A new species of Dendrocerus (Hymenoptera, Megaspilidae) from southern Brazil.

A new species of the megaspiline genus Dendrocerus Ratzeburg is described and figured. Dendrocerus riograndensis sp. n., is known from a series of males from the central region of Rio Grande do Sul, Brazil, and were captured with Malaise traps from an agricultural tobacco field.

Introduction

The parasitoid wasp family Megaspilidae includes more than 450 species in 11 genera worldwide (Dessart 2006), but the fauna of South America remains little known. Johnson and Musetti (2004) noted the genus PageBreak Ratzeburg to be cosmopolitan, with 96 described species, but only 11 of them are recorded from the Neotropical Region. Four species of are known from Brazil: Dessart, collected in Pará State, (Curtis), collected in many regions of Brazil, (Rondani), recordered in Rio Grande do Sul State and Dessart, collected in São Paulo State (Dessart and Cancemi 1986; Dessart 1987; Tavares 1996; Dessart 1996; Martinez 2003).

Among species in males of the halidayi species group are characterized by their flabellate antennae, with long branches on the proximal 4, 5, or 6 flagellomeres. There are 21 species of this group distributed on all continents except Antarctica, with the following four species from the New World tropics: Dessart (Chile), Dessart (Mexico), Dessart (Brazil) and Martinez (Argentina) (Dessart 1999; Martinez 2003). The objective of this paper is to describe a new species of belonging to the halidayi group.

Material and methods

Specimens were collected with a Malaise trap in an organically managed cultivation of tobacco ( L.) during the 2011–2012 crop, in Santa Cruz do Sul, Rio Grande do Sul, Brazil. The material was studied using a stereoscopic microscope trinocular Motic Quimis Q764ZT and is deposited in the .

Coleção Entomológica de Santa Cruz

The morphological nomenclature, format for the description, and measurements employed follow that of Dessart (1999), while Martinez (2003) is followed for features of the flagellomeres and side branches. The relative measures, except the entire body length, are expressed in millimeters.

Results

Pezzini & Köhler sp. n.

http://zoobank.org/F2786CA1-6E1C-4860-8A4D-E34368737B16

Etymology.

The specific epithet is based on the state of Rio Grande do Sul from where the type series was captured.

Diagnosis.

Male head moderately transverse; antenna with five rami on first to fifth flagellomeres (antennomeres three through seven), not articulated, remaining flagellomeres without rami. Mesoscutellum without grooves or lateral carina; propodeum without armature. Metasoma smooth and shining, without punctures.

Description.

Male: Total body length 1.32 mm, forewing length 0.85 mm. Coloration: Brownish throughout; Metasoma, mouthparts, and legs light brown; trochanters, femoral apices, tarsi, and tibial bases lighter. Wings hyaline with brown venation.

Head: Coriaceous, pubescent; moderately transverse. Ocelli forming an isosceles triangle with wider base, median ocellus bordered anteriorly by an obvious depresPageBreaksion; preoccipital depression bounded by only a groove posterior to lateral ocelli and separated by a distance shorter than diameter; preoccipital suture visible until base of ocellar triangle. Compound eyes subcircular, pubescent, setae distinctly shorter than those on remainder of head. Supraclypeal depression conspicuous, with adjacent areas glabrous; intertorular carina present. Antenna flabellate, with coarse bristles (Fig. 6), with elongate rami laterally on proximal five flagellomeres (flagellomeres I–V, or antennomeres III–VII), A8–11 cylindrical and without lateral rami; scape: 18 (5); pedicel: 1 (1); A3: 2, R1: 15; A4: 2, R2: 12, A5:2, R3: 8, A6: 2, R4: 7,5; A7: 3, R5: 7; A8:5 (2); A9: 2 (1); A10: 7 (5); A11: 3 (1).

Figure 6.

Detail of the antenna with coarse bristles, of sp. n. Scale: 0.1 mm.

Mesosoma: Mesoscutum, axillae, and mesoscutellum pubescent, coriaceous (Fig. 7). Anterior border of mesoscutum in dorsal view strongly inclined, notauli complete, weakly crenulate; sulci between axillae and mesoscutellar disc roughly crenulate. Mesoscutellum transversely convex and longitudinally simple, not carinate laterally. Mesopleuron slightly coriaceous, with some bristles anteriorly, and separated ventrally from metapleuron by crenulate suture. Propodeum without armature. Metanotal sulci extending posteriorly, convergent medially; propodeal carina transverse, forming X-shaped structure, posterior propodeal area smooth.

Figure 7.

Head, mesoscutum, axilla, and mesoscutellum (dorsal view), of sp. n.. Scale: 0.1 mm.

Wings: Forewing without cells, marginal vein long and pubescent, membrane with numerous microtrichia, pterostigma well developed (as in all species of the family), 0.12 mm diameter, poststigmal veins well defined and long (Fig. 5); no other veins present, hind wing without venation.

Figure 5.

Detail of forewing with pterostigma, of sp. n. Scale: 0.1 mm.

Metasoma: Nine visible segments, integument smooth and shiny; fusiform, more convex ventrally than dorsally, ovoid in dorsal view.

Female: Unknown.

Biology.

Unknown.

Comments.

The number of lateral rami on the antenna, the dimensions of each flagellomere (length × width), and the form of the forewing veins serve to distinguish sp. n. from the other species of the halidayi species group. belongs to the halidayi group, but only the female is known, separated from the other species by the possession of longitudinal grooves on TIII.

Distribution.

sp. n. is known presently only from the central region of Rio Grande do Sul, Brazil. Future surveys will be needed in order to better ascertain its total potential distribution.

Material examined.

Holotype: BRAZIL. Rio Grande do Sul: Santa Cruz do Sul, (Agronomy, Development, Extension and Training Center ‘‘ADET’’, 29°48'22.92"S, 52°19'42.00"W, 102m), Malaise trap, Köhler A. Leg., 1♂, 16.XII.2011, (CESC 43389/17). Paratypes: Eight males with the same data as the holotype: BRAZIL. Rio Grande do Sul: Santa Cruz do Sul, (Agronomy, Development, Extension and Training Center ‘‘ADET’’, 29°48'22.92"S, 52°19'42.00"W, 102m), Malaise trap, Köhler A. Leg., 1♂, 16.XII.2011, (CESC 43364/20); 1♂, 20.XII.2011, (CESC 44067/11); 2♂, 27.XII.2011, (CESC 45553/14); 1♂, 03.I.2012, (CESC 46152/13); 1♂, 10.I.2012, (CESC 46511/10); 2♂, 17.I.2012, (CESC 46916/16).

Detail of male antenna of (redrawn from Dessart 1991).

Detail of male antenna of (redrawn from Dessart 1991).

Detail of male antenna of (redrawn from Martinez 2003).

Detail of male antenna of sp. n.

1	Antenna with five unarticulated branches; TIII smooth, without punctures	2
–	Antenna with five articulated branches basally (Fig. 1); TIII with punctures	Dendrocerus mexicali
2	A8 same length as A7; A8 approximately same length as A11.	3
–	A8 twice length of A7; A8 longer than A11 (Fig. 2)	Dendrocerus araucanus
3	Antennal branches relatively thin; A7 and A8 of similar width; R1 smaller than R2; R5 length approximately similar to A7 (Fig. 3)	Dendrocerus ranquel
–	Antennal branches relatively thick; A7 thinner than A8; R1 and R2 of same length; R5 much longer than A7 (Fig. 4)	Dendrocerus riograndensis sp. n.