Tachysphex gryllivorus Pulawski ex Krombein & Pulawski 1994

Tachysphex gryllivorus Pulawski

We found several females, 8.5–9.5 mm long, nesting in flat, damp sandy loam in two different areas of the Padaviya Antiquities Site, Anuradhapura District, on 13 October 1977 between 0930 and 1340.

NEST CONSTRUCTION.—During burrow excavation this species removed the grains of soil and spread them in a spoil heap that went around half of the entrance. The heap was about 65 mm wide and extended 30 mm beyond the entrance. One nest was begun shortly after 1030; at 1330 the wasp was making a temporary closure by coming to the burrow entrance headfirst, emerging, and then dragging some of the soil backward into the burrow. However, burrow excavation was usually more rapid. Another female was digging her burrow by 0925, completed it between 1000 and 1025, and brought in her first prey at 1028. Another began her burrow at 0950, completed it at 1052, left without making a temporary closure, and returned with her first prey at 1057.

HUNTING AND PROVISIONING.—Prey was brought in rapidly and the entrance was not filled once provisioning began. One female brought in eight prey between 1057 and 1130, their capture requiring from 30 seconds to 9 minutes (mean 4.0 minutes). This wasp remained in the nest between provisioning flights for periods ranging from 30 seconds to 4 minutes (mean 1.1 minute).

Another wasp made two provisioning flights of three and four minutes each, and remained in the nest for periods of from one to three minutes between flights.

NEST STRUCTURE.—In three nests the burrow went downward at an angle of 30° for about 30 mm, and the burrow was vertical in the two other nests to depths of 32 and 40 mm. The burrow diameter at the entrance varied from 4 to 7 mm. The number of cells in completed nests ranged from one to three. The cells varied from almost spherical (5–6 mm) to rather elongate, 8–10 mm long and 5 mm wide.

We captured two wasps while they were closing nests in which the initial section of the burrow went downward at an angle of 30°. The section was 30 mm long in one nest and the burrow then continued at a lesser angle to a depth of 40 mm and 60 mm from the entrance. The single cell at the end contained 13 crickets, the largest with a wasp egg. The first cell found in the second nest was at a depth of 25 mm and was 25 mm from the end of the burrow. The cell contained three crickets, one with an egg. A second cell, probably the last one constructed, was at a depth of 30 mm and directly beneath the entrance. Because it contained only two crickets but no egg, this cell may not have been completely provisioned. A third cell, 35 mm deep (probably the first cell completed), was 50 mm from the burrow entrance, and contained three crickets and an egg.

A completed vertical nest had a seal of compacted soil 5 mm thick at the entrance. An older vertical cell at the bottom of the burrow at 40 mm depth was 10 mm high and contained 13 crickets but no egg. A soil partition, 2–3 mm thick, was above this cell and then an unsealed vertical cell, 8 mm high, containing nine crickets and no egg.

PREY.—The wasps preyed only upon nymphal crickets (Gryllidae, Gryllinae) identified as probably a species of Teleogryllus and a species of Gymnogryllus or genus near it. The majority were 4.5 to 6.0 mm long, but one was 4.0 mm long and another 8.0 mm long.

Apparently the paralysis resulting from the wasp sting is transitory. Most of the crickets began hopping for distances as great as 25–50 mm after the cells were opened with a trowel. It is quite possible that a lightly attached wasp egg might have been dislodged before we captured the crickets, thus accounting for the absence of eggs in some of the cells. The relatively few inactive crickets probably were those paralyzed most recently.

IMMATURE STAGES.—Three slightly curved eggs were 2.2–2.5 mm long and 0.4–0.6 mm wide. Two were attached between the left fore- and midcoxae; one extended across the thorax and protruded laterad of the fore- and midcoxae, and the other protruded beyond the right forecoxa. The third egg was attached between the forecoxae near the base of the right, extending across the sternum and protruding between the fore-and midfemora on the left side.

Tachysphex gryllivorus Pulawski

NAME DERIVATION.—The name gryllivorus derives from the Latin words gryllus, a cricket, and vorare, to devour; with reference to prey of this species.

DIAGNOSIS.—The propodeal dorsum of gryllivorus is microareolate or partly rugose or ridged, with setae inclined posterad (at least laterally), the propodeal side is finely punctate or at most with rudimentary ridges along the margins, and the forebasitarsus has no ventral spines. The female has an unusually short midtarsomere II (Figure 47), with length 1.5–1.6 × apical width (while more than twice in other Tachysphex), the pygidial plate is emarginate apically (Figure 44), and subsidiary recognition features are: punctures of the pygidial plate relatively dense (Figure 44), apical tarsomeres with no spines on venter or lateral margins (Figure 49).

In the male, the propodeal characters are the same as in the female, the black gaster and largely black femora are combined with the red tibiae, and the foretarsus has no rake. The male of haematopus is similar, but unlike gryllivorus the femora are largely red. In addition, the clypeal lip corner is not prominent in gryllivorus (prominent in haematopus), the trimmal cleft is small (unusually large in haematopus, Figure 57), and flagellomere I is markedly shorter than II (about 0.6 of the latter instead of 0.8). Some extralimital species resemble gryllivorus as well. Males of mundus W. Fox (Nearctic), spinulosus Pulawski (Neotropical), and some galeatus Pulawski (Australian) have the same coloration and body sculpture, and they lack a foretarsal rake. In gryllivorus, however, the forefemoral notch is deep and has a longitudinal swelling (Figures 50, 51), the setae of sterna III–V are erect or inclined posterad (sternal setae appressed in the other three).

DESCRIPTION.—Mesopleural punctures fine, averaging more than one diameter apart; interspaces microsculptured but somewhat shiny. Propodeal dorsum uniformly microareolate or partly rugose or ridged; side in most specimens finely punctate, ridged anteriorly and posteriorly, but all microsculptured or all ridged in some males. Hindwing vein cu-a vertical in most specimens, but slightly inclined in some (vein anterior end closer to wing base than posterior end). Hindcoxal dorsum: inner margin practically not expanded basally. Forebasitarsus without ventral spines. Sternum I in most specimens with median, longitudinal carina, prominent apicomesally, but carina absent and prominence vestigial in smallest males.

Setae erect, as long as midocellar diameter on vertex; on scutal disk uniformly inclined posterad, shorter than mid ocellar diameter; along hypostomal carina erect or nearly so, about 0.3 × basal mandibular width; on propodeal dorsum in most specimens inclined posterad except inclined anterad on basomedian, triangular area (apex of triangle not reaching dorsal hindmargin); all setae inclined posterad in one male examined.

Head, thorax, and gaster black; mandible dark reddish mesally in female, yellowish red in male; scape all yellowish red in some males except black basodorsally. Tegula and humeral plate light brown. Wings yellowish (weakly so in some males), veins light brown. Legs black in female, in male femoral apex, tibiae, and tarsi ferruginous. Terga I–IV silvery fasciate apically. Frontal and clypeal vestiture golden in male.

.—Labrum with shallow, rudimentary notch. Clypeus (Figure 42): bevel markedly shorter than basomedian area; lip weakly arcuate, not emarginate, with two lateral incisions on each side. Vertex width 1.0–1.1 × length. Dorsal length of flagellomere I 1.3–1.4 × apical width, equal to 0.7 of II. Punctures of scutal disk fine, averaging two to three diameters apart. Forefemoral venter shiny, with minute punctures that are about two to three diameters apart, and also with a few large, sparse punctures. Outer surface of foretibia with a few thin, erect bristles, but without spines. Forebasitarsus with 8–10 rake spines. Midtarsomere II unusually short (Figure 47): length 1.5–1.6 × apical width. Tarsomeres IV as long as wide, dorsal emargination weakly acute (Figure 48); apicoventral margin weakly concave. Tarsomeres V stout; venter with one long, erect preapical seta; apicoventral margin barely convex (Figure 49). Pygidial plate narrow, emarginate apically, sparsely setose (Figure 44), punctate; large punctures intermixed with small ones; many punctures less than one diameter apart. Length 9.0–10.0 mm.

.—Clypeus (Figure 43): bevel ill defined; lip arcuate or weakly sinuate, with well-defined corner; distance between corners 1.1–1.2 × distance between corner and orbit. Vertex width 0.7–1.1 × length. Dorsal length of flagellomere I 1.1–1.2 × apical width, equal to 0.6 of II. Scutal punctures less than one diameter apart in most specimens, but slightly more than one diameter in some. Forefemoral notch large (Figure 50), finely punctate, setose, with longitudinal swelling (Figure 51). Outer margin of forebasitarsus without preapical spines. Apical tarsomeres without ventral spines. Punctures fine on sternum II but becoming gradually larger on following sterna. Volsella: Figure 45. Penis valve: Figure 46. Length 7.0–9.5 mm.

Setae dense and erect or inclined posterad on sterna II–IV, 0.5–1.0 × midocellar diameter long on III, about 1.0 × midocellar diameter long on IV.

COLLECTING PERIOD.—January through March, 21–25 May, 14 July, 25–26 August (Nepal), 8–14 October.

HABITAT.—Within Sri Lanka, gryllivorus is widespread in the Dry Zone at low elevations with average annual rainfall not more than 1700 mm, and it occurs sparingly in the Intermediate Zone; one specimen was collected at Gilimale in the Wet Zone with an average annual rainfall of nearly 4000 mm (Figure 52).

GEOGRAPHIC DISTRIBUTION.—Nepal to Sri Lanka.

RECORDS.—Holotype: , Sri Lanka, Anuradhapura District, Padaviya, 13 Oct 1977, PBK (USNM).

Paratypes: INDIA: KERALA: Walayar Forests, P. Susai Nathan (2, OSU, RMNH). Also: Bombay Presidency [now Gujarat and Maharashtra States]: Sigiri, E. Comber (2, 1, BMNH) [a locality not found on available maps and gazetteers; most likely the specimens came from one of the following Sri Lankan localities in Matale District and were subsequently mislabeled: Sigiriya, 7°57′N, 80°45′E; Sigiri Wewa, 7°55′N, 80°45′E; or Sigiri Oya, 8°00′N, 80°44′E].

NEPAL: Adhabhar near Simra, 600 ft., Canadian Nepal Expedition (1, CNC).

SRI LANKA: ANURADHAPURA DISTRICT: Padaviya, KVK (3 , USNM); Padaviya, archaeological site, PBK, PF, TW, MJ (1 , CAS); Wildlife Society Bungalow, Hunuwilagama in Wilpattu National Park, D. Davis and W. Rowe (1, USNM). KANDY DISTRICT: 5 mi (8 km) NW Mahiyangana, P. and P. Spangler (2, CAS, USNM). JAFFNA DISTRICT: Kilinochchi, KVK, PF, DWB, VG (2, USNM). MANNAR DISTRICT: 0.5 mi (0.8 km) NE Kokmotte in Wilpattu National Park, KVK, PF, DWB, VG (1, USNM), KVK, TW, SS, TG (1, 1 , CAS; 1, USNM); same locality, KVK, PBK, SK, DWB (1, USNM); Kondachchi, PBK, TW, MJ, GR (1, 1, USNM); Marichchukkaddi, PBK, TW, MJ, GR (1, USNM). MONARAGALA DISTRICT: Angunakolapelessa, KVK, TW, LW (1, CAS; 4, USNM), KVK, PBK, TW, SS, TG (2, CAS; 4, USNM); Nilgala, PBK (1, CNC). RATNAPURA DISTRICT: Gilimale, Induruwa Jungle, KVK, PF, DWB, VG (1, USNM). TRINCOMALEE DISTRICT: China Bay, KVK, PBK, PF, TW, MJ (1, USNM).