Conostigmus schwarzi ( Ashmead, 1893 )

Trietsch, Carolyn, Mikó, István, Ezray, Briana & Deans, Andrew R., 2020, A Taxonomic Revision of Nearctic Conostigmus (Hymenoptera: Ceraphronoidea: Megaspilidae), Zootaxa 4792 (1), pp. 1-155 : 85-86

Conostigmus schwarzi ( Ashmead, 1893)

Fig. 46

Species Comments and History. Ashmead (1893) described this species from a single female specimen collected in the Washington, D.C., area by E. A. Schwarz, for whom the species is named. Dessart (1996) gives an overview of the troubled naming of the species: Ashmead (1893) refers to the species as schwarzi in a key to female species on pg. 113, but then uses the spelling schwarzii in the actual species description on pg. 115. Kieffer (1909, 1914) adopts the spelling schwarzii, then Brues (1916) introduces the new spelling schwartzii. Muesebeck and Walkley (1951) go back to Ashmead’s first spelling, schwarzi , but then Masner and Muesebeck (1968) use Ashmead’s second spelling, schwarzii, in their catalog of specimens at the USNM. Dessart (1996) resolved this naming controversy by selecting schwarzi as the correct spelling, citing that it is the simplest spelling, the first spelling used by Ashmead, and the spelling used in American catalogs at the time.

The lectotype female specimen is present at the USNM in good condition. We found a second female specimen at the CNC ( PSUC _FEM 56057), bearing a label with Ashmead’s handwriting. This specimen is labeled as a paratype, though further work is needed to determine whether this specimen is a valid type specimen because Ashmead never labeled specimens as holotypes or paratypes. It is unclear who labeled this specimen as a paratype. The specimen is included in the material examined section below for further reference .

The female lectotype at the USNM bears the following characteristics: facial pit present; postocellar carina present; median process on the intertorular carina present and acute, extending towards the dorsal margin of the clypeus; and the sternaulus present and elongate, exceeding 3/4 of the mesopleuron length at the level of the sternaulus. However, there are several species that share these characters (including C. laeviceps , C. bipunctatu s, C. minimus , and C. musettiae ), and neither individual characters nor the combination of characters is distinct enough to match this female to any of them at this time. We consider C. schwarzi as a species inquirenda.

It is worth noting that the female specimen has a mite attached to the metasoma. A similar mite was found on the metasoma of the female type specimen of Ceraphron carinatus . Dr. Michael Skvarla and Dr. Barry O’Connor identified the mites as phoretic deutonymphs belonging to the family Acaridae (Astigmata) . Depending on the species, deutonymphs can be generalists, found on many different types of insects, or specialists, which rely on certain insects to transport them to certain areas or hosts (Skvarla and O’Connor, pers. comm). It is unknown what hosts Ceraphron carinatus or Conostigmus schwarzi parasitize, or what the natural histories of these species are, so it is not possible to know where they acquired the mites. This illustrates the need for more work on the life histories of Ceraphronoidea species.

Material Examined. Lectotype female: USA: USNMENT01339767 ( USNM).

Non-type material (1 female): USA: 1 female. PSUC _FEM 56057 ( CNC) .

Figures

FIGURE 46. Conostigmus schwarzi (Ashmead, 1893) female lectotype (USNMENT01339767). A. Lateral view, with a mite attached to the metasoma. B. Dorsal view.