Thyreodon maculipennis, CRESSON, 1874

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 : 334-335

17. THYREODON MACULIPENNIS CRESSON

Thyreodon maculipennis Cresson, 1874: 375 . Lectotype ♀, MEXICO, designated by Townes & Townes, 1966: 189 (PANS) [examined].

Fore wing length 15.2–19.1 mm; clypeus weakly convex, with margin flared outwards, with apex pointed medially; malar space about 0.3 times basal mandibular width; maxillary palp long with second palpomere strongly broadened and flattened; lower face centrally finely and sparsely punctate; frons swollen between antennal sockets, with a weak to moderately sharp median vertical ridge, and with a low carina extending from outer rim of antennal sockets upwards, close to and parallel with eye margin; frons centrally rather smooth; ocelli large, the lateral ocellus separated from eye by about 0.3 times its own maximum diameter; head in dorsal view with gena rather evenly rounded behind eye, occipital carina strong, its lower end weakly raised, not reaching hypostomal carina; antenna setaceous, with 48–52 flagellomeres, the 20th subquadrate, about 1.0 times as long as broad, the subapical ones with setae which are longer than the diameter of the flagellomere. Pronotum short with anterior margin moderately strongly and broadly reflexed, and with posterior margin centrally swollen, but not angulate, separated from the anterior margin by a broad U-shaped groove; epomia absent; propleuron very sparsely punctate, with lower corner rounded, peripherally not impressed; mesoscutum finely punctate, with sharply impressed, deep notauli which are close together posteriorly, inner anterior margin of notaulus unspecialized; scuto-scutellar groove very deep, laterally margined by a strongly raised, simple, thickened carina; scutellum finely punctate, weakly convex; mesopleuron finely punctate, without a sharp sternaular impression; metapleuron finely punctate, sometimes with a few obscure diagonal ridges; propodeum laterally slightly flattened, reticulate with interstices coriaceous, with a low rounded ridge above and behind the spiracle; propodeum posterodorsally reticulate, with transverse rugae posterolaterally, centrally with a very shallow median longitudinal impression. Fore leg of female slender, with coxa without a rounded protuberance behind trochanteral insertion, with 5th tarsomere 0.4–0.5 times as long as the preceding two tarsomeres, with tarsal claw quite short, with fine, close pectinae; hind coxa in profile moderately large, its hind end projecting slightly beyond level of hind end of propodeum; hind femur slender, about 6 times as long as maximally deep; hind tarsus of male with dense, moderately long pubescence ventrally. Fore wing with abscissa of Cu 1a between Cu 1b and 2 m-cu 1.1–1.2 times as long as abscissa of Cu 1 between cu-a and 1 m-cu. Metasoma with tergite I slender, anteriorly subcylindrical; tergite II, in lateral view, 2.1–2.6 times as long as posteriorly deep. Male with subgenital plate small and convex, covered with fine sparse hair; claspers quite long, the distal part slightly tuned up-wards, the dorsal apex obliquely truncate, the lower margin not angulate before apex, the upper margin with a broad shallow notch, the part proximal to this slightly expanded ( Fig. 53 ); aedeagus in profile with apex expanded, distally slightly flattened, with a lateral vertical sharp keel.

A blackish brown species with flagellum dark brownish, rarely with mesoscutum dark reddish brown; wings basally and apically blackish infumate, centrally almost hyaline.

Remarks: Structurally Thyreodon maculipennis closely resembles T. rivinae . Both lack strong interantennal carinae, and an epomia, and both have the fore leg slender with the 5th tarsomere slightly shorter than the 3rd. Both also have the fore wing peripherally dark but centrally hyaline. T. maculipennis differs most conspicuously from T. rivinae in not having the posterior ocelli contiguous with the eyes, and having the flagellum blackish or dark brown.

Biological notes: Thyreodon maculipennis is unambiguously a specialist on the small green caterpillars of Perigonia ilus (Sphingidae) in ACG dry forest [81- SRNP-65; 84-SRNP-1049; 84-SRNP-1289; 85-SRNP- 280; 85-SRNP-280.1; 89-SRNP-316; 89-SRNP-744; 91-SRNP-1715; 91-SRNP-1720; 91-SRNP-1725; 91-SRNP-2042; 92-SRNP-2488; 93-SRNP-1660; 93-SRNP-4042; 98-SRNP-8361; 98-SRNP-9316; 01-SRNP-14556] ( Table 2). Of 392 rearings of wildcaught P. ilus caterpillars, 9.9% were parasitized by this wasp, and 41% of the cocoons produced adult wasps. No other species of Thyreodon attacks Perigonia ilus in the ACG. P. ilus primarily feeds on the low foliage of Calycophyllum candidissumum (Rubiaceae) , but is rarely found on a sympatric tree, Guettarda macrospermum (Rubiaceae) . T. maculipennis parasitized P. ilus on both food plants. Perigonia lusca (which is extremely similar to P. ilus ) usually feeds on G. macrospermum and only very rarely on C. candidissimum . There remains the remote possibility that some of the few ‘ P. ilus ’ larvae feeding on G. macrospermum and parasitized by T. maculipennis were misidentified as P. lusca , but this is not the most parsimonious deduction. Perigonia ilus (and P. lusca ) breed throughout the range of wild-caught adults of T. maculipennis caught in other parts of Costa Rica.

Material examined: Lectotype ♀, MEXICO: Orizaba ( PANS).

Non-type material: COSTA RICA: Guanacaste Prov.: 1 ♀, 1 ♂, Barra Honda National Park, 3 km NW Nacaome, 100 m, vii, x–xi.1992 (Reyes) ( INBio ); 1 ♀, Guanacaste National Park, Los Almendros, 300 m, vi.1994 (Lopez) ( INBio ); 8 ♀, 9 ♂, Guanacaste National Park, reared as per data above (Janzen & Hallwachs) (JHVC); 2 ♀, Guanacaste National Park, Finca Jenny, 31 km N Liberia, 240 m, vi–vii.1992, vi–vii.1995 (Araya) ( INBio ); 2 ♀, 2 ♂, Santa Rosa National Park, 300 m, v–vi.1985 (Janzen & Hallwachs) ( INBio ); 3 ♀, same locality, vi.1989 (Gauld) (BMNH); 1 ♀, same locality, vi.1992 (Parataxonomists) ( INBio ); 1 ♀, Refugio Palo Verde, 50 m, vii.1985 (Solís) ( INBio ): Puntarenas Prov.: 1 ♀, Carara Biological Reserve, Estacion Quebrada Bonita, 50 m, viii–ix.1989 (Gauld) (BMNH); 17 ♀, 11 ♂, same locality, v–vi.1990, v.1992, v.1993 ( Zuñiga, Bello, Rojas & Saborio ) ( INBio ); 1 ♂, Osa Peninsula, Corcovado National Park, Estacion Sirena, 0–100 m, vii.1992 (Saborio) ( INBio ).

Figures

Figures 53–63. Apex of metasoma and male genital capsule, lateral; 53, T. maculipennis; 54, T. erythrocera; 55, T. whitfieldi; 56, T. laticinctus; 57, T. zitaniae; 58, T. papei; 59, T. morosus; 60, T. schauffi; 61, T. darlingi; 62, T. rufothorax; 63, T. atriventris.