THE EFFECT OF SEASON ON BODY AND LERP SIZE OF Cardiaspina retator TAYLOR (HEMIPTERA:PSYLLIDAE)

The effect of season on body and lerp size of Cardiaspina retator was studied in the open parklands around La Trobe University Bundoora campus. Thirty samples of each instars of psyllid were taken from the field during three different seasons (spring, summer and winter) with three period of sampling (spring – summer 1998, winter – spring 1999 and winter-spring 2000). The lerp size and body sizes of each development stage of nymph C. retator were measured in the laboratory using an eyepiece graticule with a Nikon® stereomicroscope. SPSS version 9.0 was the statistical program used in the data analysis Univariate GLM (General Linear Model) and linear regression was used in most of the analysis. The results of this study indicated the body and lerp size of C. retator were significantly affected by season for every stage of instars development. Body and lerp size of C. retator were developed in cold season (winter-spring) smaller than those were developed in hot season (spring-summer). Keywords : lerp, Cardispina retator, psyllid, instar,nymph