VARIATION IN SIZE AND LIPID-CONTENT OF ADULT SOUTHERN PINE BEETLES, DENDROCTONUS-FRONTALIS ZIMMERMANN (COLEOPTERA, SCOLYTIDAE) IN RELATION TO SEASON

Variations in size, weight, and lipid content of brood adult southern pine beetles, Dendroctonus frontalis Zimmermann, were investigated using a spectrophotometric technique to determine total lipid content of individual beetles. Large seasonal variations in these parameters were found with significant differences occurring between months and years. Patterns of variation, however, were not consistent with those reported in previous studies, leading to the conclusion that these variations do not have regular seasonal patterns. Variations in beetle measurements were not related to tree characteristics. Female beetles, on average, were heavier and contained more lipid than male beetles. The spectrophotometric technique used improves on a similar technique recently reported. The technique allowed more extensive measurements, including total lipid content, dry weight, and percent lipid content, to be taken on individual beetles.