-The acute toxicity of pellitorine, an amide isolated from Piper tuberculatum (Piperaceae) which is studied as a biopesticide in European corner borer, was evaluated on larvae and newly emerged adults of honeybee Apis mellifera by means of contact and ingestion bioassays. Workers in the larval and adult phase were separated in groups, which received pellitorine in different concentrations. The larvae were maintained in their own original cells, receiving feeding and normal care from the nurses. The adults were confined in wooden cages with screens, receiving artificial diet made up of sugar and water (1:1). The concentrations of 40, 200, 1 000, 5 000 and 25 000 ng a.i./individual were obtained diluting pellitorine in 98% ethanol. LD 10 values of 39.14, 36.16 and 13.79 ng a.i./insect were determined for larvae, for adults by ingestion and adults by contact, respectively. The honeybee larvae were shown to be highly susceptible to the amide pellitorine.Apis mellifera / toxicity / contact / ingestion / pellitorine / biopesticide

The isobutyl amides pellitorine (compound 1) and 4,5-dihydropiperlonguminine (compound 2) were extracted from the seeds of Piper tuberculatum Jacq. (Piperaceae) in yields of 6.10 and 4.45% respectively. The acute toxicities to the velvetbean caterpillar, Anticarsia gemmatalis (Hübner) (Lepidoptera: Noctuidae), of extracts of seeds, leaves and stems of P. tuberculatum, and of compounds 1 and 2, were evaluated by means of contact bioassays. The extracts caused 80% mortality when doses higher than 800.00 microg insect(-1) of extract of seeds, leaves and stems were administered to the velvetbean caterpillars. Compounds 1 and 2 showed 100% mortality at doses of 200 and 700 microg insect(-1) respectively. The LD(50) and LD(90) values were respectively 31.3 and 104.5 microg insect(-1) for compound 1, and 122.3 and 381.0 microg insect(-1) for compound 2. The potential value of extracts and amides derived from P. tuberculatum as efficient insecticides against velvetbean caterpillars is discussed.

RESUMO: A quantidade e qualidade das folhas de amoreira (Morus alba L.) exercem influência marcante sobre o desenvolvimento do bicho-da-seda e são, por sua vez, influenciadas por fatores como a idade das folhas, época do ano e características genéticas dos cultivares. Avaliou-se a produção e a qualidade nutricional de folhas de cinco cultivares de amoreira em diferentes épocas do ano e de colheita, objetivando verificar sua adaptação na região de Jaboticabal (SP). As folhas dos cultivares 'Miura', 'Korin', 'Calabresa', 'FM86' e 'FM Shima-Miura' foram colhidas na primavera, verão e outono após 45, 60, 75 e 90 dias da poda (DAP) e avaliadas quanto à produção de folhas níveis de proteína bruta (PB) e fibra em detergente neutro (FDN). As melhores produções foram verificadas em 'FM Shima-Miura', principalmente aos 75 DAP na primavera e no verão e aos 90 DAP no outono. No verão, as colheitas efetuadas aos 60, 75 e 90 DAP resultaram em produções mais elevadas. As épocas de colheita que resultaram em maiores níveis de PB foram aos 45 e 60 DAP e em menores níveis de FDN aos 60 DAP, respectivamente. Foi possível conciliar altos níveis de PB, baixos níveis de FDN e relativamente alta produção de massa foliar somente na colheita efetuada aos 75 DAP. Palavras-chave: Morus alba, bicho-da-seda, sericicultura, massa foliar, proteína bruta LEAF PRODUCTION AND QUALITY OF MULBERRY IN RELATION TO SEASON AND HARVEST TIMEABSTRACT: The amount and quality of mulberry (Morus alba L.) leaves have remarkable influence on the development of the silkworm and they are, therefore, influenced by factors as the age of the leaves, season and genetic characters of the cultivar. The production and the nutritional quality of leaves of five mulberry cultivars were evaluated under different seasons of the year and harvest times, having in view the indication of cultivars for the area of Jaboticabal, SP, Brazil. Leaves of cultivars 'Miura', 'Korin', 'Calabresa', 'FM86' and 'FM Shima-Miura' were harvested in spring, summer and autumn, 45, 60, 75 and 90 days after pruning (DAP) and evaluated through leaf mass production, crude protein (CP) and neutral detergent fiber (NDF). Best productions were verified in 'FM Shima-Miura', mainly at 75 DAP for spring and summer and at 90 DAP for autumn. For summer, the harvest made at 60, 75 and 90 DAP resulted in highest productions. Harvest times that resulted in largest CP levels were 45 and 60 DAP and in smallest NDF level was 60 DAP, respectively. It was possible to reunite high PB levels, low NDF levels and relatively high leaf mass productions only at the harvest time of 75 DAP.

The boll weevil (Anthonomus grandis Boheman) (Coleoptera: Curculionidae) is an introduced pest in Brazil, which in 30 yr has successfully expanded to various eco-regions and became the most important pest of cotton (Gossypium hirsutum, Malvaceae). Given the limited knowledge about the adaptive mechanisms that allowed successful establishment of the pest population in a tropical region, in this work we studied the potential of the Midwest population of boll weevils to enter a reproductive dormancy and identified the importance of the feeding source for induction of dormancy. We investigated morphological and physiological characters as indicators of the dormancy. We also investigated the occurrence of reproductive dormancy in boll weevils populations from cotton farms of the Midwestern region of Brazil during the cotton and noncotton seasons of 2009 and 2010. The studies revealed that boll weevils entered facultative reproductive dormancy; however, unlike what has been observed for boll weevils from temperate and subtropical regions, the hypertrophy of fat body and hexamerin levels did not straightly correlated to reproductive dormancy. The food source and field conditions during early adult development were decisive factor for the induction of reproductive dormancy. The incidence of reproductive dormancy increased progressively as the phenology of cotton plant advanced, reaching approximately 90% at the end of the crop season. During the noncotton season, the boll weevil was predominantly found in reproductive dormancy, especially females; however, there is evidence of use of multiple adaptive strategies to colonize the next harvest.

The boll weevil Anthonomus grandis Boheman (Coleoptera: Curculionidae) is the most important cotton pest in Brazil. A large-scale field-testing of a Boll Weevil Suppression Program (BWSP) was implemented to assess its technical and operational feasibility for boll weevil suppression in the state of Goiás, Brazil. The pilot plan focused on 3,608 ha of cotton during the 2006/2007 and 6,011 ha in the 2007/2008 growing seasons; the areas were divided into four inner zones with an outer buffer zone. We analyzed data on boll weevil captures using pheromone traps installed in the BWSP fields, on the detection of the first insect and the first damaged floral bud, greatest damage, and number of insecticide applications. The nonparametric Mann-Whitney U test was used to evaluate the differences between presuppression and suppression years. Fourteen pheromone-baited trapping evaluations were used to compare the weevil populations from 2006/2007 and 2007/2008 growing seasons. The BWSP regime reduced in-season boll weevil captures from 15- to 500-fold compared to presuppression levels in the preceding year. The low capture rates were related to delays in infestation and damage by weevils. The smaller population size measured by trapping and field monitoring reduced the number of required insecticide treatments. The BWSP strategy was efficient in suppressing populations of this pest and is a viable program for cotton production in subtropical and tropical regions, with long-term economic and environmental benefits.

Juvenile hormone analogues have been tested as insect growth regulators in silkworm (Bombyx mori), seeking an increment of silk production. These chemical products, when applied in small or moderate rates, promote the extension of the last larval instar. To understand the physiologic consequences on silk production by the silkworm strain C115 x N108, the application of methoprene, a juvenile hormone analogue, was performed to evaluate its effects on larval development and silk production. Methoprene was topically applied 48h after the fourth larval ecdysis, on the dorsal integument of the 2nd thoracic segment of the insects, at seven rates between 0 and 20 ng a.i. Methoprene influenced positively the duration of the fifth instar and the weight gain of the insects. The application of 1ng methoprene resulted in the heaviest silkglands, cocoons, shell cocoons and pupae weights. Comparatively to the control, the increment on silk production (approximately 24%) by the use of 1ng methoprene was more accentuated than the corresponding negative effects on the cocooning rate (approximately 12%). Key words: Bombyx mori, JHA, sericulture, juvenile hormone DESENVOLVIMENTO E PRODUÇÃO DE SEDA POR LAGARTAS DO BICHO-DA-SEDA APÓS APLICAÇÃO TÓPICA DE METHOPRENERESUMO: Análogos do hormônio juvenil têm sido testados como reguladores de crescimento de insetos em Bombyx mori, com vistas ao incremento da produção de seda. Estes produtos químicos, quando aplicados em pequenas ou moderadas doses, promovem prolongamento do último ínstar larval. O presente estudo visou o entendimento das conseqüências fisiológicas na produção do bicho-da-seda da linhagem C115xN108 face a aplicação de methoprene, um análogo do hormônio juvenil, através da determinação de seus efeitos sobre o desenvolvimento larval e a produção de seda. Methoprene foi aplicado, por via tópica, 48 horas após a quarta ecdise larval, sobre o tegumento dorsal do segundo segmento torácico dos insetos, em sete doses entre 0 e 20 ng de i.a. Methoprene influenciou positivamente a duração do ínstar e o ganho de peso dos insetos. A aplicação de 1 ng de methoprene resultou nos pesos mais elevados de glândulas sericígenas (1,89 g), casulos cheios (2,36 g), casulos vazios (0,62 g) e pupa (1,74 g). Comparativamente ao controle, o incremento na produção de seda pelo uso de 1 ng de methoprene (aproximadamente 24%) foi mais acentuado que os correspondentes efeitos negativos na taxa de encasulamento (aproximadamente 12%).

According to the LD(50) and LD(90) for compounds 1 and 2, it can be inferred that the values reflect an acute lethal response to both compounds, based on interaction(s) of the toxicants with a primary target or series of targets. Thus, the amides were demonstrated to have potential value in the control of the sugarcane borer.

RESUMOO crescimento dos insetos é regulado por um complexo hormonal que inclui o hormônio juvenil, que assegura ao inseto a retenção de suas características larvais, prevenindo a maturação. A aplicação de análogos do hormônio juvenil em Bombyx mori tem promovido o incremento da produção de seda; entretanto, altas doses podem provocar efeitos deletérios sobre a biologia do inseto. Este estudo avaliou a pulverização de diferentes análogos do hormônio juvenil sobre o bicho-da-seda e seus efeitos sobre o desenvolvimento larval e a produção de seda. Lagartas foram expostas a piriproxifeno, metopreno e fenoxicarbe a doses de 20, 2 e 0,02 ppb de ingrediente ativo, respectivamente, através da pulverização dos insetos e do alimento a 48 horas após a quarta ecdise. A administração de análogos do hormônio juvenil promoveu aumentos no período larval, massa de glândulas sericígenas, peso de casulos e de pupas. Os produtos testados afetaram negativamente a taxa de encasulamento. Metopreno promoveu o maior incremento na produção de seda e menor taxa de mortalidade, podendo seu uso ser recomendado na sericicultura.PALAVRAS-CHAVE: Sericicultura, piriproxifeno, metopreno, fenoxicarbe, neotenin. ABSTRACT DEVELOPMENT AND SILK PRODUCTION OF THE SILKWORM BOMBYX MORI L. EXPOSED TO JUVENILE HORMONE ANALOGUES. Insect growth is regulated by a hormonal complex that includes the juvenile hormone, which assures to the insect the retention of its larval characteristics, preventing maturation. Applications of juvenile hormone analogues on Bombyx mori have induced increases in silk production; however, high doses may promote deleterious effects on the biology of the insect. The present study evaluated the spraying of different juvenile hormone analogues on the silkworms and their effects on the larval development and silk production. Larvae were exposed to piryproxyfen, methoprene and fenoxycarb at titers of 20, 2 and 0.02 ppb a.i., respectively, sprayed on the insects and food at 48 hours after the fourth ecdysis. The administration of juvenile hormone analogues promoted increases in the larval period, silk glands, cocoon and pupae weight. The tested products had a negative effect on the cocooning rate. Methoprene promoted a larger increment in the silk production and smaller fall in the cocooning rate, and its use can be recommended in sericulture.