Aplochares imitator (Smith), 1864

Pitts, James P. & Sadler, Emily, 2017, Association and description of the male of Aplochares imitator (Smith) (Hymenoptera: Pompilidae), Zootaxa 4300 (1), pp. 135-141 : 136-140

Aplochares imitator (Smith)

Pompilus imitator Smith, 1864 , Jour. Ent., 2: 267 [Type: Female, BRAZIL: Ega, Amazonas (BMNH, no. 19, 701)]. Aplochares imitator: Banks, 1944 , Zoologica, 29: 111. Banks, 1947 Bull. Mus. Comp. Zool., 99: 412.

Diagnosis of female. The female of this species can be easily recognized by the unusual color pattern for a pompilid, having the integument black (except the mandibles, which are largely ferruginous, the legs, which fade to a dull ferruginous apically) contrasting with the wing coloration, which is wholly infuscated except for the extreme apex of fore wing is stark white (the size, shape and shade of the white apex can be variable and in older specimens can even be somewhat worn away) ( Fig. 1 , 6 ). Additionally, the pubescence is brownish with obscure bluish reflections on the metasoma, but with golden reflections on the middle and hind coxae, the clypeus has a sharply defined emargination ( Fig. 2 ), the front is very narrow (MID 0.46–0.50×TFD; UID 0.80–0.86×LID), the POL is subequal to or slightly exceeding the OOL, LA3 is 1.15–1.25 X the UID, the front basitarsus has three slender comb spines and rarely has a weak fourth with the apical spine about 0.5× as long as second tarsal segment, the MC is separated from wing tip by about 0.8× its own length, and the SMC3 is narrowed above by 0.5–0.66 ( Fig. 6 ).

Diagnosis of male. The male of this species can be differentiated from other Pompilinae by the enlarged clypeus ( Fig. 4 ), the unmodified fore tarsi, the bifid claws, the thin band of whitish integument on the posterior margin of the pronotum ( Fig. 3 ), the postnotum being a thin parallel strip, the 3rd discoidal cell being narrower than the 2nd discoidal cell ( Fig. 7 ), wing coloration ( Fig. 7 ), the lack of distinctly contrasting setal banding or maculations on the dorsum of the metasoma ( Fig. 5 ), and the lack of setal modifications on the venter of the metasoma.

Description of male. Length 8.8–10.4 mm.

Coloration ( Figs 3–5 ). Color of integument black, except for yellow to white band on posterior margin of pronotum, and palpi, mentum, and tarsal segments which tend towards ferruginous. Scape ventrally and first three flagellomeres orange. Hind tibia with yellowish integumental stripe running almost entire length of tibia on dorsal surface, located between dorsal two rows of spines, sometimes indistinct. Wing bicolored longitudinally, infuscated on approximately anterior third, remainder posteriorly hyaline. Practically entire body silvery or brownish sericeous; face, vertex, and posteriorly on propodeal declivity obvious silver sericeous, while clypeus, remainder of mesosoma, legs, anterior half of propodeum and metasoma brownish sericeous, with clypeus and mesonotum being more obviously brown. Silvery pubescence located posteriorly on propodeum, coarser than elsewhere. Front, vertex, gena and posterior of propodeum with additional long erect setae; pronotum and front coxae with few erect setae; remainder without erect setae.

Head. Clypeus ( Fig. 4 ) about 1.7–1.8× as broad as high, apical margin slightly truncate to somewhat rounded, disc convex; slightly wider than lower front. Head slightly broader than high (FD equals 1.1×TFD). Front not very broad, MID 0.57 to 0.66×TFD; inner orbits nearly parallel, converging slightly dorsally (MID equals 0.9×LID; MID equals 1.2×UID). Ocelli large, slightly broader than right triangle; POL approximately equal to OOL. Antennae slender, of moderate length, first four segments in ratio of about 4:1:4:3.5, LA3 about 2.3× as long as thick.

Mesosoma. Pronotum short, its posterior margin arcuate. Postnotum much shorter than metanotum. Propodeum without rugae, slope low and even, median line not indicated. Longer spur of hind tibia slightly over 0.75 X length of basitarsus. Legs strongly spinose, hind tibia with two dorsal rows of strong spines and two rows of ventrolateral spines that are slightly weaker. Venation as in Fig. 7 .

Metasoma. First 3 segments longer than remaining segments, forming slight arch, in resting position remaining segments more or less telescoped into these three. Apical segments scarcely compressed. Subgenital plate ( Fig. 8 ) broadly subspatulate, apex rounded, its margin short-setose; median line of plate elevated.

Genitalia ( Fig. 9 ). Parameres with basal third as wide as parapenial lobes, afterwards very slender, more slender than parapenial lobes, bearing posteriorly directed tooth ventrally at basal third with dense setae, remaining apical 2/3 with less dense setae throughout; basal hook present; digiti spatulate, clothed with dense setae of moderate length ventrally and dorsally along outer lateral margin; parapenial lobes and aedeagus slightly shorter than parameres, simple.

Distribution. This species is found from Honduras south to British Guiana, Venezuela, Colombia, and to the Amazon basin of Brazil. For South America records, see Banks (1947) and Evans (1966).

Specimens examined. Costa Rica: Alajuela, Bijagua , 20 km S Upala, 1 ♀, 24.Jun–22.Jul.1991, F.D. Parker ( EMUS) ; Heredia, Est. Biol. La Selva , 2 ♂, 1.Apr.1996, 1 ♂, 15.May.1995, 1 ♂, 17.Jul.1995, 2 ♂, 1.Aug.1995, 2 ♂, 16.Aug.1995, 9 ♂, 31.Aug.1995, 1 ♀, 29.Sep.1995, INBio-OET ( EMUS) . Honduras: Atlantida, Lancetilla Tela , 1 ♀, 30.Apr.1995, R. Cave ( EMUS) .

Remarks. The sex association is based on distributional data. The male described here is congeneric with Aplochares and was collected in Costa Rica. Collection and identification of 10,000’s of Costa Rica pompilid specimens have revealed only a single species of Aplochares , A. imitator , in Costa Rica. Thus, this is the male of A. imitator . Additionally, the wing venation matches that of the female, general coloration and morphology, including genitalia, matches that of the males of A. adrastes , and these males were taken at the same site as a female. A third undescribed species cannot be completely ruled out, but is highly unlikely. It, however, must be remembered that this method of sex association has typically been used broadly for most insect taxa, not just spider wasps or Hymenoptera , without the aid or observational or molecular data. As such, few sex associations are wholly above suspicion.

The females of this species have the body and wings blackish, but the apices of the fore wings abruptly whitish, which is unusual for a spider wasp. This coloration is also seen in several social Vespidae that occur commonly in this region, such as Parachartergus apicalis Fabricius , as well as species of Hoplisoides Gribodo (Crabronidae) and Leucospis Fabricius (Leucospidae) . The deep emargination on clypeal margin is similar to that of the Anoplius subgenera Notiochares Banks and Lophopompilus Radoszkowski , but the generic characters listed here along with coloration will serve to separate Aplochares females from the remainder. The male of this species looks unlike its conspecific female, but has the same coloration as the male and female of A. adrastes . These three must be members of a different mimicry complex than the female of A. imitator . As such, this is a case of dual sexlimited mimicry that is seen in other spider wasp species, such as Aimatocare argentinicus (Banks) , and velvet ants ( Mutillidae ), such as Dasymutilla Ashmead species ( Evans1968; Wilson et al. 2015).

Evans (1966) tentatively placed Aplochares in the key to the males of Central American genera based on males of A. adrastes and this species does key out to Aplochares in his key. At first glance, however, the males looks similar to those of Anoplius Dufour (1834) , especially by having the bifid claws, and are likely in collections as undetermined Anoplius . The males can be separated from most of the subgenera of Anoplius , except Anopliodes Banks (1939) , by the lack of a modified apical tarsomere on the front leg or modifications of the venter of the metasoma in Aplochares . From Anopliodes , though, Anoplochares can be separated by wing venation and coloration. In Anopliodes , the second recurrent vein is found on the subdiscoidal vein at about half the distance or less than half the distance from the base of the subdiscoidal vein to the outer wing margin (i.e. the 2nd and 3rd discoidal cells are roughly the same size). Also, Anopliodes males have grey setal banding on the anterior margins of the metasoma. In contrast, in Aplochares the 3rd discoidal cell is much narrower than the 2nd discoidal cell, the second recurrent vein is found on the subdiscoidal vein more than half the distance from the base of the subdiscoidal vein to the outer wing margin, and the metasoma lacks setal banding.

Figures

FIGURES 1 – 5. Aplochares imitator; Fig. 1. Habitus, female; Fig. 2. Habitus, male; Fig. 3. Face, female; Fig. 4. Face, male; and Fig 5. Mesosoma and legs, male, dorsal view.

FIGURES 6 – 7. Aplochares imitator; Fig. 6. Wings, female; and Fig. 7. Wings, male.

FIGURES 8 – 9. Aplochares imitator; Fig. 8. Male, subgenital plate; and Fig. 9. Male genitalia, dorsal right, ventral left.