Rhopalomyia caldeniae Cornejo & Martínez, 2019

Cornejo, Laura Gabriela, Molas, Bárbara Mariana Corró, Kuzmanich, Nicolás & Martínez, Juan José, 2019, New species of Rhopalomyia and Dasineura (Diptera: Cecidomyiidae) associated with Prosopis caldenia Burkart (Fabaceae) in Argentina, Zootaxa 4691 (2), pp. 161-170 : 162-164

Rhopalomyia caldeniae Cornejo & Martínez , new species

( Figs. 1–2 )

Description

Adults. Head: ( Fig. 1a ) With circular ommatidia widely joined at the vertex. Antennae with 12 flagellomeres. Male flagellomeres with distinct necks, about half as long as nodes, except for the two apicalmost, which do not have distinct necks: circumfila composed of a continuous basal band and a partial apical band joined by two connectives, ventrally with about 20 setae with enlarged alveoli ( Fig. 2a ). Female flagellomeres without necks, the two apicalmost fused: circumfila composed of basal and apical bands joined by two connectives and ventrally with about 7–8 setae with large alveoli ( Fig. 2b ). Frons with 8–12 setae on each side of the midline. Palpus three-segmented, each with many setae, the first segment about 0.6 times as long as the second and 0.5 times as long as the third.

Thorax: Wing length, male 1.4–1.5 mm (n=5); female 1.4 mm (n=5), with R5 reaching C slightly anterior to wing apex ( Fig. 1b ). Anepimeron with 10–20 setae. Apodemes: tarsal claws with basal tooth; empodia slightly longer than claws; pulvilli short.

Male abdomen: Tergites I–VII rectangular, completely setulose, with a transverse row of setae on the posterior margin and scattered scales. Tergite VIII smaller than the preceding, uniformly setulose and with some setae distributed through its surface. Sternites I–VII rectangular, setulose and with setae uniformly distributed. Sclerites without an anterior pair of trichoid sensilla Terminalia ( Fig. 1c ): cerci oval, separated by a deep V–shaped incision, covered by microtrichia with four to six setae on each lobe dorsally and with about three setae ventrally Hypoproct rectangular to bilobed, uniformly covered by microtrichia, with 1 apical seta on each lobe. Gonocoxites robust, setulose and covered with setae. Gonostyli subcylindrical, uniformly setulose, with numerous setae dorsally and ventrally; with apical tooth. Gonocoxal mediobasal lobes setulose, shorter than the aedeagus, with three apical papillae bearing setae.

Female abdomen: Tergites I–VI rectangular, completely setulose, with a transverse row of setae on the posterior margin. Tergite VII slightly constricted beyond midlength, the posterior margin with many setae. Tergite VIII undivided longitudinally and weakly sclerotized, without setae and with anterior margin slightly indented ( Fig. 1d ). Sternites I–VII rectangular, completely setulose with a transverse row of setae on the posterior margin. Sclerites without an anterior pair of trichoid sensilla. Ovipositor with cerci covered with microtrichia, with two types of setae beyond hypoproct, long and thin on the base, short and thick pegs on the apex ( Fig. 2c ).

Pupa: Length 1.6–1.8 mm (n=4). A pair of long cephalic setae. Base of the antennae without horns or spines. Facial papillae indistinct. Prothoracic spiracle short ( Fig. 2d ). Integument of abdominal tergites without spines.

Third instar larva: Length 1.4–1.9 mm (n= 20). Head wider than long. Integument white, covered by verrucae. Spatula absent. Lateral and terminal papillae are not apparent.

Material examined: HOLOTYPE MALE: Argentina, La Pampa, Santa Rosa, Provincial Forest Nursery . 12.II.2016. Collected from leaf galls of Prosopis caldenia . L. G Cornejo col. (MACN) . PARATYPES: four males, eleven females same data as holotype (MACN) except dates, ranging from 4 to 12 February 2016 ; seven larvae Argentina, La Pampa, Santa Rosa , Provincial Forest Nursery , 6.II.2016, from leaf galls of Prosopis caldenia . L. G Cornejo col. (MACN) ; five pupae Argentina, La Pampa, Santa Rosa , Provincial Forest Nursery , 4.II.2016, from leaf galls of Prosopis caldenia . L. G Cornejo col. (MACN).

Etymology: The specific name is the genitive of the host plant name.

Remarks: Rhopalomyia prosopidis Kieffer is the only species of the genus previously known to induce galls in the subfamily Mimosoidea ( Fabaceae ). Its hosts include Prosopis alpataco , P. campestris , P. flexuosa and P. alba from Mendoza and San Luis provinces, Argentina. The type material of this species is presumed lost ( Gagné & Jaschhof, 2017), and the only stages described are the larva and the pupa. They are consistent with those of R. caldeniae (absence of larval spatula, absence of pupal antennal horns and absence of pupal abdominal tergal spines). Despite its association with the same host plant genus and the general similarity with the available and scarce morphological information of R. prosopidis , the morphology of the galls on Prosopis caldenia is noticeably different. While individuals of Rhopalomyia caldeniae induce bivalve galls composed of two contiguous pinnulae, those of R. prosopidis induce galls on the buds entirely covered by modified and reduced leaves ( Kieffer & Jörgensen 1910; Jörgensen 1917). Due to the differences on the biological behavior and the distinct gall, we consider Rhopalomyia caldeniae as a distinct species.

Figures

FIGURE 1. Rhopalomyia caldeniae Cornejo & Martínez sp. nov.: a, head of male in anterior view; b, wing; c, male genitalia; d female tergites VII and VIII.

FIGURE 2. Rhopalomyia caldeniae Cornejo & Martínez sp. nov.: a, male third flagellomere; b, female third flagellomere; c, detail of the distal end of female genitalia showing apical stout sensorial pegs; d, pupa, head and anterior area of thorax in anterolateral view, arrow indicates the position of the prothoracic spiracle.