Efeito de inseticidas em insetos predadores em culturas de algodão Effect of insecticides on predator insects associated with cotton

Com o objetivo de verificar o efeito de inseticidas em insetos predadores em cultura de algodão (Gossypium hirsutum L.), instalaram-se, em 1993-1994, dois experimentos, um no campo, e outro, em laboratório. No experimento realizado no campo, os tratamentos foram: Fipronil 200 SC (75 g/ha de i.a.); Fipronil 800 WDG (64, 80 e 100 g/ha de i.a.); Endosulfan 350 CE (700 g/ha de i.a.); e testemunha. Em laboratório, além das formulações à base de Fipronil foi utilizado o Paration metílico 600 CE (480 g/ha de i.a.). Fipronil foi seletivo para os artrópodes predadores (Scymnus sp., Geocoris ventralis, Cycloneda sanguinea e Doru lineare) no campo, e a Cycloneda sanguinea (L.), em laboratório, e pode ser recomendado em programas de manejo integrado de pragas na cultura do algodoeiro para o controle de Alabama argillacea (Rueb.), e Anthonomus grandis Boh. Endosulfan foi seletivo em relação a Scymnus sp., Geocoris ventralis Thomazini e Doru lineare (Eschs) no campo, com uma redução dos insetos inferior a 30%, e o Paration metílico não foi seletivo para C. sanguinea em laboratório.<br>To assess the selectivity of insecticides to predator insects in cotton (Gossypium hirsutum L.) crops two, trials, 1993-1994, under field and laboratory conditions were conducted. Under field conditions, the following treatments were compared: Fipronil 200 CS (75 g/ha of a.i.); Fipronil 800 WDG (64, 80 and 100 g/ha of a.i.); Endosulfan 350 EC (700 g/ha of a.i.); and control. Under laboratory conditions, in addition to Friponil, Methyl parathion 600 EC 480 g/ha of a.i. was also tested. Fipronil was selective to predators (Scymnus sp., Geocoris ventralis, Cycloneda sanguinea and Doru lineare) under field condition and to Cycloneda sanguinea (L.) under laboratory conditions. This product can be used in integrated pest management programs in cotton crops to control Alabama argillacea (Rueb.), and Anthonomus grandis Boh. Endosulfan was selective to Scymnus sp., Geocoris ventralis Thomazini, Cycloneda sanguinea (L.) and Doru lineare (Eschs) under field conditions, with a 30% reduction of insects, while Methyl parathion was not selective to C. sanguinea in laboratory

Aspectos biológicos, morfológicos e comportamentais de Aspidiotus nerii Bouché, 1833 (Hemiptera: Diaspididae) Biological, morphological and behavioral aspects of Aspidiotus nerii Bouché, 1833 (Hemiptera: Diaspididae)

O presente trabalho teve por objetivo estudar os aspectos biológicos, morfológicos e comportamentais de uma linhagem unipariental de Aspidiotus nerii Bouché, 1833 (Hemiptera: Diaspididae), sob condições controladas (25&plusmn;1oC, 70&plusmn;10% de UR e 12 horas de fotofase), tendo abóboras híbridas "cabotiá" como hospedeiro. Ninfas recém-eclodidas foram transferidas da criação massal para abóboras "cabotiá", devidamente higienizadas, dispostas em câmaras climatizadas. O período médio para fixação das ninfas móveis foi de 2,4&plusmn;0,33 horas. A duração média do 1&deg; e 2&deg; estádios, após a fixação das ninfas, foi de 8,3&plusmn;0,06 e 19,4&plusmn;0,11 dias, respectivamente, totalizando fase ninfal média de 27,9&plusmn;0,11 dias. Das ninfas que atingiram a fase adulta, 36 fêmeas foram acompanhadas diariamente até o final do ciclo. A duração média dos períodos pré-reprodutivo e reprodutivo foi de 17,3&plusmn;0,18 e 68,2&plusmn;4,33 dias, respectivamente. O número total médio de ninfas/fêmea foi 175,5&plusmn;10,29 e o número médio de ninfas/fêmea/dia foi 2,7&plusmn;0,11. A longevidade média das fêmeas foi 100,5&plusmn;4,51 dias.<br>The objective of this work was to study the biology, morphology and behavior of Aspidiotus nerii Bouché, 1833 (Hemiptera: Diaspididae) under controlled conditions (25&plusmn;1&deg;C, 70&plusmn;10% R.H. and 12 hours of photophase), using "cabotiá" cucumber pumpkins as hosts. Nymphs of the 1st stage obtained of mass rearing (mother culture) were transfered to "cabotiá" pumpkins, properly cleaned and disposed in acclimatized cameras. The medium period for fixation of the nymphs was of 2.4&plusmn;0.33 hours. The 1st and 2nd stages, after the fixation of the nymphs, lasted 8.3&plusmn;0.06 and 19.4&plusmn;0.11 days, respectively, totalizing a nymphal phase of 27.9&plusmn;0.11 days. 36 females were observed daily until the end of the cycle. The pre-reproductive and reproductive periods lasted 17.3&plusmn;0.18 and 68.2&plusmn;4.33 days, respectively. The medium total number of nymphs/female was 175.5&plusmn;10.29 and the medium number of nymphs/female/day was 2.7&plusmn;0.11. The female's longevity was 100.5&plusmn;4.51 days

Eficácia de herbicidas em diferentes quantidades de palha de cana-de-açúcar no controle de Euphorbia heterophylla Efficacy of herbicides in different amounts of sugar cane straw on Euphorbia heterophylla control

Este trabalho foi realizado com o objetivo de estudar o efeito de diferentes quantidades de palha de cana-de-açúcar, colhida sem queima prévia do canavial, sobre a eficácia de alguns herbicidas recomendados para esta cultura. O experimento foi conduzido em campo no Centro de Ciências Agrárias/UFSCar, em Araras, SP. Os tratamentos consistiram dos herbicidas trifloxysulfuron-sodium + ametryn (1.463 + 37 g i.a ha-1), imazapic (84 g i.a ha-1), imazapyr (200 g i.a ha-1), ¹diuron + hexazinone (1.170 + 330 g i.a ha-1) e ²diuron + hexazinone (1.330 + 160 g i.a ha-1) aplicados em pré-emergência de Euphorbia heterophylla e sobre cinco quantidades de palha de cana-de-açúcar (0, 5, 10, 15 e 20 t ha-1). A eficácia de controle das plantas daninhas foi avaliada aos 7, 14, 21 e 28 dias após a aplicação dos tratamentos (DAT). A palha (15 e 20 t ha-1) reduziu a população de E. heterophylla. À medida que se aumentou a quantidade de palha, houve redução na eficácia dos herbicidas; com 15 t ha-1 de palha, o controle foi considerado satisfatório (90%) apenas para os tratamentos ¹diuron + hexazinone e trifloxysulfuron-sodium + ametryn. Com 20 t ha-1, nenhum herbicida foi eficaz; entretanto, a palha foi eficiente na supressão dessa espécie, verificando-se que o número de plantas emergidas foi menor mesmo na testemunha.<br>This work aimed to study the effect of different amounts of sugar cane straw, collected unburned, on the efficacy of some herbicides recommended for this culture. The experiment was carried out in the field, at the Centro de Ciências Agrárias/UFSCar, Araras, SP. The treatments consisted of herbicides trifloxysulfuron-sodium + ametryn (1,463 + 37 g a.i ha-1), imazapic (84 g a.i ha-1), imazapyr (200 g a.i ha-1), diuron + hexazinone (1,170 + 330 g a.i ha ¹) and ²diuron + hexazinone (1,330 + 160 g a.i ha-1) applied in pre emergence of Euphorbia heterophylla and five increasing amounts of sugar cane straw ( 0, 5, 10, 15 and 20 t ha-1).Weed control efficacy was evaluated on 7, 14, 21 and 28 days after treatments (DAT). Straw (15 and 20 t ha-1) reduced the population of E. heterophylla. As the amount of straw increased, herbicide effectiveness decreased; with 15 t ha-1 straw, control was satisfactory (90%) only for the treatments ¹diuron + hexazinone and trifloxysulfuron-sodium + ametryn. With 20 t ha-1 straw, no herbicide was effective; however, in this case, straw was efficient in suppressing this species, since the number of emerged plants was smaller, even in the plots without herbicide

Egg quality during storage and deposition of minerals in eggs from quails fed diets supplemented with organic selenium, zinc and manganese

Three experiments with Japanese laying quails were performed aiming to assess the effect of supplementation with minerals in organic form on the egg quality during storage and the deposition of minerals in eggs. The assessments of each experiment were related to one mineral, thus, experiment 1 assessed the supplementation with selenium in 0.35-, 0.70- and 1.05-mg/kg levels of feed; experiment 2, the supplementation with zinc in 50-, 100- and 150-mg/kg levels of feed; and experiment 3, the supplementation of manganese with 60-; 120- and 180-mg/kg levels of feed. All diets were evaluated compared with a control diet without mineral supplementation. Birds were distributed in a completely randomized experimental design, with eight birds per plot and six replicates per treatment. Fifty-five days after the beginning of diets, the yolks of three eggs from each plot were collected for selenium, zinc and manganese quantification, whereas the albumens of three eggs from each parcel were collected for analysis of selenium concentration. Eggs were collected at the last days of the experimental period from each experiment, to be stored at room temperature (28±2 °C) and refrigeration (4 °C) during different periods (0, 10, 20 and 30 days), except for experiment 3, in which eggs were stored at 0, 10 and 20 days. Percentages of albumen and yolk, yolk index, Haugh unit and moisture loss of eggs were evaluated. The supplementation with selenium is able to maintain the egg yolk index unchanged over the storage periods; however, supplementation with zinc and manganese is not effective to keep the quality of stored eggs. Supplementation with selenium and manganese is effective to increase the concentration of these minerals at 328.66% in the albumen and at 74.47% in the yolk, respectively. The different levels of zinc do not change the egg composition