In the Lower Middle São Francisco Valley, Tetranychus urticae Koch is controlled by the application of acaricides; however, the intensive use of these products in this region has caused control failures in the field. In the present study, concentrationeresponse curves were constructed periodically to monitor the toxicity of abamectin to T. urticae in two vineyards over two years. Diagnostic concentrations of 1 mg and 9 mg of abamectin/L water were established based on the monitoring period to detect T. urticae resistance in different vineyards in the region. Concentration-response curves were obtained for abamectin, bifenthrin and carbosulfan for the populations considered resistant to abamectin. T. urticae were confined in arenas on cotyledonary leaf discs from jack bean (Canavalia ensiformis L.) that had been immersed in acaricide solution. Mite mortality was assessed after 48 h of exposure to the acaricides. The lethal concentration (LC) values varied over time in both of the vineyards studied, which was most likely a result of crop management. An additional 35 vineyards were sampled, and 20 additional populations were established. The results indicated that 45% of the populations exposed to the 9 mg/L abamectin diagnostic concentration experienced less than 80% mortality and were considered resistant to abamectin. The frequency of resistant mites ranged from 4.1% to 80.4%. The resistance ratio ranged from 2406-fold to 8272-fold compared to susceptible populations in the laboratory. Resistance to bifenthrin was also confirmed in the present study, though resistance to carbosulfan was not. No cross-resistance between abamectin and bifenthrin was observed though this requires further investigation.

Resumo -O objetivo deste trabalho foi avaliar a ocorrência de espécies de tripes em videira e a flutuação populacional, das espécies mais frequentes e abundantes, em diferentes fases fenológicas e sistemas de manejo. O experimento foi realizado em Petrolina, PE, em cinco parreirais -três da cultivar Sugraone (certificada, semiconvencional e convencional) e duas da cultivar Brasil (certificada e convencional). Foram coletadas folhas e inflorescências durante dois anos consecutivos (2008)(2009)(2010), em 15 plantas. Foram realizadas análises de correlação entre as médias de infestação de tripes e os fatores meteorológicos temperatura, umidade relativa do ar e precipitação pluvial. O número médio de larvas e adultos de tripes foi comparado entre os sistemas de manejo e as fases fenológicas. Nas folhas, foram constatadas as espécies Heliothrips haemorrhoidalis, Retithrips syriacus, Selenothrips rubrocinctus, Frankliniella schultzei, Frankliniella sp. e Scolothrips sp., além de larvas de Aelothripidae. Nas inflorescências, foram identificadas apenas espécies de Thripidae, F. schultzei, F. brevicaulis, F. rodeos, F. gardeniae e Frankliniella sp. Não houve correlação de temperatura, umidade relativa e precipitação pluvial com o número médio de tripes. Existe um complexo de espécies de tripes na videira, e a fenologia da planta exerce influência na abundância desses insetos.Termos para indexação: Vitis vinifera, abundância, fatores meteorológicos, fenologia, Thysanoptera. Seasonal variation of thrips species in grapevine according to phenological stages and management systemsAbstract -The objective of this work was to evaluate the occurrence of thrips species and the population fluctuation, of the most frequent and abundant ones, in different management systems and phenological stages of grapevine. The experiment was carried out in Petrolina, PE, Brazil, in five vineyards -three with the cultivar Sugraone (certified, semi-conventional, and conventional) and two with the cultivar Brasil (certified and conventional). Leaves and flowers were collected during two subsequent years (2008-2010) from 15 plants. Correlation analyses were performed between the means of thrips infestation and the meteorological variables temperature, relative humidity, and rainfall. The average number of larvae and adult thrips was compared between the management systems and phenological stage. The thrips species found on leaves were: Heliothrips haemorrhoidalis, Retithrips syriacus, Selenothrips rubrocinctus, Frankliniella schultzei, Frankliniella sp., and Scolothrips sp., as well as nymphs of Aelothripidae. On flowers, only the Thripidae species was found: F. schultzei, F. brevicaulis, F. rodeos, F. gardenia, and Frankliniella sp. There was no correlation between temperature, relative air humidity, and rainfall with the average number of thrips. There is a thrips species complex on grapevine, and plant phenology affects the abundance of the insects.

Considered a generalist species among the coccinellids, the multicolored Asian lady beetle Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) feeds upon small arthropods and non-prey plant products, a practice which might enhance its ability to colonize various ecosystems but carries the potential to expose it to prey quality variation and insecticide use. Thus, we examined the effect of four different diets on the development, reproduction, and response to the insecticide lambda-cyhalothrin in this species. Three groups of larvae received laboratory-reared diets: (i) eggs of Anagasta kuehniella (Zeller) (Ak); (ii) eggs of Sitotroga cerealella (Olivier) (Sc); and (iii) eggs of A. kuehniella + S. cerealella at the proportion 1:1; and one group received wild-caught cotton aphids, Aphis gossypii Glover (Ag). Notwithstanding the generalist feeding behavior of H. axyridis, development and reproduction results were superior with diets of Ag or Ak compared with the diet combining 1:1 Ak + Sc or the diet of Sc eggs only. Furthermore, the Sc diet did not result in satisfactory development and reproduction. Despite this significant variation in biological responses, insecticide susceptibility studies using adults that had been reared on these diets showed no statistically significant differences in susceptibility to the lambda-cyhalothrin.

From those of the mealybug family, the citrus mealybug,

-In vineyards, thrips are listed as pests in many countries in continental Europe and the United States, attacking fruits, flowers, leaves and buds. In Brazil, many species have been reported in vineyards. This work aimed to evaluate the best technique and sampling unit, and the number of samples required in a conventional plan for sampling thrips in a vineyard. The studies were carried out in areas of Vitis vinifera, cultivar Sugraone, without application of insecticides. An area of 2.240m2 was subjected to sample collection of leaves in different strata of 15 plants, and leaves on strata of branches for two subsequent years, totalizing 47 sampling dates. Furthermore, the sampling techniques of beating the inflorescence on a tray and whole inflorescence collection were also addressed. To calculate the sampling time, productive vineyards were used, with the varieties Sugraone and Thompson Seedless. Linear regressions of the relative densities as a function of absolute densities for thrips on branch per plant and leaves per branch were estimated. The technique of beating inflorescence on a tray was the one that best represented the results. The sampling unit that best represented the population was composed of one leaf collected from the median part of the branch. Thrips sampling should be conducted in 10 plants and 10 inflorescences per hectare to estimate the thrips population properly on plants and flowers, respectively. Index terms: Vitis vinifera. Thysanoptera. Sampling unit. Integrated pest management. TÉCNICA DE AMOSTRAGEM CONVENCIONALPARA TRIPES EM VIDEIRA RESUMO -Na cultura da videira, os tripes são mencionados como pragas em diversos países do continente Europeu e nos Estados Unidos, atacando frutos, flores, folhas e brotos. No Brasil, muitas espécies têm sido relatadas nesta cultura. Deste modo, o objetivo deste foi definir a melhor técnica, unidade amostral e o número de amostras exigidas em um plano convencional para a amostragem de tripes em uva. Os estudos foram realizados em áreas de Vitis vinifera, cultivar Sugraone, sem aplicação de inseticidas. Uma área de 2.240m 2 foi submetida a coleta de amostras em diferentes estratos de folhas e ramos, em 15 plantas, durante dois anos, totalizando 47 datas de amostragem. Além disso, também foram abordadas as técnicas de amostragem de batida da inflorescência na bandeja e coleta da inflorescência. Para o cálculo do tempo de amostragem foram utilizados parreirais com as variedades Sugraone e Thompson Seedless. Foram estimadas equações de regressões lineares entre as densidades relativas e absolutas de tripes por folha e ramo. A técnica da batida da flor foi a mais adequada para a amostragem dos tripes em inflorescências. A unidade amostral composta por uma folha localizada no meio do ramo mediano da planta foi o plano de melhor representatividade. A amostragem deve ser realizada em 10 plantas e 10 inflorescências por hectare para detectar os tripes na folha e na flor da videira, respectivamente. Termos de indexação: Vitis vinifera. Thysanoptera. Uni...