Abstract Aniara sepulchralis specimens sampled at different locations (Belém and Bragantina microregions) show differences in size of some morphological structures such as head width, pronotum width, distance between eyes, pronotum base width, labral length, labral width, and spur of the third pair of legs. These changes may be due to biotic, abiotic, and structural factors peculiar to each environment. Differences in structures and morphological measurements of males and females of Aniara sepulchralis were observed, characterized as sexual dimorphism in relation to their teeth and labral-clypeal suture. Females present apical teeth and rectilinear suture, whereas males present a more rounded shape in both teeth and the labral-clypeal suture. Regarding measurements, females have greater body length, head width, eye distance, pronotum length, pronotum width, labral length, and pronotum base width than males. Belém microregions eyes length legs biotic abiotic environment observed labralclypeal clypeal suture

ABSTRACT Crop pests have negative impacts on yield. This paper proposes a spatiotemporal geostatistical modeling to compare data of adult Syrphidae fly count and corn leaf aphid Rhopalosiphum maidis (Fitch, 1856) colonies in corn crops. The use of a geostatistical model that allows the space-time variation makes the approach more interesting because it is a more complete model. Multiple regression was used to model the trend component for the variable response adult Syrphidae fly count and corn leaf aphid colonies, with the coordinates serving as covariates and the spatiotemporal variations around the deviation are described by a random spacetime residual field. Finally, the prediction map obtained by kriging may be a biological indicator of possible corn leaf aphid colonies in the corn crop. It was possible to verify that the occurrence of the pest provided a significant increase in adult predators and seminatural habitats may favor populations of natural enemies.

RESUMO A espécie Abaris basistriata é dominante em agroecossistemas e habitats naturais, podendo ser beneficiada pela criação de áreas de refúgio próximas ou ao centro de culturas. Para confirmar essa hipótese, este estudo teve como objetivo analisar a distribuição espacial e verificar a dinâmica populacional desse predador em uma área de rotação soja e milho e uma área de refúgio central. A área experimental apresentava um hectare dividido ao meio por uma faixa de plantas herbáceas de dois metros de largura por 80 metros de comprimento. Os besouros foram coletados com armadilhas pitfall com amostragens quinzenais na safra e mensais na entressafra, totalizando 27 amostras. A flutuação populacional foi analisada e relacionada com o total de espécimes e as fases fenológicas das plantas. Utilizou-se análise de regressão múltipla com seleção de variáveis "stepwise", para verificar a influência dos fatores meteorológicos na ocorrência da espécie. Para determinar a distribuição espacial, os dados foram analisados por meio dos índices de dispersão e modelos probabilísticos, com base na distribuição de frequência dos coleópteros. A visualização da distribuição foi verificada por mapa de interpolação linear. Um total de 143 espécimes de A. basistriata foi coletado, sendo 83 na cultura de soja/milho e 60 na área de refúgio. Os períodos de elevada população ocorreram, durante a estação de alta precipitação pluvial, com temperatura mínima e máxima elevada. Com base na análise da distribuição espacial de A. basistriata, verifica-se que essa espécie ocorre de forma agregada, preferencialmente, na área de refúgio.

ABSTRACT Abaris basistriata, a beetle species dominant in agroecosystems and natural habitats, may benefit from the establishment of nearby refuge areas or crop field centers. To confirm this hypothesis, we analyzed the spatial distribution of the species and verified the population dynamics of this predator in a soybean/corn rotation crop and a central refuge area. The 1-ha experimental area was divided in half by a range of herbaceous plants (2 m in width and 80 m in length). Beetle samples were collected using pitfall traps every fortnight during the in-season and every month during the off-season (a total of 27 sampling occurrences). Population fluctuation was analyzed by correlating the total number of specimens with plant phenology. We used multiple regression analysis with variable (stepwise) selection to examine the influence of meteorological factors on species occurrence. To determine the spatial distribution, data were analyzed using dispersion indices and probabilistic models based on the Coleoptera frequency distribution. Distribution visualization was assessed using a linear interpolation map. A total of 143 A. basistriata specimens were collected, with 83 from the soybean/corn area and 60 from the refuge area. Periods of large population size occurred during a season with high rainfall and high maximum and minimum temperatures. On the basis of the spatial distribution analysis of A. basistriata, it is likely that the beetles occur in an aggregate form, preferably in the refuge area.