Progress 10/01/00 to 09/30/05
Outputs
The most diverse group of beetles (Insecta: Coleoptera) associated with plasmodial or true slime molds (Myxomycetes or Mycetozoa) belong to the tribe Agathidiini of the family Leiodidae. By far, the largest and most complex genus within the tribe is Agathidium. We have completed the first comprehensive review of the species of Agathidium for North and Central America in over fifty years, published as two monographs in the Bulletin of the American Museum of Natural History. We reviewed the approximately fifty known species in the region and described and named 65 new species. This makes the species of this genus, widely distributed in temperate forested ecosystems, accessible to forest entomologists, ecologists and evolutionary biologists for further study. In separate publications, we also described two new genera of Agathidiini and investigated the the evolution and behavior associated with unusual dimorphic horns in males of some Agathidium species. These horns are
used both in male-male conflict and in courtship behavior. We also initiated the first in-depth, broadly comparative study of the male genitalia of the approximately thirty families of the superfamily Cucujoidea. We have completed about 80 percent of the dissections and drawings required for the study and anticipate completing the entire study within the next twelve months. This will contribute to our understanding of the phylogeny of one of the least-understood of all higher groups of beetles. Such a framework is necessary in order to interpret the numerous and diverse associations of cucujoid beetles with fungi and wood decay.
Impacts
Our studies make possible the identification of certain beetles associated with fungi and slime molds and the interpretation of their biologies in the context of their phylogenetic history. Such beetles and their fungal and slime mold hosts are important, integral components of temperate forest ecosystems and they provide insights into habits that appear to have characterized many ancestral beetle lineages.
Publications
- Wheeler, Q. D. and Miller, K. B. 2005. Slime-mold beetles of the genus Agathidium in North and Central America, Part I. Coleoptera: Leiodidae. Bull. Amer. Mus. Nat. Hist. 290: 1-95.
- Miller, K. B. and Wheeler, Q. D. 2005. Slime-mold beetles of the genus Agathidium in North and Central America, Part II. Coleoptera: Leiodidae. Bull. Amer. Mus. Nat. Hist. 291: 1-167.
- Miller, K. B. and Q. D. Wheeler. 2005. Two new genera of Agathidiini from the Nearctic and Neotropical Regions (Coleoptera: Leiodidae), with descriptions of six new species. Coleopt. Bull. 58: 466-487.
- Miller, K. B. and Q. D. Wheeler. 2005. Asymmetrical male mandibular horns and mating behavior in Agathidium Panzer (Coleoptera: Leiodidae). J. Nat. Hist. 39: 779-792.
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Progress 01/01/03 to 12/31/03
Outputs
We focused during the reporting period on two primary goals. First, the completion of a monographic revision of the species of the genus Agathidium (Coleoptera, Leiodidae) in North and Central America. The fifty known species were reviewed and 65 new species described. The monograph has been accepted for publication by the American Museum of Natural History Bulletin, and will appear in 2004 in two parts. Second, the first detailed comparative study of the male genitalia of the approximately 30 families of the vast Superfamily Cucujoidea. Dissections and illustrations have been completed for about two-thirds of the family taxa and the work continues.
Impacts
The taxonomic monograph will facilitate accurate identifications of the more than one hundred Agathidium species of North and Central America that are associated with wood decay and Myxomycetes hosts in particular. The cucujoid study will improve understanding of the relationships among the 17,000 species of cucujoids at higher taxonomic levels, providing an important evolutionary context in which to explore the origins of major, economically important beetle clades including Chrysomeloidea and Curculionoidea.
Publications
- Keller, R. A., Boyd, R. N., and Q. D. Wheeler. 2002. The illogical basis of phylogenetic nomenclature. Botanical Review 69, 93-110.
- Miller, K. B. and Q. D. Wheeler. 2004. Revision of the genus Agathidium of North and Central America, Part II (Coleoptera: Leiodidae). Bulletin of the American Museum of Natural History, in press.
- Miller, K. B. and Q. D. Wheeler. 2002. Two new genera of Agathidiini from the Nearctic and Neotropical Regions (Coleoptera: Leiodidae), with descriptions of six new species. J. Nat. Hist., in press.
- Miller, K. B. and Q. D. Wheeler. 2002. Asymmetrical male mandibular horns and mating behavior in Agathidium Panzer (Coleoptera: Leiodidae). Coleopterists Bull., in press.
- Wheeler, Q. D. and K. B. Miller. 2004. Revision of the genus Agathidium of North and Central America, Part I (Coleoptera: Leiodidae). Bulletin of the American Museum of Natural History: in press.
- Wheeler, Q. D., Raven, P. H. and E. O. Wilson. 2004. Taxonomy: impediment or expedient? Science, 303: 285.
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Progress 01/01/02 to 12/31/02
Outputs
A taxonomic revision of the species of the genus Agathidium (Coleoptera: Staphylinoidea: Leiodidae) was completed for North and Central America, including the description of about 65 species as new and treatment in total of about one hundred species. This genus is the largest single group of insects known to feed predominantly upon the plasmodial and fruiting stages of host slime molds (Myxomycetes or Mycetozoa). These conclusions are published in a two-part monographic treatment. Both parts have been submitted for publication to the Bulletin of the American Museum of Natural History. Males of several species of Agathidium have been observed to possess a conspicuous horn on the left male mandible of previously unknown function. In another manuscript, also submitted for publication, we report the first behavioral observations on one of these species, Agathidium pulchrum, and conclude that the horn is used primarily in male to male aggression but also in a pre-mating
ritualistic way with conspecific females. The evolution of this unusual structure is discussed in that publication. Two new species of Neotropical Aglyptinus are described in a manuscript co-authored by undegraduate presidential research scholar Ainsley Seago. These species are remarkable in two respects. First, grossly asymmetrically enlarged pre-club antennomeres and second, in possession of dorsal diffraction gratings on the cuticular surface of the elytra of males. The latter is the first report of sexual dimorphism in such diffraction gratings, previously widely reported in Coleoptera, and assumed to function in protection from predators via interruption of visual depth perception. Work continues on two additional major projects. One, in collaboration with Dr. Christopher Marshall, is a comparative study of the male genitalia and postabdominal morphology of the families of Cucujoidea (Coleoptera). The other, a database project, continues to compile fungus host data for
Coleoptera.
Impacts
Fungi and beetles are two of the most diverse groups of living organisms and their interactions play a critically important role in nutrient cycling and processes of decomposition in forest ecosystems. Improved understanding of the origin and diversification of fungus-associated insects will ultimately contribute to the management of such natural systems.
Publications
- No publications reported this period
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Progress 01/01/01 to 12/31/01
Outputs
The first modern comprehensive comparative study of the male genitalia (aedeagus) and associated postabdominal morphological structures were undertaken for representatives of all major lineages of the complex and enigmatic superfamily Cucujoidea (Insecta: Coleoptera). Cucujoidea includes about 30 families and 17,000 described species of beetles, many of which are associated with various groups of host fungi. Related in unspecified ways to other major beetle radiations including Chrysomeloidea, Cleroidea, Lymexyloidea, Curculionoidea and Tenebrionoidea, no complete knowledge of the origin or diversification of mycophagy in Coleoptera is possible without a thorough study of cucujoids. Several hundred illustrations were completed during the year, and the analysis of the possible phylogenetic and classificatory significance of the observations are currently underway. It is anticipated that a manuscript will be submitted by mid year 2002. With funding from the Bay
Foundation, New York, we began creating a digital library of images of representatives of families of beetles associated with fungal hosts. This digital library will be connected to a database of fungus/host associations soon to go on-line. We have also completed the manuscript for part I of a taxonomic revision of the species of Agathidium (Coleoptera: Leiodidae) of North and Central America, a primitive group of staphylinoid beetles associated closely with fruiting bodies and plasmodia of Myxomycetes (or Mycetozoa).
Impacts
The cucujoid study is the first modern, comprehensive comparative morphology study of these diverse beetles that are both ecologically and phylogenetically important to our emerging understanding of the origin of mycophagy. It will point to and help make possible many additional, more in depth, studies of various families of cucujoids and provide valuable comparative data for studies of other major groups of beetles particularly Cleroidea, Lymexyloidea, Chrysomeloidea, Curculionoidea, and Tenebrionoidea.
Publications
- Wheeler, W. C., Whiting, M., Wheeler, Q. D., and J. M. Carpenter. 2001. The phylogeny of the extant hexapod orders. Cladistics 17: 113-169.
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