Species Complex and Temporal Associations between Coccinellids and Aphids in Alfalfa Stands in Spain.

Alfalfa is known to be an important reservoir harboring natural enemies. The reduction in insecticide sprayings in recent years has allowed us to study the coccinellid species complex in this crop and the relationship between these predators and aphids. Alfalfa was sampled by sweep-netting throughout its productive period in several commercial stands each year between 2010 and 2021. The numbers and species of aphids and coccinellids were recorded. Sixteen coccinellid species were found. and were, by far, the most prevalent species, with the former dominating during the first and second intercuts, whereas the latter dominated from the third to the fifth intercut. and were the most abundant aphid species, peaking in the second and fourth intercuts, respectively. Positive correlations were found between the abundance of and at the second intercut, between and at the fourth intercut, and between and the total number of aphids in the fifth intercut. This study helps to increase the knowledge on the predator-prey relationships of this crop and allows for designing strategies of conservation biological control against aphids.