Centre for Integrative Ecology, School of Life and Environmental Sciences, Deakin University, Burwood, Victoria, Australia.
Faculty of Information Technology, Monash University, Clayton, Victoria, Australia.
PLoS One. 2021 May 14;16(5):e0251572. doi: 10.1371/journal.pone.0251572. eCollection 2021.
Over one third of crops are animal pollinated, with insects being the largest group. In some crops, including strawberries, fruit yield, weight, quality, aesthetics and shelf life increase with insect pollination. Many crops are protected from extreme weather in polytunnels, but the impacts of polytunnels on insects are poorly understood. Polytunnels could reduce pollination services, especially if insects have access issues. Here we examine the distribution and activity of honeybees and non-honeybee wild insects on a commercial fruit farm. We evaluated whether insect distributions are impacted by flower type (strawberry; raspberry; weed), or distance from polytunnel edges. We compared passive pan-trapping and active quadrat observations to establish their suitability for monitoring insect distribution and behaviour on a farm. To understand the relative value of honeybees compared to other insects for strawberry pollination, the primary crop at the site, we enhanced our observations with video data analysed using insect tracking software to document the time spent by insects on flowers. The results show honeybees strongly prefer raspberry and weed flowers over strawberry flowers and that location within the polytunnel impacts insect distributions. Consistent with recent studies, we also show that pan-traps are ineffective to sample honeybee numbers. While the pan-traps and quadrat observations tend to suggest that investment in managed honeybees for strawberry pollination might be ineffective due to consistent low numbers within the crop, the camera data provides contrary evidence. Although honeybees were relatively scarce among strawberry crops, camera data shows they spent more time visiting flowers than other insects. Our results demonstrate that a commercial fruit farm is a complex ecosystem influencing pollinator diversity and abundance through a range of factors. We show that monitoring methods may differ in their valuation of relative contributions of insects to crop pollination.
超过三分之一的农作物依赖动物传粉,而昆虫是最大的传粉群体。在一些作物中,包括草莓,水果的产量、重量、品质、美观和货架期都会随着昆虫传粉而增加。许多作物在聚氯乙烯温室中免受极端天气的影响,但温室对昆虫的影响知之甚少。聚氯乙烯温室可能会减少授粉服务,尤其是如果昆虫存在进入问题。在这里,我们研究了商业水果农场中蜜蜂和非蜜蜂野生昆虫的分布和活动情况。我们评估了昆虫的分布是否受到花的类型(草莓、覆盆子、杂草)或距离温室边缘的影响。我们比较了被动的诱捕和主动的方格观察,以确定它们是否适合监测农场中昆虫的分布和行为。为了了解与其他昆虫相比,蜜蜂对草莓授粉的相对价值,我们对该地点的主要作物进行了增强观察,使用昆虫跟踪软件对视频数据进行分析,记录昆虫在花朵上的停留时间。结果表明,蜜蜂强烈偏爱覆盆子和杂草的花朵,而不是草莓的花朵,并且温室内部的位置也会影响昆虫的分布。与最近的研究一致,我们还表明,诱捕器不能有效地用于取样蜜蜂的数量。虽然诱捕器和方格观察倾向于表明,由于作物内的蜜蜂数量持续较低,投资管理蜜蜂进行草莓授粉可能无效,但摄像头数据提供了相反的证据。尽管蜜蜂在草莓作物中相对较少,但摄像头数据显示它们在花朵上停留的时间比其他昆虫多。我们的研究结果表明,一个商业水果农场是一个复杂的生态系统,通过一系列因素影响传粉者的多样性和丰度。我们表明,监测方法可能会在评估昆虫对作物授粉的相对贡献方面存在差异。