Influence of Mineral Particle Films and Biomaterials on Guava Fruits and Implications for the Oviposition of Anastrepha obliqua (Macquart) (Diptera: Tephritidae).

Anastrepha obliqua (Macquart, 1835) is an important pest of tropical fruits, especially Anacardiaceae and Myrtaceae, in the Americas. The objective of this study was to evaluate the influence of mineral films and biomaterials on the coloring of guava fruits (Psidium guajava L.) and implications for the oviposition of A. obliqua. Before the bioassays, color, firmness characteristics, total soluble solids, pH, and titratable acidity were determined to characterize the maturation stage of the fruits. Pieces of guava fruit covered in aluminum foil were immersed in suspensions of mineral particles (Surround® WP kaolin; kaolins 605, 607, 608, and 611; and talc) and biomaterials (chitosan, cassava and potato starch, and guar gum) and distilled water (control). After drying, the fruits were exposed to two A. obliqua pairs for 48 h in choice and non-choice tests, and the numbers of eggs per fruit were counted. Mineral films (Surround® WP kaolin, and kaolins 605, 607, 608, and 611) and biomaterials (cassava and potato starch) interfered with the color of guava (luminosity, chroma, and hue angle), inhibiting the oviposition of A. obliqua. Talc, chitosan, and guar gum did not influence the oviposition of A. obliqua in guava.

Oviposition preference and biological performance of Ceratitis capitata in Anacardiaceae, Cactaceae and Vitaceae fruit / Preferência de oviposição e performance biológica de Ceratitis capitata em frutos de Anacardiaceae, Cactaceae e Vitaceae

The objective of this study was to compare the use of fruits of great economic and social importance for the northeast of Brazil by Ceratitis capitata Wied. (Diptera: Tephritidae) for oviposition, larval development, size and longevity of adults. Fruits of mango (Mangifera indica L.), quiabento (Pereskia bahiensis Gürke), forage palm [Opuntia fícus indica (L.) Mill] and grape (Vitis vinifera L.) were used, as well as flies from a hybrid laboratory population. Initially, four treatments (fruits) and six replications were used; the fruits were offered to 10 C. capitata couples, with later (96 hours) egg count. The second was conducted with six treatments and 10 replicates, offering two types of fruits simultaneously, combined two to two, to 10 C. capitata couples. The last bioassay comprised four treatments and six replicates, where 20 g of fruit were offered to 20 first-instar C. capitata larvae. After six days, the larvae were placed in plastic pots containing vermiculite until pupation, quantifying larval and pupal periods, viability and pupal mass, besides longevity and adult size. The data were submitted to ANOVA using the R Core Team software. Ceratitis capitata oviposits and completes its biological cycle in the four hosts studied, exhibiting no preference for oviposition and low biological performance in quiabento fruits. It yielded smaller adults and lower grape survival. Cactaceae palm and quiabento allow the survival of C. capitata in the laboratory, and this knowledge has been reported for the first time, proving that they can act as alternative hosts in the field.(AU)

O objetivo do estudo foi comparar a utilização de frutos de importância econômica e social para o nordeste do Brasil por Ceratitis capitata Wied. (Diptera: Tephritidae) para oviposição, desenvolvimento larval, tamanho e longevidade de adultos. Foram utilizados frutos de manga (Mangifera indica L.), quiabento (Pereskia bahiensis Gürke), palma-forrageira [Opuntia fícus indica (L.) Mill] e uva (Vitis vinifera L.) e moscas procedentes de uma população híbrida de laboratório. Inicialmente, utilizaram-se quatro tratamentos (frutos) e seis repetições, com o oferecimento dos frutos a 10 casais de C. capitata, com posterior (96 horas) contagem de ovos. O segundo teste foi conduzido com seis tratamentos e 10 repetições, oferecendo-se dois tipos de frutos simultaneamente, combinados dois a dois, a 10 casais de C. capitata. O último bioensaio compreendeu quatro tratamentos e seis repetições, sendo oferecidos 20 g de fruto a 20 larvas de primeiro instar de C. capitata. Após seis dias, as larvas foram colocadas em potes plásticos contendo vermiculita até a empupação, quantificando-se: períodos larval e pupal, viabilidade e massa pupal e longevidade e tamanho do adulto. Os dados foram submetidos à análise de variância (ANOVA) pelo Programa R Core Team. Ceratitis capitata oviposita e completa seu ciclo biológico nos quatro hospedeiros estudados, exibindo não preferência para oviposição e baixa performance biológica em frutos de quiabento. Este proporcionou adultos menores e a uva permitiu a menor sobrevivência. As cactáceas palma e quiabento permitem a sobrevivência de C. capitata em laboratório, sendo esse conhecimento relatado pela primeira vez, comprovando que essas espécies podem atuar como hospedeiros alternativos no campo.(AU)

Nest architecture development of grass-cutting ants

ABSTRACT Atta bisphaerica is a species of grass-cutting ants commonly found in the Cerrado biome. The Brazilian Cerrado (savanna) biome covers 2 million km representing 23% of the area of the country. It is an ancient biome with rich biodiversity, estimated at 160,000 species of plants, fungi and animals. However, little is known about their nest architecture development. This study investigated the architecture of fourteen A. bisphaerica nests from Botucatu, São Paulo, Brazil. Molds were made of the nests by filling them with cement to allow better visualization of internal structures such as chambers and tunnels. After excavation, the depth and dimensions (length, width, and height) of the chambers were measured. As expected, there was a lateral development in the nests and increase in the number of chambers over time. Results showed that in nests with an estimated age of 14 months, the average depth was 1.6 ± 0.4 m; for those with 18 months it was 2.2 ± 0.7 m and at 28 months it was 2.5 ± 0.7 m. The number of chambers varied from 4 to 7 in 28-month nests, 2 to 4 in 18-month nests, and from 2 to 3 in 14-month nests. With respect to the dimensions of the internal tunnels, there were variations in their average width, increasing with time. The fungus chambers were located beneath the largest mound of loose soil. This study contributes to a better understanding of the so far unknown nest architecture development of A. bisphaerica grass-cutting ants.

Discovering the Giant Nest Architecture of Grass-Cutting Ants, Atta capiguara (Hymenoptera, Formicidae).

Atta capiguara is a grass-cutting ant species frequently found in Cerrado biome. However, little is known about the giant nest architecture of this ant. In this study, we investigated the architecture of three A. capiguara nests from a fragment of Cerrado in Botucatu, São Paulo, Brazil. Casts were made of the nests by filling them with cement to permit better visualization of internal structures such as chambers and tunnels. After excavation, the depth and dimensions (length, width, and height) of the chambers were measured. The results showed the shape of Atta capiguara nests consisting of mounds of loose soil with unique features resembling a conic section. The fungus chambers were found distant from the mound of loose soil and were spaced apart and distributed laterally at the soil profile. The waste chambers were located beneath the largest mound of loose soil. Both the fungus and waste chambers were separated and distant. Our study contributes to a better understanding of the so far unknown nest architecture of the grass-cutting ant A. capiguara.

Seletividade de inseticidas a alguns dos inimigos naturais na cultura do algodão / Selectivity of insecticides to some natural enemies in the culture of cotton

O objetivo foi estudar a seletividade de inseticidas aos inimigos naturais na cultura do algodão (Gossypium hirsutum L.r. latifolium Hurtch), cultivar DeltaOpal, no município de Malhada (BA) e conhecer a fauna benéfica associada. O trabalho foi conduzido na safra 2010/2011, com delineamento experimental em blocos ao acaso, com seis tratamentos e quatro repetições, sendo os tratamentos: (1) Fipronil 200 SC (0,38 L.ha-1); (2) Alfacipermetrina 100 SC (0,30 L.ha-1); (3) Lufenuron 50 CE (0,30 L.ha-1); (4) Imidacloprid 200 SC (0,30 L.ha-1); (5) Paration Metil 600 CE (1,00 L.ha-1); e (6) Testemunha (água). A aplicação dos produtos foi feita 80 dias após a emergência, com avaliações um dia antes da aplicação e 1, 7 e 14 dias após a aplicação (DAA) por meio do pano de batida e armadilha Moericke. Em laboratório, os insetos foram triados, contados e identificados em famílias. A toxicidade dos produtos varia em função do grupo do inimigo natural. A Imidacloprida é seletiva às aranhas, sendo os demais inseticidas medianamente tóxicos (Alfacipermetrina e Paration Metil: 1º e 14º DAA; Lufenuron: 14º DAA) ou tóxicos (Fipronil e Alfacipermetrina: 7º DAA). Fipronil (1º DAA), Alfacipermetrina (7º DAA) e Paration Metil (14º DAA) são medianamente tóxicos aos adultos de joaninhas. Os inseticidas estudados são tóxicos às larvas de joaninhas, com mais impacto até os sete dias após a aplicação, com exceção do Paration Metil, classificado como inócuo até esse período. Registra-se a ocorrência de 13 famílias de aranhas e 18 famílias de hymenópteros parasitoides em agroecossistema de algodão na região de Malhada (BA).(AU)

The aim of this work was study the selectivity of insecticides in favor of natural enemies in cotton (Gossypium hirsutum latifolium Hurtch Lr), DeltaOpal cultivar, in the city of Malhada (BA), and to know the associated beneficial fauna. The study was conducted at the agricultural year of 2010/2011. The design was conducted in randomized blocks with six treatments and four replications. The treatments were: (1) Fipronil 200 SC (0.38 L.ha-1); (2) Alphacypermethrin 100 SC (0.30 L.ha-1), (3) Lufenuron 50 EC (0.30 L.ha-1), (4) Imidacloprid 200 SC (0.30 L.ha-1), (5) Methyl parathion 600 EC (1.00 L.ha-1), and (6) control (water). The product was applied 80 days after emergence, and the evaluations were performed one day before application and 1, 7 and 14 days after application (DAA). The samples were taken using the sampling method beating cloth and Moericke traps. Natural enemies were brought to the laboratory for sorting, counting and identification by family. The toxicity of the products ranged according to the group of natural enemies. Imidacloprid is selective to the spiders and insecticides are moderately toxic (Methyl Parathion and Alphacypermethrin: 1 and 14th DAA; Lufenuron: 14th DAA) or toxic (Fipronil and Alphacypermethrin: 7thDAA). Fipronil (1 DAA), Alphacypermethrin (7th DAA) and Methyl Parathion (14th DAA) are moderately toxic to adult ladybirds. The analyzed insecticides are toxic to the larvae of ladybirds, with more impact until seven days after the application, with the exception of Methyl Parathion classified, as innocuous until this period. The occurrence of 13 families of spiders and 18 families of parasitic Hymenoptera is registered in cotton agroecosystems in the region of Malhada, in the state of Bahia.(AU)