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Sampling plans are an essential part of integrated pest management programs. Sequential sampling plans enable rapid and low-cost assessment of pest densities. Thrips are emerging pests in soybean crops, and the main method used in pest control is chemical. In soybean crops, insecticides are applied mainly using tractors or airplanes. Thus, this work aimed to determine sequential sampling plans for thrips in soybean crops with insecticide applications using a tractor or airplane. Data were collected in 56 soybean fields, and each field was 20 ha. Sampling plans were determined and validated. The lower (m0) and upper (m1) limits of the sequential sampling plans were: m0 = 1.72 and m1 = 3.43 (by tractor applications) and, m0 = 2.27 and m1 = 4.53 thrips. sample−1 (by airplane applications). The slope (S) and the lower (h0) and upper (h1) intercepts of the sequential sampling plans were: S = 2.42, h0 = −5.79, and h1 = 5.79 (by tractor applications) and, S = 3.19, h0 = −6.83, and h1 = 6.83 (by airplane applications). Sequential sampling plans allowed for correct decisions to be made in all situations using a maximum of 10 samples. The sequential plan reduced the sampling effort by over 87% compared to conventional sampling plans. Therefore, these control decision-making systems have proven feasible and advantageous for implementing integrated pest management programs for controlling thrips species in soybean crops.

The relationship between herbivorous insects and plants is an example of an ‘evolutionary arms race’. Understanding the relationship between insects and their host plants makes it possible to determine critical points in the bioecology of these herbivores. In this relationship, insects and plants use strategies to overcome, avoid and mitigate the actions of the other. Insect‐induced galls are one of the great examples of this ‘arms race’. Psyllids (Hemiptera: Psylloidea) are among the most important gall‐inducing insects. The psyllid Triozoida limbata (Triozidae) is an important pest of guava (Psidium guajava) in the Neotropics. Thus, this work aimed to determine the morphological, anatomical, and biochemical changes in guava leaves caused by T. limbata to study the ‘arms race’ between these two organisms. Therefore, the process of gall formation on guava leaves during the psyllid life cycle was described. A comparative study of the anatomy and levels of phytohormones in leaves attacked and not attacked by the psyllid was carried out. It was found that the psyllid attack triggered the plant's defence by increasing the jasmonic acid content in the leaves. The psyllid attack caused anatomical changes in the leaves (such as cell non‐differentiation), allowing the insect to survive feeding on the plant. In addition, the psyllid‐induced galls provided shelter for the psyllid.

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Detritivorous arthropods are essential because they participate in recycling organic matter, decomposing pesticides, improving soil properties, conserving water, and reducing problems with plant diseases. Practices such as no-till and straw on soils can affect soil properties and populations of detritivorous arthropods. Brazil is the largest producer and consumer of common beans (Phaseolus vulgaris). Thus, this work aimed to determine the impact of no-till and straw planting on detritivorous arthropods on the "surface over ground" in common bean crops. In this way, common beans were cultivated in tillage and no-till with and without straw on the soil. During cultivation, the density of detritivorous arthropods on the soil was monitored using a pitfall trap. Sixteen morphospecies of detritivorous arthropods were observed on the surface of the ground. No-tillage and straw did not affect the number of detritivorous arthropod species. The most abundant morphospecies was the Collembola Entomobryidae and Hypogastrura sp. and the Coleoptera Scarabaeidae and Colopterus spp. No-till and straw positively affected the abundance of detritivorous arthropods. Therefore, no-tillage and straw in bean crops provide conditions for increasing detritivorous arthropod populations, improving soil properties.

Background: Herbivores cause biochemical, physiological, and morphological changes on plants. The ultimate effects of the herbivore activities are damages on the plant's body that can lead from local tissues death to the plant death. The intensity of herbivore attack and the plant's capability to defend itself determine the outcomes of herbivory. When the plant under attack has economic importance, such damages can diminish the productivity of the plantation and compromise the economy of families and the local communities. Although the adverse effects of herbivory on plants and economy are entirely known, some biological mechanisms underlying these damages remain unclear, especially at the anatomical and hormonal levels. The psyllid Triozoida limbata (Hemiptera: Triozidae) is a critical guava (Psidium guajava) pest in the Neotropical region, causing productivity plantation losses up to 55%. Psyllids cause visible morphological changes on guava leaves; however, there is a lack of detailed studied of the cellular, anatomical, and hormonal aspects of the subject. Thus, this work aimed to determine the alterations caused in guava leaves by T. limbata through anatomical and hormonal analyzes. Results: We found that the psyllid's nymphs feeding causes cells hypertrophy and hyperplasia determining the formation of the leaf-roll galls. Although there was no anatomical differentiation of the mesophilic tissues, the cells accumulate starch. Along with the anatomical changes, we observed increasing in the jasmonic acid and reduction of zeatin concentrations in the leaves. Conclusions: The alteration of phytohormone contents and the anatomical changes indicates that the feeding of T. limbata activates plant defenses, but it is not active toward the insects off. The insect nymphs live inside the leaf-roll galls until adults' phase, feeding on the guava leaves xylem and phloem. In commercial guava orchard, the control of T. limbata nymphs have been difficult. Thus, the understanding of the composition of this protective layer can help to find the most effective and efficient control solution for this pest.