Data/hora: 02/06/2024 15:31:14

Biblioteca(s): | Embrapa Soja.
Data corrente: | 30/01/2001
Data da última atualização: | 18/09/2007
Autoria: | GAZZONI, D. L.
Título: | Effect of combined effect of HPR and insecticide on soybean pests.
Ano de publicação: | 2000
Fonte/Imprenta: | In: INTERNATIONAL CONGRESS OF ENTOMOLOGY, 21., 2000, Foz do Iguassu. Abstracts... Londrina: Embrapa Soja, 2000.
Volume: | v.2
Páginas: | p.678.
Idioma: | Inglês
Conteúdo: | In order to study the effect of combined effect of host plant resistance and insecticide application on the survival of the velvetbean caterpillar (VBC) Anticarsia gemmatalis, five experiments were set up on the Embrapa Soja entomology laboratory (Londrina-PR). Fresh leaflets of the uppermost completely developed  leaves of BR-16 (susceptible) and IAC-100 (resistant) commercial varieties were collected in the field each other day, being sterilized in the laboratory and conserved on the refrigerator at +- 5.C. A set of gerbox were prepared with filter paper in the bottom. At the beginning of the investigation, only one box was used for each variety, in order to avoid the bias effect of stressing larvae by either rearing them apart from one another, and also by manipulating them during the early stages. Inside each box a soybean leaflet, with its petiole involved with humid cotton ball was placed besides a chart with ca. 50 two days old A. gemmatalis eggs. After egg hatching, the larvae were observed daily, data regarding survival and development were recorded, and food supplied whenever necessary, but not later that the second day. During the experiment, boxes containing the larvae were maintained on a BOD chamber regulated for 27.C +- 1.C, average air humidity on the range of 70-80%, and photo phase of 14h light: 10h dark, simulating the summer conditions for the londrina region. When the larvae reached the 3 rd instar, 10 larvae were maintained in boxes, containing a soybean leaflet of the same variety they were been reared on. When the larvae changed to the 6 th instar (about 50 mm long) they were individually isolated on single boxes, using only 30 boxes for each variety. Dics measuring 10 cm2 were cut the from the soybean leaflets. Discs received an application of 25ul of five different rates of endosulfan, each other rate doubling the insecticide concentration, plus the check where the discs received only distilled water. On the first day three discs were placed in each box, and they were replaced whenever necessary, according to observations made twice a day. On one of the assessments, data regarding insect survival were recorded. Non consumed discs or part of them were collected and measured. to establish the exact amount of food the insects ingested. Evaluating were made during the whole sixth instar (up to 96h) and also the adult hatching from the pupa was observed. Results indicated that larval mortality increases progressively along the evaluation time during the 6th instar, showing a delayerd effect of mortality factors (insecticide or plant resistance associated compounds). In all experiments the larval mortality observed on A. gemmatalis feeding on the resistant IAC-100 variety, indicating that a synergism or interaction occurs between the two mortality factors, probably due to higher insecticide susceptibility of larvae stressed by feeding inadequate food present on resistant variety.
Palavras-Chave: | Brasil; Cultivar IAC-100; Inseto praga; Interaction of mortality factors; Manejo integrado de praga; Soybean.
Thesagro: | Anticarsia Gemmatalis; Soja.
Thesaurus Nal: | Brazil; Insecta; integrated pest management; varieties.
Categoria do assunto: | --
Registro original: | Embrapa Soja (CNPSO)
Exemplares: | CNPSO - (18178-1) - UMT - PL - -- - RF 339 -  -  - DIS