Myrmecophilus jordanicus, Stalling, 2024

Stalling, Thomas, 2024, Myrmecophilus jordanicus, a new species of ant cricket from Jordan and Israel, with notes on the synonymy of Myrmecophilus nigricornis (Orthoptera: Myrmecophilidae), Israel Journal of Entomology (Oxford, England) 53 (17), pp. 25-32 : 26-30

Myrmecophilus jordanicus n. sp.

( Figs 1, 2)

LSID: urn:lsid:zoobank.org:act:68AC20F4-8A4E-431C-9EF3-D1E25A4280F3 .

Etymology: This species is named after the Jordan River, which flows in the midst of its distribution area.

Diagnosis: Myrmecophilus jordanicus n. sp. differs from M. (Myrmophilina) ochraceus and M. (Myrmophilina) cyprius Stalling, 2017 in having the overall darker body and visibly shorter setae (setae on frons only about half as long as the diameter of the antennae on the third segment, but about as long as the diameter of the antennae in M. ochraceus and M. cyprius ; appressed setae on pronotum and tergites about 0.02 mm long, while they are about 0.03 mm in M. ochraceus and M. cyprius ). The ovipositor of M. jordanicus n. sp. has straight outer edges in the apical area, whereas it has convex outer edges in M. ochraceus and M. cyprius . The new species differs from M. (Myrmophilina) americanus in being paler and much larger (the latter is dark reddish brown with a pale beige mesonotum, and has an average body length of 1.9 mm in females and 1.4 mm in males) and in having only one spine in the proximal third on the basitarsus (usually two spines, one proximal and one distal, are present in M. americanus ). The female ovipositor is elongated in M. jordanicus n. sp., whereas the outer valvae of the ovipositor are ladle-shaped in M. americanus .

Description:Adult female. Measurements: boDy length 2.3 mm; pronotum 0.9 mm long and 1.4 mm wide; hind femur 1.3 mm; hind tibia 1.1 mm; cerci 1.3 mm;

ovipositor 1.3 mm. Body hump-backed; pronotum arched, narrowed distally; body rufous-ochreous, except slightly paler posterior half of pronotum ( Fig. 1). Pronotum and tergites densely covered with short, about 0.02 mm, appressed setae; frons with about 0.05-mm-long setae. Antennae almost as long as body and dark ochreous; first two segments pale ochreous. Labrum, labium and palpi dark ochreous; maxillar palpi five-segmented; labial palpi three-segmented. Eyes black, round. Hind legs: hind femur 1.4× as long as wide; hind tibia with five spurs on inner side and three spines on outer side; first segment of basitarsus slender with one spine in proximal third and two apical spurs. Cerci round in cross-section, pointed distally, and densely covered with appressed setae, with long, robust, erect setae among them. Epiproct small and rounded, not recessed. Subgenital plate rounded, not recessed; inner valvae (viewed ventrally) rounded, about 5× as long as wide; outer valvae in lateral view elongated with rounded tip, slightly flattened apically ( Fig. 2).

Male. Males appear similar to females, but slightly smaller (boDy length 2.1 mm), with subgenital plate short and recessed, covered with golden-yellow setae. Male phallic complex has dorsal ends of clearly visible epiphallic ancorae. (The internal male phallic complex has not been dissected to preserve the only existing male paratype.)

Variability: The paratypes vary in size only.

Holotype: ♀ aDult Jordan: “ 20.5.2009 / JOR-Shawbak / N 30° 31' 44.3" / E 35° 33' 01.9", 1400 m / leg. D. & T. Stalling / Holotype Myrmecophilus / jordanicus / Stalling, 2024 ”. There is also a host ant specimen on the needle ( Messor sp. ). The holotype is deposited in the SMNHTAU collection . Paratypes: Jordan: Ma'an Governorate: 2♀ nymphs, Shawbak , 30°31'44"N 035°33'02"E, 1400 m, 20.v.2009, D. & T . Stalling , in Messor nest ( RCTS); Ajloun Governorate: 2 ex. (♂ aDult anD nymph of unidentified sex), Ajloun, 32°19'21"N 35°43'50"E, 890 m, 29.v.2009, D. & T . Stalling, in Messor luridus Santschi, 1927 nest ( RCTS) . Israel: ♀ aDult, Samarian Desert: Migdalim , 32°05'06"N 035°21'05"E, 700 m, 8.xii.2017, L. Friedman (SMNHTAU) .

Distribution: Israel and Jordan.

Biology and habitat: The new species lives in the nests of the harvester ants of the genus Messor Forel, 1890 . In Jordan, the species was found in the semi-arid Mediterranean bioclimatic zone in stony grassland with small perennial bushes grazed by goats (Shawbak, Fig. 3), and in the sub-humid Mediterranean bioclimatic zone in limestone hills, covered by evergreen Kermes Oak forest ( Quercus coccifera ), partly cultivated with olive groves and crop fields (Ajloun). Both localities belong to the Mediterranean vegetation region ( Al-Eisawi 1996). In Israel, the species was found in the transition area—between the Mediterranean zone and a semidesert consisting of bare hills—covered by the Mediterranean scrub comprising Sarcopoterium spinosum , Amygdalus sp. and Crataegus sp. , with geophytes such as Drimia maritima (L. Friedman, pers. comm., Fig. 4).

Remarks: Myrmecophilus jordanicus sp. n. belongs to the subgenus Myrmophilina Silvestri, 1912 with respect to the following characteristics: outer valvae of female (viewed laterally) rounded (vs. double-pointed in the subgenus Myrmecophilus ); setae on the front and antenna long, erect and bushy (vs. short and inconspicuous in the subgenus Myrmecophilus ); hind basitarsus with one spine in the proximal position (two or three dorsal spines in the proximal, medial and sometimes distal positions in the subgenus Myrmecophilus ).

The internal male phallic complex has not been dissected in order to preserve the only existing male paratype, and because its significance for the differentiation of the Myrmecophilus species is unclear.