SUBFAMILY HELCONINAE

M. J. SHARKEY

Hymenoptera Institute, 116 Franklin Ave., Redlands, CA 92373, U.S.A., msharkey@uky.edu

INTRODUCTION. Helconinae is treated here as synonymous with the tribe Helconini following Sharanowski et al. (2011) who showed that the wider concept of Helconinae, including Diospilini and Brachistini, is not monophyletic. Helconinae is worldwide in distribution and contains 14 genera, three of which are found in the New World. Yu et al. (2016) cataloged the World species of Helconini. The monotypic genus Eumacrocentrus Ashmead is almost certainly a derived member of Helcon Nees but formal synonymy requires a detailed cladistic analysis. There are no identification keys to New World species. PHYLOGENY. Sharanowski et al. (2011) showed that showed that the wider concept of Helconinae, used in the Manual of New World Genera (Wharton et al., 1997) is not monophyletic and that it Topaldios is a member. There have been no attempts at a detailed molecular phylogenetic analysis of the genera of Helconinae, and the monophyly of most genera is suspect. BIOLOGY. Members of the Helconini are solitary endoparasitoids of cerambycid beetle larvae and possibly other wood-boring beetles (Tobias, 1967; Shaw and Huddleston, 1991). COMMON GENERA. Wroughtonia Cameron is the only genus routinely collected. DISTRIBUTION. Cosmopolitan. In the New World, members appear to be restricted to temperate areas. In North America two species are found as far south as Mexico, and in South America some species of Helcon are found as far north as the Brazilian state of Paraña. DISTINGUISHING FEATURES. Members of Helconinae are rather large and robust and may be recognized by the following combination of characters: second submarginal cell of fore wing narrowed anteriorly; clypeus rugose dorsally and smooth ventrally; 2a of forewing present; lateral (outer) apex of foretibia with a distinct sclerotized lamella (van Achterberg, 1987).

KEY TO THE NEW WORLD GENERA OF THE SUBFAMILY HELCONINAE

1. A. Hind femur with ventral tooth or strong rugose ridge. ............................... Wroughtonia Cameron

- B. Hind femur lacking ventral tooth or strong rugose ridge ............................................................... 2

2(1). A. Propodeum smooth with a large, wide, central cell. .............................................. Topaldios Papp B. Propodeum rugose and usually lacking a central cell, if cell present it is longer than wide with

rough sculpture. ................................................................................................................................... 3

3(1). A. Fore wing with one “a” crossvein. .......................................................... Eumacrocentrus Ashmead B. Fore wing with two “a” crossveins. ................................................................................................. 4

4(3). A. Metasomal terga 2-3 smooth, widespread. ................................................................. Helcon Nees B. Metasomal terga 2-3 sculptured, southern South America. ................ Vervoortihelcon Achterberg

GENERIC TREATMENTS Eumacrocentrus Ashmead, 1900

Diagnosis. Tooth lacking on ventral side of hind femur; ovipositor much longer than body. Forewing lacking second “a” crossvein. Biology. Unknown, probably an endoparasitoid of larval Cerambycidae (Marsh, 1979). Diversity. One described species. Distribution. Nearctic, eastern U.S.A. Publications. Distribution: eastern U.S.A.; one described species. Biology: unknown,

Figure 1. Eumacrocentrus americanus Cresson, 1873.

Helcon Nees, 1812 Diagnosis. Forewing with 2 ‘a’ crossveins; hind femur lacking a ventral tooth. Biology. Biology: endoparasitoids of larval Cerambycidae (Marsh, 1979). Diversity. 4 described Nearctic species, many undescribed Neotropical species. Distribution. Holarctic and Neotropical, widespread in temperate and subtropical New World. Publications. No key exists for New World species.

Figure 2. Helcon tardator Nees, 1812.

Topaldios Papp, 1995 Diagnosis. Propodeum with a large, wide cell medially Biology. Unknown. Diversity. 2 described species from Argentina, many more undescribed. Distribution. Southern South America. Publications. Papp (1995) described two species.

Figure 3. Topaldios sp.

Vervoortihelcon Achterberg, 1998 Diagnosis. Metasomal terga 2-5 heavily sculptured. Biology. Unknown. Diversity. One described species, few if any others. Distribution. Known only from Chile. Publications. Achterberg (1998) described the sole species.

Figure 4. Vervoortihelcon scaramozzinoi (from van Achterberg, 1998)

Wroughtonia Cameron, 1899 Diagnosis. Hind femur with ventral peg(s) or spine(s); female antenna often with white band at midlength. Biology. Endoparasitoids of larval Cerambycidae (Marsh, 1979; van Achterberg, 1987). Diversity. Six described Nearctic species Distribution. Holarctic. Publications. The Nearctic species are in scattered publications. There is not a key to Nearctic species. Note. Van Achterberg (1987) treats Helconidea Viereck as a genus distinct from Wroughtonia, whereas here they are treated as subjective synonyms. Specimens of Helconidea do not have a white band on the flagellum.

Figure 5. Wroughtonia sp.

REFERENCES Achterberg C van 1987. Revision of the European Helconini (Hymenoptera: Braconidae: Helconinae).

Zoologische Medelingen Leiden 61: 263-285. Achterberg C van. 1998. Vervoortihelcon, a new genus of the subfamily Helconinae Foerster

(Hymenoptera: Braconidae) from Chile. Zoologische Verhandelingen Leiden. 323:401-405. Marsh PM. 1979. Family Braconidae. Pp. 14~295. In: Krombein, K.V., Hurd, P.D., Smith, D.R., and Burks,

B.D. (Eds.). Catalog of Hymenoptera in America North of Mexico, Smithsonian Institution Press, Washington, D.C.

Sharanowski BJ, Dowling AP, Sharkey MJ. 2011. Molecular phylogenetics of Braconidae (Hymenoptera: Ichneumonoidea), based on multiple nuclear genes, and implications for classification. Systematic Entomology 36: 549-572.

Shaw MR, Huddleston T. 1991. Classification and biology of braconid wasps (Hymenoptera: Braconidae). Handbooks for the Identification of British Insects 7(11): 1-126.

Tobias VI. 1967. The Far East as a center of abundance of the tribe Helconini. In: Harmful and useful insects of the Far East. Trudy Zoologicheskogo Instituta Akademii Nauk SSSR 41: 222-238. (In Russian.)

Wharton RA, Marsh PM, Sharkey MJ. 1997. Manual of the New World genera of the family Braconidae (Hymenoptera). Special publication of the International Society of hymenopterists 1: 1-439.

Yu DSK, Achterberg C van, Horstmann K. 2016. Taxapad 2016, Ichneumonoidea 2015. Database on flash-drive. www.taxapad.com, Ottawa, Ontario, Canada.