Structure and genetic variation among populations of Euschistus heros from different geographic regions in Brazil

Abstract

The Neotropical brown stink bug, Euschistus heros (Fabricius) (Hemiptera: Pentatomidae), is a major Brazilian soybean pest. Aiming to provide relevant information to implement pest and insecticide resistance management, new microsatellite loci were developed for E. heros and used in a study of genetic diversity and population structure. The population analysis was performed using eight microsatellite loci from 17 samples (n = 243 individuals) collected in the major soybean‐producing regions in Brazil (northeastern, midwestern, and southern regions). These microsatellite loci provided high genetic diversity values on the whole extension for the studied region (He = 0.895; total number of alleles = 400). Neotropical brown stink bug populations in general displayed low genetic structure levels among the samples (overall ΦST = 0.009). An exception was the sample from the northeastern region, which showed a significant genetic differentiation (pairwise ΦST = 0.031–0.063). Bayesian cluster analysis confirmed these results, did not show population subdivision, and indicated considerable levels of gene flow. Significant correlations between genetic differences and geographic distance were obtained. The lowest estimate of migration was found in the population from São Desidério, which was also the most distant from the remaining populations based on genetic distance. Some plausible hypotheses for the low genetic differentiation among these populations are the fast expansion of soybean production areas, the main food source of E. heros, polyvoltinism, and possible influence of anthropogenic dispersal. All these factors could have led to high population densities, a wide distribution that may contribute to reduced population differentiation, and increased genetic diversity.

Prevalence, damage, management and insecticide resistance of stink bug populations (Hemiptera: Pentatomidae) in commodity crops

“…The reasons for the decline in N. viridula and increase in E. heros and Dichelops populations have not been unveiled yet, although this phenomenon can be attributed to several factors. Among them, adaptability of these insect pests to soybean as a result of the availability of large areas with this host plant (Panizzi & Corrêa‐Ferreira, ; Husch et al ., ), global climate changes that favour species adapted to warmer conditions (Robinet & Roques, ; Saluso et al ., ), multiple cropping systems that affect host weeds (Smaniotto & Panizzi, ), inter‐specific competition among pentatomids, competitive release of nontarget pest outbreaks (stink bug populations) associated with Bt‐crops (Zeilinger et al ., ) and indeterminate soybean genotypes with longer pod filling stages. In addition, not adopting tillage practices may have mainly favoured Dichelops species that require sheltered conditions under crop stubble (Panizzi, ; Panizzi & Lucini, ).…”

Comunidade De Coleoptera De Solo De Floresta De Restinga Da Área De Proteção Ambiental Guanandy- Espírito Santo, Brasil

“…Entretanto, durante todo o ciclo de produção da cultura, existe fatores fitossanitários que comprometem a sua produtividade. Dentre eles, se destacam a constante presença de insetos-praga, quem podem ocorrer desde a semeadura até a fase de maturação dos grãos, caracterizando-se como um dos principais fatores limitantes para a exploração da cultura, e consequentemente, sua produção (Ávila; Schlick- Souza, 2015;Husch et al, 2018).…”

Population Genomics of the Neotropical Brown Stink Bug, Euschistus heros: The Most Important Emerging Insect Pest to Soybean in Brazil

“…The northern lineage showed higher haplotype diversity, whereas the southern lineage had lower haplotype diversity. High levels of genetic diversity found using both the mtDNA (Soares et al, 2018) and nDNA (Husch et al, 2018) in secondary contact putative areas compared to the pure-bred areas, suggests hybridization between the two lineages. However, currently, the potential for population admixture between the two lineages have not been accessed.…”