Micronecta (Micronecta) acuminata, Tran, 2021

Ha, Tuyet Ngan & Tran, Anh Duc, 2021, Taxonomy of Micronectidae (Heteroptera: Nepomorpha) from Vietnam, with descriptions of 11 new species, European Journal of Taxonomy 756, pp. 1-82 : 38-40

Micronecta (Micronecta) acuminata sp. nov.

urn:lsid:zoobank.org:act:525BBA05-C47E-447A-A643-64535995CF4F

Figs 5I , 11

Diagnosis

Body length 1.3–1.5. Pronotum: longer than median head length. Hemelytron punctate, yellowish with indistinct yellowish brown markings.

Males: fore femur with two spines on middle third, one pair of spines in distal third dorsally; fore tibia without spine; palar claw distally widened, apical margin rounded ( Fig. 11A ). Median lobe of sternite VII short, with angular apex and one or two long setae ( Fig. 11C ). Free lobe sub-rectangular, mesial angle rounded, lateral angle square, with ca 12 long setae, posterior margin slightly sinuate ( Fig. 11D ). Left paramere: shaft broad, flat, strongly constricted before an acute apex; basal lobe longer than wide, sub-rectangular, distal margin curved ( Fig. 11F ). Right paramere: shaft parallel sided, distal fourth strongly curved (by nearly 45°) and slightly thickened before rounded apex; pars stridens processus with ca 20 ridges ( Fig. 11E ).

Etymology

The word ‘ acuminata ’ refers to the acuminate apex of the left paramere.

Material examined

Holotype

VIETNAM • ♂, Dong Nai Prov., Vinh Cuu, Ma Da stream, near Rang Rang Forest ranger station (near bridge); 13 Apr. 2010; T.D. Pham leg.; PTD1006 ; ZVNU.

Paratypes

VIETNAM – Dong Nai Prov. • 2 ♂♂, 2 ♀♀; same locality data as holotype; ZVNU • 1 ♂, 3 ♀♀; Vinh Cuu, Ma Da stream, near Rang Rang Forest station (near bridge); 9 Apr. 2009; A.D. Tran leg.; TAD0902 ; ZVNU • 3 ♂♂, 3 ♀♀; Vinh Cuu, Ma Da, Suoi Sai (Sai stream), near bridge; 11 Apr. 2009; A.D. Tran leg.; TAD0907 ; ZVNU • 1 ♂; Vinh Cuu, Vinh An, Rang stream; 20 Apr. 2009; A.D. Tran leg.; TAD0913 ; ZVNU • 2 ♀♀; Cat Tien N.P. , Sa Mach stream , near Sa Mach Forest ranger station; 20 Apr. 2009; A.D. Tran leg.; TAD0914 ; ZVNU .

Description

COLOUR ( Fig. 5I ). Dorsum brownish yellow to brown. Frons and vertex pale yellowish, eyes dark brown. Pronotum light yellowish brown, disk unmarked. Clavus with a hyaline band covered by microscopic red dots along anterior margin. Corium with scattered small brownish marks. Membrane generally transculent. Venter of thorax and abdomen, and legs light yellow.

Structural characteristics

MACROPTEROUS MALES. Body length 1.3–1.47 (holotype: 1.44), width 0.72–0.82 (holotype: 0.81). Head width 0.59–0.63 (holotype: 0.61). Head slightly wider than pronotum. Pronotum short, about four times as wide as long (0.59: 0.15). Synthlipsis ca 1.5 times as wide as posterior width of an eye (0.28: 0.18). Lengths of leg segments: fore leg: femur 0.2, tibia 0.14, pala 0.16; middle leg: femur 0.47, tibia 0.19, tarsus 0.24, claw 0.12; hind leg: femur 0.4, tibia 0.29, tarsus I 0.27, tarsus II 0.14, claw 0.03.

Prestrigilar flap on segment V with prolonged apex ( Fig. 11B ). Strigil present. Median lobe of sternite VII, free lobe, and parameres as in diagnosis.

MACROPTEROUS FEMALES. Body length 1.37–1.53, width 0.76–0.81. Head width 0.59–0.63. Head slightly wider than pronotum. Pronotum short, nearly four times as wide as long (0.58: 0.16). Synthlipsis 1.5 times as wide as posterior width of an eye (0.30: 0.18). Lengths of leg segments: fore leg: femur 0.21, tibiotarsus 0.2; middle leg: femur 0.5, tibia 0.2, tarsus 0.27, claw 0.14; hind leg: femur 0.41, tibia 0.27, tarsus I 0.27, tarsus II 0.14, claw 0.03.

Distribution

Vietnam: Dong Nai.

Remarks

Among species of Micronecta occurring in Vietnam, four species, M. anatolica , M. arcuata sp. nov., M. fulvopicta sp. nov., and M. acuminata sp. nov., may be more closely related to each other, based on the general shapes of the prestrigilar flap (see Figs 9A, G , 10B , 11B ), the median lobe of sternite VII (see Figs 9B, H , 10C , 11C ), the free lobe (which is sub-rectangular, see Figs 9C, I , 10D , 11D ), and the general form of the left and right parameres. In particular, the shaft of their right paramere is mostly parallel sided and straight at the proximal part, strongly bent at the distal fourth, and the apical part is simple, not distinctly broadened. The shaft of their right parameres is broad and flat, with the lateral margin sinuate and without any projection; and the basal lobe of the right paramere is very large and broad.

All four species mentioned above, however, can be reliably separated from each other by the following characteristics.

In M. anatolica , the basal lobe of the left paramere is elongate and subovate, while that of other three species is broader and sub-rectangular. The base of the right paramere of M. anatolica has a distinct hump on the mesial margin near the beginning of the shaft, whereas this hump is less distinct in M. arcuata sp. nov., and absent in both M. fulvopicta sp. nov. and M. acuminata sp. nov. The apical part of the right paramere of M. anatolica is similar to that of M. fulvopicta sp. nov., which narrows towards the apex, while that of M. arcuata sp. nov. is more similar to that of M. acuminata sp. nov., which is slightly thickened before the apex.

Micronecta arcuata sp. nov. is distinct from the other three species in the form of the shaft of the left paramere, which is distinctly curved laterad. That of M. acuminata sp. nov. is also different, with an acuminate apical part. The form of the left paramere of M. acuminata sp. nov. is similar to that of M. acuta (Lundblad, 1933) ; however, the latter species lacks a strigil and its right paramere is clearly different (see Lundblad 1933b: fig. 37e).

Besides structural charateristics, Micronecta fulvopicta sp. nov. has a distinct colour pattern on the dorsum, with strongly defined dark marks on the head, pronotum, and hemelytra ( Fig. 5H ). Its colour pattern is somewhat similar to that of M. vietnamica sp. nov., but the dark marks on the hemelytra of M. fulvopicta sp. nov. are broader than in the latter species. The structure of the parameres will also separate the two species (see also Remarks under M. vietnamica sp. nov.).

Figures

Fig. 5. Habitus photos of species of Micronecta Kirkaldy, 1897, ♂♂. A. M. grisea (Fieber, 1844) (ZRC). B. M. guttatostriata Lundblad, 1933 (ZVNU). C. M. drepani Nieser, 2000 (ZVNU). D. M. erythra Nieser, Chen & Yang, 2005, right hemelytron (ZVNU). E. M. cultellata sp. nov., holotype (ZVNU). F. M. anatolica Lindberg, 1922 (ZVNU). G. M. arcuata sp. nov., holotype (ZVNU). H. M. fulvopicta sp. nov., holotype (ZVNU). I. M. acuminata sp. nov., holotype (ZVNU), right hemelytron and genitalia dissected. J–L. M. vietnamica sp. nov., J = holotype (ZVNU). All to the same scale.

Fig. 11. Morphological features of Micronecta acuminata sp. nov., ♂, paratype (ZVNU). A. Fore leg. B. Prestrigilar flap. C. Median lobe of sternite VII. D. Free lobe. E. Right paramere. F. Left paramere.

Fig. 9. Morphological features of species of Micronecta Kirkaldy, 1897, ♂♂. A–E. M. anatolica Lindberg, 1922 (ZVNU). F–K. M. arcuata sp. nov., paratype (ZVNU). A, G = prestrigilar flap; B, H = median lobe of sternite VII; C, I = free lobe; D, J = right paramere; E, K = left paramere; F = fore leg.

Fig. 10. Morphological features of Micronecta fulvopicta sp. nov., ♂, paratype (ZVNU). A. Fore leg. B. Prestrigilar flap. C. Median lobe of sternite VII. D. Free lobe. E. Right paramere. F. Left paramere.