The Wharton Lab

Fopius Wharton, 1987: 68-69. Type species: Rhynchosteres (Fopius) silvestrii Wharton, 1987 (original designation).

Type locality of type species: Cameroon, Nkolbisson; holotype female in US National Museum.

First described as a subgenus, then elevated to generic rank by van Achterberg and Maeto (1990).
Current status: valid genus.

Prior to 1987, most of the species now placed in the genus Fopius were placed either in Opius or Biosteres, and sometimes in Diachasma or Parasteres. Wharton (1987) initially proposed the name Fopius as a subgenus of Rhynchosteres. Van Achterberg and Maeto (1990) elevated Fopius to generic status, where it currently remains. Wharton (1999) partially revised the genus, and included a tabular key to species.

Occipital carina nearly always present laterally, extending dorsally more than half height of head. Labrum completely to almost completely concealed by clypeus (Figure 1); outer surface of clypeus usually relatively flat to weakly and evenly convex, ventral margin varying from thin and evenly convex throughout to variously thickened and protruding medially, sometimes as a distinct tooth. First flagellomere shorter than second in most species. Propleuron with oblique carina immediately dorsad propleural flange, the carina bordered ventrally by crenulate to rugose sculpture. Notauli deep, complete to midpit, crenulate throughout (Figure 2). Postpectal carina present. Hind tibia dorso-posteriorly without basal carina. Fore wing (Figure 3) with second submarginal cell short; m-cu arising basad or directly in line with 2RS. Hind wing (Figure 4) with RS virtually absent in nearly all species (represented by a very weakly infumate crease in caudatus); m-cu well-developed as a distinctly pigmented crease extending nearly to wing margin in nearly all species, rarely (5%) poorly developed in some individuals, extending only half way to wing margin in caudatus. Metasoma of several species with second and rarely third terga striate; metasoma otherwise unsculptured beyond petiole. Ovipositor long, extending well beyond the tip of the abdomen.

Fopius, like Diachasmimorpha, is characterized by the small second submarginal cell, the loss of hind wing RS, and the well developed hind wing 2M and m-cu. Fopius, however, has a more heavily sculptured body (especially frons, notauli, and propleuron). The species of Rhynchosteres are similarly heavily sculptured, but usually have both clypeus and mandibles greatly modified. Additionally, most species of Fopius have the hind wing m-cu slightly recurved near the wing margin.

Fopius was originally described as a subgenus of Rhynchosteres (Wharton 1987), despite the fact that the type species of Fopius lacked the highly modified, tubular clypeus originally used to characterize Rhynchosteres. Wharton’s (1987) placement of Fopius in Rhynchosteres was based on a study of several Afrotropical species that had the midventral margin of the clypeus variously thickened and protruding, suggesting a morphocline leading to the more elaborate modifications found in Rhynchosteres sensu stricto. Van Achterberg and Maeto (1990), dissatisfied with the broadening of the concept of Rhynchosteres that this entailed, removed Fopius from Rhynchosteres and accorded it separate generic rank. The Fopius desideratus species group is particularly critical for an understanding of the relationship between Fopius and Rhynchosteres. Althought the mandible lacks the modifications found in most species of Rhynchosteres, the midventral portion of the clypeus in members of the Fopius desideratus species group is at least slightly thickened and weakly protruding. Additionally, the relative length of the first two flagellomeres in the Fopius desideratus species group is as in Rhynchosteres, the petiole is similarly structured (flatter and narrower than in more typical species of Fopius such as Fopius silvestrii), and most significantly, the ovipositor sheath shows an identical pattern of setal reduction.

All species of Fopius reared as of 2000 are parasitoids of Tephritidae. A few generalizations can be made about hosts and distribution patterns, even though our current knowledge is somewhat limited. Native hosts in all of the species groups of Fopius treated here include members of the subtribes Ceratitidina and/or Dacina, both in the tephritid tribe Dacini, subfamily Trypetinae (Norrbom et al. 1998). Except where they have been introduced for biological control, members of the persulcatus species group occur outside the range of fruit-infesting Ceratitidina, and several of them have been reared from members of the tribe Trypetini in addition to members of the Dacina. Rearing records from within their native ranges (Clausen et al. 1965, Steck et al. 1986) suggest that the 17 species of Fopius for which we have host records are restricted to fruit-infesting tephritids, but that there are different levels of specificity. Some are currently known only from a single host, others (e. g. Fopius caudatus on ceratitidines) have only been reared from a narrow group of hosts, and several have been reared from both Dacini and Trypetini. Where introduced outside their native range for biological control, Fopius arisanus and Fopius vandenboschi have been able to attack other fruit-infesting tephritids (Clausen et al. 1965, Wharton et al. 1981). Although some of the species of Diachasmimorpha introduced to Hawaii to control fruit-infesting Tephritidae occasionally attack gall-making (but not flower-infesting) Tephritidae, Fopius arisanus and Fopius vandenboschi do not (Duan et al. 1996).

Unless you are already on this page, considerably more information on species groups and use in biological control can be found on the Fopius page (and associated links) of the Paroffit website page: http://mx.speciesfile.org/projects/8/public/public_content/show/8319?content_template_id=88

Oviposition in the egg stage of the host is an intriguing biological feature, and one that has been of considerable interest to biological control workers. This phenomenon has been well documented in Fopius arisanus (Sonan), (most of the biological information on this species was published under the species name oophilus Fullaway), perhaps the most significant parasitoid introduced to Hawaii for tephritid biological control (Clausen et al. 1965). Evidence that this biological trait is found in several other species of Fopius is gradually accumulating (see discussion by Waterhouse 1993). Based solely on ovipositor morphology, it is likely that the following species share this trait with arisanus: Fopius carpomyiae (Silvestri), Fopius persulcatus (Silvestri), Fopius schlingeri Wharton and Fopius caudatus (Szépligeti) (Wharton 1999). More recently, several studies have demonstrated that both Fopius caudatus and Fopius ceratitivorus can successfully oviposit in host eggs (Wharton et al. 2000, Lopez et al. 2003, Wang et al. 2004, and Bokonon-Ganta et al. 2005).

Fopius is an Old World group, with nearly all of its 25 described species (as of 1999) from the tropics (Wharton 1999).

Chinajariyawong et al. provide an extensive list of opiine species and their tephritid hosts collected in Thailand and Malaysia during surveys conducted between 1986 and 1994 (Chinajariyawong et al. 2000). The specimens were primarily collected from various Bactrocera spp. and include the following Fopus species: arisanus (Sonan), deeralensis (Fullaway), persulcatus (Silvestri), skinneri (Fullaway), and vandenboschi (Fullaway) with arisanus and vandenboschi being the most commonly collected species of Fopius.

Both Fopius and Rhynchosteres will key out together in the general key that accompanies the Paroffit web site (because the sternaulus is heavily sculptured in both). From there you will be referred here to the Fopius page. For differences between the two, see the diagnosis and relationships sections.

This page was assembled by Bob Wharton and Danielle Restuccia. It is part of a review of the genera of World Opiinae, conducted at Texas A&M University. We are particularly grateful to Xanthe Shirley, Andrew Ly, Patricia Mullins, Trent Hawkins, Lauren Ward, Cheryl Hyde, Karl Roeder, and Andrea Walker, who did nearly all of the imaging (together with Danielle) for this project. Matt Yoder and Istvan Miko provided guidance on databasing issues associated with our use of mx and HAO respectively. This project would not have been possible without the kindness of many curators at museums throughout the world who gave generously of their time to Bob Wharton and his students. In particular, I thank Henry Townes (deceased) and David Wahl (American Entomological Institute, Gainesville), Gordon Nishida (Bernice P. Bishop Museum, Honolulu), Norm Penny, and Bob Zuparko (California Academy of Sciences, San Francisco), Bill Mason (deceased), Mike Sharkey, Andrew Bennett, and Henri Goulet (Canadian National Collection, Ottawa), Paul Dessart (deceased) (Institut Royal des Sciences Naturelles de Belgique, Brussels), Marc De Meyer (Koninklijk Museum voor Midden-Afrika, Tervuren), Axel Bachmann (Museo Argentino de Ciencias Natureles, Buenos Aires), Eberhard Koenigsmann (deceased) and Frank Koch (Museum fuer Naturkunde der Humboldt-Universitaet, Berlin), J. Casevitz Weulersse and Claire Villemant (Museum National d’Historie Naturelle, Paris), James O’Connor (National Museum of Ireland, Dublin), Jenö Papp (National Museum of Natural History, Budapest), Kees van Achterberg (National Museum of Natural History, Leiden), Max Fischer, Herb Zettel, and Dominique Zimmermann (Naturhistorisches Museum, Wien), Per Persson and Lars-Åke Janzon (Naturhistoriska Riksmuseet, Stockholm), Ermenegildo Tremblay (Silvestri Collection, Portici), Erasmus Haeselbarth (Staatliche Naturwissenschaftliche Sammlungen Bayerns, Munich), Tom Huddleston and Gavin Broad (The Natural History Museum, London), Paul Marsh and Robert Kula (USDA Systematic Research Laboratory and US National Museum of Natural History, Washington, D. C.), Vladimir Tobias (deceased) and Sergey Belokobylskij (Zoological Institute, Academy of Sciences, St. Petersburg), and Roy Danielsson (Zoological Institute, Department of Systematics, Lund) for facilitating loans and general assistance associated with examination of holotypes and other material in their care. This work was supported largely by NSF/PEET DEB 0328922 and 0949027, with REU supplements 0723663, 1026618, 1213790, and 1313933 (to Wharton). Page last updated July, 2015. The material on this page is freely available, but should be acknowledged if used elsewhere.

This material is based upon work supported by the National Science Foundation under Grant Numbers DEB 9300517, DEB (PEET) 9712543, DEB (PEET) 0328922 with REU supplements 0723663 and 1026618 and DEB 0949027 with REU supplements 1213790 and 1313933. 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.