Acanthagrion apicale Selys, 1876

DeMarmels, Jurg, 1992, Dragonflies (Odonata) From The Sierras Of Tapirapeco And Unturan, In The Extreme South Of Venezuela, Acta Biologica Venezuelica 14 (1), pp. 57-78 : 62

Acanthagrion apicale Selys, 1876

Figures 25-29 (larva)

Material. 3♂ 1♀ (reared, with exuviae), Base Camp.

Larva. Occipital lobes bulging, but not angled, beset with spines; occipital border deeply excavated. Labium ( Fig. 25 ) reaching to beyond first pair of coxae. Antennae seven-jointed ( Fig. 26 ), Hind border of pronotum with lateral angles pro· duced, but not pointed. Wing sheaths reaching to base of segment 5 ( Fig. 27 ). Tibiae and tarsi with scattered soft hairs. Adomen dark with a pale longitudinal dorsomedian line; posterior angles of segments 4-8 strongly marked off and beset with spinules; ovipositor slightly surpassing end of segment 10, valves beset with about four larges spines and a few very smaIl ones, in a single row ( Fig. 28 ). Lateral and central caudal gills of same length, sharply pointed ( Fig. 29 ).

Measurements. Total length (excl. gills) 10.5; caudal gills 7.0; hind femur 2.5.

Remarks. The larva of A. apicale comes closest to that of A. luteum Racenis described by Geijskes (1941) sub " A. ascendens Calvert ", but specimens were not compared directly. The larva was found in a small stagnant pool in close vicinity of a sandy creek, in the forest. The pool was filled with leaf litter, had a sandy ground and clear wa· ler.. A larva of Fylgia amazonica lychnitina De. Marmels was found in the same pool (see below).

Figures

Plate IV: Figures 25-29. Acanthagrion apicale. female ultimate instar exuviae. (25) labium, dorsal view; (26) left antenna; (27) exuviae (left lateral gill lost). dorsal view; (28) tip of abdomen with gonapophyses, ventral view; (29) median gill (at left) and right lateral gill, right lateral view. Figure 30. Acanthngrion chacoense, female mesostigmal laminae and m sepisternal fossae, dorsal view.