Polyphagy and adult body size in geometrid moths.
We compared the average body size (wing span) of Finnish geometrid moth species in relation to their degree of polyphagy and quality of food. The first hypothesis, originally constructed for mammals and birds, states that smaller species should more often be specialists than large species, because of the different relationships between body size and home range size, and body size and daily energy requirements. According to the second hypothesis, smaller species should feed more often on herbs than do larger species, because of the different defence mechanisms of herbs and woody plants. The results support both of these hypotheses. Specialist species are smaller than oligophagous or polyphagous species, and small species concentrate on herbs. We conclude that quality and quantity of food resources may explain the pattern.
Department of Zoology, Division of Ecology, University of Helsinki, P. Rautatiekatu 13, P.O. Box 17, FIN-00014, Finland.
J
J
Lindström
Zoological Museum, University of Helsinki, P. Rautatiekatu 13, P.O. Box 17, FIN-00014, Finland.
L
L
Kaila
Department of Forest Ecology, Finnish Forest Research Institute, P.O. Box 18, FIN-01301, Vantaa, Finland.
P
P
Niemelä
Body size; Geometridae; Polyphagy