The Wharton Lab

Synodites Foerster, 1869: 211. Type species: Typhon assimilis Holmgren, 1858 [= a junior subjective synonym of Synodites notatus Gravenhorst, 1829]. Subsequent designation by Viereck (1914: 141) from among several species first included by Thomson (1894: 2002).

Zootrephes Foerster, 1869: 162. Type species: Bassus (Zootrephes) hilaris Woldstedt. Subsequently included by Woldstedt, 1880: 175. Monobasic. Synonymized under Synodites by Townes et al. (1965: 264).

Sychnoportus Foerster, 1869: 208. Type species: Sychnoportus rufopectus Ashmead, 1898 [= a junior subjective synonym of Synodites olympiae Ashmead, 1896]. Subsequently included by Ashmead (1898: 169). Monobasic. Synonymized under Polyterus by Townes (1945: 523).

Listrota Foerster, 1869: 209. Type species: Phobetes canadensis Harrington, 1894. First subsequent inclusion by Davis (1897: 289). Monobasic. Synonymized under Polyterus by Townes (1945: 523).

Polyterus Foerster, 1869: 209. Type species: Polyterus franconiaensis Davis, 1897. Subsequent designation by Viereck (1914: 121) from among two species first included by Davis (1897: 289). Synonymized under Synodites by Townes et al. (1965: 264).

Camponastes Foerster, 1869: 212. Type species: Camponastes basilicus Davis, 1897. First subsequent inclusion by Davis (1897: 292). Monobasic. Synonymized under Polyterus by Townes (1945: 524).

Sarcorychus Foerster, 1869: 212. Type species: Tryphon notatus Gravenhorst, 1829. Subsequent designation by Perkins (1962: 450). Synonymized under Synodites by Perkins (1962: 450).

Zootrephus Thomson, 1890: 1486. Unjustified emendation.

Synodytes Thomson (1894: 2002). Unjustified emendation.

The above synonymy follows Townes (1970: 131). Anaglymmus was included as a synonym of Synodites by Yu and Horstmann (1997). In Yu et al. (2012), the genus is listed as a synonym of Synodites, but the two originally included species are placed in Syndipnus. Townes (1970: 135) treats Anaglymmus as a synonym of Syndipnus. Lathrophagus has an even more convoluted history: it was first synonymized under Hypamblys by Perkins (1962), and this treatment is followed by Townes (1970: 136). Aubert (2000) lists it as a synonym of both Synodites and Hypamblys. Yu et al. (2012) includes the type species in Synodites, citing an inventory of a Dutch natural area by Zwakhals et al. (1996). Since the list of included species cited on this page is from Yu et al. (2012), it includes breviusculus, the current valid name for the type species of Lathrophagus.

The following valid species were included by Yu et al. (2012) for this holarctic genus:

Synodites alpigenator Aubert, 1998
Synodites amoenus (Roman, 1909)
Synodites basilicus (Davis, 1897)
Synodites breviusculus (Fonscolombe, 1849)
Synodites breviventris (Gravenhorst, 1829)
Synodites canadensis (Harrington, 1894)
Synodites carinatus (Holmgren, 1857)
Synodites consors (Davis, 1897)
Synodites decipiens (Woldstedt, 1877)
Synodites erosus (Holmgren, 1857)
Synodites facialis (Thomson, 1894)
Synodites fasciellus (Holmgren, 1857)
Synodites franconiaensis (Davis, 1897)
Synodites genalis (Habermehl, 1925)
Synodites hilaris (Woldstedt, 1880)
Synodites humeralis (Gravenhosrt, 1829)
Synodites leucopygua (Holmgren, 1869)
Synodites lineiger (Thomson, 1894)
Synodites masculinus (Kiss, 1929)
Synodites notatus (Gravenhorst, 1829)
Synodites olympiae (Ashmead, 1896)
Synodites orbitalis (Thomson, 1894)
Synodites parviceps (Thomson, 1894)
Synodites salinus (Kiss, 1924)
Synodites virginiensis (Ashmead, 1890)

Synodites is presently characterized largely on the basis of the absence of a fore wing areolet and clypeal margin that is sharp laterally and also usually medially. The species are short and somewhat stocky, unlike the long, slender species of Mesoleptidea that often have the fore wing areolet absent. In habitus and several specific features, they resemble species in Synomelix, Pantorhaestes, and Syndipnus. Synidpnus has a clypeus similar to those species of Synodites with the ventral margin medially thickened, but metasomal T2 and T3 are partially fused in Syndipnus. The absence of a fore wing areolet is all that really separates Synodites from Synomelix and Pantorhaestes.

There remains some doubt about the placement of several species in Synodites vs. Syndipnus and Hypamblys. Part of the issue is the placement of species in which the apical margin of the clypeus is neither entirely blunt nor entirely sharp. The second issue is the utility of the metasomal character used by Townes (1970: 129) to separate Syndipnus (with T2+3 fusion) from Hypamblys and other genera that have T2 and T3 clearly separate and overlapping. Aubert (2000) specifically states that the fused tergite character used by Townes does not work for some of the European species and Aubert says that Syndipnus is better characterized by the presence of warts on T2. Aubert also notes that Syndipnus is very difficult to separate from Hypamblys.

Clypeus (Figs 2, 3) somewhat narrow, with surface finely punctate; ventral margin highly variable: sharp throughout in some species, thickened medially but sharp laterally in other species, when sharp, not distinctly impressed; shape of ventral margin varying from truncate medially, angled upwards laterally to bilobed with median emargination as in Figs 2 and 3, to more evenly convex; epistomal sulcus narrow, distinct, often sharply impressed; clypeus in profile flat to weakly bulging. Inner eye margins parallel. Malar space (Fig. 2) well-developed, varying from 1.0 to slightly less than 0.5 times basal width of mandible; malar sulcus absent. Mandible (Figs 2, 3) broader and tapering more gradually from base to apex in some species than in others; dorsal tooth usually broader and either equal in length to ventral tooth or very slightly longer; ventral margin distinctly carinate. Maxillary palp shorter than height of head, less commonly equal to height of head; antenna (Fig. 4) equal to or slightly shorter than body, first flagellomere usually short relative to species in genera such as Hadrodactylus. Ocelli small to moderate in size, diameter of lateral ocellus less than distance from lateral ocellus to eye in females, about equal distance from lateral ocellus to eye in most males. Hypostomal carina meeting occipital carina distinctly above base of mandible; occipital carina complete dorsally. Epomia present, though sometimes weak and somewhat obscured by adjacent sculpture. Epicnemial carina variable: reaching anterior margin of mesopleuron in some species, but not in others; weak dorsally in some species. Notaulus present usually as a deep, distinct impression on anterior declivity (the depression sometimes weakly sculptured), becoming distinctly weaker and shallow on disk, extending posteriorad level of tegula in at least two species. Groove between propodeum and metapleuron absent to very weakly indicated, not u-shaped as in pionines; pleural carina present, usually strongly elevated, though weak posteriorly in a few species; median longitudinal carinae very well-developed, forming flask-shaped median section with rugulose petiolar area (Fig. 5) broad and distinct, variable in size and shape: extending at least over posterior half of propodeum similar to Synomelix in a few species, shorter in others, with carinae narrowly separated over most of length anteriorly, petiolar area and areola sometimes delimited by transverse carina as in Fig. 5; lateral longitudinal carina weaker than median longitudinal carina, nearly always extending to spiracle from posterior margin but usually absent anteriorly, transverse carinae absent in nearly all species examined. Legs with apical margin of mid tibia expanded into a tooth that is either as well-developed as or a little more rounded and not quite as well-developed as that of fore leg; apical comb on posterior side of hind tibia weakly developed to absent; posterior hind tibial spur 0.35-0.5 times length of hind basitarsus, most commonly in the shorter range as in Fig. 1; tarsal claws not pectinate; fifth tarsomere of hing leg normal, not unusually elongate (relative to fourth) (Fig. 1). Fore wing (Fig. 6) with areolet absent; stigma moderately broad as in Fig. 6, Rs+2r usually arising at or very slightly basad midpoint but near basal 0.4 in one species. Hind wing (Fig. 7) with first abscissa of CU1 longer than 1cu-a. T1 varying from relatively slender (Figs 8, 9) to somewhat broader: very gradually to more strongly expanding posteriorly; ventral margin straight in profile; dorsal carinae present, varying from low, barely extending to level of spiracles (weakly developed as in Fig. 9) to distinctly elevated and extending distinctly posteriorad spiracles (well-developed); basal depression at dorsal tendon attachment varying from absent to broad, distinct (Fig. 9); dorsal-lateral carina complete between spiracle and apex of T1; spiracle often placed basad midpoint of T1 (Fig. 8); glymma absent. S1 not extending to level of spiracle. T2 thyridium readily visible in at least some species. Laterotergites of T2 and T3 separated by creases from median tergite. Ovipositor and sheath (Fig. 1) straight, ovipositor with distinct dorsal, subapical notch.

The above description is considerably modified from Townes (1970), and based on numerous specimens in the Texas A&M University collection, including one specimen of the type species of Synodites.

Hosts are largely nematine Tenthredinidae (Yu et al. 2012 provide a summary).

This page was assembled by Bob Wharton as part of a larger collaborative effort on the genera of Ctenopelmatinae. Page last updated April, 2015.

This work would not have been possible without the groundwork provided by Ian Gauld’s study of the Australian and Costa Rican faunas, and we are particularly grateful for his assistance in many aspects of this study. We thank David Wahl of the American Entomological Institute, Gavin Broad of The Natural History Museum, London, and Andy Bennett of the Canadian National Collection for extended loans of the material used for this study. We also thank David Wahl for useful feedback throughout our study and Dimitry Kasparyan for a greater understanding of genera such as this one. Matt Yoder provided considerable assistance with databasing issues, and our use of PURLs (http://purl.oclc.org) in this regard follows the example of their use in publications by Norm Johnson. Heather Cummins, Andrea Walker, Patricia Mullins, Caitlin Nessner, Amy James, Karl Roeder, Danielle Restuccia, and Cheryl Hyde graciously assisted us with image processing, formatting, and literature retrieval. This study was supported by the National Science Foundation’s PEET program under Grant No. DEB 0328922 and associated REU supplement nos DEB 0616851, 0723663, 0822676, 0923134, and 1026618.

This material is based upon work at Texas A&M University supported by the National Science Foundation under Grant Number DEB 0328922 with REU supplements DEB 0616851, 0723663, 0822676, 0923134, and 1026618.. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.