Biological Control of Leaf-Cutting Ants Using Forage Grasses: Nest Characteristics and Fungus Growth

2001 ◽  
Vol 187 (4) ◽  
pp. 259-267 ◽  
Author(s):  
K. Michels ◽  
N. Cromme ◽  
A. Glatzle ◽  
R. Schultze-Kraft
2021 ◽  
Vol 45 ◽  
Author(s):  
Tarcísio Marcos Macedo Mota Filho ◽  
Luis Eduardo Pontes Stefanelli ◽  
Roberto da Silva Camargo ◽  
Carlos Alberto Oliveira de Matos ◽  
Luiz Carlos Forti

ABSTRACT Chemical control using toxic baits containing the active ingredient sulfluramid at 0.3% (w/w) is the main method for controlling leaf-cutting ants of the genera Atta and Acromyrmex. However, since 2009, when sulfluramid was included in Annex B of the Stockholm Convention on Persistent Organic Pollutants, there has been an intense search for new methods that are efficient in controlling these insects. Among said new methods, biological control using pathogenic fungi has shown promising results in laboratory conditions. The objective of this study, given the context presented, was to assess the potential of the fungi Beauveria bassiana and Trichoderma harzianum in controlling Atta sexdens. Colonies of A. sexdens were exposed to the fungi by means of formulated baits provided in a foraging chamber, or of suspensions sprayed on the fungus garden, and had their behavioral changes recorded for 21 days. For both formulations, concentrations of 10 and 20% (w/w) of the fungi being studied were used. The results allowed concluding that baits containing 10 and 20% (w/w) of the fungi B. bassiana and T. harzianum were not efficient in controlling colonies of A sexdens. On the other hand, spraying suspensions of 20% (w/w) of B. bassiana and 10% and 20% (w/w) of T. harzianum was efficient and resulted in 100% mortality of the colonies 11, 9 and 7 days after application, respectively. These findings indicate that the fungi B. bassiana and T. harzianum are promising as agents for the control of A. sexdens colonies, when sprayed on the fungus garden, although there are still some challenges as to their use related to the development of technologies for the application of the pathogen.


2019 ◽  
Vol 128 ◽  
pp. 111-117 ◽  
Author(s):  
Luciana Elizalde ◽  
Mariella Superina

2016 ◽  
Vol 107 (4) ◽  
pp. 487-492 ◽  
Author(s):  
C.F. Farder-Gomes ◽  
M.A. Oliveira ◽  
P.L. Gonçalves ◽  
L.M. Gontijo ◽  
J.C. Zanuncio ◽  
...  

AbstractThe leaf-cutting ant Atta sexdens Forel (Hymenoptera: Formicidae) is one of the most damaging agricultural pests in the Neotropics. Management strategies predominantly rely on the use of general insecticides. What is needed are more species-specific and environmentally friendly options. Parasitioids such as phorid flies (Diptera: Phoridae) may be one such option, but a greater understanding of the ecology of the flies and their ant hosts is essential to devise biological control strategies. Here we report parasitism rates, ant host size, parasitoid abundance per host and resultant sex ratios of two phorid species Apocephalus attophilus Borgmeier and Eibesfeldtphora tonhascai Brown parasitizing A.sexdens. The two species achieved parasitism rates of 1.48 and 1.46%, respectively and the pupal period was 14.7 ± 1.1 days and 22.1 ± 2.8 days, respectively. There was no significant difference between the head capsule width of ants parasitized by either A. attophilus or E. tonhascai. Likewise, there was no significant effect between the head capsule width of parasitized and unparasitized ants for both species. A significant positive correlation was found between the head capsule width of the parasitized ants and the number of adult parasitoids A. attophilus emerged. Ants parasitized by E. tonhascai survived significantly longer than those parasitized by A. attophilus. There was no significant effect of ant head width on the sex ratio of the offspring of either parasitoid species and no significant difference in the sex ratio (male: female) of their offspring. In summary, these data addressed here are important steps when considering natural enemies for biological control. Studying survival of the parasitized ants, parasitoid offspring sex ratio and host size preference allows for a better understanding of ant natural biological control in the field and can help in rearing of A. attophilus and E. tonhascai in laboratory.


2016 ◽  
Vol 9 (1) ◽  
pp. 26-30 ◽  
Author(s):  
Aline Silvestre Pereira Dornelas ◽  
Renato de Almeida Sarmento ◽  
Gil Rodrigues Dos Santos ◽  
Mariela Otoni Nascimento ◽  
Danival José De Souza

Resumo. As formigas-cortadeiras, Atta e Acromyrmex, são consideradas as principais pragas no sistema agroflorestal da Região Neotropical. Isso porque cortam material vegetal que servirá de alimento ao fungo simbionte que elas cultivam.  Diversos fungos, que ocorrem em condições naturais no solo, podem ser encontrados associados às formigas-cortadeiras, muitos deles comprovadamente entomopatogênicos. No entanto, esses agentes não têm sido usados em programa de controle biológico dessas formigas. O objetivo deste estudo foi isolar e identificar fungos filamentosos associados às operárias de Atta sexdens e Atta laevigata e testar sua patogenicidade contra operárias da formiga A. sexdens. Para isolamento dos fungos, foi coletado um total de 180 operárias forrageadoras em seis colônias (30 por colônia), sendo 90 de A. sexdens e 90 de A. laevigata. Dentre os fungos isolados das operárias de A. sexdens,foram identificados Metarhizium anisopliae (Metchnikoff) Sorokin, Aspergillus flavus Link, Acremonium sp. 1, Aspergillus sp.1, Colletotrichum sp. e Acremonium sp. 2. Os fungos encontrados em associação com as operárias da A. laevigata foram Mucor sp., Aspergillus flavus,  Fusarium solani (Martius) Saccardo, A. niger van Tieghem. A patogenicidade de três desses fungos (A. flavus, A. niger e M. anisopliae) foi testada em operárias de A. sexdens. Nos testes com A. niger e M. anisopliae, o tempo para causar mortalidade de 50% das operárias foi de cinco dias (TL50 = 5 dias) e, nos dois casos, o TL50 foi significativamente inferior ao tratamento controle. Assim, testes devem prosseguir com esses isolados que apresentam potencial no uso do controle biológico das formigas-cortadeiras.Filamentous Fungi Associated With Atta sexdens (Linnaeus) and Atta laevigata (F. Smith) (Hymenoptera: Formicidae)Abstract. Leaf-cutting ants, Atta and Acromyrmex genera, are considered major pests in a neotropical agroforestry system because they cut plant material that will serve as food for the symbiotic fungus cultivated by them. Several fungi naturally occurring in the soil can be found associated with leaf-cutting ants, many of them are demonstrably entomopathogenic. However, these agents have not been used as biological control of leaf-cutting ants. The aim of this study was to isolate and to identify filamentous fungi associated with forage workers of Atta sexdens (Linnaeus) and Atta laevigata (F. Smith) and to test their pathogenicity against workers from laboratory colonies. To isolate filamentous fungi, it was collected a total of 180 forage workers (30 in each colony) in six field colonies, 90 of A. sexdens and 90 workers of A. laevigata. Six fungi species from A. sexdens were isolated and identified: Metarhizium anisopliae (Metchnikoff) Sorokin, Aspergillus flavus Link, Acremonium sp. 1, Aspergillus sp. 1, Colletotrichum sp. and Acremonium sp. 2. In A. laevigata, it was found four species: Mucor sp., Aspergillus flavus, Fusarium solani (Martius) Saccardo, Aspergillus niger van Tieghem. Three of these fungi were selected for pathogenicity tests against workers of the leaf-cutting ant A. sexdens: A. flavus, A. niger and M. anisopliae. The LT50 (time to cause 50% mortality of workers) in tests with A. niger and M. anisopliae were five days and significantly lower than the control group. Therefore, further tests should proceed with those isolates to demonstrate their potential use in the biological control of leaf-cutting ants.


Sign in / Sign up

Export Citation Format

Share Document