Biological aspects and first record of Leucothyreus alvarengai Frey (Coleoptera: Melolonthidae: Rutelinae) in sugarcane (Saccharum officinarum L) (Poaceae) fields of Mato Grosso do Sul state, Brazil

Abstract Larvae of Leucothyreus spp. have been reported causing damage to several crops in Brazil. From May 2012 to April 2013, adults and immatures of Leucothyreus alvarengai Frey (Coleoptera: Melolonthidae: Rutelinae) samples were obtained from sugarcane (Saccharum officinarum L.) (Poaceae) fields in the municipalities of Naviraí and Nova Andradina, Mato Grosso do Sul, Brazil. Adults were collected with the aid of light traps, whereas immatures were sampled by opening two trench sizes (30 x 30 x 30 cm and 80 x 50 x 40 cm) in the soil, beside the plants. The collected larvae were reared in laboratory conditions, fed by sugarcane seedlings. The biological cycle of L. alvarengai was completed in 230 days, displaying three larval instars with mean size of the cephalic capsule of 1.68, 2.46, and 3.00 mm for the first, second, and third instar, respectively. Adults were collected in greater numbers in December 2012, and first-instar larvae were observed as of January 2013. Conversely, pupae were observed in the field from July 2012 to January 2013. This is the first record of larvae and adults of L. alvarengai in sugarcane fields in Mato Grosso do Sul state, contributing with the knowledge about its biology and temporal distribution in the field

Biology and Management of Pest Diabrotica Species in South America

The genus Diabrotica has over 400 described species, the majority of them neotropical. However, only three species of neotropical Diabrotica are considered agricultural pests: D. speciosa, D. balteata, and D. viridula. D. speciosa and D. balteata are polyphagous both as adults and during the larval stage. D. viridula are stenophagous during the larval stage, feeding essentially on maize roots, and polyphagous as adults. The larvae of the three species are pests on maize, but D. speciosa larvae also feed on potatoes and peanuts, while D. balteata larvae feed on beans and peanuts. None of these species express a winter/dry season egg diapause, displaying instead several continuous, latitude-mediated generations per year. This hinders the use of crop rotation as a management tool, although early planting can help in the temperate regions of the distribution of D. speciosa. The parasitoids of adults, Celatoria bosqi and Centistes gasseni, do not exert much control on Diabrotica populations, or show potential for inundative biocontrol plans. Management options are limited to insecticide applications and Bt genetically modified (GM) maize. Other techniques that show promise are products using Beauveria bassiana and Heterorhabditis bacteriophora, semiochemical attractants for monitoring purposes or as toxic baits, and plant resistance.Facultad de Ciencias Naturales y Muse

Efeito de Diferentes Tipos de Injúrias Causadas nos Estádios Iniciais de Desenvolvimento da Soja

The soybean, Glycine max (L.), is a crop that can be damaged by insect pests throughout its phonological cycle, particularly in the early stages of development of this culture. The aim of this study was to evaluate the response of soybean to different types of artificial injuries caused in its early stages of development. The experiments were carried out at Embrapa Agropecuária Oeste using the cultivars FTS Campo Mourão and BRS Potência. These cultivars were submitted to nine treatments of artificial injuries, as follow: 1) removal of one cotyledon; 2) removal of two cotyledons; 3) removal of two cotyledons and one unifoliate leaf; 4) removal of two cotyledons and two unifoliate leaves; 5) removal of one unifoliate leaf, 6) removal of two unifoliate leaves; 7) cut below the unifoliate leaves; 8) cut below the trifoliate bud; 9) untreated (without injury). The plant height, the number of pods/plant and fresh weight of aerial part in Campo Mourão cultivar were lower than that observed with the Potência cultivar. There was also reduction of the plant height in the treatments 3, 4, 6 and 7 when compared to the control (without injury). The grain yield (Kg ha-1) was similar in both cultivars and was not influenced by the different types of injuries applied in plants of both cultivars. The weight of 100 seeds (g) was higher in cultivar Campo Mourão when compared to Potência cultivar. Regardless of the types of injuries that are caused, the plants have resilience to damage.A soja, Glycine max (L.), é uma cultura que pode ser prejudicada por insetos-praga durante todo o ciclo fenológico, principalmente nos estádios iniciais desta cultura. O objetivo deste trabalho foi avaliar a resposta da cultura da soja a diferentes tipos de injúrias artificiais causadas nos seus estádios iniciais de desenvolvimento. O experimento foi conduzido na área experimental da Embrapa Agropecuária Oeste, utilizando-se as cultivares FTS Campo Mourão e BRS Potência, as quais foram submetidas aos seguintes tipos de injúrias iniciais: 1) Remoção de um cotilédone; 2) Remoção de dois cotilédones; 3) Remoção de dois cotilédones e uma folha unifoliolada; 4) Remoção de dois cotilédones e duas folhas unifolioladas; 5) Remoção de uma folha unifoliada; 6) Remoção de duas folhas unifolioladas; 7) Corte abaixo das folhas unifolioladas; 8) Corte do broto trifoliado; 9) Testemunha (sem injúria). A altura das plantas, o número de vagens/planta e o peso verde da parte aérea da cultivar FTS Campo Mourão foram menores quando comparado com os valores desses parâmetros obtidos na cultivar BRS Potência. Foi também constatado redução na altura das plantas de soja nos tratamentos 3, 4, 6 e 7 quando comparado à testemunha. O rendimento de grãos (Kg ha-1) foi semelhante nas duas cultivares e não foi influenciado pelos diferentes tipos de injúrias causados nas plantas. Já o peso de 100 sementes (g) foi maior na cultivar FTS Campo Mourão quando comparado a cultivar BRS Potência. Independente dos tipos de injúrias que são causadas, as plantas apresentam capacidade de recuperação ao dano