Figs. 1-8 from Rehn & Grant (1956), showing diagnostic characteristics of the head and pronotum.
Orthoptera: Caelifera: Tridactylidae: Ellipes minutus (Scudder, 1892)
(Written by Trish Mullins with input from Andrew Ernst)
The genus Ellipes can be distinguished from other members of the family Tridactylidae by the extreme reduction of the hind tarsi which are found as a small flap hidden between the large hind tibial spurs. The genus also lacks the prosternal spur that is found in the genus Neotridactylus (1). A key to the New World genera of Tridactylidae is provided by Gunther (1975). Marjanyan (2007) provides a key to several families of Orthoptera based on the distinctive genual part of the apical portion of the hind femur in Orthoptera.
Most people are familiar with the larger grasshoppers, katydids, and crickets of the Orthoptera, but it takes a keen eye to see the much smaller pygmy mole crickets of the family Tridactylidae. Pygmy mole crickets are minuscule, usually about 12mm long. They burrow beneath the soil and live in sandy areas near water (1). Several species of Tridactylidae have fully developed wings in order to fly away to find new sources of water if their habitat dries up (1). However, Ellipes minutus has reduced wings, as the picture below shows. The species is edaphic, meaning it is confined to soil for the entirety of its life (3). The front legs are fossorial (modified for digging) with toothed tibia.
Ellipes minutus is sometimes known as the minute pygmy locust, or pygmy mole cricket. Don’t confuse the pygmy mole cricket with the “mole crickets“, which are in the family Gryllotalpidae, though they do somewhat superficially resemble the mole crickets. Ellipes is more closely related to the Acrididae (short-horned grasshoppers) and Tetrigidae (pygmy grouse locusts). Many orthopterists no longer call tridactylids “pygmy mole crickets” since they are not crickets and instead call them “pygmy mole grasshoppers” (1).
The species must live near a water source with a good supply of algae, as it is their main source of food. For this reason, Ellipes is most often found in wet areas such as swamps and marshes and the edges of streams and lakes (1).
Specimens have been collected soon after it rains. According to Deyrup (2005), if the sand is dry near the surface and damp a few centimeters under the surface, it may be possible to lure specimens from their borrows by watering the ground with a watering can. Yellow pan traps have recently proven effective in collecting tridactylids (2).
There are 124 specimens of Ellipes minutus in the NCSU Insect Museum, but all were collected before 1950! Interestingly, most specimens were collected by past professors of Entomology at NCSU. Specimens have been collected from Aberdeen, Clinton, Raleigh, Hendersonville, Burgaw, Wilmington, Balsam, Blantyre, Ft. Macon, Parmele, Montreat, and from Cabarrus County. The oldest specimens were collected in 1907 from Raleigh and Hendersonville. We encourage you to go out and collect some fresh specimens!!
For more information:
1. Deyrup, M. 2005. A new species of flightless pygmy mole cricket from a Florida sand ridge (Orthoptera: Tridactylidae). Florida Entomologist 88, 141-145.
2. Missa, O., Basset, Y., Alonso, A., Miller, S.E., Curletti, G., Meyer, M.D., Eardley, C., Mansell, M.W., and Wagner, T. 2009. Monitoring arthropods in a tropical landscape: relative effects of sampling methods and habitat types on trap catches. J. Insect Conservation 13, 103-118.
3. Villani, M. G., Allee, L. L., Dıaz, A. and Robbins, P. S. 1999. Adaptative strategies of edaphic arthropods. A. Rev. Entomol. 44, 233–256.
4. Marjanyan, M.A. 2007. On the morphology of the genual part of the hind Femur in Orthoptera (Insecta). Entomological Review 87, 38-42.
5. Gunther, K.K. 1975. Das Genus Neotridactylus Gunther, 1972 (Saltoria, Tridactylidae, Insecta). Mitt. Zool. Mus. Berlin 51, 305-365.
GBIF – 295 occurrence records
Beautiful image of a Carolina leaf roller, Camptonotus carolinensis. Captured by Kim Fleming.
Orthoptera: Gryllacrididae: Camptonotus carolinensis (Gerstaecker, 1860)
(written by Charlie Plush, with input from Andy Deans)
Natural History: The Carolina leaf-roller (Camptonotus carolinensis) is the only species of Gryllacrididae (the raspy crickets) found in the U.S. Adults have been described as resembling a cross between a cricket and grasshopper, with a drab brown/green coloration and antennae up to five times its body length (12-15mm). Adult females posses an ovipositor that curves back over the abdomen. Its common name is derived from the distinctive leaf-rolls created by adults that serve as a shelter during the day. Both adults and nymphs use silk produced from glands on the mouth to hold the leaf-roll together. Adults are active only at night, during which they hunt and prey on aphids. While little research has been done specifically on the Carolina leaf-roller, there have been extensive studies on related species in Australia, which harbors the greatest diversity of Gryllacrididae species. Such research has produced reports of interesting and unique life-history traits that could possibly be seen in the Carolina leaf-roller. Australian gryllacridids, for example,have been found to communicate acoustically through “foot stomping” and abdominal drumming, and both nymphs and adults can produce sound through a femoral-abdominal apparatus. Interestingly, adults do not possess a known auditory organ, so sound production is thought to be used solely as a means of defense. Also, some Australian gryllacridids have been shown to produce individually recognizable pheromones which may function in helping individuals relocate their leaf roll or burrow after a night of hunting. Individually recognizable pheromone production is currently thought to be unique to Gryllacrididae (Rentz 1997). Adult gryllacridids are extremely territorial, and the ferocity at which they attack intruders has been noted frequently by entomologists. In a lab setting, individual leaf-rollers must be housed separately, or else they will immediately begin attacking, and subsequently killing, one another with little hesitation (Lockwood 2006).
Range: Carolina leaf-rollers are ubiquitous in North Carolina. They are restricted to the Eastern region of the U.S., from Indiana to New Jersey, south to Florida and Mississippi.
NCSU Insect Museum Specimens: There are 19 specimens of Camptonotus carolinensis in the NCSU Insect Museum. Collection dates range from 1977 to 2000, with a majority of specimens being collected prior to 1990.
Collection and Preservation: At night, Carolina leaf-rollers can be captured by sweep-netting tree foliage and other mid-height vegetation where adults may be searching for aphids. Shaking tree limbs with a net held underneath may also be an effective form of capture. During the day, locate adults by searching the tree limbs for the diagnostic leaf rolls in which adults hide inside. The best seasons to collect in North Carolina are late summer to fall with nymphs being prevalent from July-August and adults from September-October. Adult specimens are typically preserved by pinning individuals, but they may also be stored in alcohol.
Find out more:
Lockwood, J. A. 2006. The nature of violence. Orion 25: 14-19.
Rentz, D. F. 1997. The World’s most unusual gryllacrid. Journal of Orthoptera Research 6:57-68.
Encyclopedia of Life species page: Camptonotus carolinensis (Gerstaecker, 1860)
Specimen records available through GBIF. (none from NC at this time)
References to Camptonotus carolinensis in the Biodiversity Heritage Library.
Species Camptonotus carolinensis - Carolina Leaf-roller on BugGuide: http://bugguide.net/node/view/29828. Accessed 30 December 2009
Beautiful image of a Carolina leaf roller in its leaf roll. Captured in Tennessee by Kestrel360.