Aphodiinae

Status

Beneficial

Common name(s)

aphodiine dung beetles

Taxonomy

Family: Scarabaeidae Subfamily: Aphodiinae

Adult diagnosis

The subfamily Aphodiinae is diverse in species, but fairly uniform in body shape. The subfamily is characterized by small body size and an elongate, cylindrical body form. Coloration is usually brown to black (Ratcliffe and Paulsen, 2008Ratcliffe and Paulsen, 2008:
Ratcliffe B and Paulsen P. 2008. The scarabaeoid beetles of Nebraska (Coleoptera: Scarabaeoidea). Bulletin of the University of Nebraska 22: 138-248.), though more colorful exceptions are known. In Hawaii and Guam, size range is 1.7–8.5 mm (.07–.33 in). Species known from the islands are dark brownish to black, with the exception of Aphodius fimetarius which has shiny reddish elytraelytra:
the hardened and chitinous wing-cover of a beetle that protect and overlie the flight wing
. The antennaeantennae:
paired sensory organ on head, formed from numerous segments
are 11-segmented, with 3 segments forming the antennal clubantennal club:
the enlarged portion of the antennae, usually towards the apex (end) of the antennae
.

Larval diagnosis

(Ritcher, 1966Ritcher, 1966:
Ritcher P. 1966. White grubs and their allies: a study of North American scarabaeoid larvae. Oregon State University Monographs, Studies in Entomology 4: 1-219.): Grub C-shaped, not usually hump-backed, cylindrical, and cream-colored. Maxillamaxilla:
set of paired mouthparts located posterior to the mandibles
with galeagalea:
outer branch or lobe of the maxilla
and lacinialacinia:
inner portion of the maxilla
close together but distinctly separated. Epipharynxepipharynx:
lobe on the interior surface of the labrum or clypeus
trilobed with tormaetormae:
in scarab larvae, sclerotized structures on the ends of the clypeolateral suture extending towards the mesal line
united mesallymesally:
at or near midline of body
. AntennaeAntennae:
paired sensory organ on head, formed from numerous segments
with 4 or 5 apparent segments. Legs 4-segmented with well-developed claws. Anal lobes whitish or yellowish, lacking setaesetae:
small, hair-like structure
.

Native range

Worldwide. The Aphodiinae are among the most widespread of all scarab beetles, occurring on all continents except Antarctica. They occur in habitats varying from tropical rainforest to alpine tundra (Elias et al., 2000Elias et al., 2000:
Elias S, Berman D, Alfimov A. 2000. Late Pleistocene beetle faunas of Beringia: where east met west. Journal of Biogeography 27: 1349–1363. full text (accessed 2015)).

Plant host(s)

The majority of Aphodiinae are dung feeders and are not associated directly with plants. Most species recycle dung and are beneficial for ranching and farming, thus posing no threat to crops or ornamental plants. However, a few species are known to feed on the roots of grasses, particularly Ataenius spretulus and Aphodius granarius (Shetlar and Niemczyk, 1999Shetlar and Niemczyk, 1999:
Shetlar D and Niemczyk H. 1999. Black turfgrass Ataenius amp; Aphodius . Turfgrass Insect Fact Sheet Series, H.D.N. Books, Wooster, OH. full text (accessed 2015)). Neither species is known from Hawaii or Guam.

Life history

This diverse subfamily shows a wide range of life history traits. Most are dung “dwellers” that breed and feed within dung and do not usually tunnel under or roll fecal matter (Ritcher, 1966Ritcher, 1966:
Ritcher P. 1966. White grubs and their allies: a study of North American scarabaeoid larvae. Oregon State University Monographs, Studies in Entomology 4: 1-219.). A few species, however, are associated with ant or termite nests, are parasitic on other scarabs, or feed on grass roots (Ritcher, 1966Ritcher, 1966:
Ritcher P. 1966. White grubs and their allies: a study of North American scarabaeoid larvae. Oregon State University Monographs, Studies in Entomology 4: 1-219.).

Pest potential

Minor. The majority of aphodiine dung beetles are either harmless or beneficial to agriculture and horticulture. Indeed, several species were purposely brought to the islands to aid in control of the horn fly (Haematobia irritans), a biting pest of livestock (Markin and Yoshioka, 1998Markin and Yoshioka, 1998:
Markin G and Yoshioka E. 1998. Biological control of the horn fly, Haematobia irritans L., in Hawai'i (Diptera: Muscidae). Proceedings of the Hawaiian Entomological Society 33: 43-50. full text (accessed 2015)). A few exceptions, such as Ataenius spretulus and Aphodius granarius, are known to be minor pests of sod and turf (Shetlar and Niemczyk, 1999Shetlar and Niemczyk, 1999:
Shetlar D and Niemczyk H. 1999. Black turfgrass Ataenius amp; Aphodius . Turfgrass Insect Fact Sheet Series, H.D.N. Books, Wooster, OH. full text (accessed 2015)). Neither of these species is currently known from Hawaii or Guam.

Status in Hawaii

Established. Several species of aphodiines are established in Hawaii (Nishida, 2002Nishida, 2002:
Nishida G (editor). 2002. Hawaiian terrestrial arthropod checklist, fourth edition. Bishop Museum Technical Report 22: 1-313.). Members of the Aphodiinae are recorded from all the major Hawaiian islands except for Kaho‘olawe (Nishida, 2002Nishida, 2002:
Nishida G (editor). 2002. Hawaiian terrestrial arthropod checklist, fourth edition. Bishop Museum Technical Report 22: 1-313.). Species identification may be hampered by changes in classification and taxonomy (Gordon and Skelly, 2007).

Status in Guam

Established. Specimens examined at the University of Guam indicate that several species of Aphodiinae occur on the island, as do species checklists by Bourquin (2002) and Cartwright and Gordon (1971).

Potential distribution and dispersal pathway

Several species of aphodiines were intentionally released in Hawaii, as biocontrol agents (Markin and Yoshioka, 1998Markin and Yoshioka, 1998:
Markin G and Yoshioka E. 1998. Biological control of the horn fly, Haematobia irritans L., in Hawai'i (Diptera: Muscidae). Proceedings of the Hawaiian Entomological Society 33: 43-50. full text (accessed 2015)). Other species may have been unintentionally transported to the islands (Nishida, 2002Nishida, 2002:
Nishida G (editor). 2002. Hawaiian terrestrial arthropod checklist, fourth edition. Bishop Museum Technical Report 22: 1-313.).

Similar species

Aphodiine dung beetles can be separated from the true dung beetles (Scarabaeinae) by examination of antennaeantennae:
paired sensory organ on head, formed from numerous segments
(Aphodiinae with 11 segments versus Scarabaeinae with 8 or 9 segments), small size (Aphodiinae at 1.7–8.5 mm [.07–.33 in] versus Scarabaeinae at 2.0–40.0 mm [0.07–1.57 in), and body shape (Aphodiinae are typically elongate and cylindrical versus Scarabaeinae that vary widely in form from rounded or oval to oblong or rarely cylindrical).

Special note

Species level fact sheets for the Aphodiinae will be released pending completion of a review of the Hawaiian and Guamanian fauna. Unfortunately, species level identifications for Hawaiian and Guamanian specimens are usually incorrect, and any non-authoritative identification should be regarded cautiously.

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