Enhancing crop diversity and ecosystem services to promote biological control of fall armyworm in smallholder cropping systems

撒哈拉以南非洲的小农社区尤其容易受到虫害造成的作物损失的影响，因为他们通常负担不起杀虫剂，而且作为自给自足的农民，他们的粮食安全直接依赖于作物。秋粘虫最近入侵并迅速蔓延到非洲的大片地区，在那里它已成为农业和可持续粮食生产的主要威胁。这种入侵对粮食安全和生计构成了严重且日益严重的威胁，已经影响到至少40万公顷土地，估计每年造成价值30亿美元的作物损失。我们的项目将采用四管齐下的方法来对付秋粘虫，利用作物和伴生植物的自然防御机制。首先，我们将评估农民可获得的玉米、谷子和高粱作物的自然抗性水平，以确定哪些品种对秋粘虫的抗性最强。然后，我们将尝试使用驱虫间作（推）将害虫从主要作物赶走，同时用诱捕植物（拉）将它们吸引到其他地方。这种技术被称为“推拉”连作系统，目前已成功地用于对付干虫害虫。最后，我们将尝试利用其他伴生植物的防御机制来引入作物宠物的本地捕食者。这些“早期食草品种”能够探测到虫卵，并发出气味，吸引害虫的天敌到种植作物的地区。这种基于抗、驱、捕、杀四种策略的新型病虫害治理设计，将提供一种能够抵御秋军虫和其他主要害虫侵袭的新型种植制度。设计这样一个系统需要详细了解捕食者和寄生虫，它们是入侵肯尼亚的秋粘虫的主要天敌。因此，该项目的一个主要部分将是了解作物种植地区目前害虫和捕食者的关系。一旦确定，我们将能够测试这种伴生作物和预警作物如何使用肯尼亚农民容易获得的作物来减轻秋军虫造成的作物损失。这样一个系统只能通过与当地农民的密切合作而产生。我们将与他们共同设计解决方案，这样我们就可以从一开始就确信，所创建的新型种植系统不仅适合他们的需求，而且可以利用他们可用的资源切实实施。

Smallholder farming communities in sub-Saharan Africa are particularly vulnerable to crop losses to pests because they generally cannot afford pesticides and as subsistence farmers, they depend directly on the crops for their food security. Fall armyworm has recently invaded and rapidly spread across large areas of Africa, where it has become a major threat to agriculture and sustainable food production. This invasion is a serious and growing threat to food security and livelihoods and already affects at least 400,000 ha causing estimated crop losses worth $3 billion a year. Our project will employ a four-pronged attack on the fall armyworm, utilising the natural defence mechanisms of the crop and companion plants. Firstly, we will assess the natural resistance levels of the maize millet and sorghum crops available to the farmers to determine which varieties would be most robust against the fall armyworm. We will then attempt to drive pests away from the main crop using a repellent intercrop (push), whilst attracting them to alternative locations with trap plants (pull). This technique is known as a "Push-Pull" companion cropping system and is used currently, successfully, against stemborer pests. Finally, we will attempt to utilise the defence mechanism of other companion plants to bring in local predators of the crop pet. These 'early herbivore varieties' are able to detect insect eggs that have been laid on them and emit odours to attract the natural enemies of the pests to the area where the crop is being cultivated. This novel design of pest management based on the four strategies of resist, expel, trap and kill should provide a novel cropping system which can withstand attack by fall army worm and other major pests.Design of such a system requires a detailed understanding of the predators and parasites that are the key natural enemies of the invasive fall armyworm in Kenya. Therefore, a major part of this project will be to understand the current pest and predator relationship where the crops are being grown. Once determined, we will be able to test how such companion cropping and early alert crops could mitigate crop losses to the fall army worm using crops that are readily available to the farmers in Kenya. Such a system could only be generated through close partnership with the local farmers. We will co-design solutions with them so that that we can be assured from the onset that the novel cropping system that is created is not just appropriate for their requirements but can be feasibly implemented with the resources available to them.