RESUMO Populações de percevejos Piezodorus guildinii e Dichelops furcatus são naturalmente reguladas por predadores e parasitoides de ovos. No entanto, esses inimigos naturais podem ser afetados pela aplicação de inseticidas não seletivos comumente utilizados no controle químico dos percevejos. Objetivou-se avaliar a toxicidade de dinotefurano em predadores e parasitoides de ovos associados a populações de P. guildinii e D. furcatus (Hemiptera: Pentatomidae) em condições de campo. Predadores e parasitoides de ovos foram registrados semanalmente de V2 a R7, em parcelas de soja tratadas e não tratadas com dinotefurano. Telenomus podisi (Hymenoptera: Scelionidae) estava presente em 100 % das massas de ovos parasitados em ambas as espécies de percevejos e tratamentos. Não foram encontradas diferenças significativas na proporção de parasitismo e na razão sexual entre os tratamentos para nenhuma das espécies. A proporção de emergência da massa de ovos mostrou diferenças significativas entre os tratamentos para P. guildinii, mas não para D. furcatus. A aplicação de dinotefurano não afetou a presença de predadores generalistas como Araneae, Syrphidae e Chrysopidae. Dinotefurano pode ser considerado seletivo para esses predadores, mas não para P. guildinii. entanto Objetivouse Objetivou se P D Hemiptera (Hemiptera Pentatomidae campo V R7 R Hymenoptera (Hymenoptera Scelionidae 10 Araneae Chrysopidae 1

ABSTRACT Piezodorus guildinii and Dichelops furcatus stink bug populations are naturally regulated by predators and egg parasitoids. However, these natural enemies can be affected by the application of non-selective insecticides commonly employed for stink bug chemical control. This study aimed to evaluate the dinotefuran toxicity on predators and egg parasitoids associated with P. guildinii and D. furcatus (Hemimpera: Pentatomidae) populations under field conditions. Predators and egg parasitoids were recorded weekly from V2 to R7, in dinotefuran-treated and untreated soybean plots. Telenomus podisi (Hymenoptera: Scelionidae) was present on 100 % of the egg masses parasitized on both stink bugs species and treatments. No significant differences were found in parasitism proportion and sex ratio between treatments for either species. The egg mass emergence proportion showed significant differences among the treatments for P. guildinii, but not for D. furcatus. The dinotefuran application did not affect the presence of generalist predators as Araneae, Syrphidae and Chrysopidae. Dinotefuran can be considered selective for these predators, but not for P. guildinii. However nonselective non control P D Hemimpera (Hemimpera Pentatomidae conditions V R7 R dinotefurantreated treated plots Hymenoptera (Hymenoptera Scelionidae 10 Araneae Chrysopidae 1

The Attini, mainly the genera Atta Fabricius and Acromyrmex Mayr, are called leaf-cutting ants. Acromyrmex has scarce records referring to the geographical distribution of its species in Buenos Aires province. The objective of the present work was to gather existing information, to update these data with our own investigation, and to apply different criteria to establish relations with the use of the land. Of the total records for the province, 87 localities of 56 provincial districts were counted. To perform a hierarchical classification of similarities in the distribution patterns of the species, binary data matrices were constructed, analyzed by the weighted average method, calculating squared euclidean distances. The cophenetic indexes obtained were 0.883 for the geographical subregions, 0.943 for the municipal conglomerates and 0.877 for the agricultural areas. Eleven species of ants of the genus Acromyrmex are present in the province of Buenos Aires: A. ambiguus, A. fracticornis, A. heyeri, A. hispidus, A. hystrix, A. landolti, A. lobicornis, A. lundii, A. rugosus, A. silvestrii and A. striatus. The genus Acromyrmex is characterized by nesting in the soil, whereby anthropic practices for productive, industrial and urban purposes directly affect its pattern of occurrence.

Las Attini, representadas principalmente por los géneros Atta Fabricius y Acromyrmex Mayr, son llamadas hormigas cortadoras. Acromyrmex cuenta con escasos registros referidos a la distribución geográfica de sus especies en la provincia de Buenos Aires. El objetivo del presente trabajo fue reunir los datos existentes, actualizar con aportes propios la distribución y aplicar distintos criterios que permitan establecer relaciones con el uso de la tierra. Del total de registros para la provincia, se contabilizaron 87 localidades de 56 partidos. Para realizar una clasificación jerárquica de similitudes en los patrones de distribución de las especies, se construyeron matrices de datos binarios, analizadas por el método del promedio ponderado calculando las distancias euclídeas al cuadrado. Los índices cofenéticos obtenidos fueron 0.883 para las subregiones geográficas, 0.943 para los conglomerados municipales y 0.877 para las zonas agropecuarias. Para la provincia de Buenos Aires se han registrado 11 especies de hormigas del género Acromyrmex: A. ambiguus, A. fracticornis, A. heyeri, A. hispidus, A. histrix, A. landolti, A. lobicornis, A. lundii, A. rugosus. A. silvestrii y A. striatus. El género Acromyrmex se caracteriza por nidificar en el suelo, por lo cual las prácticas que realiza el hombre con fines productivos, industriales y urbanísticos afectan en forma directa su patrón de ocurrencia.

Myzus persicae (Sulz.), Brevicoryne brassicae L. and Lipaphis erysimi (Kalt.) are pests of oilseed rape-canola crops, Brassica napus L, as well as other cultivated crucifers. The aim of this study was to estímate the biological attributes and population parameters of aphids on the varieties Impact and Teddy under laboratory conditions. Aphids were collected on a cañóla crop and were multiplied in an insectary. For the study were reared 2 cohorts of 20 neonate females, for each aphid species and cañóla cultivar, at 20 ± 1°C, 60-70% relative humidity and 14:10 hs light dark cycle. The main differences among aphids species were observed in the extent of reproductive and post-reproductive periods, longevity and fecundity. M. persicae had the greatest longevity and fertility, was the most long life and fecund in Impact, while in Teddy the highest fecundity was to L erysimi and the highest longevity to M. persicae. With regard to population parameters, the highest net reproductive rate (R") was 58.43 (Q/Q/generation) for M. persicae on Impact. Instead in Teddy R0 (63.17) was bigger for L erysimi. At Impact the greater intrinsic rate of increase (r m) was for M. persicae (0.24) and for L. erysimi in Teddy (0.29 ♀/♀/day). These studies would indicate that, according to the cultivated employed rapeseed cultivar, taking into account the population growth rate of different aphid species, it could infer the dominant aphid species and the potential damage they would cause to the rapeseed canola crop.

Myzus persicae (Sulz.), Brevicoryne brassicae L. y Lipaphis erysimi (Kalt.) constituyen plagas del cultivo de colza cañóla, Brassica napus L, y de otras crucíferas cultivadas. Los pulgones fueron colectados en un cultivo de cañóla y se multiplicaron en un insectario. Para el estudio se criaron 2 cohortes de 20 hembras neonatas, para cada especie de áfido y cultivar de colza, a 20 ± 1°C, 60-70% de humedad relativa y 14:10 horas de fotofase. Las principales diferencias entre especies de pulgones se observaron en la duración de los períodos reproductivo y post-reproductivo, la longevidad y la fecundidad. M. persicae fue el áfido más longevo y fecundo en Impact, mientras que en Teddy el más fecundo fue L erysimi y el más longevo M. persicae. Con respecto a los parámetros poblacionales, la mayor tasa de incremento poblacional (R0) fue de 58,43 (♀/♀/generación) para M. persicae en Impact. En cambio en Teddy la mayor R0 (63,17) fue para L erysimi. La tasa intrínseca de crecimiento natural (r m) más elevada fue para L erysimi en Teddy (0,29 ♀/♀/día) y para M. persicae en Impact (0,24 ♀/♀/día). Estos estudios indican que, de acuerdo con el cultivar de colza empleado, teniendo en cuenta la tasa de crecimiento poblacional de las diferentes especies de pulgones, se podría inferir cuál será la especie dominante y el daño potencial que ocasionarían al cultivo.