Odontacolus Kieffer

A. Valerio, Alejandro, Austin, Andrew D., Masner, Lubomir & Johnson, Norman F., 2013, Systematics of Old World Odontacolus Kieffer s. l. (Hymenoptera, Platygastridae s. l.): parasitoids of spider eggs, ZooKeys 314, pp. 1-151 : 8-10

Odontacolus Kieffer

Odontacolus Kieffer 1910a: 294. Original description. Type species: Odontacolus longiceps Kieffer, by monotypy and original designation. Kieffer 1910b: 100, 104 [description, list of species, keyed]; Kieffer 1912a: 54 [redescribed as new]; Kieffer 1912b: 88 [description]; Dodd 1914a: 59 [keyed]; Kieffer 1926: 132, 145 [description, keyed, key to species]; Muesebeck and Walkley 1956: 376 [citation of type species]; Masner 1976: 66 [description, key to Odontacolus Kieffer and Ceratobaeus Ashmead]; De Santis 1980: 313 [catalog of species of Brazil]; Austin 1981: 88 [diagnosis, synonymy, discussion of taxonomic status]; Galloway and Austin 1984: 6, 92 [description, list of species described from Australia, keyed]; Austin 1988: 176 [keyed]; Johnson 1992: 443 [catalog of world species]; Kononova 1992: 132 [description]; Masner and Denis 1996: 90 [keyed]; Kononova and Kozlov 2001: 340, 401 [description, keyed]; Loiácono and Margaría 2002: 557 [catalog of Brazilian species]; Austin and Iqbal 2005: 19 [discussion of relationships]; Valerio et al. 2010: 6 [phylogeny and discussion of relationships between Cyphacolus and Odontacolus ]; Veenakumari and Mohanraj 2011 [key to species for females].

Ceratobaeoides Dodd 1913: 337. Original description. Type species: Ceratobaeoides hackeri Dodd, original designation. Dodd 1914a: 59 [keyed]; Dodd 1914b: 125 [description]; Kieffer 1926: 264, 273 [description, keyed, key to species]; Muesebeck and Walkley 1956: 341 [citation of type species]; Masner 1976: 65 [taxonomic status]; Austin 1981: 89 [junior synonym of Odontacolus Kieffer]; Carpenter 1992: 471 [fossil references].

Odontacolus urn:lsid:zoobank.org:act:BED2BB8F-3D3B-4D20-975E-4441CA26154F

Odontacolus urn:lsid:biosci.ohio-state.edu:osuc_concepts:9359

Cyphacolus Priesner 1951: 123. Original description. Type species: Cyphacolus veniprivus Priesner, by monotypy and original designation. [see Valerio et al. 2010: 4 for bibliography] syn. n.

Odontacolus urn:lsid:zoobank.org:act:85B4E914-30E6-481C-8678-766A449E5B62

Odontacolus urn:lsid:biosci.ohio-state.edu:osuc_concepts:468

Description.

Female. Tiny to small wasps, 1.01-2.38 mm in length; body slightly elongate, generally moderately slight in form.

Head. In anterior view varying in shape from suboval or subtriangular, to elongate and broad in buccal region. Frons smooth or sculptured, median area often defined by difference in sculpture compared to surrounding face, central keel present and often reaching almost to medial ocellus, sometimes virtually absent. Compound eyes large though appearing smaller in species with elongate buccal region, usually setose though sometimes setae tiny and eyes appearing glabrous. Mandibles with three teeth, normally subequal in size, sometimes with middle tooth slightly longer or lower tooth slightly shorter. Head in lateral view rather narrow, tapering to mouth, particularly in species with elongate malar region. Head in dorsal view curved around anterior mesosoma. Occiput well exposed. Ocelli usually large, touching or close to orbital margin. Occipital carina complete dorsally, sometimes faint because of surrounding sculpture. Antenna 7-segmented, clava large and appearing unsegmented or with distinct suture lines so that clava comprises 4 segments.

Mesosoma. Mesoscutum wider than long, usually flat or virtually so, sometimes dorsally convex. Notauli usually present as distinct grooves reaching no more than about half way to anterior margin of mesoscutum, sometimes virtually absent or hidden by coarse longitudinal sculpture. Mesoscutellum either flat or transverse, with posterior margin usually straight medially, or dorsally convex and semicircular or oval in shape. Propodeum with pair of broad, elongate spines which are blunt or truncate apically and flank the T1 horn.

Wings. Macropterous, never brachypterous. Fore wing narrow basally, broad in apical half, sometimes fore margin sinuate and surface of apical half convex (spoon-shaped) and molded to convex dorsal surface of metasoma (i.e. subelytriform). Fore wing venation with tubular submarginal (Sc+R) and stigmal veins (r-rs), marginal vien (C+R) very short, postmarginal vein (R1) very short or absent; in Odontacolus veniprivus species group venation lacking except for incomplete submarginal vein, with pronounced infuscate patch at position of marginal (C+R) and stigmal veins (r-rs). Fore wing color varying from hyaline to having dark infuscate bands.

Metasoma in dorsal view subpedunculate. T1 square or longitudinally slightly longer than wide (rarely more transverse), with parallel or slightly curved lateral margins. Metasoma widest in posterior half; in lateral view dorsal surface slightly to strongly convex. T1 with large, laterally compressed hornlike process (i.e. ellipsoidal in cross-section) which reaches to level of posterior mesocutellum or higher. T3 the largest tergite, slightly longer than T2, sometimes subequal in length with T2. Ovipositor at least 1.5 × length of metasoma, with shaft curled back on itself within rounded head of the T1 horn. Gonoplacs elongate, approximately 0.75 × length of metasoma.

Male. Antenna short, 11-segmented, often appearing to be 9- or 10-segmented as distal antenomeres are closely joined, distal antenna becoming progressively broader so as to be subclavate. Metasomal horn absent, but anterior part of T1 inflected upwards.

Diagnosis.

Odontacolus s.l. can be distinguished from all other genera of Platygastroidea by three unique characters: T1 of the female has a laterally compressed T1 horn (elliptical in cross-section); the ovipositor is retracted within the metasoma and curled around within the curved head of the T1 horn so that it forms an elongate, U-shape (compared to Idris species where it is straight or slightly curved, see Figs 1 A–B); the propodeum in both sexes has a pair of spinelike flanges that (in the female) flank the T1 horn. In addition, all species are macropterous, never brachypterous, and the metasoma is subpedunculate in shape.

Distribution and regional diversity.

Odontacolus is clearly more widespread than previously thought and, in the Old World, is found throughout Africa south of the Sahara, the Middle East ( Odontacolus veniprivus group only; see Valerio et al. 2010), India, Sri Lanka, Nepal, south-east Asia (with one species extending north into China), and Australasia extending east in the Pacific to Fiji (Fig. 4, link to distribution map30). Australasia is the most species rich region (19 spp., four of which are endemic to Fiji), followed by India/south-east Asia (14 spp.) and Africa/Madagascar (11 spp.), the remainder of species have a broader distributions across regions.

Biology.

Like other members of the Baeini , Odontacolus species are endoparasitoids of spider eggs. However, of the 52 species here recorded from the Old World only five species have been reared. Veenakumari and Mohanraj (2011) record Odontacolus markadicus from eggs of an unknown salticid spider in southern India; Odontacolus pintoi has been reared from Clubiona cycladata Simon from under tree bark in South Australia (recorded as Odontacolus sp. in Austin (1984, 1985) (specimens in WINC); Odontacolus berryae has been reared from eggs of the salticid Trite planiceps Simon (specimens in LUNZ); Odontacolus whitfieldi has been reared from an unknown spider from China (specimens in UCRC), while Odontacolus harteni has also been reared from an unknown spider from Pakistan (specimens in BMNH) ( Valerio et al. 2010). Although hosts are only from two spider families, Clubionidae and Salticidae , it is likely that Odontacolus species attack a much greater range of host spiders given the number of species and diversity of habitats from which they have been collected (e.g. rainforest, tropic dryforest, eucalypt forest, coastal dunes, mangroves, grasslands, etc.; see Appendix IV).

Although nothing is known about the ovipositional behavior of Odontacolus species, we predict that females employ their long ovipositor to parasitize host eggs from outside the egg sac, by pushing the ovipositor through the silk wall, in a similar way as has been described for Idris (Ceratobaeus) species ( Austin 1984, 1985) that also have a T1 horn, albeit of a different shape (Figs 1B, C). Although documented for only a few species, the stategy of Baeus species ( Stevens and Austin 2007), Idris s.str. and other baeines that lack a T1 horn, is to burrow through the silk wall of the egg sac and oviposit into eggs while in direct contact with them.

Species excluded from Odontacolus .

The previously described species Odontacolus longispinosus Girault (Fig. 1) and Odontacolus amoenus Kononova are here transferred to the genus Idris Försterand should therefore be treated as new combinations. We were unable to borrow the holotype of Odontacolus amoenus but one of us (NFJ) during a recent visit to the UASK was able to examine a female paratype and confirm that the species does indeed belong to Idris .

Key to the females of Old World species of Odontacolus Kieffer