Evidence of Seasonal Variation in Body Color in Adults of the Parasitoid Cirrospilus pictus (Hymenoptera: Eulophidae) in Sicily, Italy

SIMPLE SUMMARY: Many studies highlighted that the body color variation in insects is an adaptation factor that preserves them from possible population reductions due to adverse conditions such as low temperatures. In this study, the coloration seasonal changes of Cirrospilus pictus, parasitoid of the citrus leafminer Phyllocnistis citrella were observed. Adults were obtained from field sampling carried out during four consecutive years and grouped in different classes depending on sex and color. Results highlighted a phenotypic pigmentation variation in head, thorax, gaster and legs of the adults. Individuals were yellow–green in summer months while having dark pigmentation in autumn and winter months. In both sexes a correlation between color patterns and seasonal temperatures was evident. These observations can contribute to the description of the intraspecific variability of this species, improving its identification. ABSTRACT: As part of the studies on the morphological color variation of insects, a case study on the seasonal body color variation of Cirrospilus pictus (Nees) (Hymenoptera: Eulophidae: Eulophinae) parasitoid of leafminers is reported. Observations were made from January 2000 to December 2003 in north-western Sicily (Italy), in relation to sex, body regions of adults and seasonal periods. Wasps parasitizing Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae) were collected from organic citrus orchards (Citrus limon L., var. “Femminello zagara bianca” and “Femminello comune”). Adults were grouped in classes: yellow males, black males, yellow females, yellow–black females and black females. The results highlighted a phenotypic pigmentation variation in the head, thorax, gaster and legs of individuals influenced by the season of sampling. Adults were yellow–green in summer months, whereas individuals with dark pigmentation were found in autumn and winter months. A correlation between color patterns and seasonal temperatures was found for both females and males. This work provides a contribution to the description of the intraspecific variability of this species, improving its identification.