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Pathogenicity of Bacillus thuringiensis isolated from two species of Acromyrmex (Hymenoptera, Formicidae)
Pinto, L. M. N.;Azambuja, A. O.;Diehl, E.;Fiuza, L. M.;
Brazilian Journal of Biology , 2003, DOI: 10.1590/S1519-69842003000200015
Abstract: the control of acromyrmex leaf-cutting ants is necessary due to the severe damage they cause to diverse crops. a possibility was to control them using the bacterium bacillus thuringiensis (bt) that characteristically produces insecticidal crystal proteins (icps). the icps have been effective in controlling lepidopterans, dipterans, and coleopterans, but their action against hymenopterans is unknown. this paper describes an attempt to isolate bt from ants of two acromyrmex species, to evaluate its pathogenicity towards these ants, and to test isolates by pcr. bacterial isolates of bt obtained from a. crassispinus and a. lundi have been assayed against a. lundi in the laboratory. the bioassays were carried out in bod at 25°c, with a 12-hour photoperiod, until the seventh day after treatment. the bt isolates obtained were submitted to total dna extraction and tested by pcr with primers specific to cry genes. the results showed bt presence in 40% of the assessed samples. the data from the in vivo assays showed a mortality rate higher than 50% in the target population, with the bt ha48 isolate causing 100% of corrected mortality. the pcr results of bt isolates showed a magnification of dna fragments relative to cry1 genes in 22% of the isolates, and cry9 in 67%. cry2, cry3, cry7, and cry8 genes were not detected in the tested samples, and 22% had no magnified dna fragments corresponding to the assessed cry genes. the results are promising not only regarding allele identification in new isolates, but also fort the assays aimed at determining the bt ha48 lc50's, which can eventually be applied in controlling of acromyrmex leaf-cutting ants.
Pathogenicity of Bacillus thuringiensis isolated from two species of Acromyrmex (Hymenoptera, Formicidae)  [cached]
Pinto L. M. N.,Azambuja A. O.,Diehl E.,Fiuza L. M.
Brazilian Journal of Biology , 2003,
Abstract: The control of Acromyrmex leaf-cutting ants is necessary due to the severe damage they cause to diverse crops. A possibility was to control them using the bacterium Bacillus thuringiensis (Bt) that characteristically produces insecticidal crystal proteins (ICPs). The ICPs have been effective in controlling lepidopterans, dipterans, and coleopterans, but their action against hymenopterans is unknown. This paper describes an attempt to isolate Bt from ants of two Acromyrmex species, to evaluate its pathogenicity towards these ants, and to test isolates by PCR. Bacterial isolates of Bt obtained from A. crassispinus and A. lundi have been assayed against A. lundi in the laboratory. The bioassays were carried out in BOD at 25degreesC, with a 12-hour photoperiod, until the seventh day after treatment. The Bt isolates obtained were submitted to total DNA extraction and tested by PCR with primers specific to cry genes. The results showed Bt presence in 40% of the assessed samples. The data from the in vivo assays showed a mortality rate higher than 50% in the target population, with the Bt HA48 isolate causing 100% of corrected mortality. The PCR results of Bt isolates showed a magnification of DNA fragments relative to cry1 genes in 22% of the isolates, and cry9 in 67%. Cry2, cry3, cry7, and cry8 genes were not detected in the tested samples, and 22% had no magnified DNA fragments corresponding to the assessed cry genes. The results are promising not only regarding allele identification in new isolates, but also fort the assays aimed at determining the Bt HA48 LC50's, which can eventually be applied in controlling of Acromyrmex leaf-cutting ants.
DETERMINACION PRELIMINAR DE SUBCASTAS EN OBRERAS DE ACROMYRMEX LOBICORNIS EMERY 1887 (HYMENOPTERA: FORMICIDAE)
Quirán,Estela M; Corró Molas,Bárbara M; Caramuti,Valeria E; Bernardos,Jaime;
Gayana (Concepción) , 2001, DOI: 10.4067/S0717-65382001000100004
Abstract: in the social structure of formicidae there is a caste of sexed members in charge of reproduction and a caste of sterile members or worker ants in charge of the rest of the works of the society. subcastes can ofter be identified within the worker caste. the aim of the present work is to determine if morphological variations allow separate worker caste from acromyrmex lobicornis emery 1887 in subcastes. we identified two morphologically distincts subcastes with different functions
DETERMINACION PRELIMINAR DE SUBCASTAS EN OBRERAS DE ACROMYRMEX LOBICORNIS EMERY 1887 (HYMENOPTERA: FORMICIDAE) PRELIMINARY DETERMINATION OF WORKER SUBCASTES OF ACROMYRMEX LOBICORNIS EMERY 1887 (HYMENOPTERA: FORMICIDAE)  [cached]
Estela M Quirán,Bárbara M Corró Molas,Valeria E Caramuti,Jaime Bernardos
Gayana (Concepción) , 2001,
Abstract: En la estructura social de formícidos se distingue una casta de individuos sexuados encargada de la reproducción y una casta de individuos estériles u obreras encargada del resto de las tareas de la sociedad, tales como cuidado de la prole, construcción del nido y defensa. Dentro de la casta obrera puede existir división de labores, reconociéndose en algunas especies subcastas polimórficas o poliéticas. El objetivo del presente trabajo fue determinar si las variaciones morfológicas entre las obreras de Acromyrmex lobicornis Emery 1887 permiten separar a la casta obrera en subcastas, y si esta variación está relacionada con alguna/s tarea/s en particular. Se colectaron obreras en tres sitios del nido: túmulo, honguera y camino y en laboratorio se tomaron las medidas corporales. Los datos fueron sometidos al análisis de discriminantes. De los resultados se obtiene que en A. lobicornis se diferencian dos subgrupos morfológicos con funciones particulares In the social structure of Formicidae there is a caste of sexed members in charge of reproduction and a caste of sterile members or worker ants in charge of the rest of the works of the society. Subcastes can ofter be identified within the worker caste. The aim of the present work is to determine if morphological variations allow separate worker caste from Acromyrmex lobicornis Emery 1887 in subcastes. We identified two morphologically distincts subcastes with different functions
Occurrence of polygyny in Acromyrmex subterraneus molestans Santschi 1925 (Hymenoptera: Formicidae)
Souza, Danival José de;Lino Neto, José;Lucia, Terezinha M. C. Della;Peternelli, Ethel;
Ciência Rural , 2004, DOI: 10.1590/S0103-84782004000500045
Abstract: polygyny denotes the coexistence of two or more mated and fertile queens in the colony. a colony of acromyrmex subterraneus molestans santschi containing 14 queens was collected on campus of the universidade federal de vi?osa, brazil, aiming to verify if they were all egg-layers and fertile . the volume of the fungus garden in the nest was about 500 ml with a large number of larvae and pupae. observation of the ovarian development and spermathecae indicates that 13 queens had copulated and ovary did not show morphological differences among them. this could indicate that polygyny is not accidental and may represent an adaptative strategy to optimize the development of the initial colony in a. subterraneus molestans.
Occurrence of polygyny in Acromyrmex subterraneus molestans Santschi 1925 (Hymenoptera: Formicidae)  [cached]
Souza Danival José de,Lino Neto José,Lucia Terezinha M. C. Della,Peternelli Ethel
Ciência Rural , 2004,
Abstract: Polygyny denotes the coexistence of two or more mated and fertile queens in the colony. A colony of Acromyrmex subterraneus molestans Santschi containing 14 queens was collected on campus of the Universidade Federal de Vi osa, Brazil, aiming to verify if they were all egg-layers and fertile . The volume of the fungus garden in the nest was about 500 ml with a large number of larvae and pupae. Observation of the ovarian development and spermathecae indicates that 13 queens had copulated and ovary did not show morphological differences among them. This could indicate that polygyny is not accidental and may represent an adaptative strategy to optimize the development of the initial colony in A. subterraneus molestans.
Isoenzyme variation in the leaf-cutting ants Acromyrmex heyeri and Acromyrmex striatus (Hymenoptera, formicidae)
Diehl, Elena;Cavalli-Molina, Suzana;Araújo, Aldo Mellender de;
Genetics and Molecular Biology , 2002, DOI: 10.1590/S1415-47572002000200010
Abstract: this is the first study of isoenzyme variability in the leaf-cutting ants (myrmicinae, attini) acromyrmex heyeri (forel, 1899) and a. striatus (roger, 1863) which are common throughout the southern brazilian state of rio grande do sul. we studied the alloenzyme variability of malate dehydrogenase (mdh), a-glycerophosphate dehydrogenase (a-gpdh) and amylase (amy) in 97 colonies of a. heyeri and 103 colonies of a. striatus. five loci were found for these enzyme systems, one locus (amy-1) being monomorphic in both species and four loci (mdh-1, a-gpdh-1, amy-2, and amy-4) being polymorphic. for each species there were exclusive alleles for the mdh-1 and amy-2 loci and differences were also found in the allele frequencies for the other polymorphic loci. ontogenetically different gene activity was detected for the mdh and a-gpdh systems, with between-caste differences, probably related to flight activity, also being found for a-gpdh.
Isoenzyme variation in the leaf-cutting ants Acromyrmex heyeri and Acromyrmex striatus (Hymenoptera, formicidae)  [cached]
Diehl Elena,Cavalli-Molina Suzana,Araújo Aldo Mellender de
Genetics and Molecular Biology , 2002,
Abstract: This is the first study of isoenzyme variability in the leaf-cutting ants (Myrmicinae, Attini) Acromyrmex heyeri (Forel, 1899) and A. striatus (Roger, 1863) which are common throughout the southern Brazilian state of Rio Grande do Sul. We studied the alloenzyme variability of malate dehydrogenase (MDH), alpha-glycerophosphate dehydrogenase (alpha-GPDH) and amylase (AMY) in 97 colonies of A. heyeri and 103 colonies of A. striatus. Five loci were found for these enzyme systems, one locus (Amy-1) being monomorphic in both species and four loci (Mdh-1, alpha-Gpdh-1, Amy-2, and Amy-4) being polymorphic. For each species there were exclusive alleles for the Mdh-1 and Amy-2 loci and differences were also found in the allele frequencies for the other polymorphic loci. Ontogenetically different gene activity was detected for the MDH and alpha-GPDH systems, with between-caste differences, probably related to flight activity, also being found for alpha-GPDH.
Eficiência de isca formicida aplicada sobre o monte de terra solta de ninhos de Atta sexdens rubropilosa (Hymenoptera: Formicidae)
Zanetti, Ronald;Zanuncio, José Cola;Souza-Silva, Alan;Abreu, Luiz Gonzaga de;
Revista árvore , 2003, DOI: 10.1590/S0100-67622003000300019
Abstract: the efficiency of a granulated bait formulated with sulfluramid (0.3%) for the control of atta sexdens rubropilosa forel, 1908 (hymenoptera: formicidae) was evaluated. treatments consisted of applying this bait at a dose of 8g/m2 from the ant nest. this bait was applied near entrances over ant nests (treatment t1) or near those outside these nests (treatment t2). a total of 192 ant nests of a. sexdens rubropilosa were used in the two treatments. percentage of transport and devolution of the bait by a. sexdens rubropilosa was evaluated two days after its application and control efficiency, 150 days after application. percentage of bait transport was higher when applied outside the ant nest (100.00%) than over it (89.5%). however, control efficiency was similar between treatments. for this reason and due to lower costs, it is recommended to apply this bait near entrances over ant colonies to control a. sexdens rubropilosa.
ACROMYRMEX LOBICORNIS EMERY 1887 (HYMENOPTERA:FORMICIDAE) Y EL PESO DE LA CARGA, EN CONDICIONES DE LABORATORIO
Quirán,Estela M.; Steibel,Juan P.;
Gayana (Concepción) , 2001, DOI: 10.4067/S0717-65382001000200002
Abstract: leaf-cutting ants belonging to the genera atta fabricius and acromyrmex mayr (attini) are efficient harvesters. workers frequently carry leaf fragments to the nest, which weight is related to the ant body weight. in this paper the effect of two foraging distances are evalued on the relationship between these two variables. observations were made in an artificial nest of acromyrmex lobicornis. results indicated that at short distances leaf weight is linearlly related with the ant weight while at longer distances this relationship is weakened. thus, we conclude that acromyrmex optimum leaf harvest is a complex process that could be affected not only by the ant weight but also environmental conditions, plant chemical composition, and colony nutritional demands
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