Field sexual attraction in the sorghum midge, Contarinia sorghicola (Coquillett, 1899) (Diptera, Cecidomyiidae).

No campo, fêmeas da mosca do sorgo, Contarinia sorghicola (Coquillett, 1899), atraem machos da especie para o acasalamento atraves da emissao de feromonio, o que foi comprovado atraves da utilizacao de armadilhas adesivas contendo femeas virgens ou extratos destas, a nivel de campo. O periodo de maior atratividade ocorreu entre 7:30 e 8:30 horas.Suplemento

Selection of the fall armyworm Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae) for survival on Cry 1A (b) Bt toxin.

Plantas transgênicas que expressam toxinas da bactéria Bacillus thuringiensis (Bt) representam um importante avanço para o controle de lepidópteros-pragas de milho. Híbridos de milho Bt expressando a toxina Cry1A(b) têm mostrado significativo nível de resistência à lagarta-do-cartucho (LCM), Spodoptera frugiperda (Smith) (Lepidoptera: Noctuidae), embora larvas dessa espécie tenham sido observadas em campo e em laboratório sobrevivendo nesses híbridos. Resistência de S. frugiperda também tem sido registrada para diferentes inseticidas. Em bioensaios, seleção de insetos sobreviventes mostrou um aumento do nível de tolerância à toxina do Bt Cry1A(b) em populações da lagarta-do-cartucho, após quatro gerações, indicando que essa tolerância é herdada. Palavras-chave: Insecta, resistência, plantas transgênicas

Reduction and approximation in gyrokinetics

The gyrokinetics formulation of plasmas in strong magnetic fields aims at the elimination of the angle associated with the Larmor rotation of charged particles around the magnetic field lines. In a perturbative treatment or as a time-averaging procedure, gyrokinetics is in general an approximation to the true dynamics. Here we discuss the conditions under which gyrokinetics is either an approximation or an exact operation in the framework of reduction of dynamical systems with symmetryComment: 15 pages late

KLP+ ("hat") trap with semiochemical lures suitable for trapping two diabrotica spp. exotic to Europe.

The KLP+ (“hat”) trap baited with pheromone or floral lures is a highly efficient non-sticky trap for the western corn rootworm, Diabrotica v. virgifera. We tested the suitability of this trap design for the related species, D. speciosa and D. barberi, baited with their respective lures. Both species are exotic to Europe: the former inhabits South America, and the latter occurs in some parts of North America. In screening tests performed in Brazil, several synthetic floral compounds and their combinations were found to be attractive to D. speciosa. However, the greatest effect was recorded for the previously described attractant 1,4-dimethoxybenzene. When the most active compounds in the preliminary test, 2-phenylethanol, methyl anthranilate, eugenol or benzaldehyde were added to 1,4-dimethoxybenzene, no synergistic effects were observed. When1,4-dimethoxybenzene was formulated in three types of polyethylene (PE) dispensers in KLP+traps, PE bag dispensers were superior to two types of PE vial dispenser, and caught hundreds of D. speciosa. Unbaited traps caught only negligible numbers. There was an interesting non-target effect. KLP+ traps with 1,4-dimethoxybenzene caught large numbers of the cornsilk fly, Euxesta eluta, which is known as a maize pest. For D. barberi, both a pheromone and a potent floral lure are already known. In tests with KLP+ traps, we found that the pheromone and floral lures can be applied together in the same trap to maximize both male and female catches. In conclusion, for early detection programs in Europe, the application of KLP+ traps baited with 1,4-dimethoxybenzene in PE bag dispensers could be recommended for D. speciosa, and KLP+ traps with dual (pheromone and floral) lures for D. barberi. In the case of D. barberi, one should note that the lures also show some attraction for D. v. virgifera, and the ratio of D. barberi vs. D. v. virgifera in the catch will be pre- dominantly determined by the relative population densities at the given site

Initial studies of mating disruption of the tomato moth, Tuta absoluta (Lepidoptera : Gelechiidae) using synthetic sex pheromone

The potential of the synthetic major component of T. absoluta (Meyrick) sex pheromone for mating disruption was studied in small plots (0.01 hectares) with fresh-market tomato crop. The effects of the application of the sex pheromone 3E,8Z,11Z-14: Ac (from 0 to 80 g a. i./ha) were assessed on male orientation to pheromone baited traps, mating in cages and plant damage. The highest levels of interruption in male orientation (60-90%) were found in plots treated with 35 to 50 g/ha of sex pheromone. However, no treatment with pheromone was capable of significantly reducing the percentage of mined leaflets or bored fruits or the frequency of mating in cages compared to the control plots. The failure in mating disruption technique may be attributed to the composition of the synthetic pheromone, doses used, high pest population density, and mated female migration to the area treated

Invariants of solvable rigid Lie algebras up to dimension 8

The invariants of all complex solvable rigid Lie algebras up to dimension eight are computed. Moreover we show, for rank one solvable algebras, some criteria to deduce to non-existence of non-trivial invariants or the existence of fundamental sets of invariants formed by rational functions of the Casimir invariants of the associated nilradical.Comment: 16 pages, 7 table

Determinação do número de fêmeas virgens por armadilha e periodicidade de captura de machos de Helicoverpa zea (Boddie) (Lepidoptera: noctuidae).

Avaliou-se em lavouras de milho em fase de liberacao de estilo-estigmas, na EMBRAPA/CNPMS, em Sete Lagoas, MG, a atratividade de diferentes numeros de femeas virgens de Helicoverpa zea (Boddie) em armadilha adesiva, alem de uma formulacao comercial do feromonio sintetico, proveniente dos E.E.U.U. A maior atividade de procura por acasalamento teve inicio nas primeiras horas da noite. Nao houve diferenca significativa ente medias de insetos capturados com uma, tres ou cinco femeas. Cinco femeas por armadilha tornam o monitoramento pouco pratico: uma apenas pode comprometer a captura por disfuncao fisiologica ou mesmo morte. Nao houve captura nas armadilhas contendo feromonio sintetico, que, ao inves, capturou machos de Mythimna, outro Noctuidae. A maior frequencia de captura nas armadilhas ocorreu apos a meia noite, diminuindo proximo do alvorecer. O horario de inicio de chamamento e captura esteve estreitamente relacionado com a temperatura ambiente