Diabrotica collicola Cabrera & Cabrera Walsh, new species
Creators: name: Cabrera, Nora
name: Walsh, Guillermo Cabrera
Publisher: name: Zenodo
Year: 2010
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Coleoptera
Chrysomelidae
Diabrotica
Diabrotica collicola

description: Diabrotica collicola Cabrera & Cabrera Walsh, new species
(Figs. 1−19)
Diagnosis. Small-sized species, body oval, slightly convex. Coloration parrot green with yellowish vittae. Genal space less than 1/4 maximum length of the eye. Antennomeres 2 and 3 subequal in males, 3 longer in females, together more than 1/2 length of 4. Elytra with two weak sulci, basal inner surface of elytra with single binding patch. Pro- and mesothoracic tarsi of males with ventral adhesive patch. Receptacle of spermatheca subcylindrical. Internal sac of the median lobe with four sclerites.
Holotype male. (Fig. 1). Color. Head yellowish brown, one-third of mandibles chestnut colored. Antennomeres chestnut colored, with all surfaces of antennomere 1 green. Disc of pronotum green, tinged with yellowish brown. Each elytron parrot green with two yellowish vittae, one medial, widest at middle area, tinged with brown, the other marginal, both vittae partly or entirely confluent at apex; epipleura yellowish; humeral calli yellowish brown. Scutellum amber. Coxae and basal third of femora yellowish brown, tarsi chestnut colored. Venter with prosternum parrot green, meso-metasternum and abdomen yellowish tinged with brown.
Head. Vertex finely and sparsely punctate, depressed above antennal calli; antennal calli oval, elevated over surface of vertex, as wide as diameter of the antennal sockets, supracallinal sulcus and midfrontal sulcus deeply impressed, supra-antennal sulcus barely indicated; antennal sockets adjoining anterior margin of eyes, interantennal space smaller than transverse diameter of eye; frontal ridge moderately raised in lateral view; anterofrontal ridge not separated from frontal ridge. Genal space very small, less than 1/4 the maximum ocular length. Antennae inserted approximately at midline of eyes, extending to middle of elytra; antennomere 2 and 3 short, subequal in length, antennomeres 2+3 together longer than antennomere 4; antennomeres 3−10 elongate, similar in length, antennomere 11 apically acuminate. Clypeus with eight preapical setae. Labrum (Figs. 2−3) approximately rectangular, anterior margin with small mesal notch, a row of six long setae at mid length, three short fine setae close to notch apically, twelve short, thick sensilla on each side. Mandibles (Fig. 4) symmetrical, pyramidal, five-toothed apically, only teeth 3−5 visible on external face; tooth 3 and 4 narrow, acute, tooth 3 more than twice as long as 4; tooth 4 almost two times longer than 5, which is small, blunt at apex; inner margin of mandible with two very short denticles; mola longer than wide. Maxillae (Fig. 5) with cardo widened apically and with eight long setae; basistipes with five long setae situated on latero-external margin; galea and lacinia with a fringe-like pilosity apically, galea surpassing lacinia, subcylindrical, apically wider than base. Maxillary palpi well developed; palpomere 1 subrectangular; palpomere 2 and 3 subconical, the latter longer than 2; palpomere 4 subconical, with narrow base, patch of digitiform sensilla (Fig. 9) on the externo-basal corner, formed by twelve embedded sensilla, evident with higher resolution. Labium with four long setae between bases of palps. Labial palp three-segmented, with palpomere 1 subrectangular; palpomere 2 subcylindrical, more than 2.0 times as long as 1; palpomere 3 subconical with very narrow base.
Thorax. Pronotum slightly convex, shiny, evenly, finely punctate, rectangular, 1.18 times wider than long, widest near middle, PW 1.55−1.81mm, posterolateral foveae weakly impressed; anterior and posterior margins almost straight, posterolateral margins slightly expanding anteriorly; one long, thin seta on each anterolateral and posterolateral angle. Prosternum convex; procoxal cavities contiguous, positioned midway between anterior and posterior margins of prosternum; intercoxal prosternal process thin, incomplete, extending about one-half length of procoxae. Mesoscutum and scutellum fused; scutellum triangular, nearly as wide as long, rounded at apex. Mesosternum shorter than metasternum at midline, intercoxal mesosternal process thin, extending to one-half length of mesocoxae; mesocoxal cavities inserted on posterior margin, nearly contiguous, open laterally to mesepimeron. Metanotum (Fig. 8) transverse, wider than long, metanotal apodeme “d intersecting apodeme “c posterior to midpoint of “c. Metendosternite (Figs. 7 and 10) with stalk longer than wide; lateral arms, thin, divergent, apically deflexed, mesofurcal-metafurcal tendons poorly developed, inserted close to the apex of the stalk. Hind wings (Fig. 6) with veins RA, MP, CuA well sclerotized, whereas veins SC, CuA2 and AA scarcely sclerotized. Vein SC connected to RA beyond half its length, radial cell darkly pigmented, well developed, subtriangular; RP-MP2 long, reaching r4; AA unbranched, connected to CuA3+4 less than one-half distance from origin of CuA; CuA2 attached to CuA; cubital anal cell closed, elongate. Elytra with surface densely, irregularly punctate, punctures somewhat coarser than on pronotum; elytra slightly wider than pronotum; humeral calli rounded; greatest width near apical third of elytra, EW/HW 1.10−1.36; two weak elytral sulci present; epipleura subvertical, basally broad, gradually narrowed apically. Basal inner surface of elytra with single binding patch (Figs.13−16) narrowed at apex, with stump-shaped spicules occupying anterior middle part, with sharktooth-shaped spicules, sometimes bidentate, on basal, apical and external borders; surface near basal angle covered with thin, sparse microspicules, sometimes bidentate. Legs with metatibiae longer and slenderer than pro- and mesotibiae, apical margins of meso-and metatibiae each with short tibial spur. Tarsomere 1 of prothoracic legs subrectangular, almost equal in length or slightly longer than tarsomeres 2+3 together; tarsomere 1 of metathoracic legs slender, longer than tarsomeres 2+3 together; tarsal claws bifid. Pro- and mesothoracic legs with ventral adhesive patch covering more than half of protarsus, and approximately one-third of mesotarsus.
Genitalia. Median lobe (Figs. 11, 12 and 17) evenly curved in lateral view, constricted at about the basal fourth, anteriorly slender, tapering slightly toward apex, scarcely deflexed, apically with acute projection; orificial plate elongate, covering approximately half total length of the median lobe, apically acute, separated from apex by less than one-fourth length of the orifice plate; ostium wide, with pair of well developed triangular lobes attached to side. Internal sac (Fig. 18) with four sclerotized plates.
Female. Specimens examined similar in color and sculpturing to the males. Antenomere 3 longer than 2, together 1/2 to 3/4 length of antennomere 4. Pronotum wider than in males. Legs without ventral adhesive patches; tarsomere 1 of prothoracic legs slenderer than in males.
Genitalia (Fig. 19). Sternite 8 weakly sclerotized; apodeme (tignum) slender, wider posteriorly. Vaginal palpi, slender; apex with 10 setae. Vagina + bursa copulatrix large, undivided, with sclerotized area in the posterior part. Spermathecal duct uncoiled, distal part connecting directly to the receptacle. Receptacle of spermatheca subcylindrical, not noticeably separated from pump; pump curved, with pointed appendage at apex.
Measurements (33 and 3ƤƤ) Body length 4.55−5.21 mm (4.98+0.28), eL 0.75−0,82 mm (0.76+0.05), OD 0.58−0.66 (0.61+0.04), GL 0.09−0.13 (0.10+0.02), AD 0.42−0.46 (0.42+0.02), PL 1.28−1.51 mm (139+0.05), PW 1.55−1.81 mm (1.66+0.08), EL 4.29−4.95 mm (4.75+0.29), EW 2.64−2.93 mm (2.79+0.09), AD/OD 0.63−0.79 (0.66+0.16), GL/eL 0,11−0,16 (0.13+0.02), PW/PL 1.14−1.22(1.18+0.07), EW/HW 1.10−1.36 (1.26+0.09).
Intraspecific variation. This is a relatively uniform species, the main variability being associated with the basic pattern of the elytral vittae. Sometimes, the marking on the humeral callus continues externally of the yellow vittae, or it is interrupted and looks like two or three isolated spots. In some specimens the yellow vittae fade to yellowish brown, or the marginal vittae are absent, or they may be partly or entirely confluent at the apex and medial area. The head varies from parrot green to yellowish brown. The labrum and mouthparts vary from chestnut to dark brown. The antennae (except the basal antennomere) are unicolorous, but varying from cinnamon to dark brown. The scutellum varies from yellowish to amber colored. The femora and tibiae are frequently lime green. In some specimens, the prosternal surface varies from parrot green to yellowish brown, and the meso- and metasternum and abdomen may be green to yellowish brown.
Etymology. Collicola, meaning that lives in the hills, refers to the environment where this species has been found.
Biological notes. This species was collected on pumpkin and maize, two of the main hosts of Diabroticina throughout their distribution. Field-collected adults survived in a rearing chamber at 25+1 ºC, 14:10 (L:D) h photoperiod, in 1.5-liter cages for up to 4 weeks, during which period mating was observed, and about 80 eggs were obtained. However, no eggs hatched when incubated at 25+1 ºC in Petri dishes lined with moist tissue paper, suggesting this species has an egg diapause, a common trait of the Diabrotica in the D.virgifera group (Krysan 1982).
Geographic range. The specimens described herein were collected in the vicinity of Balcozna (27º53’ 30’’ S; 65º44’ 04’’ W), Province of Catamarca, at an altitude of 1300 m, and this is the only area where the authors have found this species so far.
Type material. Holotype: male, ARGENTINA: Catamarca: Balcozna, 14-II, 2002, on Cucurbita maxima Duchense (Cucurbitaceae), Cabrera Walsh col. Paratypes: 2 males and 3 females, with the same locality, date and collector as the holotype.
description: Published as part of Cabrera, Nora & Walsh, Guillermo Cabrera, 2010, Diabrotica collicola (Coleoptera: Chrysomelidae), a new species of leaf beetle from Argentina and key to species of the Diabrotica virgifera group and relatives, pp. 45-55 in Zootaxa 2683 on pages 46-52, DOI: 10.5281/zenodo.199370