Fruit flies are a major threat to the horticulture industry in Africa owing to their damage incidence and economic losses to fruit and vegetable crops, and their quarantine implications. Numerous studies with different research interests have been conducted on fruit flies throughout the African continent. Despite these studies, there is little knowledge among stakeholders about fruit fly pests in terms of the economically important species, their pest status, economic impact and control strategies. These parameters are prerequisites in designing management tools for addressing the fruit fly problem in the continent. This paper reviews the status of the fruit fly menace in Africa by reporting some of the findings of previous researchers while laying emphasis on what needs to be done.

Temperature‐dependent development, parasitism and longevity of the braconid parasitoids, Fopius arisanus Sonan and Diachasmimorpha longicaudata Ashmed on Bactorcera invadens Drew Tsuruta & White, was evaluated across five constant temperatures (15, 20, 25, 30 and 35°C). Developmental rate decreased linearly with increasing temperature for both the parasitoid species. Linear and Brière‐2 nonlinear models were used to determine the lower temperature threshold at which the developmental rate (1/D) approached zero. For F. arisanus, lower thresholds to complete development estimated with the linear and nonlinear models were 10.1 and 6.9°C, respectively. The total degree‐days (DD) required to complete the development estimated by the linear model for F. arisanus was 360. In D. longicaudata, the linear and nonlinear models estimated lower thresholds of 10.4 and 7.3°C, respectively, and the total DD estimated was 282. In F. arisanus, percentage parasitism differed significantly across all temperatures tested and was highest at 25°C (71.1 ± 2.5) and lowest at 15°C (46.4 ± 1.4). Parasitoid progeny sex ratio was female biased at all temperatures except at 20°C. In D. longicaudata, percentage parasitism was highest at 20°C (52.2 ± 4.0) and lowest at 15°C (27.7 ± 2.5). Parasitoid progeny sex ratio was female biased and similar for all temperatures. Adult longevity of both parasitoids was shortest at 35°C and longest at 15°C, and females lived significantly longer than males at all temperatures tested. Our findings provide some guidance for future mass rearing and field releases of the two parasitoids for the management of B. invadens in Africa.

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An important aspect of fruit fly management is accurate information on the species and their host spectrum. Studies were conducted between October 2011 and September 2013 to determine the host range and species diversity of pest fruit flies in the northern savannah ecology of Ghana. Fruit samples from 80 potential host plants (wild and cultivated) were collected and incubated for fly emergence; 65 (81.5%) of the plant species were positive to fruit flies. From records in Africa, 11 plant species were reported to be new hosts to the African invader fly,Bactrocera invadens(Drew, Tsuruta and White, 2005). This study documented the first records ofDacus ciliatus(Loew) andTrirhithrum nigerrimum(Bezzi) in northern Ghana although both species have been previously reported in other parts of the country. Infestation byB. invadenswas higher in the cultivated fruits;Ceratitis cosyradominated in most wild fruits. Cucurbitaceae were mainly infested by three species ofDacusandBactroceracucurbitae, a specialized cucurbit feeder. Among the commercial fruit species, the highest infestations were observed in mango, tomato, sweet pepper and watermelon, whereas marula plum, soursop, tropical almond, sycamore fig, African peach, shea nut, persimmon, icacina and albarillo dominated the wild host flora. The widespread availability of host plants and the incidence of diverse fly species in the ecology call for particular attention to their impact on commercial fruits and the development of sustainable management strategies against these economically important pests in Ghana.

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Mango farmers in Ghana are confronted with many pest problems like fruit flies, Sternochetus mangiferae (F.), and mealy bugs. Different pest management options are available to mango farmers; however, the extent to which they apply the available pest management options is not well known. A survey was conducted among 60 farmers in southeastern Ghana, from October–December 2015 mango season, to find out the level of knowledge and practice of insect pest management used by mango farmers. The results showed that most farmers use conventional insecticides to control insect pests in mango. Majority of the farmers (30%) use a composite insecticide (Cydim super; 36 g cypermethrin + 400 g dimethoate per liter), whereas 3.3% use Pyrinex (chlorpyrifos 480 g/liter). Majority of insecticides used belong to WHO category II. Ninety percent (90%) of the farmers use cultural practices and pheromone traps. Pheromone traps are, however, used for fruit flies but not for S. mangiferae. Over 80% of the respondents who used pesticides to control pests have also adopted GLOBALGAP standards for certification. The results are discussed based on the importance of adoption of IPM strategies in mango production and the possible reduction of fruit rejection during mango export in Ghana.

Plantain ( M u m AAB) , a primary food crop in Ghana, is a key component in sustainable agricultural systems in high rainfall zones. Recently, there has been a substantial yield decline and reduction in plantation life. To elucidate the context in which intervention strategies should be developed, a Participatory Rural Appraisal (PRA) was conducted at five villages in the major plantainproducing belt of Ghana. The importance of plantain as a preferred food was confirmed, although farmers tended to sell plantain for cash income, using cheaper, less preferred alternatives for home consumption. Farmers identified decreasing soil fertility, the high cost of labour for weeding, pests and diseases, lack of good quality planting material and marketing-related issues as the major production constraints. Due to declining productivity in less fertile regions, plantain has been replaced with other food crops such as cassava and maize. Farmers overestimated the importance of insect pests but were unaware of the extensive damage that could be caused by nematodes and the foliar disease, black sigatoka. They observed, however, that pest damage is more severe when soil fertility is poor. Clearly, integrated pest management is likely to be most effective when practiced within the context of cropping systems management; sustainable strategies that are being developed for resource-limited plantain farmers in Ghana are discussed.

The presence of large colonies of aphids is associated with a devastating novel necrotic disease of cabbage (Brassica oleracea var. capitata) in Ghana that is thought to be of viral etiology. In this study, we used molecular taxonomic tools to identify the aphid species present on these diseased cabbage plants. This was confirmed using two key features for morphological identification, involving the length of cornicles and shape of cauda for the wingless forms of the aphids. Two species of aphids were identified and their distribution in Ghana indicated. One was the generalist aphid Myzus persicae (Sulzer) (Hemiptera: Aphididae) but the most abundant was the brassica specialist aphid, Lipaphis erysimi pseudobrassicae (Davis) (Hemiptera: Aphididae), which is one of the most destructive pests of brassica crops in some countries in Africa and other parts of the world. L. erysimi has been reported in Benin, Mali, South Africa, India, China, and United States, but this is the first formal report of L. erysimi pseudobrassicae in Ghana. The correct identification of L. erysimi is crucial, suggesting that it has recently become one of the most common species of aphid found on cabbage plants in Ghana.