Seasonality is known to influence ant activity in many tropical rain forests in the world such as South America and Africa. We surveyed ant fauna in the leaf litter in the locality of Minko'o. The work aimed to evaluate the effect of seasonal variation on the diversity and composition of litter ants. Ants were sampled from November 2015 to June 2017, using four sampling methods: visual capture, bait, pitfall trap and extraction. Species richness, Shannon diversity index and analysis of similarities were used to characterise diversity of ant communities between seasons. We collected 306 ant species, shared out between 56 genera and 11 subfamilies. Subfamilies Myrmicinae, Ponerinae, Dolichoderinae, Formicinae, Dorylinae, Cerapachyinae and Pseudomyrmecinae occurred in all the seasons. Species richness was highest in major dry season with 243 species followed by minor rainy season with 188, major rainy season with 177 species and finally minor dry season that recorded the lowest with 155 species. Kruskal-Wallis test showed that ant species richness did not differ between seasons (p > 0.05). Species diversity index indicated that diversity was the highest during minor dry season (H′ = 4.24), followed by the major dry season (H′ = 4.23), minor rainy season (H′ = 4.21) and lowest during major rainy season (H′ = 4.06). Eight most frequents ants have been recorded: Axinidris sp.1, Camponotus flavomarginatus, Monomorium guineense, Myrmicaria opaciventris, Odontomachus troglodytes, Carebara perpusilla, Paltothyreus tarsatus and Pheidole megacephala. Assessment of the seasonal effect on diversity reveals that dry season is richer and more diverse than rainy season and the season significantly influence the diversity of litter ants. Résumé La saisonnalité est connue comme étant un facteur qui influence l'activité des fourmis dans de nombreuses forêts tropicales humides du monde à l'instar de l'Amérique du sud et l'Afrique. Nous avons étudié la faune des fourmis terricoles dans la localité de Minko'o. Les travaux visaient à évaluer l'effet des variations saisonnières | 797 TCHOUDJIN eT al.

Elevation and climate are interrelated variables which have a profound aff ect on biota. Flying insects such as dragonfl ies can rapidly disperse and select optimal habitat conditions at appropriate elevations. Such behaviour is likely to be especially important in geographical areas which are subject to major climatic events such as El Niño. Accordingly, we studied dragonfl ies and environmental variables in a series of reservoirs over an elevational range of 100-1350 m a.s.l. at the same latitude on the eastern seaboard of South Africa. Th e aim was to determine how elevation and climate (as regional processes), as well as local factors, infl uence species assemblage variability, habitat preference and phenology. Certain environmental variables strongly explained the main variation in species assemblage. Th ese included local factors such as pH, marginal grasses, percentage shade, exposed rock, marginal forest and to a lesser extent, marshes and fl ow. Diff erent species showed various tolerance levels to these variables. Elevation and climate as regional processes had very little infl uence on dragonfl y assemblages in comparison with these environmental factors. Th ese odonate species are essentially sub-tropical, and are similar to their tropical counterparts in that they have long fl ight periods with overlapping generations. Yet they also have temperate characteristics such as over-wintering mostly as larvae. Th ese results indicate evolutionary adaptations from both temperate and tropical regions. Furthermore, most were also widespread and opportunistic habitat generalists. Th e national endemics Pseudagrion citricola and Africallagma sapphirinum only occurred at high elevations. However, the endemic Agriocnemis falcifera was throughout all elevations, suggesting regional endemism does not necessarily equate to elevational intolerance. Overall, the results suggest that many millennia of great climatic variation have led to a highly vagile and elevation-tolerant dragonfl y assemblage which readily occupies new water bodies. Such an assemblage is likely to be highly tolerant of global climate change, so long as there is suffi cient water to keep the reservoirs at a constant level.

Awareness in the eyes of the public is important for involving the wider community in conservation. A dragonfly awareness trail was developed and implemented in the year 2000 at a national botanical garden in South Africa. Such a trail is not likely to always have the same number of dragonfly species either throughout the year or from one year to the next. The aim was to assess dragonfly assemblage changes that occurred along the trail over 3 years, so as to fine-tune expectations that the public may have as regards species to be seen at any particular time. A cumulative species variance for species and species-environmental relations, strongly indicated that certain measured site variables were responsible for the main variation in dragonfly species patterns over time. Habitat requirements of an odonate species may be defined primarily in terms of marginal grasses, floating and submerged vegetation, marginal herbs, sedges and reeds, and pH. Additional variables were percentage shade, exposed rock, marginal forest and water flow characteristics. Both dragonfly species richness and abundance changed over the 3 years. One of the reasons for this was a single, major disturbance, in the form of dredging the reservoir site to reverse ecological succession in 2002. Despite an impact such as this, and after accounting for vagrancy, there were in all 24 'core resident species' still to be seen along the trail from January to May. Another 11 species, including two migrants and one species lost temporarily to dredging disturbance, can be considered only as 'possibilities' on any one visit. Assurance that the 24 core species can be seen in the summer months (although only three in winter) is essential for maintaining the bona fide of such a trail, and hence conservation awareness, in the eyes of the public.

No abstract

Lepidopteran stem borers are among the most important insect pests of maize, sorghum and sugarcane in sub‐Saharan Africa. Except for Chilo partellus, the other stem borer pests in Ethiopia are indigenous to Africa and are assumed to have coevolved with some native grasses and sedges in the natural habitat. In addition to pest species, natural habitats harbour diverse non‐economic stem borer species, some of which are new to science. However, with the growing threats to natural habitats, some non‐economic stem borer species may switch or expand their host ranges to include cultivated crops and evolve as “new” pests. Besides host switch, some of the unknown species currently limited to natural habitats may disappear. We examined the diversity, abundance and interactions of lepidopteran stem borers and their wild host plants in five different vegetation mosaics in Ethiopia. The stem borer species diversity varied among vegetation mosaics and host plants. Forty‐four stem borer species belonging to 14 different genera in the families of Noctuidae, Crambidae, Pyralidae and Tortricidae were recorded from 34 wild host plants and through light trap. Among these families, Noctuidae was the highest in species richness in which 31 species were identified, out of which 15 species and two genera were new to science. This paper discusses the ecological interpretation of host plant–stem borer species interactions, particularly in relation to habitat disturbances.