Species complementarity in two myrmecophilous lady beetle species in a coffee agroecosystem: implications for biological control

Natural enemy diversity may be beneficial, through species complementarity, or detrimental, through antagonistic interactions, such as competition or intraguild predation, for the biological control of agricultural pests. We studied two coexisting myrmecophilous coccinellid beetles, Azya orbigera (Mulsant) (Coleoptera: Coccinellidae) and an undescribed species in the genus Diomus (Coleoptera: Coccinellidae), in a coffee agroecosystem in Chiapas, Mexico. As both beetles specialize on the same prey, the green coffee scale pest, Coccus viridis (Green) (Hemiptera: Coccidae), we studied the beetles’ behavior and distribution to determine if they niche partition in order to avoid extreme competition. Through field surveys and lab experiments we detected spatial segregation but not resource partitioning among A. orbigera and Diomus sp. We posit that the presence of both species can lead to improved biocontrol of C. viridis populations through species complementarity. Our work supports the growing evidence that natural enemy diversity can provide enhanced conservation biological control.