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Forest restoration is an essential tool for conserving biodiversity in tropical regions; yet, restoration outcomes in the Afrotropics remain largely understudied. Here, we investigated how the forest structure, tree diversity, community, life-history traits and habitat associations recovered over three decades of active restoration in an East African rainforest in Uganda. The vegetation surveys were initially conducted in 2013 and repeated in 2021. Altogether, the study included 45 actively restored forest sites (aged 4–26 years) and 10 primary forest reference sites. The results showed increased tree taxa richness, basal area, tree height and community similarity (i.e., the similarity of community composition of restored forests to the composition of primary forest) along the age gradient. After 20 years of planting, Simpson's diversity and canopy cover reached similar values recorded in the reference primary forest. In contrast, restored forests had not attained levels of tree taxa richness, basal area, stem density, or community similarity comparable to those of the reference primary forest within three decades. We found an age gradient from younger restored to older restored to the primary forest in the composition of tree communities. The proportion of species with animal-dispersed seeds was similar in the restored and the primary forest. The proportion of shade-tolerant and forest-interior species had increased along the age gradient in the 2021 survey. In conclusion, forest structure, diversity and community showed early signs of recovery, but the rate of change slowed over time.

The edible grasshopper, Ruspolia differens (Orthoptera: Tettigoniidae) is food and a source of income for many people in East Africa. Recent laboratory experiments have succeeded in rearing them on germinated finger millet (GFM). However, long-term mass production on such a feed would be costly. Incorporating inexpensive and locally abundant agricultural byproducts into GFM could be another option to lower the production cost while maximising its profits. We experimentally evaluated the effect of blending GFM with 25%, 50%, or 75% by weights of three agricultural byproducts (soybean hull meal, local brew waste and dry maize cob) on the survival, developmental period, adult wet weight and reproductive performance of R. differens. A total of 390 R. differens were reared individually on each of the dietary treatments, including GFM as control, till death. Data was analysed using generalised linear models. Overall, the R. differens performed optimally on GFM supplemented with dry maize cob, and poorly on GFM supplemented with soybean hull meal. However, performance varied across supplementation levels with dry maize cob. GFM supplemented with 25% dry maize cob yielded the highest overall survival (86.2%) and highest 14-day-old male adult wet weight (0.54 g). While the shortest overall developmental period (86.8 days), highest fledgling adult wet weight (0.53 g), and highest 14-day-old female adult wet weight (0.82 g) were observed on GFM supplemented with 50% dry maize cob. Supplementing GFM with 75% dry maize cob resulted in the shortest pre-oviposition period (10.6 days) and the highest percentage hatchability (82.7%). Generally, supplementing GFM with dry maize cob greatly improves the performance of R. differens. Our findings recommend including dry maize cob on the list of low-cost substrates for the farming of this endangered valuable edible insect species.

Crickets are among the most consumed insects worldwide and are one of the few edible insect species that have received significant attention for domestication as a sustainable alternative to wild harvests. However, information on domesticated cricket species and the extent of cricket farming in different parts of the world is scanty and scattered in literature, which is an impediment to the development of the sector. This review analyzed the global progress in the domestication of edible crickets in relation to species being consumed, developments in cricket farming technology, and the levels of domestication, as well as challenges faced in the domestication process. Information was collated from published research articles and edible insect platforms (International Platform of Insects for Food and Feed and Asian Food and Feed Insect Association). Despite the global consumption of 62 cricket species, we found that only 14 have successfully undergone domestication. Among the commonly domesticated species are Acheta domesticus, Gryllus bimaculatus, Gryllodes sigillatus, Gryllus assimilis, and Teleogryllus testaceus. Researchers have developed effective methods for rearing crickets using different by-products at a wide range of temperatures. Asia is the leading continent in cricket farming, with the highest number of cricket farmers in Thailand (22,000), followed by America, Europe, and lastly Africa. Generally, cricket farming is constrained by expensive feeds, markets, regulations, and policies. We recommend that promotion of cricket farming globally should focus on having harmonized regulations and policies, increasing consumer acceptability, developing rearing protocols for more species, alternative low-cost feeds, and automating rearing systems.

The long-horned edible grasshopper Ruspolia differens (Serville) (Orthoptera: Tettigoniidae) is a significant food source in Southern and Eastern Africa due to its rich nutritional profile. The declining yields from wild harvests have driven research into developing methods for mass rearing of R. differens. Despite extensive efforts, identifying cost-effective nutritious diets has been challenging. This study tested eight diets including seven diets constituted from oil seed by-products, i.e., sunflower seed cake, shea seed cake, oil palm seed cake and one control diet (germinated finger millet). The experiment was arranged as a randomised unreplicated block design. Survival of neonates to adults and adult weight of R. differens reared on sole sunflower seed cake and combinations of either oil palm seed cake or shea seed cake with germinated finger millet were statistically comparable to the R. differens reared on sole germinated finger millet (control); whereas no R. differens survived on any of the diets containing shea seed cake and the sole oil palm seed cake diet. Germinated finger millet increased the insect’s crude fat, carbohydrates and mono-unsaturated fatty acids. Conversely, R. differens reared on oil seed by-products-based diets had the highest contents of protein, minerals and polyunsaturated fatty acids than those raised on germinated finger millet. We conclude that (i) sole sunflower seed cake and/or a combination of the same or oil palm seed cake with 50% germinated finger millet are alternative diets to sole germinated finger millet in the mass rearing of R. differens and (ii) the diets based on oil seed by-products can be used to enhance the content of protein, mineral and polyunsaturated fatty acids of R. differens. We recommend further studies to increase the content of alpha linolenic acid in these diets to produce R. differens which is more nutritionally suitable for human consumption.

The loss and degradation of tropical rainforests pose significant challenges to global conservation, yet the impact of forest restoration on the functional diversity of animal communities, particularly at the intraspecific level, remains poorly understood. This study investigates the size distribution of fruit-feeding butterflies along a gradient of tropical forest restoration ages in Kibale National Park, Uganda. Study sites were categorised into three forest age groups: younger restored (10–16 years), older restored (21–26 years), and primary forests. Butterflies were sampled across 48 sites, and individual forewing lengths were measured to analyse changes in mean forewing length, diversity, skewness, and kurtosis. The mean forewing length and diversity increased, while skewness and kurtosis decreased, towards primary forest age group. Significant differences in size metrics were observed among forest age groups, with younger restored forests showing lower diversity compared to older restored and primary forests. Intraspecific differences in forewing length were detected in six of the 12 species studied, highlighting the nuanced insights provided by individual-level data compared to species-level analyses. Kernel density plots demonstrated a gradual shift towards more uniform size distributions along the restoration gradient, suggesting that morphological diversity increases as forests mature. These findings underscore the value of considering intraspecific variation in understanding community responses to forest restoration. The study highlights the prolonged but steady progress towards primary forest, offering important implications for tropical forest conservation and applied ecology.

The degree to which individuals within populations vary in whether, how far and what direction they disperse is central in order to understand many foundational questions in ecological entomology, including factors determining population and invasion dynamics, species' ability to respond to climate change or when designing conservation strategies for threatened species.

This study combined stable hydrogen isotope analysis of nymphal and adult wing chitin with population genetic analysis of the cytochrome c oxidase subunit I (COI) gene to understand long-distance movements of African edible bush cricket (Ruspolia differens) in East Africa.

Results revealed that at most 77% of non-swarming adults and 85% swarming adults originated locally, that is, within a range of a few hundred kilometres. In contrast, non-local adults captured in Uganda likely originated from Ethiopia, Kenya or South Sudan based on the H isotopic evidence. Genetic analysis revealed 150 COI haplotypes with no significant differentiation among geographic source regions and no evidence of genetic isolation by movement distance.

The observed frequent long-distance movements, together with the historical records, which indicate that the swarm movements can be irregular in their direction, suggest that the movements represent nomadism rather than regular long-distance migration. Our results thus provide a valuable case study of what characterizes nomadic movements in insects, which have been one of the outstanding open questions in movement ecology of animals.

Background: Insects are widely recognized as a valuable source of protein and solution to food security, particularly in developing countries like Uganda. This study documents the local knowledge and practices of edible insects consumed and perception and attitudes towards edible insects by different ethnic groups in northern Uganda.

Methods: This cross-sectional study was conducted from October 2023 to January 2024 in the districts of Adjumani, Nwoya, Oyam and Zombo in northern Uganda, where 600 questionnaires which comprised of both closed and open-ended questions were administered to randomly selected respondents (60% female, 40% male) in 24 villages spread across four ethnic groups (Acholi, Langi, Alur and Madi). We aimed to find out, whether differences exist in the types of edible insects consumed and which ones were preferred based on ethnicity, age, gender and education level.

Results: Our study revealed that eleven edible insect’s species belonging to two orders (Orthoptera and Isoptera) and four families—Tettigoniidae, Termitidae, Gryllotalpidae and Acrididae were consumed as food among the Acholi, Alur, Madi and Langi. These species include: Ruspolia differens, Locusta migratoria, Kraussaria angulifera, Macrotermes subhyalinus, Macrotermes bellicosus, Macrotermes michaelseni, Pseudacanthotermes militaris, Syntermes spp. soldiers, Lanista varelai and Gryllotalpa africana. L. varelai, locally known as ‘Ocene-labolo’ in Acholi, is reported as edible insect for the first time. Additionally, one unidentified edible insect, locally known as ‘Mumu’ in Alur or ‘Lakwinyekimo’ in Acholi, was reported to be used as food. Preference for edible insects varied among the ethnic groups, with R. differens being the most preferred among Alur (85%) and Acholi (41%). Conversely, M. subhyalinus (33%) and M. bellicosus (64%) were the most popular among the Langi and Madi, respectively. The respondents had positive perception on edible insect’s consumption as an alternative protein source (98%) to conventional protein source, particularly for insects that were already known to be eaten in the study areas.

Conclusions: The high diversity of utilized edible insects identified in our study area and the responses indicate that entomophagy is a common practice in the region. Therefore, along with being an important delicacy and traditional foods, edible insects can improve household nutrition status by providing an alternative protein source to alleviate food insecurity and malnutrition among rural communities.

The edible African bush cricket, Ruspolia differens (Serville), is the most sought-after nutrient-dense edible insect in East Africa, with the potential to boost employment and income opportunities and ensure food and nutritional security. However, this potential is curtailed by the reliance on the limited and unstable harvests from its wild populations. Recently, significant effort has gone into developing protocols for domesticating this species, but this information is scattered in literature and limits the standardization of rearing techniques. This contribution reviews recent research on edible R. differens rearing protocols in East African region with a view to improving its rearing practices. We searched published articles from four databases including PubMed, Google Scholar, Scopus and Web of Science following the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA) method. Of the 99 records identified, 36 reviews met inclusion criteria. We found that this species can be reared from egg to adult in a relatively short time on grass leaves, inflorescences and grains as well as on artificial diets, side-streams from industry and agricultural by-products, and at relatively high densities. More diversified diets lead to shorter development time, increased adult fresh weight, and enhanced female fecundity compared to single or less diversified diets. Increasing the protein levels in the diet by up to 17% enhances the growth, development and survival of R. differens. The suitable temperature for R. differens rearing is 28–30 °C. Suitable rearing density for young R. differens nymphs should not exceed 36 nymphs per liter, as higher densities significantly increase nymph mortality rapidly over time. A promising egg-laying medium for larger scale production is an artificial folded plastic cloth (one side covered with short fleece). We also identify knowledge gaps and challenges that need to be tackled before scaling up technologies for R. differens mass production in the East African region. Our review offers suggestions to entrepreneurs and investors who wish to finance R. differens farming endeavors.

The house cricket, Acheta domesticus (Linnaeus) (Orthoptera: Gryllidae) is one of the major insects successfully domesticated for food around the world. However, expensive feed is still a major challenge in the production of the insect, leading to low returns. This study aimed at developing an alternative diet for mass rearing of A. domesticus. We tested five diets, namely commercial chicken mash (CCM; control diet), maize bran supplemented with 50% sunflower seed cake (SFC50), 50% shea seed cake (SBC50), 50% oil palm seed cake (POC50), and 25% maize bran + 25% of each of the oil seed cakes (MSSP25). The experiment was arranged as a randomized unreplicated block design with 50 blocks, each containing one replicate of each diet treatment. Survival of A. domesticus fed on maize bran supplemented with either sunflower seed cake or oil palm seed cake was comparable to that of those fed on the control diet. However, emerging adults on oil seed supplemented diets (SFC50 and POC50) were heavier than their counterparts raised on the control diet. The shortest development time was observed among A. domesticus fed on 50% sunflower seed cake compared to all other diets. Acheta domesticus fed on the control diet was richer in protein, while those reared on maize bran supplemented with either sunflower seed cake or oil palm seed cake contained higher levels of fat, minerals (sodium, calcium, and iron) and polyunsaturated fatty acids (PUFAs). We conclude that supplementation of maize bran with 50% of either sunflower seed cake or oil palm seed cake improves survival and weight gain of A. domesticus and shortens their development time. In addition, these diets modify the nutritional composition of A. domesticus, especially lipids, minerals, and PUFAs. We recommend the use of SFC50 and POC50 as alternative diets to commercial chicken mash in the mass production of A. domesticus.