Biology of psyllid, Pauropsylla tuberculata Crawford infesting the devil tree Alstonia scholaris (L.) R.Br. studied at Bhubaneswar, Odisha

Abstract

Studies based on biology of psyllid, Pauropsylla tuberculata Crawf. in Alstonia scholaris (L.) R. Br. revealed that the life cycle of the psyllid passes through egg stage, five nymphal instars and then the adult stage. The egg have a minimum incubation period of 2-3 days which varied seasonally. The first instar nymph entered the leaf tissue, subsequently initiating formation of galls. The developing gall housed the developing nymph which completed additional four successive instars inside it. The fully matured fifth instar nymph came out by cutting a hole in the gall, moulted outside the galls and thus reached to adult stage. The average nymphal duration varied seasonally, maximum during summer (26.72±0.62 days) and minimum during rainy season (18.35±0.89 days). Adult longevity also varied seasonally, which have been recorded maximum during rainy season (17.56±0.32 days for males and 16.37±0.65 days for females) and minimum during summer (11.11±0.75 days for males and 10.01±0.85 days for females). Males were found to have been long-lived than females and possessed a longer life cycle. The life cycle of the psyllid was completed in almost 27-28 days. Prevailing temperature and relative humidity played a vital role in the growth and development of the egg, nymph and adult stages of the psyllid.