The black soldier fly, Hermetia illucens (Diptera: Stratiomyidae): Trapping and culturing of wild colonies in Ghana

The larvae of the black soldier fly (BSF), Hermetia illucens L. (Diptera: Stratiomyidae), are promising candidates to be utilized in alternative organic waste management and for fish and livestock feed production. The scalability of this technology in Ghana will depend on a steady source of large numbers of BSF larvae. The objectives of this study were to identify the most attractive organic manure dumps or heaps in the study area for trapping wild BSF egg clutches and assess the effect of local environmental conditions on the trapping and laboratory rearing of BSF. The study compared the number of egg clutch trapped at different microhabitats including piggery, chicken and sheep waste dumps and on a compost heap. The piggery dump waste was the most suitable site for trapping BSF egg clutches. No egg clutch was deposited nearby poultry and sheep waste microhabitats. Results showed no differences in temperature between microhabitats during egg trapping but relative humidity differed between poultry, sheep and compost, however this did not have any effect on egg clutch trapping. No significant differences in temperature and humidity were observed during larval rearing. Significant differences in weight and length of larvae from both piggery and compost sites were observed on days 5 and 10 after egg hatch. A small scale laboratory colony rearing has been successfully established in Ghana. The design of the larval breeding system appears to be suitable for respective up-scaling that could provide sufficient larval quantities for composting organic waste and producing feed components for livestock and fish

Development of Aquaculture in Ghana: Analysis of the fish value chain and potential business cases

The main aim of this study was to assess the feasibility of the formation and set-up of one or more Public Private Partnerships (PPPs) for aquaculture in Ghana. The project consisted of two phases. The first phase was a value chain analysis (VCA) of aquaculture in Ghana to identify bottlenecks and business opportunities. The second phase was to develop business cases for investments in aquaculture in Ghana. Since the demand for Tilapia in Ghana is very high, the focus of this study is mainly on Tilapia

Differences in sexual size dimorphism among farmed tilapia species and strains undergoing genetic improvement for body weight

Many tilapia (Oreochromis spp.) farmers produce all-male populations because of the superior growth rate of males compared to females. To investigate differences in body weight at harvest of males and females among different tilapia strains, we analyzed data from 62,787 individuals collected from pedigreed breeding programs of O. niloticus (GIFT from Malaysia, the Abbassa line from Egypt, and the Akosombo line from Ghana), O. shiranus (the Bunda College-Domasi selection line), O. aureus (a selection line under development in Abbassa, Egypt, and a selection line from Israel) and a synthetic selection line of Red tilapia under development in Jitra, Malaysia, derived from stock from Malaysia, Taiwan and Thailand (O. sp.). Mixed models were separately fitted to the data from each selection line. There was a significant sex effect in all strains (P < 0.001). A significant (P < 0.001) sex by generation interaction was observed in all strains (scale effect, not reversal of rankings), except Red tilapia and O. shiranus. Least squares means showed a large range in the magnitude of body weight differences between sexes across the seven strains. The largest percentage difference between females and males was in O. aureus from Egypt (female body weight was 52.2% that of males at harvest), whereas the smallest difference was observed in the GIFT strain of O. niloticus (female body weight 84.7% that of males). Female to male body weight percentages for Red tilapia, O. shiranus, Egypt O. niloticus, Israeli O. aureus and Ghana O. niloticus were 81.3, 81.0, 69.1, 61.7 and 61.0, respectively. We discuss the results in relation to the potential productivity improvements due to superior growth rates of all-male culture compared to mixed-sex culture in tilapia populations differing in the female to male body weight ratio