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Background The high dose/refuge combination is the main tactic recommended for mitigating resistance selection of target herbivore species in crops expressing insecticidal proteins of the bacterium Bacillus thuringiensis (i.e., Bt proteins). The tactic consists of the simultaneous use of Bt crops expressing high levels of the Bt protein associated with neighboring areas of refuge of the same non-Bt crop species. Nonetheless, the approach faces controversy regarding its effectiveness and scale of adoption at least in some regions. One of the concerns focuses on its potential impact on the arthropod community, including its short-term and spatially dependent impact considering the likely biota spillover effect between Bt- and non-Bt neighboring areas. Thus, the eventual spillover of Bt-maize targeted and non-targeted arthropods was surveyed along transects extending from the refuge border to the center of the Bt maize area. Results The arthropods were collected throughout the maize vegetative and reproductive stages and a total of 85 arthropod species were collected, but their richness and abundance did not vary with distance from the refuge. In contrast, the cultivation season played a significant role in distinguishing the arthropod communities. Refuge distance from the sampling point within Bt-fields did not significantly affect the food web metrics, unlike season, which affected the number of nodes integrating each food web. Winter maize cultivation exhibited higher arthropod diversity and combined values of species numeric abundance and biomass at each trophic level. Conclusions No arthropod spillover was evident between the refuge edge and Bt-maize adding further controversy to the tactic currently subjected to lower usage in the region with disputed cost-benefit relationship, as not even the target and its inter-dependent species were affected. This article is protected by copyright. All rights reserved.

International audience; Background Bemisia tabaci(Hemiptera: Aleyrodidae) represents one of the greatest threats to agricultural crops. Chemical control is the primary tool used in integrated pest management (IPM) programs. However, release of the predatorNesidiocoris tenuis(Hemiptera: Miridae) on tomato plants is a highly recommended control tactic. The objective of this study was to evaluate the efficacy of a commercial borax plus citrus oil (BCO) product againstB. tabaciin the presence and absence ofN. tenuis. The synthetic insecticide lambda-cyhalothrin was used as a positive control. We also evaluated the sublethal effects of BCO on the behavior and predation rate ofN. tenuis. Results Our results demonstrated that BCO, alone and at its maximum recommended field rate forB. tabaci, was not effective in controlling the pest under laboratory conditions. Application of BCO simultaneous withN. tenuisrelease did not reduce the increase in theB. tabacipopulation. Effective control ofB. tabaciwas achieved using onlyN. tenuis. However, synthetic lambda-cyhalothrin pyrethroid, used here as a control, caused high pest mortality and led to on-site extinction ofN. tenuis, which did not occur for insects exposed to BCO. Lambda-cyhalothrin and BCO significantly affected the foraging behavior ofN. tenuis, reducing the predation rate, especially following exposure to lambda-cyhalothrin. Conclusion The insecticide lambda-cyhalothrin achieved satisfactory results in suppressingB. tabaci, but was harmful toN. tenuis. Additionally, lambda-cyhalothrin and BCO affected predator behavior.

BACKGROUND The importance and impact of invasive species are usually considered based on their economic implications, particularly the direct damage that they cause. The West Indian drywood termite Cryptotermes brevis (Walker) is an example and is a concern in structural lumber, furniture, and other wood products. Despite its importance, its tropical wood preferences and the wood physical characteristics contributing to resistance have not been investigated to date. Here, we developed wood testing units to allow the X-ray recording of termite colonization and then subsequently tested tropical wood resistance to the termite through free-choice and no-choice bioassays using these wood testing units. The relevance of wood density and hardness as determinants of such resistance was also tested, as was termite mandible wear. RESULTS The wood testing units used allowed the assessment of the termite infestation and wood area loss, enabling subsequent choice bioassays to be performed. While pine (Pinus sp.), jequitiba (Cariniana sp.) and angelim (Hymenolobium petraenum) exhibited the heaviest losses and highest infestations; cumaru (Dipteryx odorata), guariuba (Clarisia racemosa), and purpleheart (Peltogyne sp.) showed the lowest losses and infestations; courbaril (Hymenaea courbaril), eucalyptus (Eucalyptus sp.), and tatajuba (Bagassa guianensis) exhibited intermediary results. CONCLUSION Wood hardness and in particular wood density were key determinants of wood resistance to the termites, which exhibited lower infestations associated with greater mandible wear when infesting harder high-density wood. © 2017 Society of Chemical Industry.

The development of new strategies to control pest insects is required, in combination with conventional pesticides or replacing them. Essential oils produced from botanical extracts used in management programs should be effective against pests and selective to natural enemies. Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) is one of the most destructive pests of solanaceous crops in the world, and a possible management strategy consists of releases of the predator Nesidiocoris tenuis (Hemiptera: Miridae), along with botanical applications. The objective of this study was to evaluate the effects of Prev-am (R) oil on T. absoluta offspring, either with or without the predator N. tenuis, as well as the oil's effects on N. tenuis predatory behavior and longevity. The oil's effects were compared with distilled water (control) and a synthetic pesticide (lambda-cyhalothrin). The response of populations to lambda-cyhalothrin was similar to that with Prev-am (R), compared to the control, showing that N. tenuis had higher capacity to reduce T. absoluta populations. The survival analysis of predators exposed to Prev-am (R) indicates that none of the concentrations differed significantly from the control. In addition, the canonical variate analysis indicated significant overall differences in the predator behavior submitted to different treatments, suggesting that synthetic pesticide treatment affected predator behavior when compared to control and Prev-am (R). Reduction in predatory voracity of N. tenuis adults exposed to leaves treated with pesticide and biopesticide was significant compared to the control treatment. The results obtained could improve IPM programs against T. absoluta through the Prev-am (R) applications and N. tenuis releases.

Thrips are important agricultural pests and accurate identification is important for their effective management. In order to determine species, however, they need to be mounted on slides and the traditional process is time-consuming. The aim of this paper is to describe a simple and fast method to prepare temporary slides for the routine identification of thrips, which is not dependent on their colour and hardness. Four species of thrips of different colours were used in the preparations: Frankliniella occidentalis (yellow with brown tergal markings), Frankliniella schultzei (entirely brown), Haplothrips gowdeyii (dark brown to carmine) and Caliothrips phaseoli (brown to black). Slides of each species were prepared using three different methods: traditional (3 days), simplified (6 h) and fast method (10 min). The thrips on the resulting slides were observed under a microscope and important structures used in their identification were compared. The quality of the slides prepared using the traditional method was superior to those prepared using the other two methods if only the transparency and general position of the insects on the slides were considered. The transparency of the slides prepared using the simplified method was also good, but only for the pale coloured species (yellow and grey-brown). The fast method, on the other hand, was very efficient for routine identification since it resulted in slides of sufficient quality for identifying species regardless of their colour. It is important, however, to stress that the fast method is only suitable for preparing temporary slides for routine identification and is not a substitute for the traditional method of preparing permanent slides.

Caracóis têm sido relatados infestando borbulheiras de plantas cítricas em Santa Catarina. Estes moluscos se alimentam das folhas, causando pequenas perfurações no limbo foliar e, principalmente, asco aos trabalhadores rurais. Populações elevadas têm sido observadas, porém sem a real noção das espécies, do número de indivíduos presentes e de sua capacidade de deslocamento no ambiente. Assim o objetivo deste trabalho foi identificar as espécies, estimar a população de caracóis e a velocidade de deslocamento dos indivíduos presentes em borbulheiras de plantas cítricas em ambiente protegido. Um ensaio de marcação e recaptura foi instalado, liberando-se 280 indivíduos marcados de cada espécie, sendo 180 em 18 pontos de liberação para a estimativa populacional e 100, em área central, para mensurar o deslocamento. Os caracóis foram recapturados com armadilhas do solo e por amostragem nas plantas. As espécies de caracóis Bradybaena similaris (Férussac) (Mollusca: Bradybaenidae) e Bulimulus tenuissimus (d’Orbigny) (Mollusca: Bulimulidae) foram identificadas. A população no solo de B. similaris variou de 5,4 a 5,8 indivíduos.m-2, enquanto que a de B. tenuissimus variou de 2,2 a 7,1 indivíduos.m-2. Nas plantas, essas populações foram de 15,0 a 29,6 indivíduos.m-2 e de 5,8 a 11,7 indivíduos.m-2, respectivamente. Não foi possível mensurar o deslocamento dos caracóis B. similaris e B. tenuissimus pelo método empregado.

In the original publication of the article, the authors have inadvertently missed to include a statement in the Acknowledgement section and the corrected version is given below.

In the study reported herein, we aimed to isolate a trypsin inhibitor from Ricinus communis leaves through chromatographic and spectrometric techniques and evaluate its toxic effects on the development of Spodoptera frugiperda larvae. Plant extracts were submitted to fractionation in adsorption column. The fraction 10, which showed the highest inhibitory activity, were incorporated into an artificial diet at the concentrations of 0, 0.06, 0.12, 0.25 and 0.5%, and offered to S. frugiperda larvae. Fresh weight of larvae, food consumed and weight of eliminated faeces were registered. Based on these parameters the following nutritional index were calculated: Relative Consumption Rate (RCR), Relative Metabolic Rate (RMR), Relative Growth Rate (RGR), Approximated Digestibility (AD), Efficiency of Ingested Food Conversion (EIC), Efficiency of Digested Food Conversion (EDC) and the Metabolic Cost (100 - EDC). The inhibitor at 0.5% concentration was deleterious to S. frugiperda, extending the larval stage in 11 days, with higher RCR and ECD, and lower RGR, ECI and ECD. Therefore, the trypsin inhibitor from leaves of R. communis affected the S. frugiperda larval development, being promising in studies of alternative and sustainable control methods for lepidopteran pest species. Key words: Castor beans, enzymatic inhibition, integrated pest management, plant defense against herbivory.

A produção de hortaliças é uma atividade com elevada importância socioeconômica para o Estado de Santa Catarina. Sua viabilidade técnica e econômica depende da disponibilidade da água utilizada para irrigação, cuja qualidade deve atender aos requisitos legais. O presente trabalho teve como objetivo avaliar atributos relacionados à qualidade da água empregada na irrigação de hortaliças, oriunda de reservatórios de captação de água das chuvas e de rios, açudes, poços e córregos na região do litoral Norte de Santa Catarina. Os municípios do estudo foram Tijucas, Itajaí, Itapema, Piçarras, Barra Velha, Porto Belo e Camboriú. Foram analisadas características físicas (dureza, condutividade elétrica e sólidos dissolvidos totais), químicas (pH, Ca, Mg, Na, K, Cd, Pb) e biológicas (coliformes termotolerantes e demanda bioquímica de oxigênio) das amostras de água. Os resultados revelaram que, apesar de possuir algumas inconformidades, as águas da chuva e de poços artesianos são as mais indicadas para a irrigação do cultivo de hortaliças no litoral Norte Catarinense.

Individual traits vary among and within populations, and the co-occurrence of different endosymbiont species within a host may take place under varying endosymbiont loads in each individual host. This makes the recognition of the potential impact of such endosymbiont associations in insect species difficult, particularly in insect pest species. The maize weevil, Sitophilus zeamais Motsch. (Coleoptera: Curculionidae), a key pest species of stored cereal grains, exhibits associations with two endosymbiotic bacteria: the obligatory endosymbiont SZPE ("Sitophilus zeamais Primary Endosymbiont") and the facultative endosymbiont Wolbachia. The impact of the lack of SZPE in maize weevil physiology is the impairment of nutrient acquisition and energy metabolism, while Wolbachia is an important factor in reproductive incompatibility. However, the role of endosymbiont load and co-occurrence in insect behavior, grain consumption, body mass and subsequent reproductive factors has not yet been explored. Here we report on the impacts of co-occurrence and varying endosymbiont loads achieved via thermal treatment and antibiotic provision via ingested water in the maize weevil. SZPE exhibited strong effects on respiration rate, grain consumption and weevil body mass, with observed effects on weevil behavior, particularly flight activity, and potential consequences for the management of this pest species. Wolbachia directly favored weevil fertility and exhibited only mild indirect effects, usually enhancing the SZPE effect. SZPE suppression delayed weevil emergence, which reduced the insect population growth rate, and the thermal inactivation of both symbionts prevented insect reproduction. Such findings are likely important for strain divergences reported in the maize weevil and their control, aspects still deserving future attention.