Cedar Creek
Ecosystem Science Reserve


Insects of Cedar Creek

Order HYMENOPTERA

Family FORMICIDAE

(Ants)

(Table of Species)

Ants (696 NA spp) with their ubiquitous and often enormous colonies may well contain more biomass than any other insect family. They are primarily scavengers, feeding upon dead insects, but they do not refrain from taking healthy prey if they can immobilize it, and many feed upon plant secretions or the excretions of honeydew producing insects. Roughly 45 species have been collected at Cedar Creek, but an additional 40 may well occur here. They are discussed by subfamily.

PONERINAE
A single species, Ponera pennsylvanica, has been collected. It is a woodland species said to have small colonies in acorns.

MYRMICINAE
Members of this subfamily have a binodal petiole, and the females have a sting. The most commonly encountered genus is Myrmica. Myrmica americana and Myrmica emeryana. are the two most common species. The former is larger, redder, and roughly sculptured and occurs in most fields on the area. The latter species is somewhat smaller and darker and most commonly encountered in wooded areas (look on bracken fern). Myrmica brevispinosa has been collected in swamp along the boardwalk to Cedar Bog Lake. It is likely that other species of Myrmica (lobicornis?, brevinodis?) occur on the Area. Monomorium minimum is a tiny black ant that is abundant in xeric old fields as is Solenopsis molesta (tiny yellow). Less frequently encountered are Leptothorax spp (canadensis, ambiguum, ++?). L. ambiguum is a tiny flat-backed orange ant that occurs in prairie. Pheidole spp (bicarinata, pilifera) have worker and soldier castes (with extremely large heads). They are seed-gatherers in xeric fields. Two uncommon species of Aphaenogaster (rudis?, tennesseensis?) are infrequently encountered in old fields. These species are large and red with a thin petiole. Crematogaster lineolata commonly nests in tree cavities. Its abdomen is shiny black and sharp pointed. Lee Ann Alonso has collected Stenamma diecki in litter in dense forest.

DOLICHODERINAE
Three species of Dolichoderus have been collected. Members of this genus have a concave posterior to the epinotum and are generally roughly pitted on the head and thorax. They are most commonly found on shrubs (eg. Cornus stolonifera) tending aphids. D. taschenbergii (all black) has been collected in the swamp bordering Beckman Lake. D. plagiatus and D. mariae are generally found on shrubs along woods edge. Tapinoma sessile is small, dark-brown, with low set eyes and is abundantly attracted to baits in a few fields. Iridomyrmex pruinosus is a tiny brown ant found in extremely sandy areas in the southeast part of Cedar Creek.

FORMICINAE
It is members of this subfamily (with circular, hair-fringed anal orifice that squirts formic acid) that are most abundant at Cedar Creek. Lasius neoniger, the sidewalk ant, is the abundant small brown ant found in xeric fields. Its 10 cm diameter mounds are conspicuous. Lasius alienus is darker and more commonly occurs in woods but is occasionally taken in fields. Other species of Lasius collected here are L. umbratus and L. minutus. Acanthomyops claviger and A. latipes are small yellow ants with tiny eyes that occurs in woodland. They smell of citronella as do all members of this genus. Paratrechina parvula is tiny, brown, and hairy and is common in most fields. Prenolepis imparis is larger and slender-waisted and occurs in several mesic fields in spring and fall but is absent during the summer when it frequents woods. The Carpenter ants, Camponotus pennsylvanica and Camponotus noveboracensis are common in woodlands, and not infrequently try to establish colonies in older wooded structures on the Area. Myrmentoma nearctica is common in forest litter.

The most abundant ants belong to the genus Formica (with several subgenera). The most abundant and conspicuous is Formica obscuripes, the common red-and-black thatch ant. It is abundant in the oak savanna region south of Fish Lake and occurs in several fields as well. Its large mounds (ca one meter diameter) are impossible to miss. Formica obscuriventris has been taken in BGS, Formica cinerea in a few fields (SV, MJH), Formica fusca occurs in several (TMG, FC, xxx), and Formica neorufibarbis in woodland. Also  collected are ?F. fossaceps, F. argentea, and F. subsericea?Neoformica pallidefulva is a large, shiny, long-limbed species occuring in most fields. I have nicknamed it the 'jackal' for its habit of running into baited petri plates and carrying off a morsel before the other ant occupants are aware of what is transpiring. Also fairly common in fields are the smaller shiny Proformica neogagates and less common still, Proformica lasioides. A few specimens of the slave-making genus, Raptiformica spp (sanguinea, rubicunda, ++?) have been taken in a few fields, and a raiding colony is routinely seen along the sidewalk on the lab grounds.

REFERENCES:
Wheeler GC and J Wheeler (1963)  The Ants of North Dakota. Univ of ND Press, Grand Forks, ND.


webmaster@cedarcreek.umn.edu Last updated May, 2000