Growth Rate of Mustard Aphid Lipaphis erysimi (Kalt.) on Different Rapeseed-Mustard Crops

摘要

Birth and adult weights of mustard aphid, Lipaphis erysimi (Kalt.) were recorded at three plant growth stages viz., young plant (whole), grown-up plant (leaf) and inflorescence stage plant (twig) of six crops/cultivars of rapeseed-mustard under laboratory conditions to work out relative growth rate. The average birth and adult weights were significantly higher i. e. 0.444 and 5.039 mg/10 individuals, respectively, at inflorescence stage plants as against the lower i. e. 0.394 and 4.778 mg/10 individuals, respectively, at young stage plants, irrespective of rapeseed-mustard genotypes. However, at grown-up stage plant, the birth weight was statistically on par with young stage plant, while adult weight was on par with inflorescence stage plant. Irrespective of stages of plants, the growth rate (GR) of mustard aphid was highest on BSH 1. Keeping the GR on BSH 1 as standard, the relative growth rate (RGR) was lowest on T 27 closely followed by 'Purple mutant' and HC-2. However, GSH-1 and RH 30 were almost equally suitable as BSH 1.