African Zoology

Obituary

Michael J. Lawes — 2024-09-03

No Abstract

Morphological variations in the African palm weevil, Rhynchophorus phoenicis (F) (Coleoptera: Curculionidae), in Kenya and Uganda

James P. Egonyu — 2024-09-03

We investigated morphological differences in the African palm weevil (Rhynchophorus phoenicis) from Kenya (Busia and Kwale) and Uganda using a LEICA EZ4HD stereo microscope and an absolute digimatic caliper. Ten pronotal colour patterns were recorded, of which two (brown with two black spots and black with/without very faint brown bands of variable lengths and positions) are reported for the first time. Pronota of most R. phoenicis from Busia and Uganda were black with/without very faint brown bands of variable lengths and positions. Samples of R. phoenicis from Kwale were dominated by four reddish brown and three black bands, which either ran through the pronotal length or the reddish-brown bands coalesced anteriorly. The following pronotal colour patterns were male-specific: (i) two reddish brown bands, approximately ¾ the pronotal length and coalescing anteriorly, (ii) two reddish brown bands running through the pronotal length but discontinuous towards the posterior end and (iii) a brown pronotum with two black spots. Only the females had (i) two faint reddish brown bands running through the pronotal length, fading posteriorly and (ii) four reddish brown and three black bands, two of the former on either halves coalescing posteriorly. Females had longer snouts and mesocoxal distance, and wider elytra than males. Males possessed a longer profemur than females. Morphometric polymorphism was not linked to the site of sample collection. These findings provide additional diagnostic features and improve sexing of P. phoenicis and open opportunities for further research on the mechanisms for polymorphism in the species.

The potential predators of pancake tortoises (Malacochersus tornieri) in Kenya

Jacob Mueti Ngwava — 2024-09-03

Studying the interactions between prey and predators is crucial for understanding the intricacies of predator-prey dynamics and for formulating effective conservation strategies. Yet there is almost no systematic analysis of pancake tortoise predation, and its consequences on the tortoise populations. Using camera trapping and visual encounter surveys, we recorded the animals visiting the crevices inhabited by pancake tortoises, as well as their surroundings. From our data, we propose which visitors were potential predators, and consider predator impacts on the species. We suggest ten species (21.3%) as potential predators, among the 47 visiting the tortoise crevices between July 2020 and November 2022. We encountered six adult pancake tortoises killed and eaten by unknown predators. Four of six eggs laid by pancake tortoises in May−June 2022 were also depredated. The white-tailed mongoose (Ichneumia albicauda) and the honey badger (Mellivora capensis) were recorded probing rock crevices inhabited by pancake tortoises, with their behaviour suggesting potential predation upon tortoises. We recorded the rock monitor lizard (Varanus albigularis) and common dwarf mongoose (Helogale parvula) digging pancake tortoise nest sites. This study significantly advances our understanding of the predation risk to the critically endangered pancake tortoise.

Two new species of Hemidactylus Goldfuss, 1820 (Squamata: Gekkonidae) from the coastal areas of northern Somaliland

Tomas Mazuch — 2024-09-03

The taxonomy of many Hemidactylus geckos from the Horn of Africa has recently been evaluated. However, the lack of fresh material for some species and also regions has led to the misidentification of some taxa and an underestimation of the true diversity in others. In this study we analyse new material of Hemidactylus collected from poorly known coastal areas of northern Somaliland. Our results support the existence of two yet undescribed species within the arid clade. One of the new species is small-sized and closely related to H. afarensis from the Afar Triangle in Ethiopia, and together with two other species (H. foudaii, H. sinaitus) forms the monophyletic group for which we propose here the name sinaitus species group. The other new species is medium to large-sized, known from only one locality, and belongs to the macropholis species group, where it is a sister species of H. macropholis. Both new endemic species from the northern coastal hyper-arid plains highlight the role of northern Somaliland as an important biodiversity hotspot. Furthermore, our results show pronounced genetic diversity within H. macropholis, and imply possible existence of cryptic taxa within the species. Hemidactylus arnoldi and H. tropidolepis have, for the first time, been sequenced and placed in a phylogenetic context in this study. Our results confirm that H. tropidolepis is nested within the African radiation and is most closely related to H. funaiolii. Hemidactylus arnoldi clustered within the Arabian radiation of Hemidactylus and it was recovered as a sister lineage to all other species of the radiation.

Parasitoid guild of the citrus leafminer, Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae) in Tunisian citrus orchards and a new report of Cirrospilus ingenuus Gahan (Hymenoptera: Eulophidae)

Dorra Mansour — 2024-09-03

A survey of the parasitoid species of the citrus leafminer (CLM), Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae), a cosmopolitan pest of citrus, was carried out in 2019 and 2020 in the major citrus production area of Tunisia. Four different Eulophidae species were found: Citrostichus phyllocnistoides (Narayanan), representing 81.82% of the identified parasitoids, Semielacher petiolatus (Girault) (9.40%) and the native species Pnigalio pectinicornis (L.) (2.82%). Cirrospilus ingenuus Gahan (Hymenoptera: Eulophidae) is a new report for the parasitoid entomofauna of P. citrella in the country, representing 5.96% of the identified parasitoids. It has probably spread naturally from other Mediterranean regions. Predation by generalist predators is the main mortality factor of CLM (up to 59.11% of the mortality was caused by natural enemies), followed by parasitism (oviposition) (22.47%) and host-feeding (18.42%). Second and third instar larvae of the CLM were the preferred stages for parasitism. Host-feeding and generalist predators’ attacks were most common on first and second instars. Data highlighting the ability for C. phyllocnistoides to develop and disperse clearly predominates in Tunisian citrus orchards. Citrostichus phyllocnistoides may compete with S. petiolatus, exerting a complementary action to that of C. phyllocnistoides, particularly earlier in the season when the densities of the latter species are low. Further studies focusing on inter- specific relationships between these two exotic parasitoids are needed in order to test whether the observed field results could have been estimated from laboratory assays. This will be helpful in critically evaluating the results of the classical biological control programme developed against CLM in Tunisia.

Cape genet Genetta tigrina diet in the Albany Thicket Biome, South Africa

Axola Plaatjie — 2024-09-03

The diet of the Cape genet Genetta tigrina is only well known in the coastal forests of South Africa, where either arthropods or small mammals are their dominant prey. Here, we aimed to demonstrate this species’ opportunistic behaviour by investigating its feeding habits in the Albany Thicket Biome (Great Fish River Nature Reserve, Eastern Cape). We analysed 61 scats collected across the four seasons of the year deposited at 15 latrines by Cape genets, as confirmed through video-recordings. Small mammals were primary and arthropods secondary prey, respectively. We recorded seasonal variations in both percentage occurrence and volume of food remains, with peaks in consumption of small mammals in winter, and arthropods in spring–summer. The consumption of supplementary food items such as plant material was higher in spring and autumn, and particularly seeds/fruit in autumn. Reptiles and other food items occurred as trace foods throughout the year, although birds reached a peak in winter. Intermediate to high diet diversity and low to intermediate diet breadth indices were obtained for all seasons. Inter-seasonal diet overlap was intermediate to high depending on the diet descriptor and pairs of seasons considered. Cape genet is therefore a generalist opportunist forager that likely adjusts its diet according to seasonal variations in main prey availability, potentially leading to apparent seasonal or local “specialisms”.