Malaria parasites exhibit a complex lifecycle, requiring extensive asexual replication in the liver and blood of the vertebrate host, and in the haemocoel of the insect vector. Yet, they must also undergo a single round of sexual reproduction, which occurs in the vector’s midgut upon uptake of a blood meal. Sexual reproduction is obligate for infection of the vector and thus, is essential for onwards transmission to new hosts. Sex in malaria parasites involves several bottlenecks in parasite number, making the stages involved attractive targets for blocking disease transmission. Malaria parasites have evolved a suite of adaptations (“strategies”) to maximise the success of sexual reproduction and transmission, which could undermine transmission-blocking interventions. Yet, understanding parasite strategies may also reveal novel opportunities for such interventions. Here, we outline how evolutionary and ecological theories, developed to explain reproductive strategies in multicellular taxa, can be applied to explain two reproductive strategies (conversion rate and sex ratio) expressed by malaria parasites within the vertebrate host.

疟疾寄生虫表现出复杂的生命周期，需要在脊椎动物宿主的肝脏和血液以及昆虫媒介的血腔中进行广泛的无性复制。然而，它们还必须经历单轮有性繁殖，这种繁殖发生在媒介摄入血粉后的中肠中。有性繁殖对于载体的感染是必需的，因此对于继续传播到新宿主至关重要。疟疾寄生虫的性行为涉及寄生虫数量的几个瓶颈，这使得所涉及的阶段成为阻止疾病传播的有吸引力的目标。疟疾寄生虫已经进化出一套适应措施（“策略”），以最大限度地提高有性繁殖和传播的成功率，这可能会破坏传播阻断干预措施。然而，了解寄生虫策略也可能揭示此类干预措施的新机会。在这里，我们概述了如何应用进化和生态理论来解释多细胞类群的繁殖策略，以解释脊椎动物宿主内疟原虫表达的两种繁殖策略（转化率和性别比）。