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This survey aimed at generating information to guide improvement of oil palm fruit-set in Uganda by testing the hypothesis that diversity and abundance of oil palm insect flower-visitors were influenced by sampling site, distance from natural vegetation and flower sex. Sampling was done on male and female oil palm flowers from (i) five oil palm experimental fields in different districts and (ii) oil palm plantations on Bugala Island on Lake Victoria. The plantations on Bugala Island were subdivided into near (0–15 m) and far (100–200 m) from natural vegetation. We recorded 162,677 insects in 23 morpho-species, dominated by weevils in the genera Elaeidobius and Metamasius (Family: Curculionidae); beetles (Families: Nitidulidae, Staphylinidae and Scarabidae); Diptera (Families: Muscidae, Drosophilidae and Platystomatidae); and honeybees (Apis mellifera), respectively. All morpho-species occurred on both flower sexes, except four Elaeidobius spp which occurred on only male flowers. All morpho-species recorded on both flower sexes were more abundant on male than female flowers, except Apis mellifera and one Elaeidobius sp whose mean counts were comparable between flower sexes. The insects were more abundant and divers on oil palm trees near a natural vegetation than on those positioned farther away; and on the Island than the mainland sites. This suggests a need for location specific interventions and manipulation of natural vegetation in designing strategies for boosting oil palm pollination in Uganda. Further research is necessary to understand ecology and biology of the identified oil palm flower visitors to boost oil palm pollination in Uganda. [ABSTRACT FROM AUTHOR]

This Special Issue presents the outcomes from the 23rd African Association of Insect Scientists' Conference held in Cote D'Ivoire, in connection with similar initiatives within and outside Africa. Over 65 scientific papers from several countries, worldwide, were submitted, of which about 40 were accepted and published. The issue focused on new advances in the value chain of edible insects in Africa and beyond. An innovative light-emitting diode technology for mass harvesting of edible grasshopper has been developed. The nutrient composition of insects such as the desert locust has been evaluated. Organic waste streams have been found to affect insect productivity and nutritional value. Insect-based feed increases the nutritional quality of poultry meat. Conventional processing methods reduce microbiological hazards in edible insects. Bioaccumulation of heavy metals, excessive microbial loads and pesticides residues threaten safety of some edible insects, if quality control measures are not developed. Climate change will impede availability of edible insects; hence, necessitating upscaling of mass production technologies and sound conservation practices. Safety and hygiene, on the other hand, hamper the acceptability of insects as food and/or feed, particularly in developed countries. Food fortification with insects and isolation of bioactive compounds from them are new highlights in the Special Issue, which were previously under-explored in Africa. The application of modern food processing technology in the development of new products and the medicinal or commercial value derivable from edible insects and their therapeutic functions are excellent opportunities for expanding the sector. Since disgust factors exist, mass sensitisation on the benefits of consuming insects and insect-based products is a must. We believe that the new frontiers on insects for food, feed and other uses that have been presented in this special issue will undoubtedly stimulate more debates and collaborations in the sector within Africa and beyond. [ABSTRACT FROM AUTHOR]

Euwallacea spp. (Coleoptera: Scolytidae) are polyphagous globally distributed invasive ambrosia beetles. One of the species was recently detected attacking Ricinus communis growing in Coffea canephora gardens in Uganda. This study was undertaken to: (a) determine the distribution, incidence, and relative abundance of Euwallacea sp. on R. communis in Uganda; (b) determine the influence of the presence of C. canephora on the incidence and abundance of Euwallacea sp. on R. communis; and (c) identify ambrosia fungus of Euwallacea sp. on R. communis. Five C. canephora farms with R. communis and five others with R. communis but without C. canephora were sampled in each of the six districts surveyed. Incidence of Euwallacea sp. on R. communis was measured, by inspecting the host trees in each farm for the presence or absence of the pest. Abundance of Euwallacea sp. on R. communis was estimated, by counting holes of Euwallacea sp. at the lower 1.7 m of R. communis stems. A fungus was isolated from galleries of Euwallacea sp. on R. communis and identified. Results show that Euwallacea sp. was present on R. communis in all districts surveyed, with 30–70% of the farms infested in each district and 5–28 holes of Euwallacea sp. found on each sampled stem of R. communis. Coffea canephora appeared to facilitate the infestation of R. communis by Euwallacea sp., although it did not seem to influence the multiplication of the insect inside the host. Cunninghamella echinulata appeared to be the ambrosia fungus associated with Euwallacea sp. Therefore, Euwallacea sp. is a threat to many economically important plants in Uganda that are known to be hosts of this pest. [ABSTRACT FROM AUTHOR]

Xylosandrus compactus (Eichhoff) is a serious pest of Coffea canephora and Theobroma cacao in Uganda and also attacks several common shade tree species often associated with these crops. Seedlings of 10 common hosts of X. compactus were screened for preferential infestation by X. compactus, with a view to analysing the potential role of the shade trees in escalating incidence and damage by the pest. The experiment was conducted for 8 weeks in a garden of mature C. canephora infested by X. compactus that served as a natural source of infestation for the seedlings. The seedlings that became infested by X. compactus were counted weekly and the counts subjected to generalized linear modelling. Results show marked host preference by X. compactus, with T. cacao and C. canephora being the most preferred, while Eucalyptus sp. and Albizia chinensis being the least preferred. Four simulated scenarios of incidence and damage by X. compactus on a preferred crop such as C. canephora are discussed. It is suggested that it is most unlikely for unpreferred alternate host shade tree species to markedly increase populations of X. compactus on shaded preferred host plants. However, these simulations, which are based on results from potted seedlings, need to be validated in a real field situation, taking into account other ecological parameters that are likely to influence pest populations. [ABSTRACT FROM AUTHOR]

Recent evidence has shown that improved light traps comprising modified drums and light emitting diode bulbs are more efficient and safer in mass trapping of wild swarms of Ruspolia differens compared to mercury light traps with open-ended drums commonly used in Uganda. However, financial analysis of the improved traps had not yet been conducted prior to this study. Here, we carried out a cost–benefit analysis of the improved trap compared to the existing trapping technique. A pre-tested questionnaire was used to collect data on the demographic characteristics, revenue, capital expenditures and operating costs of the current trapping method from 30 commercial R. differens trappers in Masaka Uganda. The costs and revenue from the improved trap were collected basing on the market price and estimates for the 30 trappers. Net present value (NPV), benefit–cost ratio (BCR) and payback period were computed for the improved and current method and compared using an independent sample t-test. The results revealed that the improved trapping technique was more profitable than the current technique. Moreover, high costs of electricity and harmful non-target insects, especially the Nairobi fly (Paederus sp) which causes dermatitis were other difficulties associated with the current trapping technique. We, therefore, recommend adoption of the improved R. differens trapping technique as a more profitable alternative to the current technique. [ABSTRACT FROM AUTHOR]