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Corresponding author: Hélcio R. Gil-Santana ( helciogil@uol.com.br ) Academic editor: Laurence Livermore
© 2021 Hélcio R. Gil-Santana, Jürgen Deckert.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Gil-Santana H, Deckert J (2021) Transfer of Westermannia difficilis Dohrn to the genus Polauchenia McAtee & Malloch (Hemiptera, Heteroptera, Reduviidae, Emesinae, Emesini). ZooKeys 1043: 103-116. https://doi.org/10.3897/zookeys.1043.61344
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Based on the examination of its lectotype (here designated), Westermannia difficilis Dohrn, 1860 (Hemiptera, Heteroptera, Reduviidae, Emesinae, Emesini), currently included in Dohrnemesa Wygodzinsky, 1945, is transferred to the genus Polauchenia McAtee & Malloch, 1925 with the resulting new combination: Polauchenia difficilis (Dohrn, 1860), comb. nov. An updated key to the species of Polauchenia is provided.
Assassin bugs, Colombia, Neotropical region, Venezuela
There are about 30 genera of Emesinae classified in four tribes in the Neotropics (
When describing Westermannia difficilis,
Because Westermannia Dohrn, 1860 was preoccupied by a Hübner’s genus of the same name in Lepidoptera ([1821]) (
When describing Dohrnemesa,
In the current work, we confirm that the lectotype (here designated) of Westermannia difficilis Dohrn, 1860, a species currently included in Dohrnemesa Wygodzinsky, 1945, does not belong to this genus but to Polauchenia McAtee & Malloch, 1925, resulting in the new combination: Polauchenia difficilis (Dohrn, 1860), comb. nov. The main differences are that in P. difficilis, comb. nov. the base of basal cell is pointed, emitting a single longitudinal vein, with the absence of a short free vein at this base and the humeri are spined. Both differences are sufficient to show that P. difficilis, comb. nov. does not belong to Dohrnemesa but to Polauchenia. Additionally, as commented below, several other diagnostic characteristics of Polauchenia are present in the specimen examined.
For the present study, the male lectotype (here designated) of Westermannia difficilis Dohrn, deposited in the Hemimetabola Collection of the Museum für Naturkunde Berlin, Leibniz Institute for Evolution and Biodiversity Science, Berlin, Germany (
The photos of the lectotype (here designated) of W. difficilis Dohrn, 1860 were taken with a Canon EOS 6D (Fig.
Figure
General morphological terminology mainly follows
When describing label data, a slash (/) separates the lines and a double slash (//) different labels.
Subfamily Emesinae
Westermannia difficilis
Dohrn, 1860: 251 [description], 1863: 47–48 [redescription];
Dohrnemesa difficilis;
Westermannia difficilis, male lectotype (here designated): [handwritten label]: Leptol. / difficilis / Dohrn // [blue underlined handwritten label]: Columb; Moritz. // [printed label]: 3326 // [printed label]: [at right side]: QR CODE, [at left side]: http://coll.mfn-berlin.de/u/ /123b88 // [printed red label]: LECTOTYPE / Westermannia difficilis Dohrn, 1860 / designated by H. R. Gil-Santana & / J. Deckert 2020 (
In the old catalogue of the Berliner Museum the specimen examined here was registered under the number 3326 and named as Leptolemus difficilis Dohrn (Fig.
The collector of the specimen, Moritz (Johann Wilhelm Karl Moritz 1797–1866), collected in the Caribbean islands and Venezuela, but there is a disagreement among some authors if he collected in Colombia. It is possible that the records of his collecting from Colombia originated from the confusion between Venezuela and Colombia, parts of the former having once belonged to the ancient vice-kingdom of “Nueva Granada” (
Polauchenia difficilis, comb. nov. can be separated from other species of the genus by the combination of characters presented in the key below. Polauchenia difficilis, comb. nov. shares similarities with P. paraprotentor Gil-Santana & Ferreira, 2017 but differs from this species in several characteristics, such as: the pale markings of the antenna, middle and hind femora are simple (P. paraprotentor) or bordered by darker markings (P. difficilis, comb. nov.), those on antenna narrow, with the pale annuli as long or only slightly longer (P. paraprotentor) or quite longer (four and seven times) than the width of the segment (P. difficilis, comb. nov.); fore coxa with a median pale annulus (P. difficilis, comb. nov.) or two pale annuli at submedian basal portion and approximately midportion of distal half of the segment (P. paraprotentor); distal portion of forewings with (P. difficilis, comb. nov.) or without (P. paraprotentor) a large whitish subdistal marking; petiole approximately 1.5 (P. paraprotentor) or 1.3 (P. difficilis, comb. nov.) times as long as fore lobe; humeri spined (P. difficilis, comb. nov.) or not (P. paraprotentor); spine of scutellum obliquely directed upwards (P. difficilis, comb. nov.) or backwards (P. paraprotentor); spines of scutellum and metanotum mostly pale (P. difficilis, comb. nov.) or brownish (P. paraprotentor).
Male. Measurements (mm): total length: to tip of abdomen 10.0; to tip of forewings 10.6. Coloration: brownish to light brown, with yellowish to pale markings or portions (Figs
Polauchenia difficilis (Dohrn, 1860), comb. nov., male lectotype (here designated) 8 ventrolateral view, left side 9 fore lobe of pronotum, head and right fore leg, lateral view 10 head, fore lobe and petiole of pronotum, lateral view 11 left fore leg detached from the specimen, lateral view. Scale bars: 0.5 mm (9, 10); 0.26 mm (11).
Polauchenia difficilis (Dohrn, 1860), comb. nov., male lectotype (here designated) 12, 13 forewing 13 schematic outline 14 meso and metathorax, abdomen and left hind leg, lateral view. Abbreviations: bc basal cell, dc discal cell, P Pcu cross vein, sv single vein emitted from the basal cell. Scale bars: 0.5 mm (12–14).
The transfer of D. difficilis to Polauchenia is in accordance with the aforementioned assertion that Dohrnemesa can be separated from Polauchenia by the absence/presence of spined humeri and the presence/absence of a free short vein emitted from the base of the basal cell of the forewing in the former and latter genus, respectively (
Yet, the inclusion of P. difficilis, comb. nov. in Polauchenia agrees with the following diagnostic features of the genus (
Additionally, among other characteristics of Polauchenia, the following are noteworthy and also present in P. difficilis, comb. nov.: all species are conspicuously marked with light and dark colors (e.g., Figs
The only small difference is the total length, which was recorded as being 10.6 mm for P. difficilis, comb. nov., very close to the minimum stated by previous authors (11 mm), allowing us to state 10.6 mm as the actual minimum of the genus. Moreover, it is noteworthy that
In any case, it becomes clear that the transfer of the species studied here from Dohrnemesa, the genus where it was currently included (
On the other hand, some characteristics which
The type specimen of Westermannia difficilis was designated here as a lectotype following the Art. 74.1 of ICZN.
Taking into account the taxonomical change proposed here, seven species are now included in Polauchenia and nine in Dohrnemesa (D. albuquerquei Wygodzinsky, 1966, D. buyassuana Wygodzinsky, 1958, D. carvalhoi Wygodzinsky, 1966, D. exporrecta Wygodzinsky, 1958, D. kuarajucassaba Gil-Santana & Ferreira, 2017, D. lanei Wygodzinsky, 1945, D. oliveirai Gil-Santana & Ferreira, 2016, D. reimoseri (Wygodzinsky, 1950), D. santosi Wygodzinsky, 1945) (
1 | Postocular region of the head with a median spine, besides a pair of lateral spined tubercles | unicornis Maldonado, 1968 |
– | Postocular region of the head without a median spine, with or without a pair of lateral spined or rounded tubercles | 2 |
2 | Petiole of pronotum quite longer, at least 1.3 times as long as the fore lobe | 3 |
– | Petiole of pronotum little, if any longer than fore lobe | 6 |
3 | Petiole of pronotum approximately 1.3–1.5 times as long as fore lobe; length 10.6–14 mm | 4 |
– | Petiole of pronotum at least twice longer than the length of fore lobe; length 15 mm or longer | 5 |
4 | Petiole of pronotum approximately 1.5 times as long as the fore lobe; length 14 mm; pale markings of the antenna, middle and hind femora simple | paraprotentor Gil-Santana & Ferreira, 2017 |
– | Petiole of pronotum approximately 1.3 times as long as the fore lobe; length 10.6 mm; pale markings of the antenna, middle and hind femora bordered by darker markings | difficilis (Dohrn, 1860) |
5 | Length 17.5 mm; females (males unknown) brachypterous, the forewing reaching at about middle of abdomen | marcapata Wygodzinsky, 1966 |
– | Length not more than 15 mm; female slightly brachypterous, forewing reaching far posterior to the middle of abdomen | protentor McAtee & Malloch, 1925 |
6 | Length 11 mm; postocular region of the head without projections, spines of scutellum and metanotum yellowish | schubarti Wygodzinsky, 1950 |
– | Length 16 mm; postocular region of the head with a pair of spined conical tubercles; spines of scutellum blackish | biannulata McAtee & Malloch, 1925 |
We are very grateful to Catarina Lopes (Instituto Oswaldo Cruz, Rio de Janeiro, Brazil), an anonymous reviewer, and Laurence Livermore for their valuable comments and suggestions.