Investigations into the potential impacts of selectively managing Apis mellifera on pollination ecology were carried out in several sites in Tsavo National Park of southern Kenya, a typical arid African environment. Temperature alone contributed significantly to the foraging patterns of both managed honeybees and wild bee species within the acacia–commiphora community. Honeybees, vulnerable to heat stress, foraged earlier in the day than wild bee species. Foraging patterns of the latter ranged from oligolectic to broadly non-specialized. Floral biology and adaptations were also considered in the analysis of divergent foraging trends. Observations suggest that honeybees potentially out-compete highly specialized wild bee species for scarce seasonal floral resources. No evidence was found of direct interaction on abundant seasonal floral resources such as the mass synchronous flowering of Acacia spp. at current managed honeybee densities. Investigation of visitors revealed a high diversity of potential insect pollinators, particularly high in wild bee species (Apoidea) diversity. Suggestions for the improved management of honeybees in arid African environments include shading of hives, providing access to water with protection from predators, and cultivation of indigenous, nectariferous plants close to hive colonies.

An acetone extract of Solanum trilobatum leaves was evaluated for its ovicidal activity on the mosquito species Culex quinquefasciatus and Culex tritaeniorhynchus, by exposing eggs ranging in age from 0 to 18 h to concentrations of 50–200 ppm of the extract, and assessing their percent hatchability. A 100-ppm dose of the extract killed all of the eggs from both species aged between 0 and 6 h. The 50- and 75-ppm concentrations were also highly effective against young eggs; the effect declined in older eggs. The extract was more ovicidal towards C. quinquefasciatus than C. tritaeniorhynchus. On a testé l'activité ovicide d'un extrait à l'acétone de feuilles de Solanum trilobatum sur les deux espèces de moustiques, Culex quinquefasciatus et Culex tritaeniorhynchus, en exposant des œufs âgés de 0 à 18h à des concentrations de l'extrait compris entre 50 et 200ppm et en évaluant le pourcentage d'éclosions. La concentration à 100ppm de l'extrait tue tous les œufs d'âge compris entre 0 et 6h des deux espèces de moustique. Les concentrations à 50 et 75ppm sont également très efficaces contre les jeunes œufs, mais l'effet diminue avec l'âge des œufs. L'extrait est plus efficace vis à vis de C. quinquefasciatus que de C. tritaeniorhynchus.

Volatile oils of Citrus sinensis, Ageratum conyzoides, Cymbopogon citratus, Callistemon rigidus and Ocimum gratissimum were tested as repellents against blackfly, Simulium damnosum s.l., the vector of human onchocerciaisis. Topical applications of 10 and 20% v/v concentrations of the oils with liquid paraffin as the carrier, were made on the forearms and legs of four volunteers, with ordinary paraffin oil used as the control. At 10% v/v concentration the protection time was between 30min and 1h with the Citrus, Ageratum, Cymbopogon and Callistemon oils. At 20% Citrus, Ageratum and Cymbopogon oils repelled the blackflies for up to 2h while Callistemon and Ocimum oils were effective for 3h. Application of these volatile oils, especially at the peak biting periods, would serve to reduce human–vector contact and thereby limit disease transmission.

Stingless bees are little-known organisms but important plant pollinators in Bwindi Forest. They risk disappearance, as with other pollinators and seed dispersers, as a result of pesticide and herbicide poisoning, habitat alteration, invasion by alien species (plant and animal) and insularization of habitats. Bwindi Impenetrable National Park forest has five species of stingless bees in two genera (Meliponula and Hypotrigona). The conservation of pollinators in Bwindi needs to be urgently addressed, and among the required measures are studies on plant–pollinator relationships. The study also demonstrated the accuracy of Abayanda indigenous systematic knowledge.