Cucurbits as a model system for crop pollination management

Abstract

Cucurbit crops have steadily increased in production over the last 50 years, particularly in Asia where pioneering technological advancements and genetic improvements have created new hybrid varieties. Generally, cucurbits are dependent on insect-pollination for fruit set and are popular species for pollination studies. This review systematically summarises pollination research conducted in the major food genera of cucurbits: Cucurbita, Cucumis, and Citrullus, to ask: 1) what are cucurbits’ requirement for pollination and their most effective pollinators? And 2) Does pollinator management increase pollinator visitation to, and yield of, cucurbit crops? These accounts of cucurbit pollination demonstrate that wild bee species such as Bombus terrestris, B. impatiens and Eucera spp. were frequently able to fulfil the pollination requirements of multiple cucurbit species. However, pollinator behaviour, pollen deposition on stigmas, and pollinators’ contribution to yield vary between cucurbit species and study site. Nonetheless, the provision of additional floral resources at both field and farm scales may help to encourage pollination of cucurbit species whilst supporting pollinators’ nutritional requirements beyond those already provided by the cucurbit crop. Synthesising studies on cucurbits’ requirement for pollination and how pollinators vary spatially and temporally in the landscape can extend beyond cucurbit systems to inform growers and pollination ecologists of other pollinator-dependent crop species wishing to maximise pollination services, species conservation; or both.

Pollination efficiency of bumblebee, honeybee, and hawkmoth in kabocha squash, Cucurbita maxima, production in Kagoshima, Japan

“…The fruit weight is positively correlated to the number of mature seeds (McGrady et al 2020;Petersen et al 2013). Aside from the squash bees, which are major pollinators of squash plants in origin, bumblebees and honeybees contribute to the production worldwide (Bomfim et al 2016;Knapp and Osborne 2019).…”

Impact of cucurbit crop management techniques on the foraging behavior of honeybees and hoverflies in Morogoro, Tanzania

“…Furthermore, interactions between cucurbit species and agroecological zone as well as cucurbit species and management practices affected pollinator species’ time spent on crops. A. mellifera spent more time on C. moschata flowers due to the availability of more nectars compared to in C. lanatus and C. sativus flowers because honey bees prefer more nectar to pollen [ 3 , 60 ]. Hoverflies spent more time on C. lanatus and C. sativus flowers than on squash flowers due to the easy accessibility of pollens [ 61 , 62 ].…”

“…They contribute to growth, improvement of fruit quality and setting of seeds [2]. This is because, for successful pollination, a female stigma has to be visited several times for the deposition of enough pollen [3]. Poor pollination service can result in a low fruit set, small, contorted fruit and in the absence of pollination, fruit abortion occurs [3][4][5].…”

“…This is because, for successful pollination, a female stigma has to be visited several times for the deposition of enough pollen [3]. Poor pollination service can result in a low fruit set, small, contorted fruit and in the absence of pollination, fruit abortion occurs [3][4][5]. Globally, about 85 to 90 % of cultivated flowering crops depend on insect pollinators for yield enhancement [6].…”

The pest control and pollinator protection dilemma: The case of thiamethoxam prophylactic applications in squash crops

“…Squash crops (Cucurbita pepo), as well as other monoecious cucurbits, are entirely dependent on bee pollination to produce fruits [20]. The most common and efficient bee species pollinating cucurbits in eastern North America are Apis mellifera, Bombus impatiens, and the solitary ground-nesting bee Eucera (Peponapis) pruinosa [21,22].…”