Stenopelmatus piceiventris Walker

Weissman, David B., Vandergast, Amy G., Song, Hojun, Shin, Seunggwan, Mckenna, Duane D. & Ueshima, Norihiro, 2021, Generic relationships of New World Jerusalem crickets (Orthoptera: Stenopelmatoidea: Stenopelmatinae), including all known species of Stenopelmatus, Zootaxa 4917 (1), pp. 1-122 : 69-75

Stenopelmatus piceiventris Walker

Oaxaca Jerusalem Cricket

Figs 110–119 , Tables 1 , 2

1869. Stenopelmatus piceiventris . Catalogue of the Specimens of Dermaptera Saltatoria in the Collection of the British Museum 1:197. Holotype adult female in NHMUK ( Figs 110 , 111 ): (1) red label Holotype. (2) Stenopelmatus piceiventris Walker. No locality on labels or in original description. Holotype measurements in mm: Body length 42, hind femur length 14.5, hind femur width 4.9. Hind tibia with 3 outer and 4 inner spines ( Fig. 112 ). This morphologically unique species was immediately recognized from an adult male ( Figs 113 , 114 ), with hooks and similar micropterous fore wings, collected by Matthew Van Dam, in 2004, in the mountains northeast of Oaxaca, Mexico, along Highway 175, at 2 km S La Esparanza. Measurements of that adult male, in mm: Body length 40.15, hind femur length 18.06, hind femur width 5.81. Fore tibia with 3 ventral spurs; middle leg tibia with 8 calcars, 2 ventral spurs; hind leg tibia with 4 outer and 4 inner spines, 2 ventral spurs. Face with only lateral carinae of furrow ( Fig. 115 ). There are no hind wings under the fore wings, which appear “folded” along the inner margin. If care is not taken while checking for a hind wing, this fore wing can be easily split along the fold line which then gives the false impression of a hind wing ( Fig. 115 ). Subsequent careful inspection of many early instars and adults all confirm the absence of a hind wing at any stage. There is also an area of short hairs under these fore wings ( Fig. 116 ) in both sexes.

Of notable significance, the smallest instars, around 12 mm in length and over 1+ years, and many molts from adult, have visible wing pads. Adult fore wings more oval in shape as opposed to teardrop shape of earlier instars (see Fig. 118 below). Type locality here designated: Mexico, Oaxaca, Sierra de Juárez Mountains NE Oaxaca along Highway 175 .

Distribution. Only known from the Sierra de Juárez Mountains NE Oaxaca along Highway 175.

Recognition characters. One of only 3 Stenopelmatus taxa with micropterous fore wings as adults: the smaller, similar looking S. sanfelipe , which has 2-3 outer rear leg tibial spines versus 3-4 seen in S. piceiventris ; and the smaller Mexican state of Chiapas endemic S. chiapas , whose fore wing is narrower than that of S. piceiventris (see Fig. 22 , p. 28 ). Additionally, 6 of 8 adult S. sanfelipe have no indication of a furrow while 7 of 7 adult S. piceiventris have definite furrow lateral carinae.

Drum. Despite over 30 hours of recording attempts, no drumming heard or recorded. Could this JC, at the base of the tree ( Fig. 10 ) and with the highest chromosome number in the subfamily, be the most primitive species of New World JC, with drumming being a derived character in those species that diverged later?

Derivation of name. “picei”, from piceus, could refer to dark coloration and “ventris” could refer to stomach or ventral part of specimen, which in this case, would be the dark, discolored ventral abdomen.

Habitat. Oak-pine semi-cloud forest with fairly dense vegetation, deep leaf litter, moist soil, and some light gaps where trees cut down. Individuals ( Fig. 117 ) under logs, under bark on stumps, in pine stumps, under rocks. In some situations, illegal logging appears to create “habitat” and facilitates finding specimens, as also seen for S. talpa (S08-39) near Zimapan and S. sartorianus at Metlac Canyon (S06-39). The question then becomes: where are these individuals hiding during the daytime when there are no dead trees on the ground?

Behavior. Individuals of all instars, and adults, hop.

Life cycle and seasonal occurrence. See under “Specimens examined”

Variation. See Table 1 .

Specimens examined. Mexico, Oaxaca, Sierra de Juarez, Highway 175 from Oaxaca to Tuxtepec , 2 km S La Esparanza, 17° 37’ 24.1” -96° 21’ 57.6”, 5400’, 31-v-2004, MV Dam, Ƌ 1, to black light. Hwy 175 between km 128-130, 14-vi-2015. 17° 26’ 40.74” -96° 30’ 48.36”, 9530’, DBW, DW Weissman, S 15-30, highway repaved and old chunks of blacktop discarded along roadsides – JCs under these chunks, ♀ 1, late instar ♀ 1, mid-instars Ƌ6, ♀ 3, early nymphs #2. Hwy 175, km post 129.2, 17° 26.626’ -96° 30.748’. 9648’ 19-vi-2006, DBW, DC Lightfoot, S 06-36; Ƌ1, ♀ 1, late instar ♀ 4, mid instar Ƌ2; 7 individuals under logs at log-soil interface, 2 under bark on tops of logs. 66 km SW Valle National (= 4 km SW Cerro Pelón, 2700 m, 22 & 23-vii-1990, (S90-54, 56), VF Lee; Llano de las Flores, 2-3-iv-1959, 2870m, TE Moore, UMMZ; 3 km S Llano de las Flores, 2800 m, 23- vii-1990, S90-57, VF Lee.

Probable placement. Oaxaca, Cerro Iguana, almost 95 km due south of Oaxaca at 16° 14’ 47” -97° 01’ 52”, 7504’ 4-viii-2007, MV Dam collected 1 early instar and 2 late instars ( Fig. 118 ), but no adults of what resembles S. piceiventris in both size and color. Comparing DNA ( Fig. 10. p . 15 , F2180) between these 2 late instars with individual F1775 from the type locality of S. piceiventris , reveals that they are each other’s nearest relatives, and may be conspecific.

DNA. Nuclear F1775, and mtDNA F1774 & F1775, both from type locality; and nuclear F2180, and mtDNA F2180 & F2181, both from Cerro Iguana, show this taxon lying ( Figs 9 , 10 ) at the base of the Stenopelmatus clade.

Karyotype. T15-29, T16-1, T16-2 (all S15-30), 2nƋ = 27, highest known number for subfamily confirmed in 3 individuals, of which we present ( Fig. 119 ) the two best preparations. Its location at the base of the JC DNA tree appears to indicate that 2nƋ = 27 is the primitive karyotype number for the Stenopelmatinae and that lower numbers, from 19 to 25, in other species of New World JCs, are all derived.

Discussion. There are extensive small bumps and short hairs under the fore wings ( Fig. 116 ), whose function is unknown. They cannot be used for femoral-abdominal stridulation because the wings cover the hairs. Plus, we never heard stridulation from any of our many collected specimens. Could the hairs be there to hold the pads in place while individuals move inside logs? But then what is the function of the wings?

Fontana et al. (2017), in their Orthoptera of Oaxaca, only list the JC S. minor as occurring in Oaxaca, even though their photo appears to be the physically different colored S. talpa .

Figures

FIGURE 9. 50% majority rule phylogram from a Bayesian analysis of concatenated mtDNA 12S and COI gene fragments for at least 16 species of Stenopelmatus. Posterior probabilities greater than 0.5 are displayed at each node, and posterior probabilities of 1.0 are denoted with green dots.

FIGURE 10. Coalescent-based species tree estimation using ASTRAL. Ammopelmatus clade has been collapsed. Green circles on the nodes denote 100% bootstrap support values, and the support values below 100% are shown as numbers. In samples F2004, F2152, and F2238, the species name is preceded by a “?” mark because the identity of the individual is not certain. These three samples are discussed in the text under each presumptive species.

FIGURE 15. Lectotype male (left photo), NHMUK, right rear tibia showing 3 inner and 3 outer spines.Type series second adult male (right photo), MGNG Geneva, with rear leg tibia showing 3 inner and 3 outer spines.

FIGURE 22. Holotype adult male S. chiapas, with arrow pointing to wing.

FIGURE 28. Holotype S. cusuco left rear leg tibia (left photo) showing 3 inner and 4 (1 very small—arrow) outer spines. Right photo showing minimal (arrow) furrow.

FIGURE 110. Holotype S. piceiventris adult female. Note micropterous fore wing (arrows), enlarged in next Figure.

FIGURE 111. Enlarged photo, holotype, showing fully developed (arrow), left oval fore wing.

FIGURE 112. Holotype female hind leg tibial spines: 3 outer (left) and 4 inner (right).

FIGURE 113. Adult male S. piceiventris from 2 km S La Esparanza.

FIGURE 114. Adult male S. piceiventris from 2 km S La Esparanza. In top photo, both fore wings (arrows) have been elevated for identification. Left hind tibia (bottom photo) showing 4 (1 small) outer and 4 inner spines. Right tibia with 3 outer and 4 inner spines.

FIGURE 115. Face (left photo) of above adult male, from La Esparanza, showing present, but reduced lateral carinae (arrows) of furrow. “Artifactual” small hind wing (right photo, red arrow), created by traumatic inspection of underside of fore wing (blue arrow), in same adult male from La Esparanza.

FIGURE 116. Field of pegs and hairs (arrow) under left wing in adult male of S. piceiventris from La Esperanza (head toward top of photo). Photo C. Grinter.

FIGURE 117. Live late instar S. piceiventris from Sierra de Juárez (S06-36, photo D.C. Lightfoot).

FIGURE 118. Late instar from Cerro Iguana, with arrow pointing to tear-shaped wing pad. Compare shape of this pad with more oval pad seen in adults in Fig. 111.

FIGURE 119. Karyotype S. piceiventris, 2nƋ= 27, with 6 pairs metacentric autosomes, 7 pairs rod shaped autosomes, and metacentric X. Top photo, individual T16-1. Bottom photo, individual T16-2.