Rudy Jocqué

Spatial Pattern Enhances Ecosystem Functioning in an African Savanna

Termites indirectly enhance plant and animal productivity near their mounds, and the uniform spatial patterning of these mounds enhances the overall productivity of the entire landscape.

Studies in Corinnidae: cladistic analysis of 38 corinnid and liocranid genera, and transfer of Phrurolithinae

This paper studies the phylogeny of the spider families Liocranidae and Corinnidae as they have been delimited to date, using an exemplar approach. In the analysis, 40 species belonging to 24 liocranid and 14 corinnid genera are scored for 157 morphological characters. The genera Clubiona (Clubionidae) and Gnaphosa (Gnaphosidae) are used as outgroups. Under implied weighting, a single fittest tree is found. This hypothesis seriously challenges the presently prevailing classification of the former Clubionidae sensu lato. The subfamily Phrurolithinae (Liocranidae) turns out to be the sister group of Trachelinae and is transferred to Corinnidae. In the interest of taxonomic stability, no radical rearrangement of the families constituting Clubionidae sensu lato is proposed, as it is felt that the present results should first be further corroborated by additional, more elaborate analyses on an even larger data set.

INFLUENCE OF GRAZING BY LARGE MAMMALS ON THE SPIDER COMMUNITY OF A KENYAN SAVANNA BIOME

Abstract Pitfall trap and sweep net samples were taken over a period of fifteen months (2002– 2003) in the Kenya Long-term Exclosure Experiment (KLEE), in which the presence of domestic and wild herbivores have been independently manipulated since 1995. ANOVA and ANCOVA showed that the exclosure treatments significantly affected plant cover, with the presence of cattle significantly reducing the relative vegetation cover and spider diversity. Herbivory by indigenous mega- and meso–herbivores did not have a significant influence on the diversity of the spider fauna, but abundance of three dominant species (Cyclosa insulana Costa (Araneidae), Argiope trifasciata Forskål (Araneidae) and Runcinia flavida Simon (Thomisidae)) decreased in cattle-grazed plots. In contrast, Aelurillus sp. became more prevalent where cattle have been grazing. Multivariate analyses revealed that the spider community responded to grazing pressure by aggregating into three groups that reflected control, cattle grazing and non-cattle grazing clusters. It was probable that the direct effects on vegetation mediated an indirect influence of herbivores on spider diversity. The relative vegetation cover was a positive predictor of spider diversity. Spider communities were found to be an indicator of the activity of mammals and could be used as indicators of land use changes and for bio-monitoring.

Ultrastructure of Antoonops, a New, Ant-Mimicking Genus of Afrotropical Oonopidae (Araneae) with Complex Internal Genitalia

Abstract Antoonops, a new genus of the spider family Oonopidae, is described from West Africa. The genus contains four new species, all known from both sexes: A. corbulo (type species), A. bouaflensis, A. iita, and A. nebula. All species mimic ants and exhibit a pronounced sexual dimorphism. Several new ultrastructural features are reported, including putative gland pores associated with the coxal insertions, specialized cheliceral setae, and peculiarly modified male endites. The potential of these and other traits as phylogenetically informative characters is discussed. SEM investigation of the internal female genitalia of A. corbulo reveals the presence of two peculiarly shaped sclerites embedded in the walls of the uterus externus and a reproductive tract with an apparent flow-through design.

GENITALIC POLYMORPHISM—A CHALLENGE FOR TAXONOMY

Abstract Genitalic polymorphism (including polymorphism of secondary sexual characters) is a typical example of a phenomenon that found no place in taxonomy as there was no framework to place it. Neither the speciation models used in ecology nor the species concept currently in use with taxonomists “allowed” species to have discontinuously polymorphic genitalia. Recent developments in ecological modeling that make sympatric speciation acceptable, and changing ideas about sexual selection, both imply genitalic polymorphism in particular circumstances. According to the mate check hypothesis the presence of hidden but crucial new adaptive characters is checked during courtship and mating. Sympatric speciation with changing behavioral characters without shifts in somatic traits, goes through a phase of intraspecific polymorphism during which the mating module obtains new traits backing up the newly acquired hidden character. It implies that this speciation process ends with the alteration of the recognition module. After the completion of the speciation process, cases of atavism with loss of behavioral adaptations through deleterious mutations or reversions and reappearance of ancestral genital characters, are expected to occur regularly. Without these, the mate check mechanism would be meaningless. A number of examples of both types of genitalic polymorphism in arachnids are presented. It explains why genitalic polymorphism is rarely observed although it might be a common phenomenon.

Estimating the diversity of arboreal oonopid spider assemblages (Araneae, Oonopidae) at Afrotropical sites

Abstract The abundance, species richness, and assemblage structure of arboreal Oonopidae of Afrotropical rainforests and savannahs was investigated. Canopy-dwelling spiders were collected by insecticide knockdown fogging at 11 rainforest and three savannah sites in West, Central, and East Africa. In two lowland rainforests (Luki, DR Congo, and Kakum, Ghana) and two savannahs (Faro, Cameroon, and Mkomazi, Tanzania) Oonopidae were the second most abundant spider family, comprising up to 22% of the arboreal arachnofauna. In total, 51 species and 11 genera of Oonopidae were recorded from the 14 study sites. Kakum was the most species- and genus-rich site, with 11 species and 5 genera recorded. The arboreal oonopid assemblages were almost invariably found to be dominated by the widely-distributed genera Orchestina Simon and Opopaea Simon, in terms of both abundance and species richness. Orchestina in particular can be highly abundant and can comprise more than 90% of arboreal oonopids in rainforests as well as in savannahs. Species accumulation curves and six nonparametric estimators of total species richness (Chao 1, Chao 2, ACE, first- and second-order jackknife, and bootstrap) were calculated for Luki, Kakum, and Faro to evaluate the level of inventory completeness. In Kakum and Faro the species accumulation curve respectively closely approached and reached a stable asymptote. The selected nonparametric estimators were found to lack predictive power when applied to the Faro data set and appeared to behave similarly poorly on the Kakum sample set.

HORTIPES, A HUGE GENUS OF TINY AFROTROPICAL SPIDERS (ARANEAE, LIOCRANIDAE)

Abstract Hortipes Bosselaers and Ledoux (type species Hortipes luytenae Bosselaers and Ledoux from South Africa) is a genus of small (1.5–4 mm), pale, mainly soil-dwelling spiders from sub-Saharan Africa. The genus, which is tentatively placed in the Liocranidae, is characterized by the presence of a peculiar ellipsoidal array of setae on the dorsal side of metatarsi I and II and by the large anterior median eyes with a dark retina restricted to the median portion. Ledoux and Emerit (1998) described five more species from Ivory Coast and Gabon. Sixty-three additional Hortipes species are described here as new: H. platnicki (♀), H. castor (♂♀), H. pollux (♂♀), H. fastigiensis (♂♀), H. ostiovolutus (♂♀), H. salticola (♂♀), H. exoptans (♂♀), H. scharffi (♂♀), H. cucurbita (♂♀), H. hesperoecius (♀), H. klumpkeae (♀), H. aurora (♂♀), H. echo (♀), H. stoltzei (♂), H. creber (♂♀), H. orchatocnemis (♂♀), H. contubernalis (♂♀), H. mesembrinus (♀), H. coccinatus (♂♀), H. wimmertensi (♂♀), H. irimus (♀), H. licnophorus (♀), H. schoemanae (♂♀), H. aelurisiepae (♀), H. hyakutake (♂), H. rothorum (♂), H. griswoldi (♂), H. oronesiotes (♂♀), H. penthesileia (♀),H. zombaensis (♂♀), H. atalante ♀), H. merwei (♂♀), H. leno (♂♀), H. mulciber (♀), H. libidinosus (♂♀), H. delphinus (♂♀), H. bjorni (♂), H. amphibolus (♀), H. hastatus (♂♀), H. horta (♀), H. angariopsis (♀), H. falcatus (♂♀), H. lejeunei (♂♀), H. narcissus (♂♀), H. auriga (♂), H. puylaerti (♀), H. chrysothemis (♀), H. machaeropolion (♂♀), H. centralis (♀), H. tarachodes (♂♀), H. terminator (♂), H. baerti (♂), H. robertus (♂♀), H. abucoletus ♀, H. alderweireldti (♂), H. architelones (♂♀), H. calliblepharus (♂), H. fortipes (♂), H. bosmansi (♂♀), H. sceptrum (♂♀), H. anansiodatus ♀, H. hormigricola (♂♀), and H. depravator (♂). The genus has a vast Afrotropical distribution, occurring from as far south as East London in South Africa to Sierra Leone in western Africa. So far, no specimens are available from northeastern tropical Africa. Apart from H. merwei, which seems to prefer grassland, all species are found in leaf litter or the canopy of different kinds of forests and dense thickets. In captivity, H. contubernalis readily fed on Collembola. Specimens raised from cocoons obtained in the laboratory reached adulthood after three molts. A cladistic analysis of the 34 species for which both sexes are known, largely based on secondary genitalic characters, is proposed.

SIX STRIDULATING ORGANS ON ONE SPIDER (ARANEAE, ZODARIIDAE): IS THIS THE LIMIT?

Abstract A new type of stridulatory organ is described and figured occurring in three species of Mallinella Strand from Thailand and Singapore. In one species there are four stridulatory organs, with the ridges on femora I and II and the pegs in the shape of granulations on femora II and III. In both the other species an additional pair occurs, with ridges on femora III and pegs on femora IV. To date no more than four stridulatory organs have been recorded on a single spider. Examples of various known forms of stridulatory organs on spiders are illustrated and their significance briefly discussed.

A review of the nebulosa-group of Pardosa Koch 1847 in Africa, a complex with some highly variable species (Araneae Lycosidae)

The African representatives of the Pardosa nebulosa-group are revised. This group now includes 10 species, five of which are new: P. alticola, P. kavango, P. nostrorum, P. paleata and P. thompsoni. The other five are P. gefsana Roewer 1959, P. injucunda (O.P.-Cambridge 1876), P. lusingana Roewer 1959, P. messingerae (Strand 1916), P. naevia (L. Koch 1875). P. lycosina Purcell 1903, only known from females, is a possible additional species. All the species are described and much attention is paid to intraspecific variability. In P. injucunda the high variability is thought to reflect the existence of different biospecies. An illustrated key to the males is provided. The generic placement of the group and the taxonomic level of the taxa it contains, are discussed.

A revision of the purse-web spider genus Calommata Lucas, 1837 (Araneae, Atypidae) in the Afrotropical Region

Abstract The purse-web spider genus Calommata Lucas, 1837 is revised in the Afrotropical Region. Following examination of the female type material, Calommata transvaalica Hewitt, 1916 is removed from synonymy with Calommata simoni Pocock, 1903 and revalidated. The females of both species are redescribed and their males described for the first time. While Calommata simoni is very widespread across tropical Africa, Calommata transvaalica is endemic to northern South Africa. Four new species are described, all known only from males: Calommata megae sp. n. (Zimbabwe), Calommata meridionalis sp. n. (South Africa), Calommata namibica sp. n. (Namibia) and Calommata tibialis sp. n. (Ivory Coast and Togo). Notes are presented on the biology of each species.