A theoretical basis for the study of predatory syrphid fly ecology

Abstract

Predacious syrphid fly species, also known as flower flies or hover flies, are cosmopolitan diptera that play two important ecological roles: predator and pollinator. In decades past, syrphid flies were studied by agricultural researchers due to their larvae’s ability to function as a biological control agent. In recent years, the global decline in both honey bees and various important wild bee species has led ecological researchers to investigate the role of syrphid fly pollination in both natural systems and agriculture. While these two roles have often been considered separately, they are rarely considered together in single studies. Syrphid fly population fluctuations in natural and agricultural systems are understudied, prompting calls for further study into the fundamental drivers of population dynamics of syrphid communities. In order to develop a deeper understanding of the fundamental dynamics of syrphid ecology, the present study offers a community model where both syrphid predation and pollination are incorporated into a single dynamic model. Using populations of predacious syrphid flies, herbivorous insects, and a shared resource flowering plant, the model is used to investigate community dynamics and persistence across different levels of plant reproductive dependence on syrphid pollination. Results indicate distinct levels of community viability across different pollination relationships as well as a tendency toward chaotic dynamics inherent to the trophic interactions of the community.