Abstract:
Sustainable production of pumpkin (Cucurbita maxima Duchesne) partly relies on integrated pest management
(IPM) and pollination services. A farmer-managed field study was carried out in Yatta and Masinga Sub-
Counties of Machakos County, Kenya, to determine the effectiveness of a recommended IPM package and its
interaction with stingless bee colonies (Hypotrigona sp.) for pollinator supplementation (PS). The IPM package
comprised Lynfield traps with cuelure laced with the organophosphate malathion, sprays of Metarhizium
anisopliae (Mechnikoff) Sorokin isolate ICIPE 69, the most widely used fungal biopesticide in sub-Saharan
Africa, and protein baits incorporating spinosad. Four treatments—IPM, PS, integrated pest and pollinator management
(which combined IPM and PS), and control—were replicated 4 times. The experiment was conducted
in 600 m2 farms in 2 normalized difference vegetation index (NDVI) classes during 2 growing seasons (October
2019–March 2020 and March–July 2020). Fruits showing signs of infestation were incubated for emergence,
fruit fly trap catches were counted weekly, and physiologically mature fruits were harvested. There was no
effect of IPM, PS, and NDVI on yield across seasons. This study revealed no synergistic effect between IPM
and PS in suppressing Tephritid fruit fly population densities and damage. Hypotrigona sp. is not an efficient
pollinator of pumpkin. Therefore, we recommend testing other African stingless bees in pumpkin production
systems for better pollination services and improved yields.
