COLOR PATTERNS OF SYRPHIDAE .2. ERISTALIS-INTRICARIUS

Eristalis intricarius is a Batesian mimic of bumblebees (Bombus spp.). The thoracic pubescence may be orange or black, but a range of intermediates also occurs. The orange-haired form is recessive to the darker types of pattern (alleles TAor and ThD respectively); variation within the dark-haired category seems largely influenced by environmental factors such as pupal temperature. In samples from northern parts of England there were roughly equal numbers of“orange” and “dark” morphs. These morphs are not specialised mimics of individual models, but have a good general resemblance to several species of bumblebee. © 1979 The Genetical Society of Great Britain.