Acrapex unicolora ( Hampson, 1910 )

Bruno Le Ru, Claire Capdevielle-Dulac, Boaz K. Musyoka, Beatrice Pallangyo, Mohamedi Njaku & Onésime Mubenga, 2017, Phylogenetic analysis and systematics of the Acrapex unicolora Hampson species complex (Lepidoptera, Noctuidae, Noctuinae, Apameini), with the description of Fve new species from the Afrotropics, European Journal of Taxonomy 270, pp. 1-36 : 26-28

Acrapex unicolora ( Hampson, 1910)

Figs 2H, P , 3H , 8G–J , 9B

Calamistis unicolora Hampson, 1910: 279 , pl. 143, fg. 12.

Acrapex brunneosa Bethune-Baker, 1911: 517 .

Busseola hemiphlebia Hampson, 1914: 161 .

Busseola fuscantis Hampson, 1918: 153 .

Acrapex simplex Janse, 1939: 359 .

Acrapex quadrata Berio, 1973: 150 , fg. 35.

Acrapex brunneosa – Poole 1989: 19 (catalogue).

Busseola fuscantis – Poole 1989: 181 (catalogue).

Acrapex hemiphlebia – Poole 1989: 20 (recombination, catalogue).

Acrapex quadrata – Poole 1989: 20 (catalogue).

Acrapex simplex – Poole 1989: 21 (catalogue).

Acrapex unicolora – Poole 1989: 21 (recombination, catalogue).

Diagnosis

Male easily separated from males of other species of the group by the pointed apex of the uncus, the ridge-like, roundly pointed expansion of the coastal margin and by the aedeagus having no vesica ( Fig. 2H, P ); female easily separated from females of other species of the group by the ductus bursae, which are widening and sclerotised on the ostial side, and by the narrow, band-like, slightly sclerotised antrum ( Fig. 3H ).

Material examined

Holotype

DEMOCRATIC REPUBLIC OF THE CONGO: ♂, Upper Congo, 1907, A.F.R. Wollaston leg. (BMNH 1907-269, Agrotidae genitalia slide 1458).

Other material

ANGOLA: 2 ♂♂, N’Dalla Tando, N Angola, 2700 ft, 26 Nov. 1908, Dr W.J. Ansorge leg. (BMNH, Noctuidae genitalia slide 2480).

DEMOCRATIC REPUBLIC OF THE CONGO: ♂, holotype of A. quadrata, Sankuru, Dimbelenge , 25 Nov. 1950, Dr M. Fontaine leg. (MRAC, adult; MCSN, genitalia, Berio, E prep N.3753).

MALAWI: 1 ♀, Mt Mlanje, Nyasaland, 30 Jun. 1913, S.A. Neave leg. (BMNH 1914-171, Agrotidae genitalia slide No 1345); 5 ♂♂, Mt Mlanje, Nyasaland, 26 Mar. 1913, S.A. Neave leg. (BMNH 1914- 171); 1 ♂, Luchenya River, Mlanje, Nyasaland, 26 Mar. 1913, S.A. Neave leg. (BMNH 1914-171).

NIGERIA: ♂, holotype of A. hemiphlebia, Kateregi , 12 Sep. 1910, Scott Macfe leg. (BMNH, 1911-269, Agrotidae genitalia slide No 1460).

TANZANIA: 2 ♀♀, Iringa Region, Kifanya, 09°33.443' S, 35°06.246' E, 1675 m a.s.l., 22 Mar. 2007, ex larva (in stem of Andropogon gayanus Kunth ), B. Le Ru leg. (MNHN, gen. prep. LERU Bruno/ G365-G366); 2 ♂♂, Iringa Region, Ngongwa, 09°29.665' S, 35°03.137' E, 1662 m a.s.l., 3 Mar. 2008, ex larva (in stem of Andropogon gayanus Kunth ), B. Le Ru leg. (MNHN, gen. prep. LERU Bruno/ G364-G474).

REPUBLIC OF THE CONGO: 1 ♂, Kouilou Department, Lac Nanga, 04°31.005' S, 12°04.172' E, 35 m a.s.l., 17 Apr. 2013, ex light trap, B. Le Ru leg. (MNHN, gen. prep. LERU Bruno/G538); 2 ♂♂, 2 ♀♀, Bouenza Department, Kalakundu, 04°22.145' S, 13°40.516' E, 325 m a.s.l., 7 Apr. 2013, ex light trap, B. Le Ru leg. (MNHN, male gen. prep. LERU Bruno/G577, female gen. prep. LERU Bruno/G576).

ZAMBIA: 2 ♂♂, 2 ♀♀, Luapula Province, Ngwenya, 12°58.538' S, 28°27.319' E, 1243 m a.s.l., 21 Mar. 2012, ex light trap, B. Le Ru leg. (MNHN, male gen. prep. LERU Bruno/G174, female gen. prep. LERU Bruno/G150); 1 ♀, North-Western Province, Keundwe, 13°06.596' S, 25°21.421' E, 1225 m a.s.l., 19 Mar. 2012, ex light trap, B. Le Ru leg. (MNHN, gen. prep. LERU Bruno/G158); 1 ♂, 1 ♀, Central Province, Khaembe, 14°33.107' S, 28°19.301' E, 1191 m a.s.l., 15 Mar. 2012, ex light trap, B. Le Ru leg. (MNHN, male gen. prep. LERU Bruno/G170, female gen. prep. LERU Bruno/G171).

ZIMBABWE: 1 ♂, Bulawayo Dist., 16 Jan. 1918, ex light trap, A.J.T. Janse leg. (PM, gen. prep. 3370).

Redescription ( Fig. 8G–J )

The sexes look similar; however, the general shape of the female fore wing is more elongated at the apex than in the male; antennae fuscous, fliform in female and slightly ciliate in male; fagellum fuscous, adorned with grey scales, palpus fuscous, suffused with grey scales, eyes fuscous brown. Head and base of thorax brown, thorax dark ochreous; legs brown, suffused with grey scales, ringed with grey; abdomen fuscous, suffused with grey scales.

FORE WING. Ground colour dark ochreous, suffused with fuscous and black scales, more heavily along veins, termen and costal area; reniform indicated by few white scales, surrounded by some brown scales; row of black elongated spots on veins in front of reniform; longitudinal brown median fascia along lower external margin of cell, ending obliquely at apex; veins below cell adorned with fuscous brown and white scales; row of black elongated spots between veins on margin; fringe fuscous, slightly suffused with brown. Underside of fore wing with ground colour grey, suffused with fuscous scales, more heavily on costa and close to termen.

HIND WING. Ground colour white in female, white ochreous in male, heavily suffused with fuscous scales in male; veins heavily irrorated, with fuscous scales, costa and apex more heavily suffused with fuscous scales; fringe grey, suffused with fuscous. Underside of hind wing grey, suffused with fuscous scales, but much more heavily on costa and apex; veins slightly irrorated, with fuscous scales.

WINGSPAN. 20–23 mm (8 ♂♂); 22–28 mm (7 ♀♀).

LARVAL L5 INSTAR ( Fig. 9B ). Length 20–25 mm, width 2.5 mm; head smooth, dark brown, prothoracic shield brown; body with ground colour pink, pinacula and caudal plate dark brown. Young larvae very similar to mature ones.

MALE GENITALIA ( Fig. 2H, P ). Uncus long, widening in distal third, tapering in pointed apex, tufted with long hairs on upper side. Tegumen with medium-sized rounded penniculi, vinculum pointed, with medium-sized triangular saccus, valves short and broad, cucullus rounded and tufted, with mediumsized hairs, coastal margin slightly broadened on inner side and produced into ridge-like expansion, roundly pointed and slightly curved inwardly; large juxta, plate-like, base slightly fattened, without sclerotization, with long and widening neck, slightly bilobate at apex, ending on each side with rounded expansion; aedeagus short, slightly curved.

FEMALE GENITALIA ( Fig. 3H ). Corpus bursae elongated, ovoid, without signa; ductus bursae about onethird length of corpus bursae, not sclerotised on bursa side, widening and sclerotised on ostial side. Antrum narrow, band-like, slightly sclerotised. Ovipositor lobes short (2 times as long as wide), with bluntly pointed apex, dorsal surface bearing numerous short and stout setae.

Bionomics

Acrapex unicolora is a markedly hygrophilous species of banks of streams, rivers and marshes. Larvae were collected in Tanzania from A. gayanus , Chrysopogon zizanoides (L.) Roberty, Cymbopogon schoenanthus subsp. proximus (Hochst. ex A.Rich.) Maire & Weller , Cymbopogon pospischilii (K. Schum.) C.E.Hubb. , Hyparrhenia diplandra (Hack.) Stapf and S. sphacelata (Schumach.) Moss ( Table 3 ). Larvae were collected at the bottom of young stems and were always solitary. Typically, plants exhibiting signs of infestation by A. unicolora larvae have a curled, brown central leaf. No pupae were found in stems and therefore borers probably pupate in the soil near exit holes.

Distribution

Angola, the Democratic Republic of the Congo, Malawi, Nigeria, the Republic of the Congo, Tanzania, Zambia and Zimbabwe. Known from many localities from sea level to 2147 m a.s.l. Moths were found in a mosaic of lowland rain forest and secondary grassland (Mosaic #11A), a mosaic of Zambezian dry evergreen forest and wetter miombo woodland (Mosaic #21), wetter Zambezian miombo woodland (Mosaic no 25) and undifferentiated montane vegetation (Mosaic #19) ( White 1983) ( Fig. 4 ), belonging to the Congolian and to the Zambezian bioregion, respectively ( Linder et al. 2012) ( Fig. 5 ).

Remarks

It is worth highlighting that the records of Acrapex hemiphlebia by Janse (1939) correspond to specimens from a different species that is not yet described and related to Acrapex albivena Hampson, 1910 .

Phylogenetic and molecular species delimitation analyses

Maximum likelihood analyses performed with IQ-TREE yielded a well-supported topology (49 of the 70 nodes supported by BV> 70%; see Fig. 10 ), especially when considering interspecifc relationships (17 of the corresponding 18 nodes supported by BV> 70%). The only representative of A. mediopuncta (formerly P. mediopuncta ) is recovered in a derived position among other members of the genus Acrapex . Members of the A. albivena species group are recovered as sister to the unicolora group ( A. albivena , A. salmona , A. sporobola , A. syscia and A. yakoba ), with a high support (BV of 96%), while the only representative of the stygiata species group ( A. stygiata ) is found as sister to both the albivena and unicolora group (BV of 100%).

Results of the PTP molecular species delimitation are congruent with the results of the morphological study. Interestingly, PTP analyses highlight the existence of a potential new species refered to as Acrapex sp. SECOG7537 ( Fig. 10 ). This specimen corresponds to a unique larva collected in the Republic of the Congo on Pennisetum unisetum (Nees) Benth.

Figures

Fig. 2. Male genitalia of species of Acrapex. – A, I. A. cuprescens (Hampson, 1910). – B, J. A. kafula le Ru sp. nov. – C, K. A. kavumba le Ru sp. nov. – D, L. A. kiakouama le Ru sp. nov. – E, M. A. malagasy Viette, 1967. – F, N. A. mediopuncta (Bowden, 1956). – G, O. A. parvaclara Berio, 1973. – H, P. A. unicolora (Hampson, 1910). Scale bars = 0.5 mm.

Fig. 3. Female genitalia of species of Acrapex. A. A. cuprescens (Hampson, 1910). B. A. kafula le Ru sp. nov. C. A. kiakouama le Ru sp. nov. D. A. mediopuncta (Bowden, 1956). E. A. miscantha le Ru sp. nov. F. A. parvaclara Berio, 1973. G. A. simillima le Ru sp. nov. H. A. unicolora (Hampson, 1910). Scale bars = 1 mm.

Fig. 4. Distribution map of sampled specimens of Acrapex Hampson, 1891.

Fig. 5. Major bioregions, modifed after Linder et al. (2012).

Fig. 8. Adults of species of Acrapex. – A – D. A. parvaclara Berio, 1973. A. ♂, upper side. B. ♂, under side. C. ♀, upper side. D. ♀, under side. – E – F. A. simillima le Ru sp. nov. E. ♀, upper side. F. ♀, under side. – G – J. A. unicolora (Hampson, 1910). G. ♂, upper side. H. ♂, under side. I. ♀, upper side. J. ♀, under side. Scale bars = 10 mm.

Fig. 9. Last instar larva. A. Acrapex simillima le Ru sp. nov. B. A. unicolora (Hampson, 1910). Scale bar = 10 mm.

Fig. 10. Maximum likelihood tree resulting from the analysis of the combined dataset carried out with IQ-TREE. Support of major nodes is displayed as BV (only BV> 50 % are shown). On the right, corresponding adult habitus (for species belonging to the A. unicolora species group) are also included for illustrative purposes. Results of PTP analyses are fgured using coloured branches and vertical side bars. Putative molecular species clusters are indicated using transitions between blue-coloured branches to red-coloured branches (vertical bars are also informative).