The whitefly species Bemisia tuberculata and Aleurotrixus aepim (Hemiptera: Aleyrodidae) are considered important cassava (Manihot esculenta) pests. Leaf color and other morphological characteristics can influence the pest’s interactions with the host plants. Thus, this study aimed to identify the relationship between whitefly occurrence and trichome density and leaf color in different cassava cultivars. The study was conducted in the field during the 2014/2015 and 2016/2017 crop seasons. The whitefly occurrence was surveyed in the cultivars, IAPAR 19, IPR Upira, IPR União, IAC 576-70, IAC 14, IAC 90, Catarina Branca, Santa Helena and Baianinha. The whitefly nymph quantification was correlated with non-glandular trichome density, luminosity (L*) and chroma (a* and b*) of the cassava leaves. IAPAR 19 and IAC 14 were less infested by whitefly nymphs when contrasted with IPR União, IPR Upira and Baianinha, which were the most infested. The lowest B. tuberculata infestations were correlated with lesser trichome density, highest light reflection and highest chroma in the sprout and the plant’s superior third portion leaves. Low A. aepim infestation in both crop seasons made it impossible to verify its correlation with the studied cassava plant characteristics. The cultivars IAPAR 19 and IAC 14 could contribute towards B. tuberculata management in regions with a history of whitefly infestation.

The common bean (Phaseolus vulgaris L.) is an important leguminous crop providing low-cost protein in developing countries worldwide. Insect pests are the main threats to common bean production, and this article focuses on the soybean looper (SL) Chrysodeixis includens (Walker, 1858) (Lepidoptera: Noctuidae), which feeds on leaves and pods. The recurrent use of synthetic chemicals may lead to pest resistance. Genetically resistant plants may diminish their use. Thus, the objective was to study common bean genotypes’ resistance toward SL. The plants were grown in greenhouse conditions. The biology, fertility life table, oviposition preference and free-choice feeding preference were analyzed. Phenol and flavonoid content were assessed in leaves using a biology assay. Uirapuru genotype negatively affected C. includens biology and reproduction. Tangará genotype favored these parameters. Genotypes Quero-Quero, Nhambu, Corujinha, Andorinha, ANFC 9, Siriri, BRS Radiante and Verdão were more attractive for third-instar larvae. Negative correlations between phenolic and flavonoid compounds with survival rate (from egg to adult) rate were found. Common bean genotypes with dark leaves are less preferred for oviposition.

Early maturing common-bean cultivars lack information referring to Euschistus heros (Fabricius, 1798) (Hemiptera: Pentatomidae) feeding damage assessment. This information is pertinent towards establishing economic threshold for an integrated pest management program. The aim of this study was to analyze the relationship, between the density of stink bugs and the degree of injuries towards the pod and grain production, quantity and quality, of the IPR Curió cultivar. The experiments were conducted during two seasons at the IDR-Paraná in Londrina, Paraná, in field conditions. The experimental design was randomized blocks with five repetitions. The treatments were: 0 (control); 1; 2; 3; 4; 5 E. heros m-1. The evaluated variables were number of grained and flat pods; healthy, damaged and aborted grain mass; grain yield. The economic injury level (EIL), economic threshold (ET) and spraying efficiency influence on the ET were calculated. The total number of grained pods was not affected. More than three brown stink bugs, during the summer season, significantly increases flat pod output. The rainy season resulted in greater aborted grains. Increasing E. heros densities, during the summer season, significantly reduces the healthy grain output. The damaged grain mass doubles at higher than one E. heros population densities. The total grain mass produced was not affected. During the summer season, each E. heros reduces 11% of healthy grain output, and during the rainy season 6%. During the summer season was 1.50 of E. heros m-1 and for the rainy season 1.00 E. heros m-1. The spraying efficiency should directly affect the EIL, modifying the value, thus better resembling the field conditions.

The cassava (Manihot esculenta Crantz) crop is relevant for human livelihoods, particularly in poorer regions. It is consumed fresh or as industrialized flour, and the roots and aerial parts are also used to feed livestock. Pests may limit cassava production, which may endanger food security due to the socioeconomic importance of the crop. Reports of the occurrence of three insect guilds, lace bugs, shoot flies, and whiteflies have been recorded in Paraná State, Brazil, but the distinct species and their distribution are yet to be determined. This lack of information limits the development of strategies to mitigate pest damage. Surveys were conducted in 39 counties (four farms per county) distributed throughout the state that encompass the various socioeconomic regions. The collected material was properly packed and sent to the laboratory for identification, and the following species were identified: lace bugs Vatiga illudens Drake, 1922 and Vatiga manihotae Drake, 1922 (both Hemiptera: Tingidae); whiteflies Bemisia tuberculata (Bondar, 1923) and Aleurothrixus aepim (Goeldi, 1886) (both Hemiptera: Aleyrodidae), and the cassava shoot fly Neosilba perezi Romero & Ruppel, 1973 (Diptera: Lonchaeidae) in Paraná State. Lace bugs were not found in the samples in the eastern and southern portions of the state. V. illudens was more widespread than V. manihotae. The whitefly A. aepim was not observed in three counties (eastern, southern, and central regions), whereas B. tuberculata and the cassava shoot fly were found in all regions sampled in Paraná State. Suggestions for future investigations of pest management are proposed.

Diceraeus melacanthus (Dallas, 1851) (Hemiptera: Pentatomidae) has become a key pest in Brazilian maize production, particularly during seedling establishment. This study estimated its lower and upper developmental thresholds (Tb and Tsup), thermal constant (K), and degree-day requirements, and used these parameters to model the potential annual generations (PAG) across the Mato Grosso do Sul, Paraná, and São Paulo states. Biological parameters were calculated from controlled laboratory assays, and historical meteorological datasets were combined with regression models and spatial analyses to generate phenology maps of PAG. Results indicated marked regional differences: Mato Grosso do Sul presented the highest potential, averaging eleven generations per year, São Paulo showed intermediate values with nine generations, and Paraná exhibited the lowest, with approximately seven generations annually. Latitude exerted the strongest influence on PAG, while altitude contributed the least. These findings are consistent with the known adaptability of D. melacanthus to warmer climates and highlight its capacity to persist in no-tillage soybean–maize systems and areas with volunteer plants. The results provide a predictive framework for assessing population risk and may support decision-making in integrated pest management. Further studies on host range, phenology, and distribution are required to anticipate future expansions across South America.

This study evaluated the susceptibility of common bean (Phaseolus vulgaris L.) cultivars to Euschistus heros feeding across various phenological stages. Three cultivars (IPR Curió, IPR Sabiá, and IPR Urutau) were infested with 0.5 insects per plant for eight days starting at anthesis and 8, 16, 24, 32, and 40 days after flowering (DAF) using a randomized block design with five replicates. E. heros did not significantly impact grain yield or reproductive abscission, except for the IPR Curió cultivar during flowering, which demonstrated substantial qualitative damage. Feeding injury resulted in increased grain punctures and the grading of commercial classification to Type 2. The most critical susceptibility period occurred during the grain-filling stages (16–24 DAF). IPR Curió was the most sensitive cultivar, exhibiting Type 2 status at both 16 and 24 DAF. These findings demonstrate that although common beans exhibit quantitative tolerance to E. heros at the tested density, qualitative damage during grain development significantly compromises marketability and value. Integrated Pest Management (IPM) should prioritize protecting the crop during mid-to-late reproductive stages to ensure that grain quality standards are met.