Alvimar Bavaresco

Ocorrência de Argyrotaenia sphaleropa (Meyrick) (Lepidoptera: Tortricidae) danificando pêssegos na Serra Gaúcha, Rio Grande do Sul

During the 2000/2001 season, the polyphagous leafroller Argyrotaenia sphaleropa (Meyrick) caused damage in commercial peach orchards, in Rio Grande do Sul, Brazil. Caterpillars scrape the fruit epidermis, mainly at the insertion of the stalk or in the junction of the leaves and fruits, depreciating them commercially. Despite conventional chemical treatments, losses were around 2%; however, many growers have mistaken the A. sphaleropa damage as caused by Grapholita molesta (Busck), and have used insecticides to control the last one.

Biologia e exigências térmicas de Spodoptera cosmioides (Walk.) (Lepidoptera: Noctuidae)

O objetivo do trabalho foi estudar a biologia de Spodoptera cosmioides (Walk.) em diferentes temperaturas e determinar suas exigencias termicas, visando fornecer subsidios para a criacao do inseto em laboratorio. Para isso, os periodos embrionario e pos-embrionario foram avaliados em sete temperaturas (14, 18, 22, 25, 28, 30 e 32oC), em câmaras climatizadas, com fotofase de 14h. As lagartas foram criadas em dieta artificial, tendo como fontes proteicas feijao branco, farelo de soja, levedura de cerveja, germe de trigo e leite em po. A duracao do periodo embrionario decresceu com o aumento da temperatura na faixa de 14°C a 25°C, mantendo-se constante entre 28°C e 32°C. Para os demais estagios (lagarta, pre-pupa e pupa), foi observada uma relacao inversa entre a temperatura e a duracao na faixa de 14°C a 30°C, estendendo-se a 32°C para pupas. A duracao da fase de pupa dos machos foi maior do que das femeas, o que promoveu assincronia na emergencia de adultos. As temperaturas bases do periodo embrionario, fase de larva, pre-pupa, pupa e ciclo total foram 9,34°C; 11,65°C; 9,65°C; 11,08°C e 11,23oC, com constantes termicas de 62,73 graus-dia (GD); 254,61 GD; 33,42 GD; 177,55 GD e 525,11 GD, respectivamente. Avaliando-se, separadamente, a fase de pupa, as temperaturas bases foram 11,25°C para machos e 10,81oC para femeas, com constantes termicas de 188,26 GD para machos e 165,47 GD para femeas. Para o ciclo total, a temperatura base e a constante termica para machos foram 11,28°C e 535,85 GD. Para as femeas, estas mesmas variaveis foram 11,15°C e 513,17 GD. Concluiu-se que a faixa de temperatura mais adequada para o desenvolvimento de S. cosmioides situa-se entre 25oC e 28oC, na qual pode-se obter de 9,6 a 11,7 geracoes anuais do inseto, em condicoes de laboratorio.

Atração de machos da lagarta-das-fruteiras Argyrotaenia sphaleropa (Meyrick) (Lepidoptera: Tortricidae) aos componentes do feromônio sexual sintético na cultura do caquizeiro

Argyrotaenia sphaleropa (Meyrick) has been leading to significative damage in cultivated fruits such as persimmon, peach and grape in Southern Brazil. In the present work, the response of A. sphaleropa males to different formulations and doses of the synthetic sexual pheromone was evaluated, as well as the duration of the most efficient formulations under field conditions. Formulations containing Z11,13-14Ac + Z11,13-14Al + Z11-14Al (4:4:1), Z11,13-14Al + Z11,13-14Ac (9: 1) and Z11,13-14Ac + Z11,13-14Al (9: 1) (1.0 mg/ dispenser) were the most efficient as male attractants when compared to unmated females. The concentration of 1.0 mg/ dispenser was significantly more attractive than the 0.1 mg/ dispenser for the three formulations. The formulation Z11,13-14Ac + Z11,13-14Al + Z11-14Al (4:4:1), at 1.0 mg/dispenser, was efficient for at least 75 days, while the attractiveness of Z11,13-14Ac + Z11,13-14Al (9:1) lasted 60 days. Further field experiments should employ the formulation Z11,13-14Ac + Z11,13-14Al + Z11-14Al (4:4:1) at 1.0 mg/dispenser, being dispensers replaced at 75-days intervals.

Controle químico da Argyrotaenia sphaleropa (Meyrick) (Lepidoptera: Tortricidae) e da Hypocala andremona (Stoll) (Lepidoptera: Noctuidae) em laboratório

Hypocala andremona (Stoll) (Lepidoptera: Noctuidae) and Argyrotaenia sphaleropa (Meyrick) (Lepidoptera: Tortricidae) are the main insect-pests of the persimmon in the Serra Gaucha region, State of Rio Grande do Sul (RS). No informations are available about chemical control of these caterpillars. The effect of acephate, emmamectin benzoate (+ mineral oil), clorpyriphos-ethyl, spinosad, etofenprox, fenitrothion, fosmet, methoxyfenozide, tiacloprid and trichlorphon on H. andremona and A. sphaleropa were evaluated in laboratory. Acephate (g.a.i.100 L-1) (37.5 and 75.0), emmamectin benzoate (0.375 and 0.5), clorpyriphos-ethyl (45.0 and 67.5), spinosad (4.8 and 9.6), etofenprox (10.0 and 15.0), fenitrothion (75.0), methoxyfenozide (14.4) and trichlorphon (120,0 and 150,0) resulted in a mortality of A. sphaleropa higher than 80.0%. For H. andremona, this effect was observed to acephate (37.5 and 75.0), emmamectin benzoate (0.375 and 0.5), clorpyriphos-ethyl (45.0 and 67.5), spinosad (4.8 and 9.6), etofenprox (10.0 and 15.0), fenitrothion (50.0 and 75.0), fosmet (50.0 and 100.0), methoxyfenozide (9.6 and 14.4) and trichlorphon (120.0 and 150.0). These insecticides showed potential to control caterpillars in the persimmon culture, being necessary field evaluations to use the compounds in commercial orchards.