Fungal Community Associated with the Leaf-Cutting Ant Acromyrmex crassispinus (Hymenoptera: Formicidae) Colonies: a Search for Potential Biocontrol Agents.

The leaf-cutting ant Acromyrmex crassispinus is considered an important pest in forest plantations in southern Brazil. This work aimed to study the fungal community associated with A. crassispinus colonies, subjected to treatments with subdoses of granulated baits (sulfluramid), which might reduce the ability of the ants to care for their symbiotic fungus and other fungi (maybe biocontrol fungi) would take over, to prospect for potential biological control agents. Samplings of fungus gardens and dead ants allowed the identification of 195 fungal isolates, distributed in 29 families, 36 genera, and 53 species. The most frequent genera were Trichoderma (49.2%), Penicillium (13.8%), Chaetomium (6.2%), and Fusarium (3.6%). This is the first study that conducted a survey of antagonistic and entomopathogenic fungi to A. crassispinus and its symbiotic fungus, reporting for the first time the occurrence of potential biological control agents. Escovopsis weberi, Fusarium oxysporum, Rhizomucor variabilis, Trichoderma atroviride, Trichoderma harzianum, Trichoderma koningiopsis, and Trichoderma spirale are considered some of the potential biocontrol organisms.

Effect of different diets on biology, reproductive variables and life and fertility tables of Harmonia axyridis (Pallas) (Coleoptera, Coccinellidae)

ABSTRACT The biology, reproductive variables and population growth indicators of Harmonia axyridis (Pallas, 1773) (Coleoptera: Coccinellidae) fed on three diets, namely Cinara atlantica (Wilson, 1919) (Hemiptera: Aphididae), Brevicoryne brassicae (Linnaeus, 1758) (Hemiptera: Aphididae), and frozen eggs of Anagasta kuehniella (Zeller, 1879) (Lepidoptera: Pyralidae), were evaluated. With all three diets, birth rate was higher than mortality, resulting in positive rm values and thus indicating population growth. Under the conditions used in the experiments, H. axyridis was able to survive, develop and reproduce normally. This demonstrates that are different kind of food that can be essential for supporting the reproduction of some species of Coccinellidae, but not with the same optimization of preferred prey.