Arenivaga

Sand roach burrowing

Arenivaga is a genus of sand cockroaches, of the subfamily Corydiinae, in the family Corydiidae. These cockroaches live in sandy soils and dunes in the southwestern United States, Florida and Mexico. Arenivaga comes from the Latin arena meaning sand and vagus meaning wandering.

Male. Measurements. Holotype TL = 24.6 mm, GW = 13.0 mm, PW = 8.64 mm, PL = 5.60 mm, TL/GW = 1.89, PL/PW = 0.65. EW = 0.40 mm; OW = 0.60 mm. Among paratypes range of TL 20.1–30.7 mm; range of GW 9.6–15.3 mm; range of PW 7.25–10.10 mm; range of PL 4.74–6.17 mm. Head. Two ocelli large, ovoid and protruding; vertex flat, variable in color and width, most species with small ridges between apices of eyes that extend onto ocellar tubercles; interocellar space concave, of varying width, concavity depth and color. Frons color variable, tectiform, concave and/or with fine horizontal corrugations; margined on each side by ridges extending from medial margins of ocelli laterally to margins of clypeus with long or very long setae. Anterior portion of frons of variable color, bulbous to very bulbous in most species; clypeal suture with two proximal setae demarcating anteclypeus; labrum wide. Eyes large and reniform, medially emarginate, dark brown in life but color various in dried specimens. Antennae long, delicate and filiform, arising from medial emargination of eyes; antennomere number variable from ~53–67, though determination is made difficult by frequency of broken antennae on specimens. Pronotum. Pronotum elliptical, variable in size, anterior margin convex, extending anteriorly over head; broad anterior margin translucent, waxy light brown. Setae of variable length along anterior margin; pale short dense setae projecting from ventral side of posterior margin; dorsal surface of pronotum covered with short setae; pronotal pattern may be impressed into surface or not, well demarcated or not, widely variable in color even within some species, with varying extent of aura; the pattern itself varies across the group and takes on certain distinctive appearances including semblance of “panther” or “hippo” faces, and, more rarely, a “koala” face pattern (Fig. 8). Body. Abdomen and legs dorso-ventrally flattened; all legs heavily spinous and setose. Legs and body varying in color, often within a species; white deposits of uric acid visible through exoskeleton throughout body, legs, pronotum, and wing venation. Sternites rounded and setose laterally in most species. Wing brace (Fig. 5) may be present or absent but is consistent within each species. Tarsi with tarsomere I length equal to length of II-V combined; tarsomere IV shortest; with genicular spines on meso and metalegs (but see Diagnosis, above). Two tarsal claws present in all species but one. Subgenital plate asymmetrical with posterior edge emarginated, apices variable in shape; setose along posterior edge and posterior half of dorsal and ventral surfaces. Forewings. Wings extended beyond abdominal apex to varying degrees; veins distinctly raised above surface anteriorly and laterally, becoming increasingly embedded in surface posteriorly and centrally; color ranges from pale clear golden tan to very dark brown; blotchiness absent in some species, consistent in others, variable in others; surface ranges from opaque to semi-opaque to translucent, and from matte to shiny; with variable length setae on anterior lateral edges decreasing to uniformly small posteriorly. Genitalia. Distinctive and highly sculptural, the genitalia of Arenivaga distinguish and delimit species. This revision names and describes four phallomeres, though alternate interpretations of the limits of these structures are possible. While the structures are easy to homologize between species of the genus and close relatives, they are extremely difficult to homologize with the genitalia of other cockroach families or with a “generic” cockroach and no such analysis is attempted here. The phallomeres used in this revision are the right dorsal phallomere, the right ventral phallomere, the small central sclerite, and the left phallomere which includes the genital hook (Fig. 7). The two right phallomeres are hinged together on the lateral side of the animal but are disarticulated here prior to drawing so that as much detail as possible may be shown (Fig. 7).

The genus Arenivaga is found in central Florida and from Texas to California south into Mexico. They occur from about 39°N south to about 18°N (See Fig. 10).