea L.). Total 8 species of insects under 8 different families in 3 orders were found as pollinator and their abundance ranged from 0.5 to 6.6/30 sweeps. The pollinator insects revealed statistically higher abundance compared to pest, predator and other category. The pollinators were most abundant at 11.0 hrs of the day and differed in their landing duration on flower. Ant and cabbage butterfly stayed statistically similar and longer time (24.1 and 23.5 sec., respectively). The highest yield (994.3 kg/ha) was obtained from insect managed pollination treatment followed by open (759.7 kg/ha) and enclosed condition (272.3 kg/ha). Insect pollination revealed higher percentage of germination, t100-seed weight, per cent oil and protein content but the results did not differ statistically.

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