Azotoctla punctata, Cardona-Duque, Juliana & Franz, Nico M., 2012

Cardona-Duque, Juliana & Franz, Nico M., 2012, Description and phylogeny of a new Neotropical genus of Acalyptini (Coleoptera: Curculionidae: Curculioninae) associated with the staminodes of Cyclanthaceae, Zoological Journal of the Linnean Society 166 (3), pp. 559-623 : 577-581

AZOTOCTLA PUNCTATA CARDONA- DUQUE & FRANZ SP. NOV. ( FIGS 11 , 12 )

Diagnosis: Yellowish to light reddish brown; body distinctly punctulate; mesocoxa distinctly pilose; humeri indistinct; tergites 1 and 2 divided in three sclerites; basal portion of basal plate of male sternum 9 semicircular, truncate, T-shaped; tegminal basal piece O-shaped; and female coxites basally strongly widened, sinuate. Azotoctla punctata shares with A. nana an abdominal tergite 1 that is divided into three sclerites; however, the latter species also has tergite 2 divided into three sclerites. Azotoctla punctata may be readily separated from its congeners by the punctulate sculpture; by the subtruncate and weakly sclerotized aedeagal apex; and by the incompletely sclerotized aedeagal pedon, which shows two subapical gaps.

Description: Male ( Fig. 11A ): small, length 1.7– 2.0 mm, width 0.9–1.2 mm, oval l/w = 1.6–1.9 (N = 2). Colour yellowish to light reddish brown; vestiture long, golden, most conspicuous on pronotum, elytra, metaventrite, femora, tibiae, and tarsi; sculpture punctulate. Rostrum short, 0.4–0.5 mm; r/p = 1.1–1.2, reddish brown; in dorsal view pilose and punctulate between antennal insertion and eyes; antennal insertion near apical third, scrobe subrectate, basally deep. Antennal club oval, similar in colour to funicle, I similar in length to II + III, II and III similar in length. Head reddish brown; ventrally slightly pilose, dorsally pilose. Eyes distant from pronotal margin by nearly three quarters of their diameter. Pronotum l/w = 0.6–0.7, reddish brown, in dorsal view subcircular, anterior margin 0.7¥ width of posterior margin, lateral margins rounded, greatest width near anterior third, vestiture long; posterior margin slightly bisinuate; in lateral view conical. Mesepimeron ventrally slightly projected. Prosternum subglabrous (few setae posteriad); procoxal cavities inserted at middle; prosternal process narrowly rounded; metaventrite pilose, distinctly punctulate, centrally concave; metacoxal cavities separated by distance similar to 1.5¥ mesocoxal diameter. Prothoracic legs light reddish brown; procoxa slightly pilose; profemur f/p = 1.1–1.2; protibia t/f = 0.8–0.9. Mesocoxa distinctly pilose; meso- and metatibiae anteroventrally pubescent along apical third. Scutellum short, pentagonal, reddish brown. Elytra elongate, l/w = 1.2–1.3, anterior margins rounded; humeri indistinct; lateral margins subparallel throughout anterior half, thereafter evenly rounded and converging; in lateral view dorsally flattened throughout anterior half, thereafter slightly convex; striae subequal to intervals; strial punctures large, dark brown, suboval; intervals dark yellowish brown, vestiture short. Abdomen nearly 2.5¥ length of lateral margin of metaventrite, punctulate, vestiture denser and longer than on metaventrite; sternites 1 and 2 centrally nearly flat; 1 slightly longer than 2; 2 shorter than 3 + 4; 5 slightly longer than 2. Tergites 1–2 divided in three sclerites; tergites 3–7 complete; tergites 5 and 6 lateroposteriorly with paired strigate-sculptured regions. Tergite 8 completely covered by elytra; wider than long, posterior margin straight, plicate, laterally rounded. Distal angle of sternum 8 with three to four large setae. Sternum 9 ( Fig. 11B ) with basal portion of basal plate semicircular, truncate, T-shaped; apical portion mesally emarginate; apodeme two times width of aedeagal apodemes, slightly widened at its apical end. Tegminal plate ( Fig. 11D ) developed, basal piece O-shaped, not completely closed; tegminal apodeme subrectate, nearly one third of length of aedeagus. Aedeagus ( Fig. 11C ) short, l/w = 2.1–2.3 (N = 2); longitudinal plates elongate, centrally joined; basal margin diffuse, narrowly rounded, apex subrectate, simple, apical margin weakly sclerotized mesad; tectum membranous, tissue spinose, sparse; pedon with paired, elongate, subapical gaps; endophallus with a sclerotized patch on basal half; in lateral view slender, ventral margin deflexed; aedeagal apodemes in lateral view sinuate throughout.

Female: length 1.8–2.0 mm, width 0.9–1.0 mm, l/w = 1.9–2.0 (N = 2). Rostrum 0.5 mm; r/p = 1.3–1.4, reddish brown, dorsally arcuate, ventrally subrectate; antennal insertion near apical third (slightly more basal than in male); scrobe projected to apex. Head dark reddish brown, setae converging towards a midline. Eyes distant from anterior margin of pronotum by nearly one third of their diameter. Pronotum l/w = 0.6–0.8, anterior margin 0.8¥ width of posterior margin; in lateral view subrectangular. Prosternum laterally scarcely pilose. Prothoracic legs f/p = 1.1–1.3; t/f = 0.9. Elytra light yellowish to reddish brown, l/w = 1.4–1.5. Abdominal sternites 1 and 2 fused (suture evident laterad), nearly flat; abdominal pilosity longer than in metaventrite, sternite 5 slightly shorter than 3 + 4. Tergites 1–6 incomplete; lateroposterior part of tergites 4–6 with paired strigatesculptured regions, tergite 7 simple. Tergite 8 semilunar; posterior margin simple, densely setose; anterior margin emarginate; lateral margins simple. Sternum 8 ( Fig. 12A ) with lamina mesally emarginate (appearing complete, subtriangular); furcal arms margin subtruncate. Coxites ( Fig. 12B ) slightly shorter than apodeme of sternite 8, basally strongly widened, sinuate, styli apically with two long setae. Spermatheca ( Fig. 12C ) with corpus slightly swollen; apex of cornu narrowly rounded; ramus and collum widely separated; ramus not protruded; collum slightly protruded, rugulose.

Variation: No significant variation is apparent amongst the examined specimens.

Type material: Holotype male (dissected) ‘ Costa Rica, Heredia, La Selva , 40 m, on Asplundia uncinata, VI. 18.2001, N. Franz’ ( ASUT) . Paratypes, same label information as holotype ( ASUT: 17 males, 28 females; eight dissected); ‘ Costa Rica, Heredia, La Selva, 40 m, on Asplundia uncinata, VIII. 3.1997, N. Franz’ ( ASUT: one male; dissected); ‘ Costa Rica, Heredia, La Selva, 40 m, on Asplundia uncinata, VII. 3.1997, N. Franz’ ( ASUT: two males, one female; three dissected); ‘ Costa Rica, Heredia, Guápiles , INBio farm, 10°10′ N, 83°48′ W, 250 m, on Asplundia microphylla, VI. 24.2000, R. Anderson’ ( CMNC: one male) .

Etymology: Named in reference to the distinctly punctulate body sculpture, based on the Latin feminine noun puncta, which means ‘puncture’ ( Brown, 1956).

Natural history: Azotoctla punctata is known from Costa Rica ( Fig. 35 ), where specimens were collected at La Selva Biological Station (OTS) on Asplundia uncinata Harling and Asplundia microphylla (Oerst.) Harling (see also Franz & Valente, 2005; Franz, 2007b).

Franz (1999) observed the behaviour of A. punctata on the inflorescences of A. uncinata ; therein named ‘gen. C 1 sp. C2’ and subsequently ‘Gen. 1 sp. 1’ in Franz & Valente (2005) and Franz (2006, 2007b). As these observations have not been published before, and are potentially representative (to a degree) of other congeneric species, they are provided here in some detail. Several individuals of A. punctata entered the developing inflorescences as early as one week prior to flowering. The arrival of adults continued until the late afternoon of the day before the beginning of the pistillate phase, when the spathes started to fold back and the staminodes became extended. All individuals temporarily left the inflorescence in the course of the evening. The number of individuals present on a single inflorescence varied significantly (range = 3–228 individuals; N = 15), even between inflorescences that occurred on neighbouring plants within a distance of less than 1 m from each other. No significant differences in sex ratios were noted.

The following dawn, many individuals returned to the inflorescences, together with adults pertaining to other acalyptine species (see Franz, 2007b). Apparently, oviposition occurred only during the preflowering stage, although pairs of adults were observed mating during the pistillate phase.

Prior to anthesis, in the budding stage of inflorescence development, the adults of A. punctata crawled slowly along the unextended staminodes, probing various sites with the rostrum. They often rested for long periods of time before displacing to another region of the inflorescence, thus making it difficult to follow the behaviour of the same individual continuously for several hours. All ovipositions took place into the basal regions of the staminodes (N = 12). The female drilled a shallow hole with her rostrum, which lasted 69 ± 31 s (range 38–122 s; N = 12). Then she turned 180° and laid an egg for 25 ± 8 s (range 14–42 s; N = 12). Given the shallowness of the staminodes, the egg remained partly exposed, and no covering of the oviposition site was observed.

Active males of A. punctata were seen following and mounting females to copulate. The copulation itself did not entail complex behavioural patterns – apart from characteristic recurrent movements – and lasted 56 ± 87 s (range 28–212 s; N = 18). In 91.3% of the observed cases in which the female failed to oviposit (N = 23), the male crawled away after copulating. However, in cases where the female completed oviposition (N = 12), the male remained behind her at a distance of 2–3 mm for this period, and subsequently separated and moved to different staminodes.

Conflicts between females and males were apparent in the form of chases across the staminodes that could last for several minutes. When a male attempted to mount a nonreceptive female, she typically rejected these attempts with intense vibrations of her body, thus preventing the male from copulating and resulting in his departure after 5–20 s (N = 6). In 66.7% of the cases where the female oviposited (N = 12), fights between males were observed. The attacking male pushed strongly and quickly with his rostrum against the copulating male, using a variety of angles to dislocated the latter from the top of the female. These conflicts lasted 3–15 s (N = 8). The defending male appeared to be successful in all cases, and chased the attacking male away for a distance of 2–5 cm, before returning to guard the female for the duration of the oviposition process.

As all acts of oviposition by A. punctata females were observed before the start of the pistillate phase of flowering of Asplundia uncinata , this species in effect avoided resource competition with the sympatric Staminodeus vectoris (see also Franz, 2003b). Indeed, at the time of flowering, the staminodes of some inflorescences had been so greatly damaged by the feeding and ovipositing activities of A. punctata that they failed to attract large numbers of pollinators.

Figures

Figure 11. Azotoctla punctata, male. A, habitus, lateral view; B, sternum 9; C, aedeagus, dorsal and lateral view; D, tegmen, dorsal view.

Figure 12. Azotoctla punctata, female. A, sternum 8; B, coxite, lateral view; C, spermatheca.

Figure 35. Azotoctla species distributions, I: Azotoctla angustacra, Azotoctla gomezi, Azotoctla punctata, Azotoctla tibiatra, and Azotoctla tuberquiai.