Foraging and nest maintenance activity of the leafcutter ant Acromyrmex lobicornis (Hymenoptera: Formicidae) in an organic vineyard in the Monte desert of Mendoza, Argentina

Abstract

Exclusive to the Neotropical region, leaf cutter ants are considered agricultural pests, although they can also have a positive effect on plants. In Mendoza vineyards, vegetal biodiversity is minimal, therefore they cut off this plant as a feeding resource. Acromyrmex lobicornis Emery it is mostly nocturnal and forages according to temperature. Foraging and maintenance activity was measured monthly in 14 colonies, throughout a full day at four-hour intervals, from October 2019 to March 2020. Acromyrmex lobicornis showed different seasonal patterns of foraging activity. Foraging intensity was highest throughout January and February, intermediate during December, and lowest in October and November. A bimodal feeding pattern was observed, foraging both day and night avoiding the hottest hours. The maximum collection of fragments was observed in the range of 10 and 19 °C, less between 20-39 °C, minimum between 40-49 °C and null between 0-9 °C. The nest-maintenance activity was maximum between 20-29 °C, less between 30-39 ° C, minimum between 40-49 °C and null between 0-20 °C.