Wasmannia spp. (Hym., Formicidae) and insect damages to cocoa in Brazilian farms

Diagnostic insect damage to cocoa tree leaves and fruits were compared in situations with and without the presence of the little fire ants, Wasmannia auropunctata and the closely related and sympatric W. cf rochai. No significant differences in thrips, lepidopteran, or chrysomelid beetle damage to fruits, or to young and old leaves, were associated with these ants. However, significant increases of pseudococcids Planococcus citrii, associated with areas dominated by W. auropunctata, and to a lesser degree with W. cf rochai, were present. W. auropunctata has been reported to be a canopy mosaic dominant in cocoa farms, but the lack of reduced herbivore incidences and its lack of spatial permanence do not support favoring its populations for the management of phytophagous insect control.

Potential of Acarophenax lacunatus (Prostigmata: Acarophenacidae) as a biological control agent of Rhyzopertha dominica (Coleoptera: Bostrichidae)

A recent report of the parasitic mite species Acarophenax lacunatus (Cross and Krantz) (Prostigmata: Acarophenacidae) attacking populations of Rhyzopertha dominica (F.) (Coleoptera: Bostrichidae) led to the present investigation. Maximum female size and average number of progeny per female mite were assessed at eight different temperatures (ranging from 20 to 41°C) and 60% r.h. using R. dominica as the host. The ability of the mite species to suppress eggs, first instar larvae, and adults of R. dominica was assessed at 30°C and 60% r.h. The largest female sizes of the mite and progeny numbers were obtained around 30°C (259 μm and 17 offspring/female respectively) with minimum values obtained at the most extreme temperatures used in this study. Mite densities of at least four individuals per 500 ml jar containing 50 adults of R. dominica, resulted in almost complete suppression of eggs, first instar larvae, and adults of the host species after 45 days. This same range of mite densities led to reductions of wheat weight losses of 15 and 25% after 45 and 60 days after infestation respectively. Acarophenax lacunatus shows good potential as a biological control agent of R. dominica.

Atividade tóxica de isolados de Bacillus Thuringiensis a larvas de Aedes Aegypti (l.) (diptera: culicidae)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

In utero and lactational exposure to fenvalerate disrupts reproductive function in female rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Caffeine effect on mortality and oviposition in successive generations of Aedes aegypti

OBJETIVO: Experimentos anteriores mostraram que a cafeína bloqueia o desenvolvimento de Aedes aegypti (Diptera, Culicidae) na fase larval, inibindo conseqüentemente a produção de adultos. O objetivo do estudo foi obter dados que pudessem sugerir desenvolvimento de resistência dos mosquitos à cafeína. MÉTODOS: Foi avaliada a produção de adultos em gerações sucessivas, a partir de ovos produzidos na geração anterior e a taxa de oviposição em cada geração, utilizando meios contendo cafeína a 200 e 500 µg/ml e água de torneira proveniente de poço artesiano como controle. Os experimentos foram conduzidos em São José do Rio Preto, entre 2002 e 2005. Nos testes estatísticos foram utilizados a análise exploratória de dados e algoritmos de alisamento. RESULTADOS: Ocorreu redução crescente da produção de adultos, nas duas concentrações, ao longo das gerações, mas apenas no experimento a 200 µg/ml os dados foram estatisticamente significantes. Quanto à oviposição, a análise dos números mostra redução crescente e acentuada na média de ovos por fêmea, no experimento tratado. CONCLUSÕES: Não houve evidência de resistência ao longo das gerações devido ao tratamento com cafeína. Os resultados encontrados podem reforçar a indicação da cafeína como uma alternativa aos principais agentes de controle do Ae. aegypti atualmente usados, contra os quais os mosquitos têm desenvolvido resistência.

A pest is a pest is a pest? The dilemma of neotropical leaf-cutting ants: Keystone taxa of natural ecosystems

Leaf-cutting ants of the genera Acromyrmex and Atta are considered the principal polyphagous pests of the Neotropics. Although some members of these genera are of economic importance, have a broad geographic distribution, and are extremely good colonizers, others are endemic and closely interact with native ecosystems. Control is generally practiced against any colony, irrespective of its taxonomic status. Indiscriminate control coupled with habitat destruction threatens endemic species with extinction, and, through habitat simplification, favors other pest species. As nests of Atta are large, having several square meters of nest surface, the endemic taxa can be easily used as environmental indicators for natural ecosystems. Likewise, the pest species can be used to detect environmental disturbance. As these ants are keystone species and easily identified by nonspecialists, efforts should be made to integrate these into viable conservation programs.

Ticks (Acari: Ixodidae) associated with domestic dogs in Franca region, São Paulo, Brazil

Ticks on 140 domestic dogs from both urban and rural areas of Franca region in São Paulo state were identified with 102 dogs from urban areas and 38 from rural areas. Of urban dogs, 27.5% were infested exclusively by Rhipicephalus sanguineus ticks. Of the rural dogs, 36.8% were infested with the following tick species: R. sanguineus, Boophilus microplus, Amblyomma ovale and A. cajennense. Mixed infestations included a dog hosting A. cajennense and A. ovale and another with B. microplus and R. sanguineus. The most intense infestations were detected on urban dogs. Hemolymph tests of these ticks performed to detect rickettsial or Borrelia bacteria yielded negative results.

Composição faunística de insetos predadores em fragmento florestal e em área de hortaliças na região de Jaboticabal, estado de São Paulo

A population survey was carried out in a forest fragment and in an area of vegetables, from November/1996 to February/1998, aiming to determine the predator insect species and the influence of abiotic factors. The samples were taken weekly by light traps. The results were evaluated using faunistic analysis and simple correlation with temperature, relative humidity and rainfall. In the forest fragment higher similarity in the abundance of species was observed comparing to the area of vegetables, but the largest number of captured individuals (95%) occurred in this last habitat. Metius sp., Polpochila impressifrons (Dej.), Eulissus sp. and Doru sp. were predominant species in both areas, evidencing they may play an important role as pest predators in areas of vegetables. Arthrostictus speciosus (Dej.) and Leptotrachelus sp. predominated in the forest fragment, and the same was observed with Paederus sp. in the vegetable area. This species is probably adapted for open and hot places, while A. speciosus and Leptotrachelus sp. can be adapted for dark and humid places of forests.

Estrutura genética de populações de Trichilia pallida Swartz (Meliaceae) por marcadores RAPD

Trichilia pallida Swartz is an Atlantic Forest shady climax tree of Meliaceae family that presents insecticide properties against chewing insects like as some family trees, making it interesting for forestry uses. Forty plants of Oito Pontas Farm population were collected in Bofete County, Santa Genebra Ecological Station in Campinas County, and Caetetus Ecological Station in Gélia County, all in the Sao Paulo State, Brazil. Leaf DNA analysis was used by RAPD method, that showed 10 highly polymorphic primers, with 72 dominant markers, used to estimate genetic diversity within and among populations. The polymorphism within populations varied from 90.3 to 97.2%, and the effective allele number varied from 1.46 ± 0.33 to 1.57 ± 0.33, while the average of genetic differentiation of populations varied from 0.27 ± 0.18 to 0, 33 ± 0.15. The gene diversity in the total population (H T) was 0.334 ± 0.02, while the average gene diversity within populations (H s) was 0.292 ± 0.017, and the coefficient of gene differentiation (G ST) was 0.125, Bofete and Campinas populations had the smallest Nei's genetic distance (0.049) and the distances of both with Gália were 0.117 and 0.107, respectively.

Standardization of bioassays for monitoring resistance to insecticides in Aedes aegypti

Since the reintroduction of Aedes aegypti in Brazil in the 1980s, insecticide use for its control is routine. The chemical control efficacy is threatened by vectors developing resistance to insecticides. The World Health Organization, recognizing the impact of insecticide resistance in vector control programmes, proposed standardizing bioassays for detecting and monitoring resistance using a diagnostic dose method. As Brazil has a national programme for monitoring the resistance of Ae. aegypti populations to insecticides, this study was designed to compare diagnostic bioassays at WHO suggested concentrations and those estimated for local conditions. Populations were resistant to both temephos doses. But important differences were seen for fenitrothion and malathion, which could lead to under- or over-estimation of resistance respectively. These results and inclusion of a diagnostic dose bioassay standard for larvae are discussed.

Occurrence of Enneothrips flavens moulton and Stegasta bosquella (chambers) and its effects on agronomic traits of wild Arachis accessions

Some wild species of the genus Arachis have demonstrated potential for improvement of peanuts. This work was performed to evaluate the occurrence and symptoms of Enneothrips flavens and Stegasta bosquella and its effects on agronomic traits of wild Arachis accessions. Nine accessions of wild Arachis species and a commercial A. hypogaea variety were studied in a split plot statistical scheme with a completely randomized block design and four replications. The main plots consisted of plants sprayed or not sprayed for insect control, while the subplots comprised the peanut accessions. Accessions GKP10017 (A. cardenasii) and V7639 (A. kuhlmannii) showed the lowest percentages of leaflets with E. flavens and S. bosquella. Accessions V9912, V7639 and V8979 (all three A. kuhlmannii) and V13250 (A. kempff-mercadoi) showed the lowest responses to insecticide application among the various plant traits evaluated. These accessions are of interest for further studies to identify mechanisms of resistance, to be used in breeding programs for resistance to these insects.

Análise da expressão gênica em isolados de Bacillus thuringiensis por PCR tempo real visando o controle de Spodoptera frugiperda (J.E. Smith) (Lepidoptera: Noctuidae) de diferentes populações brasileiras

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Avaliação de nematóides entomopatogênicos contra o bicudo da cana-de-açúcar Sphenophorus levis Vaurie, 1978, e efeito da associação desses agentes com inseticidas químicos

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Pulverização conjugada à fertilização para controle de Spodoptera frugiperda (J. E. Smith, 1797) (Lepidoptera: Noctuidae) em diferentes híbridos de milho, em função do volume de calda e ponta de pulverização

Pós-graduação em Agronomia (Produção Vegetal) - FCAV