New larval host plant associations of tumbling flower beetles (Coleoptera: Mordellidae) in North America.

Abstract

Previously published observations on biology of immature mordellid beetles are reviewed and discussed. New larval host plant associations are presented for 11 mordellid species and 22 plant species. Biology, ecology and a rearing technique are presented. Beetle collectors and other naturalists marvel at prolific numbers of tumbling flower beetles on various flowers, apparently feeding on pollen or nectar during spring and summer. The literature for larval hosts of Mordellidae is scant for a family represented in North America by more than 200 species. Most of literature on biology of mordellids and citations with identified host plants for immature mordellids refer to Mordellistena Costa, largest North American genus with about 150 known species. The first detailed account of a life history for a Mordellistena appears to be that of Schwarz (1887) who described association of M. splendens Smith in stems of sea oats (Uniola paniculata L.). These beetles were later identified by Riley (1892) as M. floridensis Smith. In same paper Riley associated M. unicolor LeConte with ragweed Ambrosia artemisiifolia L. and remarked about so called dorsal prolegs of larva. Ping (1915) wrote an excellent illustrated account of M. unicolor boring in pithy galls of goldenrod formed by fly Eurosta solidaginis (Fitch) (Tephritidae). Needham (1948) presented data on mordellid larvae in galls of a bucculatricid moth on Helianthus agrestis Pollard. Larval habits of mordellid were described and evidence was presented that mordellid was preying on moth larva. Several more recent studies on larval mordellids are pertinent. Weiss (1920) indicated that Mordella marginata Melsheimer was bred from polyporous fungi Gloeophyllum sepiarium (Wulf.) Karst. and G. trabeum (Pers. ex Fr.) Murrill. B0ving and Craighead (1931) illustrated Tomoxia bidentata Say (now Yakuhananomia bidentata (Say), see Jackman 1991) and Mordellistena sp., without naming host plants. Peterson (1951) illustrated larvae of Mordellistena and Tomoxia taken from weed stalks and decaying respectively. Arnett (1960) wrote of Mordellistena that the larvae are carnivorous, in rotten wood, and some are leaf and stem miners. Lawrence (1991) stated more accurately that larval host material is relatively compact and often woody substrates, in rotten wood, stems of herbaceous plants and shrubs for Mordellistena.