G. it. Ent., 10 (50): 99-102
September 2002
Review of some aspects of the biology and host plants of
Repsimus aeneus (Fabricius)
(Coleoptera, Scarabaeidae)
by
TREVOR J. HAWKESWOOD & JAMES R. TURNER
Abstract - The adult food plants of the Australian scarab beetle, Repsimus aeneus (Fabricius) (Coleoptera: Scarabaeidae: Rutelinae), are reviewed from the literature and the personal observations of the senior author. These are compared with the known adult host plants of the closely related species, R. manicatus [subspecies montanus Lea and manicatus (Swartz)]. Observations on abnormal adult colouration in both species are also discussed. Repsimus aeneus adults are known to feed on the foliage of Eucalyptus gummifera (Gaertn.) Hochr., E. torelliana F. Muell., Syzygium tierneyanum (F. Muell.) Hartley & Perry and Leptospermum laevigatum (Sol. ex Gaertn.) F. Muell. (all Myrtaceae). The only recorded adult host plant of R. manicatus manicatus (Swartz) are Leptospermum polygalifolium Salisb. (= L. flavescens Sm.) and Leptospermum spp. undetermined (flowers) (Myrtaceae). The only recorded adult host plant of R. m. montanus Lea is Callistemon sieberi DC. (= C. paludosus F. Muell.) (leaves) (Myrtaceae). The data suggest that adults of Repsimus are restricted to the Myrtaceae, a family well known for having high percentages of natural oils in the leaves and the petioles. These beetles have apparently adapted well to feed on these plants despite this plant defence mechanism, by having a digestive system which eliminates a high percentage of the ingested oil in the faeces.
