This research aimed to assess the toxicity of the pesticides abamectin 18 CE (0.02 g a.i. L-1), carbaryl 480 SC (1.73 g a.i. L-1), sulfur 800 GrDA (4.8 g a.i. L-1), fenitrothion 500 CE (0.75 g a.i. L-1), methidathion 400 CE (0.4 g a.i. L-1), and trichlorfon 500 SC (1.5 g a.i. L-1) as applied in integrated apple production in Brazil on the survival, oviposition capacity, and egg viability of the lacewing, Chrysoperla externa (Hagen) (Neuroptera: Chrysopidae) from Bento Gonçalves and Vacaria, Rio Grande do Sul State, Brazil. An attempt was made to study morphological changes caused by some of these chemicals, by means of ultrastructural analysis, using a scanning electronic microscope. Carbaryl, fenitrothion, and methidathion caused 100% adult mortality for both populations, avoiding evaluation of pesticides' effects on predator reproductive parameters. Abamectin and sulfur also affected the survival of these individuals with mortality rates of 10% and 6.7%, respectively, for adults from Bento Gonçalves, and were harmless to those from Vacaria at the end of evaluation. Trichlorfon was also harmless to adults from both populations. No compound reduced oviposition capacity. C. externa from Vacaria presented higher reproductive potential than those from Bento Gonçalves. In relation to egg viability, sulfur was the most damaging compound to both populations of C. externa. Ultrastructural analyses showed morphological changes in the micropyle and the chorion of eggs laid by C. externa treated with either abamectin or sulfur. The treatment may have influenced the fertilization of C. externa eggs and embryonic development. Sulfur was responsible for malformations in the end region of the abdomen and genitals of treated females. When applied to adults, abamectin, sulfur, and trichlorfon were harmless, while carbaryl, fenitrothion, and methidathion were harmful, according to the IOBC classification.

RESUMO Neste trabalho, foi avaliado o efeito de inseticidas sobre larvas de duas populações de Chrysoperla externa (Hagen, 1861)

The physical characteristics of a spray liquid are important in getting a good droplet formation and control efficiency over a particular target. As a function of these characteristics, it is possible to decipher which is the best adjuvant based on the respective concentration used during the spray. Therefore, ten spraying liquids were prepared, which varied in concentrations of pesticide lufenuron + profenofos, mineral oil, water and manganese sulfate. Pendant droplets formed from these mixtures were measured to examine their impact on surface tension. Droplets were applied to the surface of coffee leaves and the surface tension, contact angle formed and the leaf area wetted by the droplet, were measured. A smooth glass surface was taken as a comparative to the coffee leaves. The highest concentrations of oil resulted in lower surface tension, smaller contact angles of droplets on leaf surfaces and larger areas wetted by the droplets. Both surfaces showed hydrophilic behavior.KEYWORDS: surface tension, contact angle, wetted area, oil CARACTERÍSTICAS FÍSICAS DE CALDAS OLEOSAS E DE GOTAS FORMADAS EM SUPERFÍCIE DE FOLHAS DE CAFÉ E DE VIDRO RESUMO:As características físicas da calda de pulverização são importantes para que haja boa formação de gotas e eficiência de controle sobre determinado alvo. Em função dessas características, pode-se decidir sobre qual o melhor adjuvante, em sua respectiva concentração, poderá ser utilizado durante a pulverização. Para tanto, foram preparadas dez caldas fitossanitárias em que variaram as concentrações do inseticida lufenuron + profenofós, óleo mineral, água e sulfato de manganês. Gotas pendentes formadas a partir dessas misturas foram medidas em sua tensão superficial. Aplicaram-se gotas sobre a superfície de folhas de café e foram medidos a tensão superficial, o ângulo de contato formado e a área da folha molhada pela gota. Uma superfície lisa de vidro foi tomada como comparativo às folhas de café. As maiores concentrações de óleo resultaram em menores valores de tensão superficial, menores ângulos de contato de gotas com a superfície foliar e maiores áreas molhadas pelas gotas. Ambas as superfícies mostraram-se hidrofílicas. PALAVRAS-CHAVE:tensão superficial, ângulo de contato, área molhada, óleo.

Resumo -O objetivo deste trabalho foi avaliar a seletividade de inseticidas recentemente lançados no mercado para o controle de pragas na cultura dos citros, em adultos de Chrysoperla externa e Ceraeochrysa cubana. Os produtos utilizados e as respectivas dosagens em g L -1 de i.a. foram: tiametoxam 200 WG, 0,05; imidacloprido 700 WG, 0,07; milbemectina 50 CE, 0,008; piriproxifem 100 CE, 0,075; e espirodiclofeno 240 SC, 0,06. Em cada tratamento, 11 casais de C. externa e 13 de C. cubana, com idade de até 24 horas, foram submetidos à aplicação dos inseticidas e de água (testemunha), por meio de torre de Potter. A mortalidade dos adultos, a capacidade de oviposição num período de oito semanas e a viabilidade dos ovos foram avaliadas. O tiametoxam foi classificado como nocivo a C. externa; o imidacloprido como moderadamente nocivo e os demais inseticidas como inócuos. Para C. cubana, o tiametoxam foi considerado nocivo, o espirodiclofeno foi levemente nocivo e os demais produtos foram inócuos. Os produtos milbemectina, piriproxifem e espirodiclofeno podem ser recomendados em programas de manejo integrado de pragas visando à manutenção dessas espécies de artrópodes benéficos em áreas de citricultura.Termos para indexação: Ceraeochrysa cubana, Citrus, Chrysoperla externa, artrópodes benéficos, manejo integrado de pragas, toxicidade. Physiological selectivity of insecticides to two lacewing speciesAbstract -The objective of this work was to evaluate the effects of insecticides recently released for the control of citrus pests on adult specimens of Chrysoperla externa and Ceraeochrysa cubana. The products used and their respective dosages in g L -1 of a.i. were: thiametoxam 200 WG, 0.05; imidacloprid 700 WG, 0.07; milbemectin 50 CE, 0.008; pyriproxyfen 100 CE, 0.075; and spirodiclofen 240 SC, 0.06. In each treatment, 11 couples of C. externa and 13 of C. cubana, at an age up to 24 hours, were submitted to the application of the insecticides and water (control), through a Potter´s tower. Adults mortality and oviposition capacity were evaluated in a period of eight weeks, as well as the viability of laid eggs. Thiametoxam was classified as harmful to C. externa; imidacloprid as moderately harmful and the other insecticides as harmless. As for C. cubana, thiametoxam was considered harmful; spirodiclofen was slightly harmful and the other products were innocuous. The insecticides milbemectin, pyriproxyfen and spirodiclofen can be recommended to integrated pest management programs aiming at the maintenance of these species of beneficial arthropods in citrus areas.

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The spread and evaporation time of droplets deposited on the target affect the application efficiency of pesticides. This study aimed at evaluating the evaporation time of droplets with different sizes, under different levels of relative air humidity, containing thiamethoxam and adjuvants sprayed on sugarcane leaves. Data were collected in a climate chamber with controlled conditions, where a digital microscope was set up to record the droplet images. The evaporation time was evaluated considering three relative air humidity rates (45 %, 60 % and 75 %). For each condition, a completely randomized experiment was installed with five replications, in a 5 x 6 factorial design consisting of five sprays (water, thiamethoxam, thiamethoxam + mineral oil, thiamethoxam + vegetable oil and thiamethoxam + spreader) and six droplet diameters (337 µm, 424 µm, 486 µm, 576 µm, 831 µm and 985 µm). The evaporation time is directly and linearly related to the droplet diameter, with larger diameters requiring a longer time to evaporate. The evaporation time of droplets is also influenced by relative air humidity and spray composition. Among the adjuvants tested, the mineral oil provides the lower evaporation time for all droplet sizes.

Aiming to contribute to the development of alternative control methods of the coffee leaf miner, Leucoptera coffeella (Guérin-Mèneville & Perrottet, 1842) (Lepidoptera: Lyonetiidae), a search for plants able to produce active substances against this insect was carried out, with species collected during different periods of time in the Alto Rio Grande region, (Lavras, Minas Gerais, Brazil). Coffee leaves containing L. coffeella mines were joined with 106 extracts from 77 plant species and, after 48 hours, the dead and alive caterpillars were counted. The extracts from Achillea millefolium, Citrus limon, Glechoma hederacea, Malva sylvestris, Mangifera indica, Mentha spicata, Mirabilis jalapa, Musa sapientum, Ocimum basiculum, Petiveria alliaceae, Porophyllum ruderale, Psidium guajava, Rosmarinus officinalis, Roupala montana, Sambucus nigra and Tropaeolum majus showed the highest mortality rates.

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