Overview
The superfamily Scarabaeoidea is a large, diverse, cosmopolitan group of beetles.
Scarabaeoids are adapted to most habitats, and they are fungivores, herbivores,
necrophages, coprophages, saprophages, and sometimes carnivores. They are
widely distributed, even living in the Arctic in animal burrows. Some scarabs
exhibit parental care and sociality. Some are myrmecophilous, termitophilous,
or ectoparasitic. Many possess extravagant horns, others are able to roll
into a compact ball, and still others are highly armored for inquiline life.
Some are agricultural pests that may destroy crops while others are used in
the biological control of dung and dung flies. Scarabaeoids are popular beetles
due to their large size, bright colors, and interesting natural histories.
Early Egyptians revered the scarab as a god, Jean Henri Fabre studied their
behavior, and Charles Darwin used observations of scarabs in his theory of
sexual selection.
Characteristics
Antennal club lamellate. Prothorax often highly modified for burrowing, with
large coxae (usually with concealed trochantins and closed cavities). Protibiae
usually dentate with a single spur. Wing venation reduced and with a strong
intrinsic spring mechanism for folding. Tergite 8 forming a true pygidium
and not concealed by tergite 7. Four Malpighian tubules. Larvae scarabaeiform
(cylindrical, c-shaped). Superfamily classification: Lawrence and Britton
1991; Lawrence and Newton 1995.
Classification Status
The hierarchical level of families and subfamilies within the Scarabaeoidea
is in disarray and remains unresolved. In the previous rendition of this work
(Arnett's The Beetles of the United States, 1968), the Scarabaeoidea included
three families: Passalidae, Lucanidae, and Scarabaeidae. This three-family
system of classification was the "traditional" North American system
and had several practical and conceptual advantages. First, it recognized
the shared, derived characters that unite subfamilies within the family Scarabaeidae.
Second, it provided a classification system that allowed easy retrieval of
hierarchical information based on the fact that subfamilies were part of the
family Scarabaeidae (e.g., life history, morphology, larval type). Phylogenetic
research indicates that the family Scarabaeidae (in the traditional sense)
is not a monophyletic group. Therefore, we have chosen to follow the 12-family
system established by Browne and Scholtz (1995, 1999) and Lawrence and Newton
(1995). This system places emphasis on the differences that separate taxa
rather than the similarities that unite them. Whereas families, subfamilies,
and tribes in the staphylinoids and curculionoids are being combined because
of shared characters (thus increasing efficient data retrieval), the scarabaeoids
are being split into numerous families because of supposed differences (thus,
in our view, decreasing information retrieval). The debate concerning scarabaeoid
classification systems illustrates the weak phylogenetic foundation of the
superfamily. This problem is the result of a number of factors including (1)
lack of thorough study of all scarabaeoid taxa, (2) lack of diagnostic characters
for all taxa, (3) lack of phylogenetic study of all taxa, (4) prevailing philosophies
regarding categorical levels, and (5) emphasis in research on the less speciose
groups of scarabaeoids and lack of research on the more speciose groups (such
as the subfamilies of Scarabaeidae including the Melolonthinae, Rutelinae,
Dynastinae, Aphodiinae, and Cetoniinae).
Within the Scarabaeoidea there is a disparity in the knowledge between less
speciose basal lineages and the more speciose groups of "higher"
Scarabaeidae. For example, the family Trogidae includes approximately 300
species in four genera. Excellent revisionary, larval, and phylogenetic studies
are available for this group (Baker 1968; Scholtz 1982, 1986, 1990, 1991,
1993; Scholtz and Peck 1990). Excellent monographs are also available for
the approximately 600 species of Geotrupidae (Howden 1955, 1964, 1979, 1985a-b,
1992; Howden and Cooper 1977; Howden and Martínez 1978) and the Trogidae
(Vaurie 1955), and these will provide the foundation for addressing relationships
within this group. In comparison, the family Scarabaeidae (sensu Lawrence
and Newton 1995) includes approximately 91% of the species (ca 27,800) of
Scarabaeoidea. Within the Scarabaeidae, approximately 21,000 species are in
the subfamilies Melolonthinae, Dynastinae, Rutelinae, and Cetoniinae (the
"higher" scarabs). Only a few phylogenetic analyses have addressed
relationships of pleurostict subtribes, genera, or species (Ratcliffe 1976;
Ratcliffe and Deloya 1992; Jameson 1990, 1996, 1998; Jameson et al. 1994;
Krell 1993), and only one analysis has been conducted to address tribal or
subfamilial relationships (Browne and Scholtz 1999).
Historically, the superfamily Scarabaeoidea was divided into two generalized
groups based on the position of the abdominal spiracles; the Laparosticti
and Pleurosticti. Pleurostict scarabs were characterized by having most of
the abdominal spiracles situated on the upper portion of the sternites (Ritcher
1969; Woodruff 1973) and included taxa whose adults feed on leaves, flowers
and pollen, and whose larvae feed primarily on roots and decaying wood. Laparostict
scarabs, on the other hand, were characterized by having most of the abdominal
spiracles located on the pleural membrane between the tergites and sternites
(Ritcher 1969) and included taxa whose adults and larvae feed on dung, carrion,
hides, and feathers. The position of the spiracles, however, is not a consistent
character (Ritcher 1969), and, in recent years, subfamilies and tribes that
were once included in the Laparosticti have been raised to higher taxonomic
status (family and subfamily, respectively).
The composition of the Scarabaeoidea remains a topic of debate. Lawrence and
Newton (1995) proposed 13 families (12 found in the Nearctic, Belohinidae
is Madagascan), and Scholtz and Browne (1996) and Browne and Scholtz (1995,
1998, 1999) proposed 13 families (all Nearctic, including Bolboceratidae;
Belohinidae was not addressed). In this work we follow, with some hesitation,
the system of Lawrence and Newton (1995) and treat the Scarabaeoidea as including
12 Nearctic families (11 of which were previously considered subfamilies of
the family Scarabaeidae, and one of which was previously considered a subfamily
of the Lucanidae). Our reluctance to accept elevation of new families within
the Scarabaeoidea stems from the fact that: 1) there have been no comprehensive
taxonomic treatments of all higher categories of scarabaeoids (families and
subfamilies) and, 2) there are few comprehensive, rigorous, phylogenetic analyses
of higher scarabaeoid groups and, thus, a lack of synapomorphic characters
that establish a basis for uniform familial and subfamilial levels. We prefer
to see clades delimited by shared derived characters before the elevation
of certain taxa to family level. Despite our reluctance to accept this classification
system, we have little basis for disputing the validity of current taxonomic
conclusions other than the fact that some of these taxonomic conclusions have
been based on narrow taxonomic frame-works (only scarab taxa from certain
geographic regions rather than all scarab groups) or based on few characters
or suites of characters.
Underlying the classification problem is, of course, the fact that we are
dealing with constructs that are 200 years old and that pre-date evolutionary
theory. Linnaean classifications were based on overall morphological similarity
rather than shared, derived characters. Thus, some groups within the scarabaeoids
are not monophyletic lineages; instead, they are groups that were created
historically because they superficially resembled each other. Our system of
classification needs to convey information and concepts and allow for easy
retrieval of information. Whether a certain taxon is classified at the level
of family or subfamily may be trivial if we can continue to convey the needed
information. We remain apprehensive that the trend of elevation to many families
within the Scarabaeoidea will result, at least in the short term, in a net
loss in retrievability of information.
Despite the considerable debate, phylogenetic analyses of scarabaeoid higher
categories are on-going and their results bring us closer to understanding
relationships of the groups. A preliminary "total evidence" phylogenetic
analysis of 13 families of Scarabaeoidea (excluding Belohinidae, including
Bolboceratidae) and most of the subfamilies was conducted using 134 adult
and larval characters (Brown and Scholtz 1999). Results of this analysis showed
that the superfamily Scarabaeoidea is comprised of three major lineages: the
glaresid lineage that consists of only the family Glaresidae; the passalid
lineage that consists of two major lines--a glaphyrid line (containing Glaphyridae,
Passalidae, Lucanidae, Diphyllostomatidae, Trogidae, Bolboceratidae, and Pleocomidae),
and a geotrupid line (containing Geotrupidae, Ochodaeidae, Ceratocanthidae,
and Hybosoridae); and the scarab lineage (containing Aphodiinae, Scarabaeinae,
Orphninae, Melolonthinae (sensu lato), Rutelinae, Dynastinae, and Cetoniinae).
The series Scarabaeiformia is comprised exclusively of the superfamily Scarabaeoidea.
Monophyly of the group is well founded and undisputed (Lawrence and Britton
1991). The sister group for the Scarabaeoidea, however, is not resolved and
continues to be debated. Two groups are considered: the Staphyliniformia and
the Dascilloidea. The Scarabaeoidea and Staphyliniformia share characters
of the wing venation and the abdomen that are not present in the dascilloids
(Kukalova-Peck and Lawrence 1993). The Scarabaeoidea and Dascilloidea share
similar larval characters (lack of urogomphi that are present in Staphyliniformia,
cribriform spiracles, separate galea and lacinia) and adult characters (form
of the ommatidium, male genitalia, mouthparts) (Scholtz et al. 1994). Lawrence
and Newton (1982) argued that similarities in the Dascilloidea and Scarabaeoidea
are attributable to either plesiomorphic or convergent characters that are
associated with soil-dwelling habits.
Distribution
The Scarabaeoidea is one of the largest superfamilies in the Coleoptera and
includes approximately 2,200 genera and about 31,000 species worldwide (Dalla
Torre 1912-1913; Endrsądi 1985; Hanski and Cambefort 1991; Krikken 1984; Lawrence
1982; Machatschke 1972; Scholtz 1982). While some of the smaller groups are
well known worldwide (e.g., Geotrupidae and Trogidae), some other groups (e.g.,
Scarabaeidae that comprises 91% of the Scarabaeoidea) cannot be identified
to even genus-level with reliability.
In the Nearctic region, the taxonomy of most scarabaeoids is now fairly well
known although there remain a few areas of uncertainty. For example, the phylogenetic
position of both the Pleocomidae and the Hopliini needs to be addressed. In
this work, there are numerous changes in the author and/or date of many genera
and even some higher categories since Arnett (1968). These are the result
of greater scrutiny of the original literature rather than accepting at face
value the often erroneus or incomplete information provided in older catalogs
and faunal works.
There are approximately 170 genera and 2,000 species in the United States,
Canada, and Nearctic Mexico. Smith (2001) provided a checklist of Nearctic
scarabaeoids. Regional works: Blatchley 1910; Loding 1945; Saylor 1948b; Edwards
1949; Helgesen and Post 1967; Hatch 1971; Woodruff 1973; Kirk and Balsbaugh
1975; Shook 1978; Lago et al. 1979; Ratcliffe 1991; Downie and Arnett 1996;
Moríón et al. 1997; Harpootlian 2001.
Scarabaeoid Families and Subfamilies of the New World
Families | Subfamilies |
Aesalinae Lampriminae Lucaninae Platycerinae Syndesinae |
|
Aclopinae Allidiostomatinae Aphodiinae Cetoniinae Dynastinae Melolonthinae Orphninae Rutelinae Scarabaeinae |
|
References
Cited
ARNETT, R. H., JR. 1968. The Beetles of the United States.
A Manual for Identification. The American Entomological Institute, Ann Arbor,
MI. 1,112 pp.
BAKER, C. W. 1968. Larval taxonomy of the Troginae in North
America with notes on biologies and life histories (Coleoptera: Scarabaeidae).
United States National Museum Bulletin 279: 1-79.
BLATCHLEY, W. S. 1910. An illustrated descriptive catalogue
of the Coleoptera or beetles known to occur in Indiana. Indiana Department
of Geology and Natural Resources Bulletin, 1: 1-1386.
BROWNE, D. J. and C. H. SCHOLTZ. 1995. Phylogeny of the families
of Scarabaeoidea (Coleoptera) based on characters of the hindwing articulation,
hindwing base and wing venation. Systematic Entomology, 20: 145-173.
BROWNE, J. and C. H. SCHOLTZ. 1998. Evolution of the scarab hindwing
articulation and wing base: A contribution toward the phylogeny of the Scarabaeidae
(Scarabaeoidea: Coleoptera). Systematic Entomology, 23: 307-326.
BROWNE, J. and C. H. SCHOLTZ. 1999. A phylogeny of the families
of Scarabaeoidea (Coleoptera). Systematic Entomology, 24: 51-84.
DALLA TORRE, K. W. VON. 1912-1913. Scarabaeidae: Melolonthinae.
Coleopterorum Catalogus, pars 45, 47, 49, 50: 1-450. W. Junk, Berlin.
DOWNIE, N. M. AND R. H. ARNETT, JR. 1996. The Beetles of
Northeastern North America, volumes 1 and 2. The Sandhill Crane Press, Gainesville,
FL. 1,721 pp.
EDWARDS, J. G. 1949. Coleoptera or Beetles East of the Great
Plains. Edwards Brothers, Ann Arbor, MI. 181 p.
ENDRÖDI, S. 1985. The Dynastinae of the World. Dr. W.
Junk Publisher, London. 800 pp.
HANSKI, I. and Y. CAMBEFORT. 1991. Dung Beetle Ecology. Princeton
University Press, Princeton, NJ. 481 pp.
HARPOOTLIAN,
P. H. 2001. Scarab beetles (Coleoptera: Scarabaeidae) of South Carolina.
Biota of South Carolina, Volume 2. Clemson University, Clemson, SC. 157 pp.
HATCH, M. H. 1971. The beetles of the Pacific Northwest, part 5.
University of Washington Publication in Biology, 16: 1-662.
HELGESEN, R. G. and R. L. POST. 1967. Saprophagous Scarabaeidae
(Coleoptera) of North Dakota. North Dakota Insects, Publication Number 7:
1-60.
HOWDEN, H.
F. 1955. Biology and taxonomy of North American beetles of the subfamily
Geotrupinae with revisions of the genera Bolbocerosoma, Eucanthus,
Geotrupes and Peltotrupes (Scarabaeidae). Proceedings of
the United States National Museum 104: 151-319.
HOWDEN, H. F. 1964. A Catalog of the Coleoptera of America
North of Mexico. Family Scarabaeidae. Subfamily: Geotrupinae. United States
Department of Agriculture, Agriculture Handbook 529-34a. 17 pp.
HOWDEN, H. F. 1979. A revision of the Australian genus Blackburnium
Boucomont (Coleoptera: Scarabaeidae: Geotrupinae). Australian Journal of Zoology,
Supplementary Series, 72:1-88.
HOWDEN, H. F. 1982. Larval and adult characters of Frickius
Germain, its relationship to the Geotrupini, and a phylogeny of some major
taxa in the Scarabaeoidea (Insecta: Coleoptera). Canadian Journal of Zoology
10: 2713-2724.
HOWDEN, H. F. 1985a. A revision of the South American genus
Parathyreus Howden and Martinez (Coleoptera: Scarabaeidae: Geotrupinae).
Coleopterists Bulletin 39: 161-173.
HOWDEN, H. F. 1985b. A revision of the South American species in
the genus Neoathyreus Howden and Martinez (Coleoptera, Scarabaeidae,
Geotrupinae). Contributions of the American Entomological Institute 21: 1-95.
HOWDEN, H. F. 1992. A revision of the Australian beetle genera Eucanthus
Westwood, Bolbobaineus Howden and Cooper, Australobolbus
Howden and Cooper and Gilletus Boucomont (Scarabaeidae: Geotrupinae).
Invertebrate Taxonomy, 6: 605-717.
HOWDEN, H. F. and J. B. COOPER. 1977. The generic classification
of the Bolboceratini of the Australian Region, with descriptions of four new
genera (Scarabaeidae: Geotrupinae). Australian Journal of Zoology, Supplementary
Series, 50: 1-50.
HOWDEN, H. F. and A. MARTêNEZ. 1978. A review of the New World
genus Athyreus MacLeay (Scarabaeidae, Geotrupinae, Athyreini). Contributions
of the American Entomological Institute, 15: 1-70.
IABLOKOFF-KHNZORIAN, S. M. 1977. Uber die Phylogenie der Lamellicornia.
Entomologische Abhandlungen der Staatlichen Museum fur Tierkunde in Dresden
41: 135-200.
JAMESON, M. L. 1990. Revision, phylogeny and biogeography
of the genera Parabyrsopolis Ohaus and Viridimicus (new
genus) (Coleoptera: Scarabaeidae: Rutelinae). Coleopterists Bulletin 44: 377-422.
JAMESON, M. L. 1996. Revision and phylogeny of the Neotropical
genus Cnemida (Coleoptera: Scarabaeidae: Rutelinae). Insecta Mundi
10: 285-316.
JAMESON, M. L. 1998. Phylogenetic analysis of the subtribe
Rutelina and revision of the Rutela generic groups (Coleoptera: Scarabaeidae:
Rutelinae: Rutelini). Bulletin of the University of Nebraska State Museum
14: 1-184.
JAMESON, M. L., B. C. RATCLIFFE and M. A. MORÓN. 1994.
A synopsis of the Neotropical genus Calomacraspis Bates with a key
to larvae of the American genera of Rutelini (Coleoptera: Scarabaeidae: Rutelinae).
Annals of the Entomological Society of America 87: 43-58.
KIRK, V. M. and E. U. BALSBAUGH, JR. 1975. A list of the beetles
of South Dakota. South Dakota State University, Agricultural Experiment Station,
Technical Bulletin Number 42. 137 pp.
KRELL, F.-T. 1993. Phylogenetisch-systematische Revision des Genus
Temnorhynchus Hope, 1837 (Coleoptera: Scarabaeoidea: Melolonthidae:
Dynastinae: Pentodontini). 1. Teil. Phylogenetische Analyse, mit Anmerkungen
zur phylogenetisch-systematischen Methodologie. Beitrage zur Entomologie 43:
237-318.
KRIKKEN, J.
1984. A new key to the suprageneric taxa in the beetle family Cetoniidae,
with annotated lists of the known genera. Zoologische Verhandelingen No. 210:
1-75.
KUKALOVA-PECK, J. and J. F. LAWRENCE. 1993. Evolution of
the hind wing in Coleoptera. The Canadian Entomologist 125: 181-258.
LAWRENCE, J. F. 1982. Coleoptera, pp. 482-553. In, S.P. Parker
(ed.), Synopsis and Classification of Living Organisms. Vol. 2. McGraw-Hill,
New York.
LAWRENCE, J. F. and E. B. BRITTON. 1991. Coleoptera. The Insects of Australia, 2nd edition, Volume 1, , pp. 543-683. Melbourne University Press, Carlton.
LAWRENCE, J.
F. and A. F. NEWTON. 1982. Evolution and classfication of beetles.
Annual Review of Entomology and Systematics 13: 261-290.
LAWRENCE, J. F. and A. F. NEWTON. 1995. Families and subfamilies
of Coleoptera (with selected genera, notes, references and data on family-group
names), pp. 779-1006. In J. Pakaluk and S. A. ´Slipínski (eds.),
Biology, Phylogeny, and Classification of Coleoptera. Papers Celebrating the
80th Birthday of Roy. A. Crowson. Muzeum i Instytut Zoologii PAN, Warszawa.
1,092 pp.
LODING, H. P. 1945. Catalogue of the beetles of Alabama.
Alabama Geological Survey Monograph, 11: 1-172.
MACHATSCHKE, J. W. 1972. Scarabaeoidea: Melolonthidae, Rutelinae.
Coleopterorum Catalogus Supplementa 66: 1-361.
MORON, M. A., B. C. RATCLIFFE, and C. DELOYA. 1997. Atlas
de los Escarabajos de México. Coleoptera: Lamellicornia. Vol. 1. Familia
Melolonthidae. Subfamilias Rutelinae, Dynastinae, Cetoniinae, Trichiinae,
Valginae y Melolonthinae. Sociedad Mexicana de Entomología, A. C.,
Mexico. 280 pp.
RATCLIFFE, B. C. 1976. A revision of the genus Strategus
(Coleoptera: Scarabaeidae). Bulletin of the University of Nebraska State Museum
10: 93-204.
RATCLIFFE, B. C. 1991. The scarab beetles of Nebraska. Bulletin of
the University of Nebraska State Museum, 12: 1-333.
RATCLIFFE, B. C. and A. C. DELOYA. 1992. The biogeography
and phylogeny of Hologymnetis (Coleoptera: Scarabaeidae: Cetoniinae)
with a revision of the genus. Coleopterists Bulletin 46: 161-202.
RITCHER, P. O. 1969. Spiracles of adult Scarabaeoidea (Coleoptera)
and their phylogenetic significance. I. The abdominal spiracles. Annals of
the Entomological Society of America 62: 869-880.
SCHOLTZ, C. H. 1982. Catalogue of the world Trogidae (Coleoptera:
Scarabaeoidea). Republic of South Africa, Department of Agriculture and Fisheries,
Entomology Memoire 54: 1-27.
SCHOLTZ, C. H. 1986. Phylogeny and systematics of the Trogidae
(Coleoptera: Scarabaeoidae). Systematic Entomology 11: 355-363.
SCHOLTZ, C. H. 1990. Phylogenetic trends in the Scarabaeoidea
(Coleoptera). Journal of Natural History 24: 1027-1066.
SCHOLTZ, C. H., D. J. BROWNE, and J. KUKALOVÁ-PECK 1994.
Glaresidae, archeopteryx of the Scarabaeoidea (Coleoptera). Systematic Entomology
19: 259-277.
SCHOLTZ, C. H. and J. BROWNE. 1996. Polyphyly in the Geotrupidae
(Coleoptera: Scarabaeoidea): a case for a new family Bolboceratidae. Journal
of Natural History 30: 597-614.
SCHOLTZ, C. H., D. D'HOTMAN, and A. NEL. 1987. Glaresidae,
a new family of Scarabaeiodea (Coleoptera) to accomodate the genus Glaresis
Erichson. Systematic Entomology 12: 345-354.
SCHOLTZ, C. H. and S. PECK. 1990. Description of a Polynoncus
Burmeister larva, with implications for phylogeny of the Trogidae (Coleoptera:
Scarabaeoidea). Systematic Entomology 15: 283-289.
SMITH, A. B. T. 2001. Checklist of the Scarabaeoidea of the
Nearctic Realm (Includes Canada, the continental United States, and the following
states of northern Mexico: Baja California, Baja California Sur, Chihuahua,
Coahuila de Zaragoza, Durango, Nuevo Leon, Sinaloa, Sonora, Tamaulipas, and
Zacatecas). URL: http://www-museum.unl.edu/research/entomology/nearctic.htm.
WOODRUFF, R. E. 1973. The scarab beetles of Florida (Coleoptera:
Scarabaeidae). Part. I. The Laparosticti (subfamilies: Scarabaeinae, Aphodiinae,
Hybosorinae, Ochodaeinae, Geotrupinae, Acanthocerinae). Arthropods of Florida
and Neighboring Land Areas, 8: 1-220.