Thermal effects on the development, fecundity and life table parameters of Rhopalosiphum padi (Linnaeus) (Hemiptera: Aphididae) on barley

Abstract

The bird cherry-oat aphid Rhopalosiphum padi (Linnaeus) (Hemiptera: Aphididae) is a polyphagous species with a worldwide distribution. We investigated the development periods of R. padi nymphs, and the longevity and fecundity of apterous females. The study was conducted at six constant temperatures of 10.0, 15.0, 20.0, 25, 30.0, and 32.5°C. R. padi developed successfully from nymph to adult stage at all temperatures tested. The developmental rate of R. padi increased as temperature increased from 10.0 to 25.0°C and declined thereafter. The lower developmental threshold (LDT) and thermal constant (K) of the R. padi nymph stage were estimated by linear regression. Higher and lower temperature thresholds (TH and TL, respectively) were calculated by the Sharpe_Schoolfield_Ikemoto (SSI) model. The LDT and K of the R. padi nymph stage were 5.6°C and 100.6degree-days (DD). The temperature range of the R. padi nymph stage from TL to TH was 26.3°C using the SSI model. Developmental completion of the nymph stages was described using a two-parameter Weibull distribution model. The adult emergence frequency of R. padi over the full range of constant temperatures was simulated using developmental rate functions and the Weibull function. Daily nymph production of R. padi was estimated in relation to adult age and temperature. The biological characteristics of R. padi in relation to temperature were presented by a life table analysis. Life table parameters were estimated with the jackknife method. Biological characteristics of R. padi populations from different geographic areas were discussed.