Virbia medarda Stoll, [1781]

Cock, Matthew J. W. & Laguerre, Michel, 2021, Taxonomic changes in the Neotropical Arctiinae, Arctiini (Lepidoptera, Erebidae) relating to the fauna of Trinidad and Tobago, Zootaxa 5071 (2), pp. 253-270 : 264-268

Virbia medarda Stoll, [1781]

Figs. 10–13 . BIN: BOLD:AAW7134 (doi: pending)

This species was described as Phalaena medarda from Suriname based on an undisclosed number of syntypes from Stoll’s collection ( Stoll [1781], pp. 107–108). We are not aware of any surviving type material, so Stoll’s figure of a male ( Stoll [1781], plate 345F, shown here as Fig. 10 ) is the best indication we have of this species. Hampson (1901) treated V. medarda as a widespread species occurring from Mexico to the Amazon and Peru, and included V. mentiens Walker, 1854 (♂ type NHMUK, Venezuela), V. parva Schaus, 1892 (♂ type USNM, Peru, see Watson (1971)), and three other taxa as synonyms. Rothschild (1910) treated this group as separate species, but Seitz (1919) reverted to treating them as forms. Subsequent authors have treated all species as valid ( Watson and Goodger 1986, Zaspel and Weller 2006, Vincent and Laguerre 2014). Here we do not attempt to resolve the status of these taxa, but rather to fix the identity of V. medarda .

The figure in Stoll’s plate ( Fig. 10 ) falls within the range of variation of what we consider to be a single, moderately variable, sexually dimorphic species found both in French Guiana and Trinidad ( Fig. 11 ). The limited number of male specimens from French Guiana are smaller (26 mm wingspan) than those from Trinidad (30–33 mm wingspan). Nevertheless, we compared male genitalia of specimens from both countries and found them identical ( Figs. 12 , 13 ). The extent of the yellow markings of the dorsal hindwing of males is variable ( Fig. 11 ); the ventral hindwing mirrors the dorsal hindwing; a yellow patch on the ventral forewing may extend from the base as far as the middle of the wing, but is usually reduced and may be virtually absent. The female is similar in colour and markings ( Fig. 11 ) although the dorsal forewing is darker brown, the yellow area of the ventral forewing is normally more extensive. Females are also significantly larger, typically 40–42mm wingspan. We are only aware of one species of this appearance in both Trinidad and French Guiana. Given that these samples are from both east and west of the Suriname type locality, we conclude that we are justified in treating this species as V. medarda . We only have DNA barcode sequences available from French Guiana (BIN BOLD:AAW7134), and conclude that this BIN should be treated as V. medarda . Public DNA barcodes in BOLD indicate that Central American material identified as V. medarda (BINs BOLD:ACE9527, BOLD:ABY7927, BOLD:ABZ3957, and BOLD:ABZ6726) will be found to represent different species.

This species was first reported from Trinidad when Druce (1911) described V. birchi Druce, 1911 from Caparo, Trinidad, and Colombia based on an unspecified number of specimens. Seitz (1920–1925) incorrectly referred to this species as only occurring in Colombia. Hampson (1920) referred to Druce’s female type from Caparo being in coll. Joicey (now in NHMUK). Vincent and Laguerre (2014) report a male syntype from Caparo in NHMUK labelled ‘type’ ( Fig. 10 ). This specimen is one of two females from Caparo collected by F. Birch in NHMUK, and only females are curated as this putative species in NHMUK. Druce (1911) purportedly described the male of V. birchi only, but given the stated wingspan (1¾ inch, i.e. 44.5mm) and the material in NHMUK, it seems clear that as Hampson (1920) indicated this was an error for the female, which as noted above is significantly larger than the male. Given that Druce named this species after Frederick Birch, who collected the Trinidad material, and Trinidad is listed as the first type locality by Druce (1911), and is given as the type locality by Hampson (1920), we designate the female specimen in NHMUK labelled ‘type’ as the lectotype ( Fig. 10 ).

Kaye and Lamont (1927) treated V. birchi as a synonym of V. medarda (Stoll) (TL Surinam), although subsequent authors ( Watson and Goodger 1986, Zaspel and Weller 2006, Vincent and Laguerre 2014) treated both as valid species. Based on the material examined, we are satisfied that only one species of this appearance occurs in Trinidad, and as shown above, this is V. medarda . It follows that Kaye and Lamont (1927) were correct to treat V. birchi Druce, 1911 as a female synonym of the male V. medarda Stoll, [1781] .

Material examined. FRENCH GUIANA: 2♂ Piste de Belizon, PK 27, 15.ii.1999 [ ML]. ♂ Piste de Belizon , PK 20+1, 28.vii. 2003, 120 m [ ML]. 2♂ Piste Coralie, PK 7.5, 25.vii. 2003, 50 m [ ML, dissected Gen. ML 3077 and sequenced Sample ID MILA 0060—BOLD Process ID ARCTA060-07] . TRINIDAD AND TOBAGO, TRINIDAD: Arima: ♂ 26.iii.1939 [N. Lamont] [ NMS]. Arima Blanchisseuse Road, milestone 4, MVL: ♂ 29.x.1978 (M.J.W. Cock) [ NMHUK]. Arima Blanchisseuse Road, milestone 10.5, MVL: ♂ 6.ix.1982 (M.J.W. Cock) [ UWIZM CABI.1329]. Arima Valley, Simla, MVL: ♂ 30.vii.1981 (M.J.W. Cock) [ MJWC]; 2♂ 6.viii.1982 (M.J.W. Cock) [ MJWC, genitalia exposed]; 2♂ 18.x.1982 (M.J.W. Cock) [ MJWC, dissection 1069]; ♂ 5.v.1989 (R.G. Brown and T. Cassie) [ UWIZM CABI.1328]. Balandra: ♂ viii.1971 (F.D. Bennett) [ UWIZM CABI.1330]. Caparo: 2♀ (F. Birch) [ NHMUK as V. birchi ]; ♀ xi.1905 (S.M. Klages) [ NHMUK]; 4♂ xi.1905 (S.M. Klages) [ NHMUK as V. mentiens ]; 2♂ xii.1905 (S.M. Klages) [ NHMUK as V. mentiens ]. Caura Valley, Nr. Caura, MVL: ♂ 24.ix.1978 (M.J.W. Cock) [ MJWC]. Chatham: ♂ 9.i.1985 (M. Alkins) [ UWIZM.2014.9.1317]. Curepe, MVL: ♂ ii.1969 (R.E. Cruttwell) [ UWIZM CABI.1332]; ♂ i.1970 [ UWIZM CABI.1333]; ♂ ix.1970 (F.D. Bennett) [ UWIZM CABI.1331]; ♂ i.1972 (R.E. Cruttwell) [ UWIZM CABI.1330]. Lalaja Ridge, MVL: 7♂ 3.ix.1982 (M.J.W. Cock) [ MJWC, genitalia exposed]. Lalaja South Road, 1.5 miles: ♀ 29.viii.1978 (M.J.W. Cock) [ MJWC]. Maraval: ♂ viii.1901 [ NHMUK as V. mentiens ]. Morne Bleu, Textel Installation, at light: ♂ 13.ix.1978 (M.J.W. Cock) [ UWIZM CABI.1327]; ♂ 2.iii.1981 (M.J.W. Cock) [ MJWC]. Palmiste: ♀ 27.x.1917 [N. Lamont] [ NMS]; ♂ 4.v.1921 [N. Lamont] [ NMS as V. mentiens ]; ♂ 17.i.1922 [N. Lamont] [ UWIZM.2013.13.1185]; ♂ 23.iii.1922 [N. Lamont] [ NMS]; ♂ 7.i.1927 [N. Lamont] [ NMS]; 2♂ 21.xi.1927 [N. Lamont] [ NMS as V.mentiens ]; ♂ 26.ii.1928 [N. Lamont] [ UWIZM.2013.13.1184]; ♀ 27.ii.1930 [N. Lamont] [ NMS]; ♂ 19.vi.1947 [N. Lamont] [ UWIZM.2013.13.1183]; ♂ 9.vii.1947 [N. Lamont] [ UWIZM.2013.13.1186]. Pitch Lake : ♀ 28.viii.1982 (M.J.W. Cock) [ MJWC]. Point Fortin, clearing in forest and cultivated areas: ♀ 22.iv.1917 (R.W. Farmborough) [ OUNHM]. <15 mi from Port of Spain, <1,000 ft.: ♀ xii.1913 – iv.1914 (F.W. Jackson) [ OUNHM]. San Miguel Valley : ♀ 4.ix.1982 (M.J.W. Cock) [ MJWC]. St. Augustine : 2♂ 21.x.1952 (R.G. Fennah) [ UWIZM.2014.9.222–223 (ICTA15262–15263)]. V[erdant] Vale: ♂ 19.iv.1919 [N. Lamont] [ NMS]; ♂ 22.iv.1922 [N. Lamont] [ NMS]. Verdant Vale [almost illegible]: ♂ 19.iv.1919 (N. Lamont) [ OUNHM]. Trinidad: ♀ (Loxley) [ NHMUK as V. birchi ]; ♀ (F.W. Jackson) [ NHMUK] . TRINIDAD AND TOBAGO, TOBAGO, Cocoa Wattie: ♂ 8.iv.1907 (G.B. Longstaff) [OUNHM, as Virbia mentiens Walker ]. Charlotteville, at light: 2♂ 15–19.vi.1998 (Roger Hammond & Piers Meynell) [ UWIZM CABI.7458; NHMUK]. Englishman’s Bay , at light: 2♀ vi–xii. 2009 (J. Ingraham) [ UWIZM.2015.15.110–111]. Speyside, MVL: ♂ 14– 17.v.1982 (M.J.W. Cock) [ MJWC] .

Figures

FIGURE 10. Left, Stoll’s ([1781]) plate 345F of Phalaena medarda (edited from original copy). Right, female type of Virbia birchi Druce from Trinidad (F. Birch), in situ in NHMUK, here designated lectotype; © The Trustees of the Natural History Museum, London, made available under Creative Commons License 4.0 (https://creativecommons.org/licenses/by/4.0/). Not to scale.

FIGURE 11. Virbia medarda from Trinidad and Tobago (M.J.W. Cock) [MJWC]. A, ♂, Tobago, Speyside, MVL, 14–17.v.1982. B, ♂, Trinidad, Lalaja Ridge, MVL, 3.ix.1982. C, ♂, Trinidad, Caura Valley, Nr. Caura, MVL, 24.ix.1978. D, ♂, Trinidad, Arima Valley, Simla, MVL, 6.viii.1982. E, ♂, Trinidad, Arima Valley, Simla, MVL, 30.vii.1981. F, ♀, Trinidad, Pitch Lake, 28.viii.1982. G, ♀, Trinidad, Lalaja South Road, 1.5 milestone, 29.viii.1978. All to scale, x 1.5.

FIGURE 12. Male genitalia of Virbia medarda from Trinidad, Arima Valley, Simla, MV trap, 18.x.1982 (MJWC) [MJWC dissection 1069]. A, dorsal view; B, ventral view; C, dorsolateral view; D, aedeagus lateral view; E, aedeagus, ventral view; F, terminal segments with coremata lower right. All to scale as shown.

FIGURE 13. Male genitalia of Virbia medarda from French Guiana, Coralie track [ML dissection 3077]. A, ventral view with aedeagus in situ; B, ventral view; C, dorsalview; D, partial ventrolateral view; E, aedeagus dorsal view; F, aedeagus, lateral view. A–C, to scale shown in #B; D, enlarged; E–F to scale as shown in #E.