Seletividade de inseticidas utilizados em cultura cafeeira para larvas de Cryptolaemus montrouzieri Mulsant / Selectivity of insecticides used in the coffee crop to larvae of Cryptolaemus montrouzieri Mulsant

Assim como a maioria dos cultivos, em cafeeiro, a associação de inimigos naturais com produtos fitossanitários seletivos é uma importante estratégia no manejo integrado de pragas (MIP). Dessa forma, este estudo objetivou avaliar a seletividade de agrotóxicos utilizados na cultura cafeeira sobre larvas de Cryptolaemus montrouzieri Mulsant, 1853 (Coleoptera: Coccinellidae), em laboratório. Os bioensaios foram realizados em condições controladas (25±2°C, UR de 70±10 por cento e fotofase de 12 horas). Cada bioensaio consistiu em seis tratamentos e dez repetições, sendo cada parcela composta por duas larvas. Para as comparações das médias dos tratamentos, empregou-se um esquema fatorial inteiramente ao acaso de produtos x número de instares para os diferentes instares subsequentes à aplicação. Os inseticidas utilizados e suas respectivas dosagens de aplicação, em g de i.a. L-1 foram: tiametoxam (0,5), imidacloprido (0,7), óleo mineral (13,3), endossulfam (2,63) e dimetoato (0,48). A testemunha foi composta apenas por água destilada. A aplicação dos produtos foi realizada por meio de torre de Potter. Avaliaram-se a sobrevivência dos espécimes após serem contaminados com os produtos e os efeitos dos compostos sobre os parâmetros reprodutivos do predador. Tiametoxam (0,5), imidacloprido (0,7) e endossulfam (2,63) foram os mais prejudiciais, tendo sido observados, para os dois primeiros, 100 por cento de mortalidade de larvas de primeiro e de segundo instares um dia após a aplicação e significativa redução na sobrevivência das larvas de terceiro e quarto instares. Dimetoato (0,48) foi nocivo para larvas de primeiro instar e levemente nocivo para larvas de quarto instar. Em função da seletividade apresentada pelo óleo mineral (13,3), este pode ser recomendado em compatibilização com o predador C. montrouzieri em programas de MIP na cultura cafeeira, sem prejuízo ao desempenho do inimigo natural.

As well as most of the crops, in coffee crop, the association of selective compounds and natural enemies, composes an important tool for the integrated pest management (IPM). The objective of this study was to evaluate the selectivity of some pesticides used in coffee crops on larvae of Cryptolaemus montrouzieri Mulsant, 1853 (Coleoptera: Coccinellidae) under controlled laboratory conditions (climatic chamber) at 25±2°C, RH of 70±10 percent with a 12 h-photophase. The randomized experimental design was used, with six treatments and ten repetitions, being each composed for two larvae. For the comparisons of the averages of treatments, a factorial scheme was used with the products x number of instars for the different instars subsequent the application. The pesticides and doses in g of a.i. L-1 were: thiamethoxan (0.5), imidacloprid (0.7), mineral oil (13.3), endosulfan (2.63) and dimethoate (0.48). Distilled water was used as control. The sprayings of the pesticides were accomplished using a Potter's tower. The parameters evaluated were: specimens survival after the application of the compounds, and the compounds effects over the reproductive parameters of the predator. Thiamethoxan (0.5), imidacloprid (0.7) and endosulfan (2.63) were the most harmful to the treated individuals and for the first two compounds it was observed 100 percent of larvae mortality of the first and second instars soon at 1 day after the application and reduction in the survival of the larvae of third and fourth instars. Dimethoate (0.48) was harmful for the larvae of the first instar and slightly harmful for larvae of fourth instar. As a function of the selectivity presented by mineral oil (13.3), it can be recommended aiming its compatibilization with the C. montrouzieri natural enemy in programs of IPM in coffee crop.

Selectivity of pesticides used in integrated apple production to the lacewing, Chrysoperla externa.

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.

Efeitos da aplicação de agrotóxicos utilizados na produção integrada de maçã sobre pupas de Chrysoperla externa / Effects of pesticides application used in integrated apple production on Chrysoperla externa pupae

Devido à grande importância de Chrysoperla externa (Neuroptera: Chrysopidae) como agente de controle biológico de artrópodes-praga na cultura da macieira no Brasil, avaliaram-se os efeitos dos agrotóxicos (g i.a. L-1) abamectina (0,02), carbaril (1,73), enxofre (4,80), fenitrotiona (0,75), metidationa (0,40) e triclorfom (1,50) em pupas desse predador, oriundas de Bento Gonçalves e Vacaria, Rio Grande do Sul, bem como sobre o desenvolvimento dos adultos obtidos e sua reprodução. A aplicação dos compostos e de água destilada (testemunha) foi realizada sobre as pupas utilizando-se torre de Potter. Carbaril e triclorfom causaram mortalidade significativa de pupas tratadas de ambas as populações. Abamectina somente causou mortalidade de pupas oriundas de Vacaria; enxofre, fenitrotiona e metidationa mostraram-se inócuos ao predador. Não foram constatadas reduções no número de ovos depositados por C. externa de Bento Gonçalves; entretanto, fenitrotiona causou reduções nessa característica biológica de fêmeas provenientes de Vacaria. Apenas carbaril e abamectina não afetaram negativamente a viabilidade dos ovos depositados por C. externa oriundas de pupas tratadas, provenientes de Bento Gonçalves e Vacaria, respectivamente. Baseando-se no efeito total (E), enxofre, fenitrotiona e metidationa são inócuos, enquanto abamectina, carbaril e triclorfom são levemente prejudiciais a insetos oriundos de Bento Gonçalves. Abamectina e enxofre são inócuos a indivíduos de Vacaria, enquanto carbaril, fenitrotiona, metidationa e triclorfom são levemente prejudiciais, conforme classificação da IOBC.

Chrysoperla externa (Neuroptera: Chrysopidae) is an important biological control agent of artropod-pests in apple crop. In this research the effects of the pesticides (g a.i. L-1) abamectin (0.02), carbaryl (1.73), fenitrothion (0.75), methidathion (0.40), sulphur (4.80) and trichlorfon (1.50), on C. externa pupae from Bento Gonçalves and Vacaria regions, Rio Grande do Sul, Brazil, as well as on the development of the adults obtained and its reproduction were evaluated. The sprayings of those compounds and distilled water (control) on pupae were accomplished using a Potter tower. Carbaryl and trichlorfon caused mortality of treated pupae in both studied populations. Abamectin only caused significant mortality of treated pupae from Vacaria; sulphur, fenitrothion and methidathion presented to be harmless to the predator. None of the compounds reduced the oviposition capacity of C. externa from Bento Gonçalves, originated from treated pupae; however, fenitrothion caused reductions in that biological parameter for females from Vacaria. Among the evaluated pesticides, only carbaryl and abamectin did not reduced the viability of eggs laid by C. externa from Bento Gonçalves and Vacaria, respectively. According to the total effect (E) of each pesticide, sulphur, fenitrothion and methidathion are harmless, whereas abamectin, carbaryl and trichlorfon are slightly harmful to insects from Bento Gonçalves. Abamectin and sulphur are harmless to insects from Vacaria, while carbaryl, fenitrothion, methidathion and trichlorfon are slightly harmful, according to the IOBC classification.