Life History and Seasonal Incidence of Asparagus Beetle, Lema Downsei Baly on Asparagus Racemosus in India

Both the adults and grubs of Lema downesi were found damaging the tender spears or shoots and tender foliage and pest was active throughout the year. The pest completed its life cycle in 11.93±0.07 days, laid an average of 106.6 ± 35.0 eggs on the spear under confinement and hatched in 2 to 3 days. The grubs developed through four instars in 4.3± 0.5 days ranging from 4 to 5 days. The pupae were exarate and lasted for 5 to 6 days. The adults were metallic light brown in colour with irregular brownish spots on elytra. The length and width of the body of male and female beetles were 4.7±0.16 and 2.09±0.07 mm and 5.0±0.08 and 2.37±0.1mm, respectively. The correlation co-efficient analysis between pest population and weather factors revealed that temperature was having negative correlation with grub and adult population; however relative humidity and rainfall were having positive correlation with pest population. Though the impact of these climatic factors on the pest population was non-significant, yet their effects on growth of host indirectly influenced the pest population.