Heterochele signiferoides Viswajyothi and Clark, 2021

Viswajyothi, Keezhpattillam & Clark, Shawn M., 2021, A new genus and two new species of Galerucinae from Costa Rica (Coleoptera: Chrysomelidae), Journal of Natural History 54 (47 - 48), pp. 3103-3119 : 3116-3117

Heterochele signiferoides Viswajyothi and Clark , sp. nov.

( Figures 4–7 )

Diagnosis

See the preceding diagnosis of H. actias for characteristics that distinguish this species from the only known congener. See also the Comments section below.

Description of holotype (male)

Characteristics very similar to H. actias but differing in details. Body length 3.9 mm; body width 1.5 mm; elytra 2.7 mm long. Head completely black ( Figure 5 (b)). Antennomeres 1–4 pale, with brownish black areas dorsally; antennomeres 5–8 black; antennomeres 9–10 yellow; antennomere 11 yellow, with apex black.Pro- and mesothoraces yellow;metathorax black.Basal half of elytra mostly black, with black area extending to suture but not lateral margins, with pale transversely oval marking on each elytron in middle of black area; distal half of elytra mostly pale yellow, with large, transverse, black marking near distal fifth, narrowly attaining suture, not attaining lateral margin; epipleuron, as well as lateral and apical borders of elytra, pale yellow ( Figures 4 (a,b), 5(a)). Coxae, trochanters and femora pale yellow; tibiae and tarsi brownish black ( Figures 4 (b), Figures 5 (a)). Abdomen yellow, with terminal ventrite mostly black ( Figure 6 (d)).

Third antennomere shorter than second; antennomere length ratios: 1.0, 0.3, 0.2, 1.5, 1.4, 1.2, 1.2, 1.2, 1.1, 1.0, 1.3; antennomere length-to-width ratios: 3.4, 1.3, 1.0, 6.0, 5.0, 5.0, 5.0, 5.0, 4.5, 4.5, 5.5; antennomeres 4–10 slightly broader towards apex; antennomere 11 distally narrowed to acute apex ( Figures 4 (a,b)). Pronotum without depression; lateral edge with row of setae, inwardly curved towards pronotal disc. Epipleuron gradually narrowed posteriorly, disappearing before apex ( Figures 4 (b), Figures 5 (a)). Abdominal ventrites covered with long setae. Tarsal claws bifid; inner appendages slightly shorter than outer,of almost the same thickness as outer; inner appendages converging towards each other. Fifth ventrite with semicircular excavation, located posteromesally ( Figure 6 (d)).

Median lobe of aedeagus slender; length 1.2 mm; maximum width 0.2 mm. Apex asymmetrical in dorsal and ventral views ( Figure 6 (a,c)). Dorsal surface with long, broad channel along most of length; transverse depression present, delimiting channel at basal two-tenths. In lateral view, aedeagus strongly bent at basal two-tenths and basal four-tenths, gradually narrowed and evenly down-curved from basal four-tenths to distal nine-tenths, strongly upcurved in distal tenth ( Figure 6 (b)). In ventral view, apical third with two side-by-side channels ( Figure 6 (c)).

Female

Body similar in size and shape to male, 3.6 mm long, 1.6 mm wide; elytra 2.7 mm long. Third antennomere as long as second; antennomere length ratios: 1.0, 0.4, 0.4, 1.2, 1.1, 1.0, 1.1, 0.9, 0.9, 0.9, 1.1; antennomere length-to-width ratios: 3.2, 2.0, 1.8, 4.8, 4.5, 4.0, 4.2, 3.8, 3.8, 3.5, 4.5. Antennomeres 4–10 slightly less broadened towards apex, in comparison to male. Tarsal claws appendiculate. Spermatheca bent, without distinction between receptacle and pump, with greatest width 0.04 mm ( Figure 7 (a,f)); vaginal palpi split at distal third ( Figure 7 (b)); tignum 1.1 mm long ( Figure 7 (e)); last visible tergite without dorsal channel ( Figure 7 (c)); bursa copulatrix as in Figure 7 (f); last ventrite entire, with exceptionally long, brownish-black setae towards distal border, in addition to shorter setae ( Figure 7 (d)).

Variation

In the paratype, the pale area in the basal half of the elytron attains the suture and angularly extends towards the humerus. The metathorax is yellow and concolorous with the pro- and mesothoraces. The abdomen is entirely pale.

Holotype

‘ COSTA RICA, Puntarenas,\ Estación Biológica \ Las Cruces, near San Vito ,\ 18 April 2003,\ S.M. Clark & E.G. Riley’ (♂, BYUC).

Paratype

COSTA RICA: Provincia Alajuela: 20 km S Upala, 22–31 May 1991, F .D. Parker (1♀, INBio) .

Etymology

The species epithet, signiferoides , refers to the superficial similarity of this species to Diabrotica signifera Jacoby.

Comments

As noted in the Etymology section above, this species resembles D. signifera . The very short third antennomere of the male, the small body size,and the colour pattern are all similar. Very likely, H. signiferoides has sometimes been misidentified as D. signifera . However, female D. signifera have bifid tarsal claws (appendiculate in female H. signiferoides ), and male D. signifera lack the peculiar depression of the last abdominal ventrite that is present in H. signiferoides .

Figures

Figure 4. Heterochele signiferoides, holotype. (a) Dorsal view; (b) ventral view.

Figure 5. Heterochele signiferoides, holotype. (a) Lateral view; (b) anterior view.

Figure 6. Heterochele signiferoides, holotype. (a) Median lobe of aedeagus, dorsal view; (b) median lobe of aedeagus, lateral view; (c) median lobe of aedeagus, distal portion, ventral view; (d) male abdominal ventrites.

Figure 7. Heterochele signiferoides, female paratype. (a) Spermatheca; (b) vaginal palpi; (c) last visible tergite; (d) last ventrite; (e) tignum; (f) bursa copulatrix, with spermatheca attached.