Floral Associations of Cyclocephaline Scarab Beetles

Abstract

The scarab beetle tribe Cyclocephalini (Coleoptera: Scarabaeidae: Dynastinae) is the second largest tribe of rhinoceros beetles, with nearly 500 described species. This diverse group is most closely associated with early diverging angiosperm groups (the family Nymphaeaceae, magnoliid clade, and monocots), where they feed, mate, and receive the benefit of thermal rewards from the host plant. Cyclocephaline floral association data have never been synthesized, and a comprehensive review of this ecological interaction was necessary to promote research by updating nomenclature, identifying inconsistencies in the data, and reporting previously unpublished data. Based on the most specific data, at least 97 cyclocephaline beetle species have been reported from the flowers of 58 plant genera representing 17 families and 15 orders. Thirteen new cyclocephaline floral associations are reported herein. Six cyclocephaline and 25 plant synonyms were reported in the literature and on beetle voucher specimen labels, and these were updated to reflect current nomenclature. The valid names of three unavailable plant host names were identified. We review the cyclocephaline floral associations with respect to inferred relationships of angiosperm orders. Ten genera of cyclocephaline beetles have been recorded from flowers of early diverging angiosperm groups. In contrast, only one genus, Cyclocephala, has been recorded from dicot flowers. Cyclocephaline visitation of dicot flowers is limited to the New World, and it is unknown whether this is evolutionary meaningful or the result of sampling bias and incomplete data. The most important areas for future research include: 1) elucidating the factors that attract cyclocephalines to flowers including floral scent chemistry and thermogenesis, 2) determining whether cyclocephaline dicot visitation is truly limited to the New World, and 3) inferring evolutionary relationships within the Cyclocephalini to rigorously test vicarance hypotheses, host plant shifts, and mutualisms with angiosperms.

Molecules, morphology and Mimeoma scarabs: evolutionary and taxonomic implications for a palm‐associated scarab group

“…Three highly supported (>0.95 PP />75% BS ) clades are labelled as A , B and C . Coloured boxes directly to the right of terminal taxa indicate known host plant families (data from Moore & Jameson, ). Species without known hosts are indicated with a grey box and a question mark.…”

“…Cyclocephalines are important economically and ecologically as both root pests and pollinators (Ratcliffe & Paulsen, 2008). Adult cyclocephaline beetles have been collected from the inflorescences of nearly 60 plant genera representing 17 families where they generally feed on floral parts and mate (Moore & Jameson, 2013). The group is most strongly associated with early-diverging angiosperm families and has been shown to contribute to pollination in the Annonaceae, Araceae, Arecaceae, Cyclanthaceae, Magnoliaceae and Nymphaeaceae (Cramer et al, 1975;Beach, 1982Beach, , 1984Young, 1986Young, , 1988Gottsberger, 1989;Dieringer et al, 1999;Hirthe & Porembski, 2003;Gottsberger et al, 2012).…”

2‐Alkyl‐3‐methoxypyrazines are potent attractants of florivorous scarabs (Melolonthidae, Cyclocephalini) associated with economically exploitable Neotropical palms (Arecaceae)

“…By contrast, along with C. discicollis Arrow, 1902 and C. forsteri Endrödi, 1963, C. amazona , captured in large numbers with both IPMP and SBMP (Fig. ), is one of the most frequent anthophilous cyclocephaline scarabs associated with South American palms, having been documented from several hundreds to thousands of individuals in inflorescences of more than 20 species . Even though the differences in attractivity between IPMP‐ and SBMP‐baited traps could arguably be attributed to the predominance of the former in the floral scents of the studied species at both sites (Tables and S2), we refrain from making bolder assumptions at this point.…”

“…are noteworthy anthophilous insects in Neotropical ecosystems, where they are associated with no fewer than 1200 species of night‐blooming angiosperms . In two recent reviews, Moore and Jameson in 2013 and Nuñez in 2014 documented 35 species of these beetles recovered in inflorescences of 48 species of palms, across 12 genera and six tribes. Although past studies have pointed towards the eventual role of cyclocephaline scarabs as accessory and even main pollinators of Neotropical palms, recent evidence demonstrates their small participation in this service .…”

Aroid scarabs in the genus Peltonotus Burmeister (Coleoptera, Scarabaeidae, Dynastinae): key to species and new distributional data

“…Adult beetles use inflorescences as sites for mating and feeding, and they serve as pollinators (Moore and Jameson in press, Maia et al 2012). Species in the genus are intimately tied to host aroids and their forest habitats, and we predict that many species await discovery.…”