Effect of Temperature on the Fecundity ofPezothrips kellyanus(Thysanoptera: Thripidae)

Abstract

AbstractThe reproductive biology of a citrus pest Pezothrips kellyanus (Bagnall) was studied at four constant temperatures (15, 20, 25, and 30°C) on lemon leaf discs, under laboratory conditions. Lifetime fecundity of mated P. kellyanus was twofold higher at 20 and 25°C than at 15°C. Temperature had no significant effect on fecundity but daily oviposition rate increased as temperature increased. At 15°C, a female of P. kellyanus oviposited 1.13 offspring and at 30°C 5.35 offspring in average per day. Adult longevity was inversely related to temperature. Specifically, female longevity was longest at 15°C (53.90 d) and shortest at 30°C (13.64 d). Preoviposition, oviposition, and postoviposition periods decreased inversely to temperature. Sex ratio was strongly female biased (>60%) at 15 and 25°C. The net reproductive rate (Ro was highest at 15°C and lowest at 30°C. The intrinsic rate of natural increase (rm) as well as the finite rate of increase (λ) were related to temperature and were highest at 30°C. The mean generation time (T) and population doubling time (DT) were inversely related to temperature and were longest at the lowest studied temperature, 15°C. Almost all biological parameters (except preoviposition period) differed significantly between mated and unmated females when were tested at 25°C. The offspring sex ratio was significantly higher at mated than unmated females. Unmated females produced only a few female offspring confirming arrhenotoky in P. kellyanus.