Chondrolepis uluguru Larsen & Congdon

Larsen, Torben B., 2012, The genus Ampittia in Africa with the description of a new species (Hesperiinae; Aeromachini) and three new species in the genera Andronymus and Chondrolepis (Hesperiinae, incertae sedis) (Lepidoptera; Hesperiidae), Zootaxa 3322, pp. 49-62 : 56-59

Chondrolepis uluguru Larsen & Congdon sp. nov.

Background: In the most recent review of all African Hesperiidae Evans (1937) included four known species in the well-characterized, essentially submontane Afrotropical genus Chondrolepis Mabille , describing one new species as C. cynthia . Their colloquial name is the “snow-horned skippers” since the upperside of the male antennae is pure white.

The genus was thoroughly reviewed by de Jong (1986), who added two new species ( C. similis and C. obscurior ), both collected by Congdon and Kielland in the Udzungwa Mountains of Tanzania. He also provided excellent detailed genitalia drawings of both sexes of all species that we used for comparison. We here describe two additional species recently captured in Tanzania and the DRC that were not available to de Jong and that we have not found in any existing collections. Thus, the genus now contains nine species.

One of the nine, C. niveicornis , is adapted to more open and lowland habitats, therefore having the widest distribution. It is found in all areas where one or more of the other species fly but often does not share the same habitat; in some cases the highest altitude it reaches is at the lowest level of another. It is the only member of the genus in outlying areas such as Ethiopia, Angola, Zimbabwe, and Mozambique. The remaining eight species have much more restricted distributions, mainly in the vicinity of submontane forests, and there are never more than four species on any given mountain complex: C. nero is endemic to the Nigerian/ Cameroun Mountains; C. leggei , C. cynthia , and C. ducarmei (described below) are endemic to the mountains fringing the Albertine Rift Valley (centred on the Ruwenzori Mountains); C. similis de Jong and C. obscurior de Jong are found only at higher elevations in the Udzungwa Mountains in south-central Tanzania ( obscurior also in the Southern Highlands at the head of Lake Malawi, where it is uncommon); C. uluguru (described below) is known only from higher levels in the Uluguru Mountains in Tanzania; finally the distinctive C. telisignata is known in two subspecies [one as yet undescribed] from Mt Kenya, the mountains of the Chyulu and Teita Hills in southeastern Kenya [the status of this population uncertain], and in the mountains of southern Tanzania and northern Malawi in disjunct populations. It is not impossible that additional species still hide on isolated mountains such as Mount Rungwe in Tanzania or the Marungu Plateau in the DRC.

During 2004, an expedition to the Uluguru Mountains in northeastern Tanzania by Congdon and staff collectors under the auspices of the African Butterfly Research Institute (ABRI), Nairobi collected a new species of Chondrolepis , which is described below.

Description: Forewing 16 mm. The male antennae are snow-white above, in the female white only on the club. The palps, head, and the thorax have a distinctive rusty tone, while the abdomen is clad in rather light brown hairs that become almost ochreous on the last three segments.

Male: The forewing is brown but—uniquely in the genus—the costa above most of the cell is overlaid with dense, bright rusty scaling; there is also less dense rusty scaling in the basal third of space 1b. The ochreous hyaline spotting consists of two cell-spots, the lower longer than the upper, that touch each other slightly. There are usually three subapical spots, but the upper spot is often tiny and probably sometimes missing. A small triangular spot at the base of space 3 is separated by dark veins from the lower cell-spot and from the large spot in 2. Space 1b has a well-developed, ochreous-orange non-hyaline spot. A line drawn flush with the inner edge of the cell-spots and that in 2 will pass inside the spot in 1b or just touch its inner edge. The hindwing is uniformly brown above. The cilia is slightly lighter than the ground-colour.

The male forewing underside has the costa finely edged with black but mainly with rusty scaling that just spills into the cell and then covers most of the subapical area. Half way between the subapical spots and the apex runs a diffuse darker band and the rest of the subapical area down to space 2 is a slightly more subdued rusty brown with large faintly grey triangular marginal spots. The inner margin is silvery grey with the spot in 1b as a whitish patch. The hindwing underside is strongly overlaid with rusty scaling but the underlying ochreous tone comes through as a patch at the base of space 6, just beyond the cell, and more faintly in the submarginal area. There is a postdiscal band of blueish spots from space 1b to 4 that are edged with darker brown. There are diffuse grey triangular marginal spots in the interspaces, most noticeably in 1c to 3.

Female: The upperside is a warm brown with the same rusty scaling along the costa and space 1b as in the male. The hyaline spotting is less ochreous in tone than in the male. The two cell-spots are well-separated. There are usually three subapical spots (the upper often tiny), a spot in 3, a large spot in 2, and a non-hyaline spot in 1b. A line drawn along the inner edges of the two cell-spots and that in 2 would pass through or just miss the outer edge of the spot in 1b, depending on the size of the upper cell-spot, a form of sexual dimorphism also seen in C. obscurior . The hindwing is brown with a good deal of lighter scaling.

The female underside is quite different from that of the male, being ochreous with no rusty overlay at all. The subapical area of the forewing is almost unmarked except for weak marginal triangles in the interspaces from 2 to the apex and faint traces of brown spots between the subapical spots and the margin.

The dark hindwing markings are warm brown and disposed in a similar manner to the male, but much more contrasting because of the ochreous ground-colour. The triangular marginal spots on both wings are smaller, though better defined. In the brown postdiscal wedge of spots from 1b to 4/5 these are not blue-centered as in the male. The cilia of both wings in both sexes is beige above, clearly lighter than the ground-colour, and with a tinge of the rusty or ochreous tone of the respective sexes.

Male genitalia: The tegumen is rather short and the lateral gnathos branches spinose. The valves are only slightly asymmetrical. The left (upper in figure 9) lobe of the cucullus is larger and more rounded than in C. obscurior . The scaphium can be seen under the uncus and is quite long. The shoulders of the tegumen have blunt projections as in C. obscurior , as illustrated by de Jong (1986). Overall the colour pattern differs more than the genitalia from the latter ( Figure 9 ).

Holotype: 3 Uluguru Mts (Nyachilo— 07°00’S 37°39’E), 13.ii.2004, T.C.E. Congdon leg. (African Butterfly Research Institute ( ABRI), Nairobi).

Paratypes: 6 3 and 8 ƤƤ from same locality collected/bred during i, ii, and iii, 2004 by T.C.E. Congdon, Ivan Bampton, Martin Hassan, and Peter Walwanda ( ABRI) (genitalia SCC 706 ex tbl BJJ).

Diagnosis: The species seem most closely related to C. obscurior , which was described by de Jong from the Udzungwa Mountains south of the Uluguru and the two are linked by the sexual dimorphism in spotting pattern described above. The bright rusty scaling on the costa and base of the forewing set both sexes apart from all other member of the genus. The difference between the underside of the two sexes of C. uluguru is not present in C. obscurior , but only in C. niveicornis and C. nero . C. telisignata is also dimorphic, in the female lacking the unique white discal band on the hindwing underside, but that is a very different type of dimorphism and varies geographically.

This type of hindwing underside sexual dimorphism was considered an important phylogenetic feature by de Jong (1986), uniting C. niveicornis and C. nero as closely related, despite the considerable genital differences. We tend to think that the parallel differences in spot pattern between the males and females of both C. obscurior and C. uluguru outweigh such variation in the female underside colours, especially since the genitalia of these two species are also very similar.

The genitalia are rather similar to those of C. obscurior from the Udzungwa mountains further south and of the same fairly large size, but the large rounded shape of the upper edge of the cucullus is special.

Range, habitat, and habits: So far this species is endemic to the Uluguru Mountains where it is known from a single site. There has been a fair amount of collecting in the area since the colonial period and as the species is not easily overlooked it is probably genuinely rare and local, though probably occurring elsewhere in the Ulugurus. The discovery of an endemic Uluguru Chondrolepis is surprising only in the sense that it was not discovered until 2004; given its submontane vegetation and proximity to the Udzungwa Mountains a submontane species was to be expected. There is an outside possibility that it might be found in some of the other neighbouring mountains like the Nguru. The locality is in the pass between the North and South Ulugurus at an altitude of about 1,600 m and is an unprotected area that is in the process of being cleared for cultivation. Females lay eggs on a roadside grass ( Setaria palmifolia ) in the shade of submontane forest and the species was bred by Congdon, though we chose a wildcaught male as the holotype. More detailed information on the early stages will eventually be published in the series of papers on Hesperiidae early stages by Cock and Congdon.

Etymology: The species was given the name of the Uluguru Mountains in northeastern Tanzania, because the area is of conservation concern. Two other endemic butterflies, the nymphalid Pseudathyma uluguru Kielland (known also from one other nearby mountain) and the skipper Celaenorrhinus uluguru Kielland already bear the name Uluguru ; we wish to provide further evidence of how urgent conservation of the remaining forests of the Eastern Arc submontane mountains is. Numerous other organisms are endemic to the Uluguru . The submontane areas of these mountains are part of the Eastern Arc stretching from the Taita Hills in Kenya to the Udzungwa Mountains with a patchwork of small, isolated areas of submontane forest that is an urgent conservation concern. There is then a large gap before the mountains of southern Tanzania and the Nyika Plateau in Malawi, which can been seen as a southward extension of the Eastern Arc.

Figures

FIGURE 9. Left: The male genitalia of Chondrolepis uluguru (paratype) (SCC 706). The inset is the dorsal view of C. obscurior, which has the same blunt projections from the shoulders of the tegumen and the genitalia of the two are generally similar.