An augmentative biological control program using the egg parasitoid Telenomus podisi Ashmead (Hymenoptera: Platygastridae) is a promising tool for the management of the brown stink bug, Euschistus heros (Fabricius) (Hemiptera: Pentatomidae) in soybeans. The T. podisi are released as adults or pupae within lab-reared E. heros eggs. Because of the small size of the parasitoid and potentially limited dispersal ability, determining the optimal release pattern is critical for biological control of the target pest. This study used sentinel E. heros eggs to investigate T. podisi dispersal within soybean crops during two distinct phenological stages: the beginning of flowering (Vn–R1) and the grain-filling phase (R5–R6). Data were analyzed using semi-variograms and kriging maps. The results indicate significant differences in parasitism rates between the two plant growth stages and among different matrices. The maximum dispersal range for T. podisi was calculated at 39.0 m in the Vn–R1 stage with a maximum parasitism rate of 42%, while in the R5–R6 stage, the maximum dispersal range was calculated to be 30.9 m with a maximum parasitism of 73%. Therefore, it is recommended that release points for T. podisi be spaced no further than 30 m apart. These results provide valuable insights for future research and applications in biological control strategies, including adjustment of the logistics and release technique depending upon the crop phenological stage.

The silverleaf whitefly, Bemisia tabaci Gennadius (Hemiptera: Aleyrodidae), is a significant agricultural pest worldwide, impacting a variety of crop yields. Since the introduction of B. tabaci Mediterranean (MED) species in Brazil, limited research has measured the relative efficacy of the primary insecticides used in whitefly management. This study evaluated the susceptibility of three distinct B. tabaci MED populations to 11 insecticide active ingredients and characterized the bacterial endosymbionts within each population. The insecticides tested were acetamiprid, bifenthrin, cyantraniliprole, diafenthiuron, spiromesifen, imidacloprid, pymetrozine, pyriproxyfen, sulfoxaflor, and thiamethoxam. Results showed varying LC₅₀ and LC₉₀ values among tested insecticides and populations. Notably, populations varied in response to imidacloprid and thiamethoxam with some populations having a 6× higher tolerance. Sequencing data of endosymbionts revealed that individuals from the most susceptible B. tabaci population harbored Rickettsia and Arsenophonus, whereas these bacteria were not detected in the resistant populations. These findings highlight the need for frequent insecticide toxicity bioassays of distinct B. tabaci populations and the adoption of integrated pest management strategies to preserve the efficacy of insecticides for B. tabaci control. Additionally, the role of infection by endosymbionts to alter susceptibility should be further explored.

The tomato (Solanum lycopersicum) is an important crop to the economy of Brazil, and the whitefly Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae) is one of the limiting factors responsible for reducing its yields. These insects are part of a cryptic species group present across almost the entire globe. The most relevant cryptic species in the world are B. tabaci MEAM1 and MED due to their capability to adapt and cause damage to vegetables, grain, and ornamental crops. The arrival of MED in Brazil through the state of São Paulo represents risks to farmers in the region due to the difficulty in managing these insects. This study assessed the occurrence of both species in tomato crops in the southeastern region of Brazil in 2020 and 2021. An amount of 79 samples containing 767 insects were collected throughout the study period, and in the cities of Sumaré (SP) and Monte Mor (SP), several samples were collected from the same location throughout the year. The insects were stored and sent for molecular analysis. The results showed an increase in MED compared to MEAM1. The presence of MED in the Minas Gerais samples was not recorded. However, a higher percentage of MED was observed in the state of São Paulo, which was detected in the municipalities of Sumaré and Monte Mor. These results possibly indicate that MED could be starting to stabilize in open tomato fields in Brazil.

The whitefly, Bemisia tabaci, is a complex of cryptic species that is a significant pest of different legume hosts that inhabits various regions worldwide with diverse climates and characteristics. Its adaptability is often facilitated by the insect’s microbiome, which can contribute to both the metabolism of host plant secondary compounds and insecticide resistance. The most relevant biotypes in Brazil are Middle East-Asia Minor 1 (MEAM1) and Mediterranean (MED), because of their ability to damage different hosts. Although MEAM1 is the prevalent species in Brazil, MED has great potential to spread, and there is little current knowledge about the biology of this biotype in the country. Therefore, the objective of this study was to evaluate the development and viability of MED on two legumes, soybean and common bean, alongside cotton, bell pepper, and tomato, at temperatures of 20 °C, 23 °C, 26 °C, 29 °C, 32 °C, and 35 °C and characterize the composition of its endosymbionts. Temperatures between 23 °C and 32 °C were the most suitable for B. tabaci MED development and viability across all tested host plants, whereas 35 °C proved harmful for insects reared on legumes. We observed a temperature threshold (°C) and thermal constant (degree-days) that varied according to the host plant, ranging from 9.81 °C and 384.62 for soybean to 11.17 °C and 333.33 for bell pepper, respectively. The main endosymbionts were in a ratio of 80% Hamiltonella and 20% Cardinium. These results allow the future mapping of risk for the MED biotype on different host plants in Brazil and elsewhere in South America.

Tomato is the most widely cultivated fruit–vegetable worldwide, and the tomato leafminer (Tuta absoluta) is the primary pest of this crop. In this context, biological control using parasitoids belonging to the genus Trichogramma is crucial. This study aimed to evaluate the biological characteristics of T. pretiosum strains collected from different locations and exposed to eggs from various T. absoluta populations/generations, using parameters such as parasitism capacity, viability (percentage of emergence), sex ratio, and female longevity. The presence of endosymbionts in the T. absoluta populations was also assessed. The experiment followed a randomized design, with treatments consisting of eggs from T. absoluta populations collected in different years (2019, 2020, 2021, 2022, and 2023) and different strains of T. pretiosum. We used 20 replicates, with one female per replicate in each treatment, organized in a 5 × 4 factorial scheme (five populations of T. absoluta × four strains of T. pretiosum). The S2 strain of T. pretiosum was found to be the most efficient in terms of biological characteristics for parasitism of T. absoluta eggs, especially in T. absoluta populations collected in recent years (2022 and 2023). These results suggest that S2 is the preferred strain for future studies aimed at using this parasitoid as a control agent to combat T. absoluta. The endosymbionts Arsenophonus and Serratia were identified in T. absoluta populations collected in 2019–2020 and 2020–2021, respectively. These findings highlight the presence of these microorganisms in pest populations in different years.