26 research outputs found

    Diversity of fungus-growing termites (Macrotermes) and their fungal symbionts (Termitomyces) in the semiarid Tsavo Ecosystem, Kenya.

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    Fungus-growing termites of the subfamily Macrotermitinae together with their highly specialized fungal symbionts (Termitomyces) are primary decomposers of dead plant matter in many African savanna ecosystems. The termites provide crucial ecosystem services also by modifying soil properties, translocating nutrients, and as important drivers of plant succession. Despite their obvious ecological importance, many basic features in the biology of fungus-growing termites and especially their fungal symbionts remain poorly known, and no studies have so far focused on possible habitat-level differences in symbiont diversity across heterogeneous landscapes. We studied the species identities of Macrotermes termites and their Termitomyces symbionts by excavating 143 termite mounds at eight study sites in the semiarid Tsavo Ecosystem of southern Kenya. Reference specimens were identified by sequencing the COI region from termites and the ITS region from symbiotic fungi. The results demonstrate that the regional Macrotermes community in Tsavo includes two sympatric species (M. subhyalinus and M. michaelseni) which cultivate and largely share three species of Termitomyces symbionts. A single species of fungus is always found in each termite mound, but even closely adjacent colonies of the same termite species often house evolutionarily divergent fungi. The species identities of both partners vary markedly between sites, suggesting hitherto unknown differences in their ecological requirements. It is apparent that both habitat heterogeneity and disturbance history can influence the regional distribution patterns of both partners in symbiosis.Peer reviewe

    Cuticular Compounds Bring New Insight in the Post-Glacial Recolonization of a Pyrenean Area: Deutonura deficiens Deharveng, 1979 Complex, a Case Study

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    Background: In most Arthropod groups, the study of systematics and evolution rely mostly on neutral characters, in this context cuticular compounds, as non-neutral characters, represent an underexplored but potentially informative type of characters at the infraspecific level as they have been routinely proven to be involved in sexual attraction. Methods and Findings: The collembolan species complex Deutonura deficiens was chosen as a model in order to test the utility of these characters for delineating four infraspecific entities of this group. Specimens were collected for three subspecies (D. d. deficiens, D. d. meridionalis, D. d. sylvatica) and two morphotypes (D. d. sylvatica morphoype A and B) of the complex; an additional species D. monticola was added. Cuticular compounds were extracted and separated by gas chromatography for each individual. Our results demonstrate that cuticular compounds succeeded in separating the different elements of this complex. Those data allowed also the reconstruction of the phylogenetic relationships among them. Conclusions: The discriminating power of cuticular compounds is directly related to their involvement in sexual attraction and mate recognition. These findings allowed a discussion on the potential involvement of intrinsic and paleoclimatic factors in the origin and the diversification of this complex in the Pyrenean zone. This character type brings the first advanc

    Type Specimens of the Insect Order Isoptera in the Collection of the National Museums of Kenya

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    Volume: 60Start Page: 68End Page: 6

    Fragmentation of a peri-urban savanna, Athi-Kaputiei plains, Kenya

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    Many pastoral ecosystems around the globe are under pressure to produce more livestock or to make way for more intensive agricultural systems or new uses (Blench 2000). Some rangelands that used to be managed under communal land tenure are being privatized, with establishment of individual holdings; others are under state control (Galaty 1994). This is happening first in rangelands that receive more rainfall, are closer to urban centres, and/or contain significant key resources that are essential for successful crop cultivation (Galaty 1994). In these systems, pastoralists are either pushed onto more marginal lands for grazing or they begin to take up crop agriculture themselves, becoming agro-pastoralists (e.g., Campbell 1993, Campbell et al. 2003). One result is increased permanent settlement
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