southern mole cricket
Neoscapteriscus borellii Giglio-Tos 1894

map
map of spread
eggs
pronotal patterns
female
male
foretibia
trochantal blade
head and front legs
left foreleg
left foreleg
burrow

20 s of calling song [1.73MB]; male from Broward County, FL; 24.2°C. (WTL341-14)
6 s of calling song [262KB]; same as above but truncated and down-sampled.

Sound spectrogram
Sound spectrogram of 0.5 s of calling at 24.2°C (from WTL341-14). Dominant frequency 2.7 kHz.
Click on first half of spectrogram to hear graphed song.
Click on last 0.5 s to expand its spectrographic image.

Identification:  Tibial dactyls separated at base by space equal to at least half of basal width of a dactyl. Viewed from rear, sharp lower edge of trochantal blade extending one-half to two-thirds distance from trochantal tip to junction with femur. Forewings longer than pronotum; hindwings longer than abdomen. Length 25-32 mm.

Habitat:  Wet or moist, sandy or mucky, open areas—including fields, lawns, and the margins of ponds and streams.

Season:  One generation per year except in south Florida, where there are two. Some individuals overwinter as adults, but most do so as large nymphs. Eggs are laid in spring. Most calling is Feb.-July, but because adults are long-lived, some calling occurs year-round. Flights are heaviest in April, May, and June except in south Florida, where a second generation sometimes produces a flight peak in July or August; n. Fla. data.

Song at 25°C:  A low-pitched, ringing trill at 54 p/s that issues from a horn-shaped opening in the ground during the first 2 hours after sunset or, after heavy rains, later. The male's courtship song, sometimes produced for minutes from a closed burrow, resembles the calling song of the northern mole cricket but is higher pitched and has a slightly faster chirp rate.

Similar species:  N. vicinus has the tibial dactyls nearly touching at base. N. abbreviatus has the forewings shorter than pronotum and the hindwings concealed by the fore wings.

Remarks:  This species was long thought to be native to southeastern United States and went by the name Neoscapteriscus acletus. However, analysis of early records revealed that it first appeared in the United States in l904, near the port of Brunswick, Georgia. Subsequently it became established at other ports—Charleston, South Carolina, l9l5; Mobile, Alabama, l9l9; Port Arthur, Texas, l925—and spread from these sites to occupy most of the southeastern states (Walker & Nickle 1981). Once the source of the immigrants was identified, Nickle (1992) determined that the species had another name, Neoscapteriscus borellii. Because N. borellii was the older name it became the correct one to use.

The N. borellii introduced at Brunswick and Mobile had a mottled pronotal pattern, whereas those at Charleston and Port Arthur had four light dots arranged in a trapezoid on the dark pronotal disk (see photograph above). The two patterns initially spread from the separate sites of introduction, but today the mottled pattern is only in the vicinity of Mobile. The recent establishment of N. borellii along the Colorado River and in turf near Yuma, Arizona, raises the possibility that is will spread to other sandy well-watered areas throughout the Southwest.

The southern mole cricket is largely carnivorous and apparently does less damage to established grass than the tawny and short-winged mole-crickets, which are mostly herbivorous.

More information:  family Gryllotalpidae, genus Neoscapteriscus

References:  Hayslip 1943, see additional references on genus page.

Nomenclature:  OSF (Orthoptera Species File Online)