ABSTRACT
ABSTRACT The garden fleahopper, Microtechnites bractatus (Say) (Hemiptera: Miridae), is associated with several cultivated plant species and, despite its economic importance, little is known about its development and performance in such hosts. We described here, the morphology of immature stages, and evaluated the biology of M. bractatus in beans, potatoes, white clover, alfalfa, and wheat. The bioassays were carried out in the laboratory under controlled temperature (25±2ºC), humidity (UR70±15%), and photoperiod (12L:12D). The eggs of M. bractatus are elongated and slightly curved, without respiratory projections and light yellow in color, becoming dark at the end of the incubation period. Nymphs present an oval-shaped body, a reddish color that intensifies along with the development and dimorphic wing pads in the fifth instar. In the bioassays, the host plants influenced the biological aspects of M. bractatus, both in the immature and adult stages. Nymph survival was higher in clover and alfalfa, while in wheat, it was lower. Clover-fed insects had the longest longevity. The fecundity parameters and egg viability were favored in insects that fed on clover and alfalfa. The fertility life table showed that feeding M. bractatus with clover provides a higher net reproduction rate (R0) and a higher finite ratio of population increase (ʎ). This study contributes to bioecological and behavioral studies on M. bractatus and provides data for the recognition and characterization of individuals in the immature stage.
ABSTRACT
ABSTRACT Diabrotica speciosa (Germar) and Diabrotica viridula F. (Coleoptera: Chrysomelidae) are the two most abundant species of the genus in South America, and belong to the fucata and virgifera groups, respectively. Here, we characterize the dimorphism of the setae present on the basitarsi of males and females of these species. Dimorphism was confirmed in both species, and it was related to the presence of adhesive setae exclusively in males, which possess these structures on the basal tarsomeres of the pro- and mesothoracic legs.
ABSTRACT
Os estudos de levantamento populacional e distribuição vertical de Scaptocoris carvalhoi Becker foram realizados em área de pastagem de Paraúna, GO, entre os meses de novembro de 2004 e outubro de 2005. Em cada avaliação foram realizadas escavações de 1 m de profundidade, coletando os indivíduos e agrupando-os de acordo com a profundidade em que se localizavam no perfil do solo (0-20, 21-40, 41-60, 61-80 e 81-100 cm). Quando os insetos foram encontrados em quantidades baixas até 1 m, as escavações foram realizadas até 2 m de profundidade (junho, agosto e setembro de 2005). As ninfas foram predominantes durante todo o período. O número de adultos foi dependente das chuvas, constatando-se maior incidência com o incremento da precipitação. Ninfas e adultos mantiveram-se nas camadas superficiais do solo no período chuvoso e aprofundaram-se nos períodos de deficiência hídrica. No entanto, os adultos demonstraram menor tolerância ao estresse hídrico e aprofundaram-se logo no início da época seca, enquanto as ninfas o fizeram somente no final desse período. Os resultados obtidos nesse trabalho são semelhantes aos verificados para outras espécies de Scaptocoris, em outras regiões.
Studies on population dynamics and vertical distribution in the soil of Scaptocoris carvalhoi Becker were carried out in a pasture area in Paraúna, State of Goias, Brazil, from November 2004 to October 2005. One meter-deep holes were excavated in the soil, except on the season of lower precipitation, when 2-meter holes were excavated (June, August and September 2005). On each evaluation, the specimens were collected and grouped according to the depth they were found in the soil profile (0-20, 21-40, 41-60, 61-80 and 81-100 cm). Nymphs occurred during the entire length of the study and were more abundant than adults. Adult population augmented with the increase of rainfall. Nymphs and adults were located in the top layer of the soil during the rainy season and were found deeper in the soil during droughts. However, adults were less tolerant to hydric stress and burrowed deeper into the soil at the beginning of the dry season, while nymphs burrowed deeper only at the end of the season. Results of this study are in accordance to other studies on various species of Scaptocoris, in other regions of Brazil.