Neolasioptera aculeatae Gagné, 2011

Gagné, Raymond J., Kay, Fernando Mc & Heard, Tim A., 2011, A new species of Neolasioptera (Diptera: Cecidomyiidae) from Parkinsonia aculeata (Leguminosae) in Argentina for possible use in biological control in Australia, with a key to Neotropical species of Neolasioptera, Zootaxa 2866, pp. 61-68 : 62-66

Neolasioptera aculeatae Gagné , new species

Adult. Scale cover color pattern: head mostly white anteriorly (frons, antennal scape and pedicel, and palpi), the postcranium with dark upper central patch surrounded by white; thorax white on dorsum of anepisternum (pleura otherwise without scales), white on anterior corners of scutum and all of scutellum, remainder of scutum brown; wing margin black except for white spot at juncture of C and R5, halteres yellow, legs dark brown dorsally, white ventrally; abdomen dorsally with first segment white, second through fifth segments black except for white posterior margin, (at least in male, those of female samples mostly rubbed off) laterally and ventrally white, male terminalia black.

Head: Eyes connate dorsally, eye bridge 6–7 facets long; eye facets hexagonal and closely approximate on more bulbous ventral half of eye, circular and minimally separated on dorsal half. Antenna with 13–15 flagellomeres in male (n=10), 15–19 (n=10) in female; scape tapering from narrow base to broad apex, with several setae and densely covered with scales ventrally, bare dorsally; pedicel spheroidal, with several setae and densely covered with scales ventrally, with several setae dorsally, wider than flagellum; flagellomeres ( Fig. 17 ) shaped similarly in both sexes, barrel-shaped, broader than long, each with 2 horizontal circumfila and 2 vertical connectives, completely setulose, with a few scales proximad of basal circumfilum and basally recurved setae between the horizontal circumfila. Frons thickly covered with setae and scales. Palpus 4 segmented, first segment shortest, second and third segments approximately subequal, the fourth longest, all with widely scattered setae and scales. Labella hemispherical with scattered setae.

Thorax: Wing 1.3–1.4 mm long in male (n=5), 1.5–1.6 in female (n=5). Scutum with setae of the 2 central rows in sparse files, lateral rows present in 2–3 files and continuous along most of scutal length, scutum otherwise nearly entirely covered with scales except for midline posteriorly and 2 narrow mediolateral lines; scutellum with single horizontal row of setae, otherwise covered with scales; anepisternum with scales only dorsally, anepimeron with 10–12 setae, pleura otherwise without vestiture.

Male abdomen ( Fig. 9 ): First through sixth tergites with anterior pair of trichoid sensilla, mostly single posterior row of setae, double laterally, and otherwise covered with scales; seventh tergite on anterior half unpigmented and without vestiture, pigmented posterior half with single to double row of posterior setae and elsewhere covered with scales; eighth tergite apparent only from anterior pair of trichoid sensilla. Second through sixth sternites quadrate, setose posteriorly and laterally in single, continuous row, elsewhere covered with scales, and with pair of closely set anterior trichoid sensilla; seventh sternite similarly shaped but devoid of vestiture except for anterior pair of trichoid sensilla and double row of posterior setae with intermixed scales; eighth sternite without trichoid sensilla and apparent only posteriorly around double row of setae. Terminalia ( Figs. 10–12 ; for terminology, see Gagné 1994, except that “mediobasal lobe” is used in place of “paramere”): posterior margins of cerci and hypoproct evenly convex posteriorly, all 3 subequal in shape, the cerci with several setae ventrolaterally and apically, hypoproct with 4 setae along posterior margin; gonostylus tapering from base to apex, setulose on basal third, glabrous and ridged beyond to apical tooth; mediobasal extension of gonocoxite covered with elongate, recurved setulae, bilobed, the dorsal lobe short, convex, the ventral lobe longer, larger, projecting dorsally in lateral view; aedeagus glabrous, longer than mediobasal lobe, the apex dorsoventrally flattened, convex in dorsoventral view.

Female abdomen ( Figs. 8 , 16 ): Vestiture of first through sixth segments generally as for male. Seventh tergite quadrate, considerably smaller than sixth, with pair of trichoid sensilla anteriorly, double row of setae along posterior margin and scales present only on posterior half of sclerite. Eighth tergite modified into a pair of elongate sclerites slightly longer than preceding tergite, only vestiture on each sclerite a single trichoid sensilla anteriorly and a few short setae posteriorly. Eighth sternite not evident. Ovipositor elongate, protrusible, base of ninth segment to end of fused cerci 3.2 times length of seventh tergite; ninth segment with elongate dorsolateral sclerite on each side; fused cerci cylindrical.

Pupa ( Figs. 6–7 ). Body elongate-cylindrical. Antennal bases separate, each broadly convex anteriorly. Cephalic sclerite with moderately long, anteriorly directed seta on each side. Frons with a pair of short-setose papillae. Prothoracic spiracle horizontal. Abdominal first tergum without spicules, second to eighth terga and all sterna and pleura mostly densely covered with tiny spicules.

Third instar larva ( Figs. 4–5 ). Generally spindleform, posterior end convex. Integument entirely and evenly verrucose. Antenna about twice as long as wide. Cephalic apodemes as long as head capsule. Spatula ( Fig. 14 ) strongly sclerotized, brown, shaft nearly parallel-sided, widest anteriorly, tridentate, middle tooth convex, less than half length of the lateral teeth. Papillae with pattern basic for tribe Alycaulini ( Gagné 1994) ; lateral papillae of thoracic segment reduced to 4 instead of 6 on each side of median line, 2 of each group with short seta barely longer than basal width of papilla, the other 2 without seta; with eight terminal papillae.

Material examined. HOLOTYPE: male, reared from stem swelling of Parkinsonia aculeata , collected 9 km SE Dragones, Salta, VIII-20-2008, Fernando McKay, deposited in Museo Argentino de Ciencias Naturales ( MACN), Buenos Aires, Argentina. Paratypes: all from stem galls of P. aculeata , variously deposited as noted below in MACN, in the Biological Control Laboratory, USDA, Hurlingham, Argentina ( BCLA), in CSIRO Ecosystem Sciences, Dutton Park, Brisbane, Qld, Australia ( ESDP) for eventual deposition in the Australian Insect Collection in Canberra, or otherwise in the National Museum of Natural History, Washington, D.C.: 1 male ( BCLA), 1 female ( MACN), and 2 larvae ( BCLA), same data as holotype; 2 males, 2 females, 4 pupal exuviae, 4 larvae, Yuchán, Salta, I-2010, A. Sosa; 1 male, 1 female (both in ESDP), and 1 female ( BCLA), 20 km S Juarez, Formosa, III-19-2010, T. Heard & F. McKay.

Etymology. The name aculeatae is the genitive form of the host’s specific epithet.

Remarks. The key that follows will serve to distinguish and separate the new species fom all Neotropical Neolasioptera species. The scale-color pattern, the three views of the male terminalia ( Figs. 10–12 ) and the photo of the female postabdomen ( Fig. 8 ) serve to describe this species in a way that we recommend for future descriptions or redescriptions of additional species. The extent of vestiture (setae and scales) of the new species are used to good effect in the key, and the photograph of the fused female cerci ( Fig. 8 ) shows several different forms of setae and their distribution much more effectively than words can describe.

Distribution. The new species is known only from P. aculeata from Salta, Chaco and Formosa Provinces of northern Argentina. It probably occurs also in Paraguay where the characteristic galls have been observed on P. aculeata by FMK and TAH

Biological notes. Galls are woody, spheroidal enlargements of the nodes and range from 3–17 mm in length and 2–13 mm in width. They are initially soft but become very hard. A gall may have one to five yellow-orange larvae, each in its separate tunnel that runs the length of the gall. When full-grown, a larva reverses its direction within its tunnel, and, using its spatula, enlarges the diameter of the anterior part of the tunnel, cutting through the hard tissue up to but not including the epidermis. The resulting shavings are pushed to the rear of the tunnel ( Fig. 3 d). The larva then spins a silken cocoon ( Fig. 3 b and c) in which it will eventually pupate. When the adult is fully formed within the pupal integument, the pupa breaks through the end of the cocoon, crawls to the end of the tunnel, and pushes through the remaining layer of epidermis to the exterior. The adult then breaks through the thorax of the pupa, usually leaving the pupal integument caught halfway out the exit ( Fig. 3 a).

Figures

FIGURES 16 – 17. N. aculeatae. 16, Female abdomen, sixth segment (inclusive) to end, with details of microsculpturing of the eighth segment extended and ninth segment. 17, Male third antennal flagellomere.

FIGURES 9 – 15. N. aculeatae. 9, Male abdomen, sixth segment (inclusive) to end. 10 – 12, Male terminalia: 10, transverse section showing, left to right, cercus, hypoproct, gonostylar lobe, and aedeagus; 11, one gonopod removed (dorsal); 12, gonopod and aedeagus (ventral). 13, Silhouette of gonostylus of N. baezi (dorsal). 14, Larval spatula and associated papillae of N. aculeatae. 15, Larval spatula (distorted) of N. aeschynomensis.

FIGURES 4 – 8. N. aculeatae. 4, Larval head and thorax (ventral). 5, Larval posterior segments (dorsal). 6, Pupal head and thorax (lateral). 7, Same (dorsal). 8, Female postabdomen, fused cerci slightly askew (lateral). Scale bar = 0.1 mm.

FIGURES 1 – 3. N. aculeatae galls on Parkinsonia aculeata. 1, Galls on young shoot. 2, Old galls. 3, Branchlet with two galls, one partly cut open to show tunnel: a, pupal exuviae; b, circular cap from anterior end of cocoon; c, cocoon; d, end of tunnel with wood shavings made by full-grown larva.