Odontophotopsis Viereck

Pitts, James P., 2007, Revision of Odontophotopsis Viereck (Hymenoptera: Mutillidae), Part 1, with a description of a new Genus Laminatilla, Zootaxa 1619, pp. 1-43 : 4-6

Odontophotopsis Viereck

Odontophotopsis Viereck, 1903 . Acad. Nat. Sci. Phil., Proc. 54: 738.

Type-species: Odontophotopsis exogyra Viereck, Orig. desig.

Tetraphotopsis Ashmead, 1903. Canad. Ent. 35: 305.

Type-species: Tetraphotopsis Hubbardi Ashmead, Orig. desig.

Odontophotopsis (Periphotopsis) Schuster, 1958 . Ent. Amer. (n. s.) 37: 8 (in key), 60. NEW SYNONYM. Type-species: Odontophotopsis (Periphotopsis) mamata Schuster, Orig. desig.

Diagnosis. Male. There are no autapomorphies known for the males of this genus, and they only can be diagnosed by a unique combination of characters. Usually the mesosternum is armed with teeth or ridges (exceptions and variation are discussed under Interspecific Variation below). Plumose setae are present and are distinct and dense, especially on the apical margins of the metasomal tergites. The sternal felt line is absent or very short when compared to the tergal felt line. In addition, this genus has the following combination of characters: the integument is normally brown to dark yellow, although the metasoma can sometimes be blackish; the compound eye is entire, large and protruding; the mandible varies from lacking a ventral emargination to being greatly emarginate ventrally, and when emarginate, there is a subtending tooth or angulation; the clypeus is truncate apically and is rarely tuberculate at the base; the notaulus is usually subcomplete, being absent on the anterior third of mesoscutum, but in some cases it can be complete; metasomal segment I varies from petiolate to subsessile with the segment II; the integumental sculpture is usually weak and sparse especially on the head, although the propodeum tends to be reticulated; the paramere and cuspis of the genitalia are slender; the parameres are needle-like and do not cross each other at rest; the cuspis is rarely longer than half the free length of the paramere and usually has a pit filled with setae located basally; and the hypopygidium is convex.

Female. The females of only three species are known ( Pitts and Parker 2003; Pitts et al. 2007). A general statement concerning the generic limits for this sex is tentative at best and will need to be expanded as more females become known. Thus far, the females of Odontophotopsis can be distinguished from females of other sphaeropthalmine genera by the following combination of characters: presence of plumose pubescence that is especially dense dorsally obscuring the integument of the vertex and the dorsum of the mesosoma, the mandible with a distinct ventral tooth, absence of a dorsal carina on the antennal scrobe, antennal F1 being only slightly longer than the pedicel, absence of a genal carina, sometimes with transverse carinae located posteriorly on the dorsum of the mesosoma, the first metasomal segment subsessile to petiolate and slightly disciform, and presence of lateral carinae that define the heavily sculptured pygidium.

Nomenclatural changes. Thorough study of the nocturnal mutillid species has lead to several synonymies and new combinations related to Odontophotopsis . First, Schuster placed O. mamata in the monotypic subgenus Periphotopsis Schuster based on the unique mesosternal process. This species lacks mesosternal processes, but has a pair of swollen, convex, impunctate longitudinal elevations that are located directly anterior to the mesocoxae instead. All other characters, however, suggest that this species is best placed in Odontophotopsis s.s. in the O. parva species-group. As such, Periphotopsis is considered a junior synonym of Odontophotopsis . Second, Schuster placed O. rubriventris (Schuster) , new comb., in Sphaeropthalma because of the lack of sternal processes, but all other characters, including genitalia, suggest that this species belongs in the O. melicausa species-group. Third, Schuster placed Photomorphus piceogaster (Schuster) , new comb., in Odontophotopsis due to the spine-like sternal processes, which are normally tuberculate or lamellate ridges in Photomorphus , and due to the lack of a carinate mentum, which is normally carinate in Photomorphus . There are several species of Photomorphus that have spine-like sternal processes and lack a carinate mentum, and all other morphological characters best place this species in Photomorphus .

Members of the O. lamellifera species-group sensu Schuster (1958) sufficiently differ from the remaining Odontophotopsis species-groups by several morphological features used to differentiate Odontophotopsis from the other nocturnal genera. As such, the species previously placed in this species-group ( O. bicornigera Schuster , O. lamellifera Schuster , and O. mixtoensis Schuster ) are placed in Laminatilla , gen. nov. The reasoning behind this decision is discussed in the remarks section for the new genus. A key to the species of Laminatilla and, due to the confusing nature of these genera, a key for the Nearctic genera of Sphaeropthalmini are provided.

Interspecific variation. For Odontophotopsis males, the mandibles are useful for delineating the species. The mandibles usually are tridentate apically, but sometimes can be bidentate (e.g., in O. arcuata Mickel , O. infantula Mickel , O. erebus , O. unicornis Schuster , and O. villosa Mickel ), or rarely quadridentate (only for O. conifera Schuster , O. setifera Schuster , O. venusta (Blake) , and an undescribed species from Mexico in the O. venusta species-group). The mandibles vary from having a distinct basal tooth on the ventral margin to lacking a basal tooth.

Schuster placed great emphasis on the dentate mesosternum of Odontophotopsis males and placed any species lacking these structures into different genera or subgenera. The armature of the mesosternum is of the utmost importance in species identification and, typically, most Odontophotopsis species have the mesosternum armed with a pair of tooth-like processes situated anteromedially (just posterior to the anterior procoxal concavity on the mesosternum). Sometimes these processes can be compound (i.e., more than one process on each side of the mesosternum) with the mesosternum having two to five distinct teeth on each side of the midline (e.g., O. cockerelli (Melander) , O. exogyra Viereck , O. hexadonta Schuster , O. quadridentata Schuster , and O. quadrispinosa Schuster ). In several species, the mesosternum lacks armature. Lack of mesosternal armature occurs specifically in O. sonora (Schuster) , new comb., O. rubriventris , some specimens of O. conifera , O. edentata Schuster, O. microdonta Ferguson , one undescribed species from the O. serca speciesgroup, and one from the O. parva species-group. Odontophotopsis venusta has additional longitudinal crescent-shaped processes located laterally on the mesosternum just anterior to the mesocoxae, as well as the normal tooth-like processes found anteromedially.

I have retained the species-group classification of Schuster (1958). This is the most convenient means to associate and group species that are probably closely related. Some groups may contain species of dubious relations, however, such as the O. setifera group and O. melicausa species-group, and a discussion is provided in the remarks section if relationships are questionable. An updated key to the species-groups is provided here.

Difficulties with identification. Determining the genus of some nocturnal species can be very challenging. As mentioned above, some species of Photomorphus have spinose mesosternal processes that appear similar to Odontophotopsis , and can be confused with the latter genus. This is especially true for P. dichrous Schuster , P. cobabi Schuster and P. piceogaster . In this case, Odontophotopsis can be differentiated from these confusing species of Photomorphus by the short or absent sternal felt line, presence of plumose setae, and by parallel mesosternal processes. In these species of Photomorphus , the apices of the mesosternal processes tilt towards each other, such that the apices are closer than the bases of the processes. Furthermore, Photomorphus piceogaster can be easily identified by the unique clypeus that has the lateral arms swollen appearing as transverse carinae. Most other species of Photomorphus , however, are easily distinguished from Odontophotopsis due to the carinate condition of the mentum and the unique armature of the mesosternum. Photomorphus typically has longitudinally denticulate, transversely dentiform, transversely truncate or ridge-like processes rather than being just bidentate anteriorly. This more typical Photomorphus - type of mesosternal process is only vaguely similar to some species of Odontophotopsis ( O. cockerelli and O. hexadonta ), and is not easily confused. Furthermore, Photomorphus usually has a densely and deeply punctate head, and some species have a tubercle situated medially near the posterior margin of the clypeus.

Species of Odontophotopsis lacking mesosternal processes can be difficult to determine to genus and could be easily mistaken for Sphaeropthalma . These Odontophotopsis species, however, have the typical dense plumose setae on the apical margins of the metasomal tergites and also have typical genitalia, with the cuspis cylindrically shaped and as short as, or shorter than, half of the free length of the parameres. Sphaeropthalma species have less dense plumose setae; the plumose setae normally are sparse, being confined to a single row on the apical margins of the metasomal tergites, or, at least, is decumbent. The cuspis of Sphaeropthalma normally is longer than half of the free length of the paramere, and can be lobed, flattened, or have other modifications. Lastly, one species of Sphaeropthalma , S. macswaini Ferguson, has small mesosternal processes in some specimens and could be confused with Odontophotopsis . This species is recognized by the clypeus that projects over the mandibles, and by the mandibles, which are greatly dilated apically with a large ventral tooth.