T. Keith Philips

A phylogenetic analysis of dung beetles (Scarabaeinae : Scarabaeidae): unrolling an evolutionary history

The phylogeny of the Scarabaeinae, the largest and most important group of dung feeding beetles, is hypothesised based on 200 morphological characters of 50 taxa, representing nearly one quarter of the known genera. We present a drastically different picture of evolution of this highly successful group of beetles than those previously proposed. It is apparent that gross morphology is correlated with either rolling or tunnelling but does not accurately reflect evolutionary history. Results indicate that there are not two separate clades of dung beetles, the rollers and tunnellers, but that rolling behaviour has evolved several times from ancestral tunnellers. The Dichotomiini, Canthonini, and Coprini are poly- or paraphyletic, whereas each of the remaining nine tribes appear as well supported monophyletic clades (the monophyly of the Gymnopleurini was not tested). The genera traditionally included in the Dichotomiini are the oldest and most basal lineages and all other clades, including those of the Canthonini, evolved from ancestral dichotomiine lineages either directly or indirectly. New interpretations of the evolution of rolling, its possible loss, nesting and feeding behaviours, and future changes in classification are discussed. Evidence supports the origin of the Scarabaeinae before the Tertiary and subsequent vicariance of many clades via the breakup of Gondwanaland.

Effect of Deforestation on a Southwest Ghana Dung Beetle Assemblage (Coleoptera: Scarabaeidae) at the Periphery of Ankasa Conservation Area

Abstract During June 2003, an exploratory dung beetle survey (Coleoptera: Scarabaeidae: Scarabaeinae) was conducted in southwest Ghana at the southern edge of Ankasa Conservation Area, which is a 500-km2 conserved region of the threatened Eastern Upper Guinean rainforest. The survey provided a quantitative assessment of peripheral deforestation effects and an inventory for species on omnivore dung. Pitfall traps baited with pig dung were placed in both selectively logged and unlogged rainforest as well as in nearby oil palm and cacao plantations. The Ankasa forest inventory was mostly comprised of species previously trapped by human dung in the Western Upper Guinean rainforest of Taï National Park, Côte d’Ivoire. However, there was relatively low species abundance similarity between the June/July assemblages on omnivore dung in Taï and Ankasa rainforests, and even lower similarity between assemblages of Ankasa and the adjacent plantations. Of 29 species recorded in Ankasa forest, most were absent or rare in plantations where assemblages were numerically dominated by species previously recorded from the West African savannas. This replacement plantation fauna showed significantly lower species richness and diversity, but significantly higher abundance, compared with Ankasa forest assemblages. The results reiterate that forest reserves are essential for the conservation of specialist rainforest dung beetle species.

A phylogenetic analysis of the New World tribe Phanaeini (Coleoptera: Scarabaeidae: Scarabaeinae): Hypotheses on relationships and origins

A phylogenetic analysis of Phanaeini based on 137 morphological characters supports the hypothesis that the nine included genera, Coprophanaeus , Dendropaemon , Diabroctis , Homalotarsus, Megatharsis, Oxysternon , Phanaeus , Sulcophanaeus and Tetrameira , form a monophyletic clade. Monophyly is unaffected by the inclusion of Gromphas , Oruscatus , and Bolbites and these should also be considered phanaeines. The sister lineage is Ennearabdus (Eucraniini) and both evolved from ancestral Dichotomiini within South America. There is no support for a close relationship with the Onitini or any other remaining tribe. All phanaeine genera appear to be monophyletic except Sulcophanaeus , of which two species groups appear as sister taxa while the remaining three form an independent paraphyletic clade. Ancestral phanaeines were coprophagous with necrophagy evolving at least twice. Myrmecophily is also derived and most likely evolved only once in the common ancestor of Dendropaemon , Homalotarsus, Megatharsis and Tetramereia . Bare dung ball construction for larval development is also the most likely ancestral condition with a soil covering on the exterior ball surface and parental cooperation evolving in the more derived lineages.

Evolution of the Scarabaeini (Scarabaeidae: Scarabaeinae)

Abstract.  A phylogenetic analysis of the Scarabaeini, based on 244 morphological characters, including 154 multistate and three biological characters, is presented. Tree topologies generated from unweighted data and some weighted algorithms are similar and support only two clades in the tribe representing the genera Scarabaeus L. and Pachylomerus Bertoloni. The only supported subordinate groups treated in this paper as subgenera are Kheper Kirby stat. nov., Pachysoma MacLeay, Scarabaeolus Balthasar and Sceliages Westwood stat. nov.Drepanopodus Janssens syn. nov. is synonymised with Scarabaeus and six additional names, Madateuchus Paulian, Mnematidium Ritsema, Mnematium MacLeay, Neateuchus Gillet, Neomnematium Janssens and Neopachysoma Ferreira, remain synonyms. A single origin of flightlessness is supported with the subgenus Pachysoma, the most derived lineage in this clade. Rolling dung balls backwards is the ancestral behaviour and predominant mode of food relocation in Scarabaeini, although tunnelling, forward pushing, and carrying also are utilized by some lineages. Pushing food has evolved independently in Sceliages species and S. galenus (Westwood) and a novel mode of forward food relocation by dragging evolved in the subgenus Pachysoma. Feeding on wet dung is the plesiomorphic condition and maintained by the majority of species in the tribe. The most unusual feeding behaviours in the tribe are represented by the obligate millipede‐feeding species of Sceliages and the dry dung pellet and/or detritus feeders of Pachysoma.

Phylogenetic analysis of the New World Ptininae (Coleoptera: Bostrichoidea)

A phylogenetic analysis of the New World Ptininae (Anobiidae) was conducted with representatives of nine of ten New World genera, several Old World genera and seven more of the ten subfamilies of Anobiidae. One hundred and two characters (forty‐three multistate) from thirty‐four taxa were used. The single cladogram shows Ptininae as monophyletic and the sister group of the remaining Anobiidae, supporting their placement as subfamilies of a monophyletic Bostrichidae. Genus Niptus Boieldieu is polyphyletic supporting recognition of Pseudeurostus Heyden and the creation of a new genus to encompass the remaining New World species of Niptus. Flightlessness has evolved a minimum of three times within Ptininae and myrmecophily has probably evolved three times within just the New World taxa. The classifications of Ptininae and the remaining Anobiidae are examined and the evolution of feeding habits, myrmecophily and wing loss are discussed.

A phylogenetic analysis of the Eucraniini (Coleoptera: Scarabaeidae: Scarabaeinae)

A phylogenetic analysis of the New World Eucraniini was conducted using cladistics. The tribe is monophyletic based on an analysis of 64 morphological characters. The flying Ennearabdus is the sister taxon to the three flightless genera, Anomiopsoides, Eucranium, and Glyphoderus, and Anomiopsoides and Glyphoderus share a common ancestor. The relationship of the eucraniines to other tribes of Scarabaeinae, dung preference, a comparison to the flightless southwest African genus Pachysoma, and the biogeography of the tribe are also discussed.

PHYLOGENETIC EVIDENCE FOR AN ASSOCIATION BETWEEN TUNNELING BEHAVIOR AND THE EVOLUTION OF HORNS IN DUNG BEETLES (COLEOPTERA: SCARABAEIDAE: SCARABAEINAE)

Abstract Dung beetles employ numerous behavioral strategies to sequester dung away from other insects, and these have been broadly grouped into two categories: species that dig tunnels beneath the dung (tunnelers) and species that roll dung on the surface of the soil (rollers). Many species also are armed with rigid exoskeletal outgrowths called horns. Horns function as weapons, and horn sizes can be extreme. One widespread pattern within dung beetles is that tunneling species often have horns, whereas rolling species almost always do not, suggesting that residing (and fighting) inside tunnels at the dung deposition site may be an important ecological prerequisite for the evolution of horns in dung beetles. Here, we test explicitly for an historical association between tunneling behavior and the evolution of horns using a recent phylogeny for the scarabaeine dung beetles. We show that all eight of the independent gains of horns included in our analyses occurred on branches of the phylogeny reconstructed as tunneling, and that one of the three evolutionary losses of horns occurred on a branch that had lost tunneling behavior. We interpret this as evidence for a biologically meaningful association between tunneling behavior and the evolution of enlarged or exaggerated weapons such as horns, supporting the ideas of Eberhard and others that beetle horns may be most “beneficial” when used within the confines of restricted spaces such as burrows or tunnels.

Three new species of Canthonella Chapin from Hispaniola, with new records and Nomenclatural changes for West Indian dung beetles (Coleoptera: Scarabaeidae: Scarabaeinae)

Three new species, Canthonella jarmilae, Canthonella quesquaya, and Canthonella sikesi NEW SPECIES, are described from Hispaniola. New distribution records for Canthochilum taino Matthews and Canthonella parva Chapin expand the known range of these Puerto Rican Bank species to the northern Virgin Islands. Colonization by the Old World species Digitonthophagus gazella (Fabricius) on Jamaica, Hispaniola, Puerto Rico, St. Croix, St. Kitts, Montserrat and Guadeloupe is documented for the first time, and the mainland American species Pseudocanthon perplexus (LeConte) is recorded from Grand Bahama Island, a first record for the West Indies. Onthophagus albicornis Palisot de Beauvois and Onthophagus capitatus Laporte are re-elevated to full species NEW STATUS, and their allopatric distribution on Hispaniola documented. A list of the 45 known species from the Greater Antilles and Bahama Islands is included.

Epigamic display and unique mating position inWyeomyia arthrostigma (Diptera: Culicidae)

The mating behavior ofWyeomyia arthrostigma is more complex than that reported forW. smithii. Like some other genera in the tribe Sabethini, flyingW. arthrostigma males approach females perching on vertical sticks. A male aligns himself next to a female by seizing her wing and flipping sideways to land next to her, rather than beneath her. He then performs a series of abdominal bobbing movements, the pair achieves superficial genital coupling while the males proboscis rotates and snaps down, and the antennae spread farther apart. Finally, the pair shifts to full copulation, and in this phase insemination occurs. In the copulatory position the abdomens of male and female are almost at right angles to each other, made possible by a twisting of the males terminal segments. The nature of the mating process and its similarity to some elements ofSabethes andTopomyia mating indicate that males may be performing a courtship display.

Attavicinus, a New Generic Name for the Myrmecophilous Dung Beetle Liatongus monstrosus (Scarabaeidae: Scarabaeinae)

Abstract The Mexican dung beetle species Liatongus monstrosus (Bates) is redescribed and made the type of Attavicinus new genus. The phylogenetic evidence for the creation of this taxon and its biology and close association with the debris piles of the leaf cutter ant, Atta mexicana (Smith), are discussed. Information on the restricted distribution in Jalisco and Michoacán and the biogeography and systematics of this genus and the other New World members of the Oniticellini is also included.