Rhynchophion flammipennis, (ASHMEAD), 1945

Gauld, Ian D. & Janzen, Daniel H., 2004, The systematics and biology of the Costa Rican species of parasitic wasps in the Thyreodon genus-group (Hymenoptera: Ichneumonidae), Zoological Journal of the Linnean Society 141 (3), pp. 297-351 : 302-314

1. RHYNCHOPHION FLAMMIPENNIS (ASHMEAD)

Thyreodon flammipennis Ashmead, 1894: 125 . Holotype ♀, MEXICO (CAS) [examined].

Rhynchophion flammipennis (Ashmead) Townes, 1945: 746 .

Fore wing length 18.3–24.8 mm; clypeus weakly convex, with apex pointed bluntly medially; mandible with lower tooth slightly longer than the upper; malar space 0.7–0.8 times basal mandibular width; lower face centrally closely and coarsely punctate; frons with a weakly raised crest between antennal sockets, without a carina extending from outer rim of antennal sockets upwards parallel with eye margin; frons centrally punctate, but with the impressions above the antennal sockets transversely wrinkled; ocelli small, the lateral ocellus separated from eye by about 1.8 times its own maximum diameter; head in dorsal view with gena rather weakly rounded behind eye; antenna setaceous, with 55–60 flagellomeres, the 20th transverse, 0.6–0.7 times as long as broad, the subapical ones with setae that are shorter than the diameter of the flagellomere. Pronotum punctate, with epomia absent; propleuron punctate, with lower corner rounded; mesoscutum closely and coarsely punctate, with black coarse pubescence, scuto-scutellar groove deep but short, laterally margined by raised, simple carinae; scutellum punctate, narrow and convex; mesopleuron closely and quite finely punctate, with epicnemial carina present only ventrally; metapleuron finely and closely punctate; propodeum coriaceous without distinct carinae, although with wrinkle-like vestiges of lateral longitudinal and lateromedian longitudinal carinae posteriorly. Fore leg of female moderately stout, with 5th tarsomere 0.7–0.8 times as long as preceding two tarsomeres, with tarsal claw long and with fine, close pectinae; hind tarsomeres 1–4 of male subcylindrical, with moderately long, dense pubescence ventrally. Fore wing with abscissa of Cu 1a between Cu 1b and 2 m-cu 1.0–1.1 times as long as abscissa of Cu 1 between cu-a and 1 m-cu. Metasoma with tergite I moderately stout, anteriorly laterally compressed; tergite II, in lateral view, 1.6–1.8 times as long as posteriorly deep. Male with subgenital plate transverse, convex, covered with fine hair; claspers quite long, the dorsal apex obliquely truncate, the lower margin rounded before apex, and with a deep dorsal notch; aedeagus, in profile, with apex, weakly inflated, distal end slightly flattened, and bordered by a strong lateral keel.

This species has a black body with lower face very slightly brownish, and with antennae yellowish black to rather bright yellow. The wings are strongly yellow, basally and apically blackish infumate in most individuals but some are entirely black.

Remarks: Rhynchophion flammipennis is a very distinctive, stout species that is easily recognized by its colour pattern. Structurally it closely resembles other described species in the genus, but subtle differences in genitalia distinguishes it from the entirely orangebrown R. woodi in Costa Rica (see that species). Several individuals collected in Costa Rica differ from typical examples of this species in having the body and wings uniformly black ( Figs 7, 8 ). Structurally they seem to be identical to R. flammipennis and the single reared specimen of this dark morph (96-SRNP-5708) emerged from the same species of host from which a typical specimen was reared (91-SRNP-1336). Here we treat them as simple colour morphs, perhaps induced by different temperature or humidity regimes (e.g. Kettlewell, 1963; Janzen, 1984; Harris, 1987). Similar dark-winged and yellow-winged dichromatism has been observed within species of Pepsis ( Vardy, 2000) , presumed Batesian and Müllerian mimic models for Rhynchophion .

Biological notes: Rhynchophion flammipennis is a very widely distributed species that occurs from the south-western USA south to Ecuador and possibly northern Argentina. In Costa Rica this species has only been collected in the seasonally dry north-west of the country, where it occurs from sea-level up to about 800 m. Adults appear in the first third of the rainy season (June to early August). Capture dates in Santa Rosa are given in Figure 64 . Despite intensive sampling in the ACG dry forest, it has never ever been collected outside this short season (when the vast majority of the sphingid host caterpillar population has its single annual generation), and we conclude that it is univoltine.

Rhynchophion flammipennis is the only black and orange ‘ Pepsis mimic’ among the Costa Rican Thyreodon group. It is rarely encountered flying energetically and rapidly in the daytime through brushy edges of secondary successional dry forest in Sector Santa Rosa, ACG. It visits at least the white sprays of fly and wasp-pollinated flowers of Allophylus occidentalis (Sapindaceae) , Forsteronia spicata (Apocynaceae) and Trigonia rugosa (Trigoniaceae) . All collections in Costa Rica have been with butterfly nets, Malaise traps or rearing in the dry forests and their margins in the Pacific side of the ACG. It does not appear at light traps placed in the same ACG dry forests. We conclude that it does not occur in ACG rain forest.

The ACG larval hosts are all Manduca lefeburii ( Table 2) feeding on Casearia corymbosa (Flacourtiaceae) . What appears to be the same species has been reared once from Manduca sexta in the south-western USA ( Kester & Tuttle, 1999). A total of ten Rhynchophion cocoons, all noticeably larger than those of R. flammipennis , have been reared from four other species of Manduca in the ACG dry forest, but only one eclosed ( R. woodi ) ( Table 2). Our preliminary hypothesis is that in the ACG, R. flammipennis is a specialist on Manduca lefeburii whereas R. woodi is a Manduca generalist.

In both successful rearings of R. flammipennis , it remained dormant in the cocoon through the remaining 65% of the rainy season and nearly all of the 6- month dry season. The time between cocoon spinning and eclosion was 354 and 339 days.

R. flammipennis cocoons have the same distinctive structure as those of Thyreodon (see detailed description for Thyreodon walkerae below) but are slightly more cylindrical with a lesser bulge in the middle. The wasp cuts a round exit hole 2–4 mm in diameter through the end of the cocoon.

Material examined: Holotype ♀, MEXICO: Baja California, El Taste, 1100 m ( CAS).

Non-type material: ARGENTINA: 1 ♀, 1 ♂, no further data, 1904 (Thomas) ( BMNH) . COSTA RICA: Guanacaste Prov.: 1 ♀, Barra Honda National Park , dry forest, 100 m, vi.1988 (Gauld & Mitchell) ( BMNH); 1 ♂ , Guanacaste National Park , reared as per data above (Janzen & Hallwachs) ( JHVC); 1 ♀, 18 ♂ , Guanacaste National Park, Casa Mariksa [= Estacion Maritza], 560 m, vi–vii.1986 –88 (Gauld & Mitchell) ( AEIC, BMNH); 3 ♂ , Guanacaste National Park, Estacion Maritza, 600 m, vii.1989, vi.1990 (Parataxonomists) ( INBio ); 1 ♀, 1 ♂, Rincon de la Vieja National Park , Las Pailas , 800 m, vii.1993, vi.1994 (Taylor & Rodriguez) ( INBio ); 1 ♂, Rincon de la Vieja National Park , Estacion Las Pailas , 800 m, vii–viii.1992 ( Garcia ) ( INBio ); 4 ♀, 12 ♂, Santa Rosa National Park , 300 m, vi.1977 – vii.1987 (Janzen & Gauld) ( BMNH); 3 ♂, same locality, 300 m, vii.1992 (Parataxonomists) ( INBio ) . MEXICO: Guerrero: 1 ♂, Sierra de las Aguas Escondidas, vii. ( Smith ) ( BMNH); 1 ♀, 4 ♂, Xucumantlan, 230 m, vii (Smith) ( BMNH) .

All black individuals: COSTA RICA: Guanacaste Prov.: 1 ♂, Barra Honda National Park , dry forest, 100 m, vi.1988 (Gauld & Mitchell) ( BMNH) ; 3 ♂, Guanacaste National Park, Estacion Maritza , 560 m, vi.1987 (Gauld & Mitchell) ( BMNH) ; 1 ♂, Guanacaste National Park , reared as per data above, vi.1986 (Janzen & Hallwachs) ( JHVC) .

Figures

Figure 64. The total numbers of individuals of Rhynchophion flammipennis collected by month in Malaise traps in the Bosque Humedo, Bosque San Emilio and Administration Area of Sector Santa Rosa of the ACG compared with the monthly percentage of the annual rainfall. Traps were operated continuously for three consecutive years, 1985–87.

Figures 7–14. Fore wings, showing colour patterns. 7, Rhynchophion flammipennis, normal form. 8, Rhynchophion flammipennis, dark form. 9, Thyreodon rufothorax. 10, T. atriventris. 11. T. maculipennis. 12. T. walkerae. 13. T. zitaniae. 14. T. papei.