Browsing by Author "Nasari, Sayuni"

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Assessment of the Knowledge, Perceptions, and Reactions towards the African Apefly (Spalgis lemolea lemolea) in Tanzania
(MDPI, 2020-01-28) Nasari, Sayuni; Ndakidemi, Patrick; Mbega, Ernest
This paper reports on farmers’ knowledge, perceptions, and reactions towards the African apefly (Spalgis lemolea lemolea), which appeared to be associated with some vegetables in some locations in Tanzania. Information was obtained from a sample of 100 key respondents using a semi-structured questionnaire and from focus groups selected from key locations in five districts in the country with histories with the African apefly. Acute and sub-acute toxicity tests of the African apefly were performed on female Swiss hybrid mice (Mus musculus) to assess whether or not the African apefly was toxic to mammals. The mice were exposed to increasing apefly meal concentrations in acute and sub-acute tests, and signs of toxicity were observed for 14 and 28 days, respectively. Blood samples were collected by cardiac puncture for hematological and biochemical analysis. Gross and microscopic examinations of the internal organs were done. The survey results showed that 92.1% of the respondents perceived the African apefly as poisonous and had stopped consuming the vegetables associated with it. In the toxicity tests, however, no death or toxic signs were displayed, and there was no significant difference between the control and treated mice in weight, hematological parameters, and histo-pathological examination results. These findings strongly indicate that, despite the negative perception by farmers regarding the African apefly, it is not poisonous. However, further studies on how farmers can be trained to have a positive perception of the African apefly and how the insect can be conserved for further research regarding its role in Tanzania are recommended.
Bionomics of the African Apefly (Spalgis lemolea) as A Potential Natural Enemy of the Papaya Mealybug (Paracoccus marginatus) in Tanzania
(MDPI, 2020-04-14) Nasari, Sayuni; Treydte, Anna; Ndakidemi, Patrick; Mbega, Ernest
The African apefly (Spalgis lemolea Druce) is a potential natural enemy of the papaya mealybug (Paracoccus marginatus Williams and Granara de Willink). We studied the life history of apeflies in the laboratory at a temperature of 25–27 °C and a relative humidity of 55%–65% under a 12 h photoperiod condition. The papaya mealybugs and apefly larvae were collected from papaya plants in Tengeru, Arusha, Tanzania. The papaya mealybugs were introduced and allowed to multiply on potted sprouting potato plants in screened cages. In order to study the life cycle and predation of apeflies, an apefly egg was placed on an open screen-covered petri dish containing a moist blotter paper and observed for larva emergence. After the apefly larva emergence, a mixture of mealybug eggs (up to 1500), nymphs (200–250) and adults (100–150) was introduced in the petri dish each day and the consumption rate by the apefly larvae was quantified until the larvae reached pupal stage. Then, the apefly adults were collected and put into cages 30 cm × 30 cm × 30 cm containing cotton wool soaked in water, for observation of pre-mating, mating, egg-laying and life span. Results indicate that the apefly completed its life cycle in 23 days. The mean development period of the eggs was four days and the development period for the larva, pre-pupa, and pupa was nine, one and ten days respectively. The adult apefly emerged after 9 days of the pupa stage with mean body lengths of 10.1 ± 0.4 mm and 11.0 ± 0.8 mm for the males and females, respectively. The female laid an average of 68 eggs in groups of two to seven at different sites after 4–5 days of emergence. In this study one apefly larva was capable of consuming about 1983 ± 117, 123 ± 6 and 80 ± 9 papaya mealybug eggs, nymphs and adults respectively during larval stage. These results reveal the predatory potential of the apefly in suppressing the population of papaya mealybugs under field conditions.
Towards conservation of Apefly (Spalgis lemolea. Druce) for managing papaya mealybug (Paracoccus marginatus Williams and Granara de Willink) in Sub Saharan Africa
(Elsevier B.V., 2020-03) Nasari, Sayuni; Treydte, Anna; Ndakidemi, Patrick; Mbega, Ernest
This review compiled published information on a rare butterfly, namely Apefly (Spalgis spp) in order to conserve it and explore its potential for managing papaya mealybugs (PM) (Pracoccus marginatus Williams and Granara de Willink), which attack various crop varieties of economic importance worldwide, causing a yield loss of up to 100% in Sub Saharan Africa. One of the biggest challenges behind PM management is its ability to form a wax coat that makes it difficult for chemicals used in pest management to suppress the PM once they have attacked the crops. This review provides a comprehensive description of different Spalgis species, their distribution and how they can be used to control PMs to reduce the losses of crops in Sub Saharan Africa. About 29% of the cited literature in this review indicates the Indian Apefly (Spalgis epius) to be intensively studied with explicit information of its biological control potential. The African Apefly (Spalgis lemolea) has been mentioned by 16.8% of the cited literature with limited or without detailed information ot its biological control potential. Thus, this review recommends research on understanding the biological control potential and other key information such as the life cycles, biology, diversity and ecology of the African Apefly so that the information that will be obtained can be used to design strategies towards conservation of Apefly (Spalgis lemolea. Druce) and biological management of papaya mealybug in Sub Saharan Africa.