Neolasioptera pantaneira , a new species of Cecidomyiidae ( Diptera ) associated with Aeschynomene denticulata ( Fabaceae ) from Brazil

A new species of gall midge that induces stem galls on Aeschynomene denticulata (Fabaceae) is described based on material collected in Pantanal (Mato Grosso do Sul, Brazil). This species is unique among the Brazilian congeners in having spatula with three convex teeth, cruciate, with defined anterolateral extensions, four lateral papillae on each side of the spatula, and three pairs of terminal papillae (larva), four-segmented palpi (adult), 17 flagellomeres (female), ovipositor about 11 times length of seventh tergite.

Stem galls were found in A. denticulata in Mato Grosso do Sul.The galler was identified as a new species of Neolasioptera Felt, 1908 (Diptera, Cecidomyiidae).
Neolasioptera is known from Nearctic and Neotropical regions, and comprises 134 species, which induce mainly stem galls, but also petiole, leaf vein, or flower galls.Most live on Asteraceae, but many other plant families are hosts also.Only 11 species are associated with Fabaceae (Table 1) (Gagné and Jaschhof, 2014).
Neolasioptera is a diverse genus.It gathers the species of Alycaulini whose adults have four or three-segmented palpi and fully fused, unlobed female cerci, pupae with a non-brittle exoskeleton, and larva with the spatula usually well-developed, three or four lateral papillae on each side of the spatula and usually 6 or 8 terminal papillae, and convex and unlobed terminal segment (Gagné, 1994).

Material and Methods
Studied area.Pantanal, with diverse landscapes units differentiated by the intensity and regularity of the flood pulse, has an area of approximately 140,000 km 2 , of which more than half is covered by water at the time of the flooded (Pott and Pott, 1994) and holds 38.21% of the Upper Paraguay Basin (Silva and Abdon, 1998).The climate is sub-humid tropical -Aw (Koeppen, 1931), with dry winters and rainy summers.The average annual rainfall varies between 1,000 and 1,400 mm, concentrating between November and April (Soriano et al., 2001).The vegetation of the sedimentary foodplain is a mosaic of aquatics, foodable grasslands, riparian forests, savannas (cerrados), cerrado woodlands, dry forests, and a large area of mono-dominant savannas, and pioneer woodlands (Pott et al., 2011) and aquatic environments such as freshwater or brackish lagoons, rivers, fooding runoff ("vazantes") and anabranch ("corixos"), and the highly sandy soil (Abdon et al., 1998).
In the Pantanal, the ponds are small depressions freshwater, circular or elongated that in full season reach up to a meter deep receiving contribution of surface water, which can be aligned and connect to each other in the form of rosary, that being in drought dry (Bacani and Sakamoto, 2007).
Individuals of A. denticulata were found on the edge of a permanent pond surrounded by woody vegetation patches resistant to flooding, known locally as "capões" in the sub-region Abobral, farm São João (19°23'09.01"S,57°02'57.77"O,92 m), Municipality of Corumbá, Mato Grosso do Sul, Brazil, in March, April and May 2013, the dry season in the Pantanal.Ungalled branches were pressed and identified by GC and FML.The exsiccate (CGMS 50234) was incorporated in the herbarium CGMS/Universidade Federal de Mato Grosso do Sul.
Galled stems were removed from the plant, placed in plastic bags and taken to the laboratory for observing the emergence of the adults in their own inflated plastic bags, at room temperature.Larvae and pupae exuviae were obtained through dissection of some galls under stereoscopic microscope, all the material was fixed in 70% alcohol.
The Cecidomyiidae was mounted on microscope slides, following the method outline by Gagné (1994).The gall midge was identified to genus level based on the key in Gagné (1994).Then, we used the key to Neotropical species of Neolasioptera in Gagné et al. (2011).The species was compared to the descriptions and illustrations of the Brazilian species as well as to Neotropical species associated with Fabaceae.The most important morphological characters were illustrated, using light microscope with camera lucida.Measurements were made using a microscope slide with scale.The terminology of Gagné (1994) was adopted.Type-material is deposited in the Diptera Collection of the Museu Nacional (MNRJ)/Universidade Federal do Rio de Janeiro.The field and laboratory works were done by G.C. and F.M.L., while the description of the new species was done by V.C.M. Diagnosis.Adults with four-segmented palpi, female with 17 flagellomeres and ovipositor about 11 times length of seventh tergite.Larva with spatula with three convex teeth, cruciate, with defined anterolateral extensions, four lateral papillae on each side of the spatula, and three pairs of terminal papillae.
Male adult.Body length: 1.70-1.85mm (n=3).Head (Figure 1): eye facets circular; vertex with facets.Antenna: scape obconic, as long as large, with few setae and scales ventrally, bare dorsally; pedicel globose 1.2 times as wide as long, with several setae and densely covered with scales ventrally, with several setae dorsally, wider than flagellum; flagellomeres barrel-shaped, longer than wide, each with 2 horizontal circumfila and 2 vertical connectives, completely setulose, with a few scales proximad of basal circumfilum, setae between the horizontal circumfila and short neck (Figure 2), flagellomeres 8 + ?, 1st and 2nd flagellomeres 2 connate.Frons thickly covered with setae and scales.Labrum long-attenuate with two pairs of ventral setae; labella hemispherical, each with some lateral setae and two pairs of short setae; palpus with four segments: 1st segment shortest, globose as long as wide, 2nd-4th segments cylindrical, 2nd segment widest, 1.5 as long as wide; 3rd segment 3 times as long as wide, 4th segment longest, 3.5 times as long as wide, all with widely scattered setae and scales.Thorax: 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 irregular horizontal row of setae, otherwise covered with scales;, anepimeron with 07-09 setae, pleura otherwise without vestiture; wing: length (from arculus to apex): 1.0-1.1 mm (n=9); tarsal claws bowed beyond midlength, and toothed; empodium reaching bend in claws (Figure 3).
Abdomen (Figure 4): first through sixth tergites with anterior pair of trichoid sensilla, single posterior row of sparse setae, some lateral setae, and otherwise covered with scales; seventh tergite on anterior half unpigmented and without vestiture, pigmented posteriorly with single row of posterior setae and elsewhere covered with scales; eighth tergite apparent only from anterior pair of trichoid sensilla, 8th tergite elliptical with setae and two anterior trichoid sensilla; second through sixth sternites rectangular with a single posterior row of setae, few lateral setae, elsewhere covered with scales, and with pair of closely set anterior trichoid sensilla; seventh sternite similarly shaped with anterior pair of trichoid sensilla and double row of posterior setae, elsewhere covered with scales; eighth sternite without trichoid sensilla and apparent only posteriorly around double row of setae.Terminalia (Figure 5): gonocoxite not splayed, about 2.7-3.0 times as long as wide, about 1.9-2.0times as long as gonostylus and setose; gonostylus claviform, tapering from base to apex, setulose on basal third, glabrous and ridged beyond to apical tooth; posterior margins of cerci and hypoproct evenly convex posteriorly, all 3 subequal in shape, the cerci with several setae ventrolaterally and apically, hypoproct with 3 setae along posterior margin about as long as cerci; parameres longer than hypoproct, 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, tapering gradually to apex, the apex convex in dorsoventral view.
Etymology.The name "pantaneira" refers to the biome where the species was collected -Pantanal.
Comments.This is the second species of Neolasioptera associated with Aeschynomene L. The other one, N. aeschynomensis (Brèthes 1918) has been recorded only in Argentina, where induces gall on Aeschynomene montevidensis.It was described based on female, and Gagné et al., 2011 gave information about larva morphology.Male and pupa are still unknown.The larva is very useful to segregate both species.N. aeschynomensis and the new species have three-toothed spatula, cruciate, with defined anterolateral extensions, but they differ in the shape of the teeth, which are pointed in the former (Figure 15) and convex in the latter, as well as in the shape of the basis -more extended laterally in the new species (see Figures 12 and 15    The larval morphology also helps to segregate the new species from the other Brazilian congeners: N. eugeniae and N. fariae are the unique in having two-toothed and four-toothed spatula, respectively.All others have three-toothed spatula.Among these, N. cerei is the only one with not cruciate spatula and middle tooth at least as long as the lateral teeth, whereas the reminders have a cruciate spatula.N. cupheae has four pairs of terminal papillae, while the new species has three pairs.N. ramicola has a relatively shorter spatula shaft and more closely adjacent teeth (see Figures 12 and 17 to compare).In N. lantanae the middle tooth is longer than the lateral teeth, differing from the new species where it is appreciably shorter.Neolasioptera urvilleae is known only from an inadequate original description of the adults and has not been recorded since.The existence of the types is doubtful (Gagné, 1994).Nothing further can be said about this species until it is found again (Gagné et al., 2011).
to compare).Although the original female description of N. aeschynomensis is very brief, some differences can be pointed: the number of flagellomeres (20 in N. aeschynomensis and 17 in the new species), the length of flagellomeres necks (longer in the new species, see Figures6 and 16to compare) and the body length (1.50 mm in N. aeschynomensis and from 2.40 to 3.55 mm in the new species).