Mandible Form Relative to the Main Food Type in Ladybirds (Coleoptera: Coccinellidae)
Abstract:The Coccinellidae is an economically important family within the Coleoptera. Some members are phytophagous pests, but many are beneficial predators and valuable biocontrol agents. This study investigates the morphology of the mandibles of adult Coccinellidae in relation to diet. Using scanning electron microscopy on 86 species of Coccinellidae, it was found that the morphology of the mandibles was dictated by the general feeding method, and could only be used to indicate a phytophagous, mycophagous or carnivorous diet. Phytophagous Coccinellidae of the subfamily Epilachninae had mandibles with denticulate apical teeth and setae for feeding on leaf material. The mandibles of the mycophagous Psylloborini had secondary teeth on the ventral apical tooth for collecting fungal spores. The mandibles of carnivorous Coccinellidae and Scymninae had either a bifid or unidentate apex. The unidentate mandible seemed to be restricted to coccidophagous species. Many species also had a mandibular groove along which prey body juices were conducted. Although mandible morphology could be related to the overall feeding method, there was no relationship between specific diet or food taxon and mandible shape. Mandible shape does not appear to be especially restricting for changes in diet either in the ecological sense or over evolutionary time. Mandible morphology is of limited use in determining diet and host specificity in Coccinellidae that are being selected as potential biocontrol agents.
Document Type: Research Article
Publication date: 1997-06-01