RESUMO Neste trabalho, avaliou-se o desempenho das cultivares de batata em sistema orgânico de produção, visando identificar aquelas com maior potencial produtivo e menos danificadas por Phytophthora infestans e Diabrotica speciosa. O experimento foi conduzido durante as safras de 2013/2014 e 2014/2015. Avaliou-se as cultivares Ágata, Aracy Ruiva, Vitória, Clara, Eliza, Catucha e Cris, quanto à severidade de P. infestans e área abaixo da curva de progresso da doença (AUDPC), orifícios e galerias nos tubérculos causadas por D. speciosa e produção de tubérculos. ‘Ágata’ foi a cultivar mais suscetível, com severidade de P. infestans próxima dos 100% e AUDPC significativamente mais elevada do que as outras cultivares. Os danos externos das larvas D. speciosa foram mais intensos em ‘Eliza’ do que em ‘Clara’ e ‘Catucha’. ‘Eliza’ foi também uma das cultivares com mais danos internos em ambos os anos, enquanto ‘Catucha e ‘Vitória’ estiveram entre as menos danificadas internamente. Os resultados indicaram ‘Catucha’ e ‘Clara’ como as mais adequadas para o cultivo orgânico entre os materiais estudados.

ABSTRACT In this study we evaluated the performance of potato cultivars in the organic production system, aiming to identify those more productive and less damaged by Phytophthora infestans and Diabrotica speciosa. The experiment was conducted during the 2013/2014 and 2014/2015 crop seasons. Cultivars Ágata, Aracy Ruiva, Vitória, Clara, Eliza, Catucha and Cris were assessed for severity and area under disease progress curve (AUDPC) of P. infestans, external holes and internal galleries caused by D. speciosa, and tuber yield. Most cultivars reacted positively to P. infestans and D. speciosa. ‘Ágata’ was the most susceptible cultivar, with P. infestans severity close to 100% and AUDPC significantly higher than the other cultivars. D. speciosa larvae external damages were more intense in ‘Eliza’ than in ‘Clara’ and ‘Catucha’. ‘Eliza’ was also among the most internally damaged cultivars in both years, while ‘Catucha’ and ‘Vitória’ were among the least internally damaged. The results indicate ‘Catucha’ and ‘Clara’ as the most suitable for organic cultivation among the studied materials.

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.

RESUMO O valor comercial dos tubérculos de batata é afetado pelos danos causados por Diabrotica speciosa, cujas larvas fazem orifícios na casca dos tubérculos e túneis internos. A estimativa dos danos aos tubérculos de batata é geralmente realizada avaliando os danos externos, em detrimento dos túneis de alimentação causados por larvas. Assim, propomos um método para estimar os danos de D. speciosa, considerando os aspectos externos e internos dos tubérculos separadamente. Para tanto, plantas de batata cv. Ágata foram cultivadas sob diferentes infestações de larvas, medindo-se a área ocupada pelos buracos e o volume dos túneis de alimentação internamente, relacionando esses dados com a área total e o volume do tubérculo. A metodologia utilizada permitiu caracterizar o aumento dos danos nos tubérculos com maior infestação de larvas. A correlação entre os danos internos e externos causados por larvas de D. speciosa não foi significativa, indicando que o dano externo por si só não é um parâmetro adequado para o diagnóstico da qualidade geral do tubérculo. No entanto, o método aqui proposto fornece informações sobre o volume de polpa consumido pelas larvas, a extensão das galerias formadas e o volume relativo de danos em relação ao tubérculo total. Além disso, o método aqui proposto contempla uma análise mais precisa da área externa danificada pela herbivoria em relação à área total do tubérculo, o que não é comumente considerado em estudos de estruturas de plantas subterrâneas.

ABSTRACT The marketable value of potato tubers is affected by damage caused by Diabrotica speciosa, whose larvae create holes on the tubers’ skin and internal feeding tunnels. The estimation of potato tuber damage is usually performed by assessing the external damage to the detriment of feeding tunnels caused by larvae. Thus, we propose a method to estimate the damage caused by D. speciosa larvae, considering the external and internal aspects of the tubers separately. For that, potato plants cv. Agata were grown under different infestations of larvae, measuring the area occupied by the holes and the volume of internal feeding tunnels, relating these data to the total area and volume of the tuber. The methodology used allowed us to characterize an increase in damage in tubers with the highest infestation of larvae. The correlation between internal and external damage caused by D. speciosa larvae was not significant, indicating that external damage alone is not an adequate parameter for the diagnosis of overall tuber quality. However, the method proposed here provides information regarding the volume of pulp consumed by the larvae, the extent of the galleries formed, and the relative volume of damage concerning the total tuber. Moreover, the method proposed here contemplates a more precise analysis of the external area damaged by herbivory relative to the total area of the tuber, which is not commonly considered in studies of underground plant structures.

Abstract This study reports for the first time the plant bug Microtechnites bractatus (Say) in Crotalaria juncea and Crotalaria spectabilis, in the state of Paraná, Brazil. We characterized the injuries caused by M. bractatus and Collaria scenica Stal in cultivated plants and in Crotalaria spp. Considering that M. bractatus damage has been incorrectly attributed to C. scenica, we present here a contribution to the correct characterization of these insect pests and their damage over some agricultural crops.

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: The banana moth Opogona sacchari (Bojer) (Lepidoptera: Tineidae) is a polyphagous pest that can cause serious damage, especially to banana crops in southern Brazil. It attacks the fruit, lowering its quality and making bananas unsuitable for export. Current control measures are limited and the use of Trichogramma (Hymenoptera: Trichogrammatidae) for Applied Biological Control may be an alternative for the management of this pest. In this study, we investigated the potential parasitism effectiveness of eggs of O. sacchari by T. pretiosum, T. atopovirilia and T. galloi, three species of parasitoids commonly used in Applied Biological Control programs in Brazil. Eggs of O. sacchari were parasitized by all three Trichogramma species, and T. atopovirilia and T. galloi were the most aggressive, showing greater potential for control of this pest in the banana culture.

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.

Os objetivos deste estudo foram conhecer a guilda de parasitóides associados a pupas de Methona themisto (Hübner, 1818), avaliando a abundância relativa de cada espécie de parasitóide e o efeito do parasitoidismo na mortalidade do hospedeiro. Foram coletadas 160 pupas de M. themisto, 80 em outubro de 2001 e 80 em outubro de 2002. Essas foram mantidas em temperatura de 25 ± 2,0ºC e fotofase de 14 horas, sendo diariamente observadas, até a emergência de parasitóides ou borboletas. Os seguintes parasitóides foram obtidos das pupas de M. themisto: Brachymeria annulata (Fabricius, 1793), B. mnestor (Walker, 1841) (Chalcididae), Neotheronia sp. (Ichneumonidae), Palmistichus elaeisis Delvare & LaSalle, 1996 e Tetrastichus sp. (Eulophidae). Somente os gêneros Brachymeria e Neotheronia ocorreram nos dois anos de estudo, sendo que o primeiro foi mais abundante em 2001 e o último, em 2002. As outras espécies de parasitóides ocorreram somente no segundo ano de estudo. Este é o primeiro relato da associação de B. annulata, B. mnestor, Neotheronia sp. e P. elaeisis com M. themisto.

The goals of this study were to know the parasitoid guild associated to pupae of Methona themisto (Hübner, 1818), evaluate the relative abundance of each species of parasitoid and the effect of parasitism on the host mortality. A total of 160 pupae of M. themisto were collected, 80 in October 2001 and 80 in October 2002. They were maintained at 25 ± 2,0ºC and photophase of 14 hours, daily observed until parasitoid or butterfly emergence. Five parasitoid species were obtained from M. themisto pupae: Brachymeria annulata (Fabricius, 1793), B. mnestor (Walker, 1841) (Chalcididae), Neotheronia sp. (Ichneumonidae), Palmistichus elaeisis Delvare & LaSalle, 1993, and Tetrastichus sp. (Eulophidae). Only the genera Brachymeria and Neotheronia occurred in both years of the study, the former was more abundant in 2001 and the latter in 2002. The other species of parasitoids occurred only in the second year of the study. These are the first records of B. annulata, B. mnestor, Neotheronia sp. and P. elaeisis as parasitoids of M. themisto.