Notes on the Bionomics of the Pink Stem Borer Sesamia inferens Walker (Lepidoptera: Noctuidae): An Upcoming Pest of Wheat in India

Abstract

Wheat cultivation is of great significance in North-western plains of India and the crop was hitherto considered as almost free from serious insect attack. Recently, Pink stem borer (PSB), Sesamia inferens Walker (Lepidoptera: Noctuidae) has emerged as a new pest and is likely to pose serious threat to the successful cultivation of wheat in the North-western plains of India under largely adopted rice-wheat cropping system. Because of the paucity of data on the developmental biology of PSB on wheat crop regarding this emerging problem of insect damage, studies were initiated on biology of PSB under field as well as screenhouse conditions during seasons of 2010–2011 and 2011–2012. This is the first report on biology of PSB on wheat which indicated that the pest was able to survive well/build up populations on wheat and able to complete its life cycle. It laid eggs either at the base of wheat plant near to soil level or on soil-surface or in the left over stubble of rice plants. Eggs hatched within 7.40±0.08 days and the mean larval duration was 68.52±1.55 days. In the course of development, it passed through 8 larval instars and pupation took place near or within the left over rice stubble. Pupal period was 36.05±0.36 days in male while 37.78±0.17 days in female. The survival of adult moths was 5.31±0.26 days in male while 6.61±0.26 days in female. The mean fecundity was 118.38±11.93 eggs and 89.15 per cent of eggs hatched. The total life cycle took 116.92±2.17 and 119.95±2.05 days in males and females, respectively.