This study analyzed the toxicity by residual contact and the repellency effect of the essential oils of Rosmarinus officinalis, Mentha piperita, Melaleuca alternifolia, and Commiphora myrrha and their mixtures on adult females of Tetranychus urticae in laboratory and protected cultivation. The essential oil of C. myrrha exhibited a LC50 of 0.55 ml L-1, and the mixtures R. officinalis + M. piperita + M. alternifolia + C. myrrha, C. myrrha + M. piperita, and C. myrrha + M. alternifolia showed 68%, 60%, and 36% mortality, respectively. The essential oils of C. myrrha and M. alternifolia showed 95 and 70% of repellency, respectively. Mixtures of C. myrrha + M. alternifolia, C. myrrha + M. piperita, and C. myrrha + R. officinalis provided repellency of 85, 74 and 73%, respectively. Toxicity by residual contact of the essential oil of C. myrrha in protected cultivation exhibited 93% mortality, while the acaricide fenpyroximate showed 80%. The constituents of essential oils were eucalyptol (49.66%), M. piperita menthol (48.53%), M. alternifolia terpinen-4-ol (48.93%), and C. myrrha benzyl benzoate (97.71%). The essential oil of C. myrrha and the mixtures R. officinalis + M. piperita + M. alternifolia + C. myrrha and C. myrrha + M. piperita showed significant mortality. However, further studies are needed to assess the cost/benefit ratio and the effects on non-target organisms.

Some plants can attract natural enemy by offering resources such as alternative food and refuge. However, studies need to be conducted before agricultural landscape diversification is implement. Our objective was to determine the best floristic compositions of cosmos (Cosmos sulphureus—Asteraceae), showy rattlepod (Crotalaria spectabilis—Fabaceae), fennel (Foeniculum vulgare—Apiaceae), and jack bean (Canavalia ensiformis—Fabaceae) to attract and maintain predatory arthropods, and know the potential of these treatments for future use in diversifying agricultural systems. The experimental design consisted in seven treatments of four species in single-crop, intercrops in three densities called mix1, mix2, and mix3, and the control (weeds). For the arthropod families classified as very frequent and constant, population dynamics in intercropping treatments was plotted according to the plant phenology. We conclude that all plants cultivated in single-cropping and intercropping treatments showed high predator richness and can potentially be used to diversify cultivated areas. Sulfur cosmos as a single crop and three mixes attracts higher numbers and greater family richness. Spider families—Oxyopidae, Araneidae and Thomisidae—and insects—Chrysopidae and Coccinellidae are more frequents. The dynamics of the predator populations varied according to the mixes treatment.

O objetivo deste trabalho foi caracterizar e avaliar a atividade do óleo essencial de gengibre, Zingiber officinale Roscoe - Zingiberaceae, em ovos e lagartas de Duponchelia fovealis Zeller, 1847 (Lepidoptera: Crambidae). Para isso, o óleo essencial foi obtido por hidrodestilação, através de um aparelho Clevenger, e foi caracterizado por (CG-DIC e CG-EM). Para os testes biológicos, foi utilizado um aerógrafo para pulverizar sobre os insetos a solução do óleo essencial a 2% de concentração (m/v-1) e para avaliar o efeito nos ovos utilizados no método de imersão. O solvente utilizado na preparação das soluções dos óleos essenciais foi uma solução aquosa contendo 0,05% (m/v-1) de Tween 80 e 2% (m/v-1) de acetona e o controle negativo, o inseticida Clorfenapir como controle positivo. Os principais compostos encontrados no óleo essencial de gengibre foram: a-zingibreno (17,21%), geranial (16,46%), canfene (10,19%). Os valores estimados para as concentrações letais (CL50 e CL90) para os ovos foram 0,25 e 0,54% respectivamente, e 0,61 e 1,35% para as lagartas de primeiro estádio respectivamente, provando o potencial de óleo essencial de gengibre na mortalidade desse inseto.

The objective of this work was to evaluate the acute toxicity, sublethal effect and behavioral alteration of L. serricorne exposed to the major components of essential oils, thymol, camphor, terpineol, camphene, eucalyptol, limonene, βpinene and eugenol. The adults of L. serricorne , aged 5 days, not sexed, were submitted to acute toxicity by fumigation, used fumigation chambers, 200 ml glass containers with 20 insects, subsequently the sublethal effect, longevity and behavioral response. The results show that the major components and mixtures caused acute toxicity, reduced the survival time and production of offspring and altered the behavioral activity of L. serricorne. The major components eucalyptol and terpineol presented 65% mortality, in which the mixtures terpineol + eucalyptol and camphor + thymol presented 47 and 52% over adults of L. serricorne. The mixture between terpineol + limonene allowed only 4% ofadults to L. serricorneemerge. Behavioral activity was altered by the eucalyptol + eugenol mixture. The results showed that the major components and mixtures are promising for the preparation and production of new insecticides.

Embora os inseticidas químicos sejam usados ​​com sucesso na agricultura, vários problemas podem estar relacionados ao seu uso indiscriminado. Isso tem incentivado o desenvolvimento de métodos alternativos para o controle de pragas e insetos, bem como a pressão social por produtos livres de pesticidas. A jatropha (J. curcas) e a mamona (Ricinus communis) são plantas que apresentam potencial inseticida. Assim, o objetivo deste trabalho foi estudar folhas de J. curcas e R. communis de diferentes idades sobre o pulgão-da-couve (Myzus persicae). Foram utilizadas cinco concentrações de solução e cinco tipos de folhas. Cada tratamento consistiu de dez indivíduos M. persicae, mantidos em placas de Petri (10,0 x 1,2 cm), sobre discos de folhas de couve. Cada placa de Petri foi considerada uma repetição, totalizando dez. Para aplicação direta, utilizou-se um aerógrafo conectado a um compressor calibrado a pressão constante e 5 mL de solução por repetição. Na aplicação indireta, os discos de repolho foram imersos por cinco segundos nos diferentes tratamentos e oferecidos aos pulgões. Para ambos os testes, as avaliações foram realizadas 72 horas após a aplicação. Os dados foram submetidos à análise de regressão linear e teste de médias. Para ambas as plantas houve interação entre o tipo de aplicação, tipo de folha e concentrações. Reiteramos que as folhas de pinhão-manso e mamona, em suas diferentes idades, apresentam potencial inseticida no manejo de M. persicae.

The miner fly Liriomyza sativae (Blanchard) (Diptera: Agromyzidae) is an insect of eco nomic importance for tomato culture. The conventional control with insecticides is com plex due to the mining eating habit that provides protection to the larvae inside the leaves. Therefore, farmers can opt for biological control agents, or substances that provide protec tion to the plant. Thus, the objective of our research was to evaluate the use of silicon to in duce resistance in tomato plants against L. sativae. The results showed that in tomato plants treated with SiO 2 /F and K 2 SiO 3 /F there was a reduction in the net reproduction rate (Ro), in the intrinsic rate of increase in number (r m), in the finite rate of increase (λ), in the aver age interval between generations (IMG), in the doubling time (TD), in the number of eggs/ female/day and the accumulated egg laying of F1 females of L. sativae. The products SiO 2 /F and K 2 SiO 3 /F gave the tomato a protective effect against injuries caused by L. sativae.