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Doutoramento em Engenharia Agronómica / Instituto Superior de Agronomia. Universidade de Lisboa The fall armyworm (FAW), is an alien polyphagous insect pest with origin in Americas, where it has more than 350 host plants. Although polyphagous, FAW has preference for maize. In 2016, FAW was detected in West and Central Africa and rapidly spread to all Sub-Saharan Africa (SSA) countries including Mozambique. In SSA, maize is a staple food, and the presence of FAW is a direct threat to food security. Although well studied in its native environment, the field behavior of FAW in the new habitat is less known, which makes it difficult to manage. The objectives of the study were: a) to assess the seasonal dynamics of FAW; b) to assess the host range of FAW in the invaded areas; c) to assess the occurrence of native parasitoids of FAW, their parasitism rates and relative abundance, and; d) to assess smallholder farmers’ knowledge and management practices of FAW. To study its seasonality, 622 maize fields were surveyed for the presence of FAW egg masses and larvae in wet and dry seasons. Population density, infestation and damages were determined. To assess the host range, 35 different crops distributed in 1291 fields were checked for the presence of FAW egg masses and larvae. To verify the possible occurrence of native parasitoids, 101 egg masses and 1444 FAW larvae were collected from maize fields infested with FAW and checked for parasitism. To assess farmers’ knowledge and management practices of FAW, 200 farmers were interviewed through a semi-structured questionnaire FAW population density, infestation and damages on maize were found to be higher during the dry season. At the time of this study, no evidence was found suggesting that FAW was feeding in crops other than maize because out of 35 crops surveyed, FAW was only recorded on maize. Five larval parasitoids of FAW were recorded but no egg parasitism vii was observed. Coccygidium luteum Brullé (Hymenoptera: Braconidae) and Drino quadrizonula Thomson (Diptera: Tachinidae) were the primary parasitoid species. Total parasitism was estimated at 9.49% Although most farmers are aware of FAW and its consequences, they are unable to morphologically distinguish FAW from other caterpillars and most of them do not use any method of control against the pest. Surveys of FAW should be carried out in different parts of the country along several years to generate consistent data on its seasonality and host range. Cultural practices enhancing the performance of local occurring FAW parasitoids should be advocated among smallholder farmers. Farmers should be trained in identification of FAW stages. Results from this study could support some decisions toward a sustainable pest management strategy of FAW in Mozambique. N/A |
