Ceratricula semilutea congdoni Larsen

Larsen, Torben B., 2013, Ceratricula and Flandria — two new genera of Afrotropical Hesperiidae (Hesperiinae (incertae sedis )) for species currently placed in the genus Ceratrichia Butler, Zootaxa 3666 (4), pp. 476-488 : 481-483

Ceratricula semilutea congdoni Larsen ssp. nov.

Type locality. Uganda, Katera Forest (T.H.E. Jackson leg). Type depository: 3 British Museum (Natural History).

Description. Forewing 12–13 mm – but the size varies, with occasional tiny specimens (as small as 8.5 mm). The forewing upperside is black with limited or wholly absent hyaline spotting. The subapical spot in 6 is usually present; there may be one or two additional tiny spots in the forewing cell and/or spaces 8, 7, 3, 2, and 1b (one, more, or even all of which may be missing, especially in males). The holotype has slightly more than the average degree of spotting. The hindwing has a broad black costa that just penetrates the upper part of the cell; the rest of the hindwing is a soft ochreous-yellow. There is an ochreous-brown basal recumbent hair-tuft covering an androconial area at the base of vein 2. The forewing underside is strongly overlaid with ochreous scaling in the subapical area and usually has a small spot in space 1b, but is otherwise like the upperside. The hindwing underside is an unusual yellow-beige, distinctly lighter than the tone of the upperside (even described as “whitish” by Congdon & Collins (1998)). This colour difference comes across well in figure 4. There is a variable amount of fine brown speckling that in well-marked specimens can be seen almost to form very loose postdiscal and submarginal bands; in such specimens these seem to be faint remnants of a large cell-spot and a postdiscal band that no longer exist on the upperside, and somewhat reminiscent of Pardaleodes . The most prominent (but variable) brown markings are a more-or-less triangular patch at the end of the cell, a larger quadrangular patch in 1b, and a third submarginal patch in the tornal area. The cilia is darkened in the apical area, reflecting the black costa of the upperside.

Females of all subspecies are almost identical with the males. On balance they are slightly larger, with stronger hyaline spotting, and with more ochreous scaling on the forewing underside subapical area, but not consistently; they may also be smaller and almost unspotted as in the paratype figured (figure 4).

Type material. Holotype: 3 Uganda, Katera Forest, vii.1937 (NHM). Paratypes: 9 3 1♀ from Katera Forest, Tero Forest, and Bwindi (NHM); 10 3 Minziro (ABRI); 3 3 Minziro (coll. James Stewart);

Only material from Uganda and the adjacent Minziro Forest in northwestern Tanzania has been designated as formal paratypes, but material from Orientale, Kivu, and Shaba Provinces in the DRC and from forests in western Zambia is similar.

Diagnosis. The new subspecies differs from the nominate ssp. semilutea in West Africa by the lighter softer, ochreous-yellow of the hindwing upperside and the even lighter beige-yellow underside, which in ssp. semilutea is bright yellow with a tone similar to that of the upperside. A further difference is that the brown patch on the hindwing underside is missing from the cell and reduced or absent in space 1c of ssp. semilutea .

Evans (1937) was the first to link Ceratrichia indeterminabilis Strand from Cameroun with C. semilutea , considering it a junior synonym. It is raised to subspecies rank below. This is usually larger than the other two subspecies and differs from both in having a full and well-developed upperside spotting, in the cell and spaces 6–8 (spots almost in line), 3, 2, and 1b. The hindwing upperside ground-colour is not as warm ochreous as in ssp congdoni though the hindwing underside is similar, with a light yellow-beige tone differing strongly from ssp. semilutea . The underside of the forewing subapical area has some ochreous dusting, but less than in ssp. congdoni. Range, habitat and habits: Ssp. congdoni is the most eastern and southern of the three subspecies, covering the Albertine Rift area along the eastern DRC and western Uganda, extending into the Minziro Forest complex in the extreme northwest of Tanzania, which is the easternmost extension of the true equatorial forests in that country, but missing from the Mpanda and Kigoma districts further south, which are probably too dry. It is also found in western Zambia (Mwinilunga area) and much of Shaba, west to near the Angolan border in the DRC.

The subspecies tends to be rather local, but in the forests of Uganda it seems to be more frequent and numerous than either of the two other subspecies ever is. In the Minziro Forests in northwestern Tanzania it was widely distributed in grassy areas (low soft grasses), often coming to flowers, flying higher above the ground than the Ceratrichia in the same habitat (Congdon & Collins 1998).

Etymology. It is a pleasure to dedicate this subspecies to Colin Congdon whose contributions to our knowledge of East African butterflies are prodigious, including the discovery of several new species and the breeding of many species not previously bred. He also improved our understanding of the genus Ceratricula and recorded this new subspecies from Tanzania for the first time (Congdon & Collins 1998).