Browsing by Author "Kabota, Sija"

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Floral visitation of European honey bees and hoverflies in selected cultivated cucurbitaceous crops in Morogoro, Eastern-Central Tanzania
(PLOS One, 2025-05-12) Rweyemamu, Elvillah William; Kabota, Sija; Tryphone, George Muhamba; Meyer, Marc De; Mwatawala, Maulid Walad
Cucurbit production in many parts of the world is constrained by the absence of effective pollinators. Due to the decline of European honey bees (Apis mellifera), main pollinators of cucurbits, there is a need to explore other cucurbits flowers visiting insects to supplement pollination services and for their conservation. Studies were carried out in the two agroecological zones of Morogoro Region, Eastern - Central Tanzania. We assessed visitation abundance, visitation frequency and visitation rate of four cucurbits flowers visiting insects under the family Syrphidae [Eristalinus megacephalus, Mesembrius caffer, Paragus borbonicus and Toxomerus floralis] and A. mellifera on cucumber (Cucumis sativus), watermelon (Citrullus lana- tus) and squash (Cucurbita moschata). Field trials were conducted in a 5 × 3 × 2 × 2 factorial arrangement in a randomized complete block design for two seasons. Results showed significant effects of the interaction between agroecological zones × cucurbit species × season × flowers visiting insects on visitation abundance, visitation frequency and visitation rate (p < 0.0001) of flower visiting species. Apis mellifera was the dominant species in cucurbit flowers at both agroecological zones during the two growing seasons. Given its relatively higher visitation, T. floralis is a promising hoverfly species to be explored for its role in the pollination of C. sativus and C. lanatus. Agroecological zone, season and cucurbit species determined the visitation of European honey bees and hoverflies on cucurbits flowers. Cucurbit growers are suggested to employ management practices on farms that favour the abundance and foraging activities of these flower visiting insects for improved and sustainable cucurbit production.
Impact of cucurbit crop management techniques on the foraging behavior of honeybees and hoverflies in Morogoro, Tanzania
(BMC Ecology and Evolution, 2024) Rweyemamu, Elvillah William; Mwatawala, Maulid Walad; Tryphone, George Muhamba; Meyer, Marc De; Kabota, Sija; Bwire, Patroba Masatu
Background Poor agricultural practices have drastically threatened insect pollinators’ biodiversity. Little is known in Tanzania about how different agricultural practices affect pollinators’ foraging behavior. This study investigated the effects of the agroecological zone, season, cucurbit species and management practices on visitation frequency, visitation rate and time spent on cucurbit flowers by five pollinator species viz. Apis mellifera, Eristalinus megacepha- lus, Mesembrius caffer, Paragus borbonicus and Toxomerus floralis. The experiment was designed as a 5 × 3 × 3 × 2 × 2 factorial arrangement in a Randomized Complete Block Design (RCBD) with four replications. GAMOUR-Agroecology was tested against conventional practices and untreated control. Results This study revealed significant effects of agroecological zone × season × cucurbit species × management practice on pollinators’ visitation frequency (p = 0.007) and time spent on flowers (p = 0.005). Also, agroecological zone × season × cucurbit species × pollinator species significantly (p < 0.0001) affected pollinators’ visitation frequency. Agroecological zones × season × cucurbit species × cucurbits management practices × pollinators significantly (p = 0.001) affected pollinators’ visitation rate. Apis mellifera was the most frequent visitor in Cucurbita moschata plots treated with GAMOUR- Agroecology in the plateau zone, also, visited higher number of Cucumis sativus plots under GAMOUR-Agroecology practices in the mountainous zone during the October–November season. Further- more, it has been found that pollinators spent much in cucurbit flowers on plots with GAMOUR-Agroecology prac- tices and control. Conclusions Pollinators’ foraging behavior were enhanced by GAMOUR-Agroecology practices. Therefore, this study recommended that cucurbit growers should consider management practices that positively influence pollinator foraging activities for sustainable cucurbit production
Pathogenicity of purpureocillium lilacinum and clonostachys rosea against fall armyworm (spodoptera frugiperda) under laboratory conditions
(PLOS One, 2026-03-16) Mussa,Abel Jonathan; Kabota, Sija; Ruboha, Joseph O.; Martin, Martin John; Mwatawala, Maulid W.
Background Fall armyworm, Spodoptera frugiperda (J.E. Smith) threatens staple crops across Africa. Integrating entomopathogenic fungi into Integrated Pest Management (IPM) offers a sustainable alternative to sole reliance on insecticides. This study quantified the pathogenicity of Purpureocillium lilacinum and Clonostachys rosea against S. frugiperda under controlled conditions. Methods Second-fifth instar larvae and eggs were exposed to 1 × 107, 1 × 108, and 1 × 109 conidia mL-1 of each fungus; sterile water served as control. Mortality was recorded over 3–9 days after treatment (DAT); feeding reduction was measured gravimetrically. Larval mortality was analyzed with GLMs/GLMMs (binomial-probit); feeding reduction by ANOVA/Tukey; LD50 and LT50 were estimated from dose-response models. Results Larval mortality was significantly affected by concentration × time interaction and declined with advancing larval stage. Peak larval mortality was reached at a concentration of 1 × 109 conidia mL-1 at 9 DAT. Feeding consumption reduction was significantly affected by larval instar, EPF species, and instar × concentration. Feeding reduction reached 60−74% in early instars at the highest dose. Egg mortality was primarily concentration-dependent with maximum values (up to 82% and 88% for P. lilacinum and C. rosea, respectively) at the dose of 1 × 109 conidia mL-1 highest dose. Our findings supported the study hypothesis that efficacy of entomopathogenic fungi against S. frugiperda is primarily driven by interaction of spore concentration and exposure time across the host developmental stages, rather than the interaction of fungal species. The consistent susceptibility of early instars and the strong concentration-dependent responses highlight the functional potential of these native fungi as biologically relevant components of sustainable IPM strategies. Conclusions Native P. lilacinum and C. rosea display dose‑, stage‑, and time‑dependent pathogenicity and feeding suppression against S. frugiperda. These species are promising candidates for IPM; field validation and formulation optimization are the next steps.