Data/hora: 04/06/2024 04:29:08

Biblioteca(s): | Embrapa Soja.
Data corrente: | 23/11/2000
Data da última atualização: | 09/03/2006
Autoria: | PRANDO, H. F.; SOSA-GOMEZ, D.R.; ROSADO NETO, G. H.
Título: | Biological aspects of oryzophagus oryzae (Coleoptera: curculionidae) in water-seeded rice.
Ano de publicação: | 2000
Fonte/Imprenta: | In: INTERNATIONAL CONGRESS OF ENTOMOLOGY, 21., 2000, Foz do Iguassu. Abstracts... Londrina: Embrapa Soja, 2000.
Volume: | v.1
Páginas: | p.281.
Idioma: | Inglês
Conteúdo: | In Santa Catarina state (SC), Brazil, around 135 thousand ha of irrigated rice are cultivated under the water-seeded system. The main insect-pest in this system is Oryzophagus oryzae. Adults and larvae attack the crop. The adults cause greater damage on germinated seeds, by eliminating the epicotyl and radicle right after sowing, or on seedlings. The larvae attack the irrigated rice roots. The present research was conducted during 1997/1998 growing periods, with the purpose of investigating the biology of this pest. Adults insects were collected in Itajai SC for identification and morphological studies. At the laboratory, the oviposition site, fertility and incubation period were observed. Larval instar were based on measurements of the head capsule. O. oryzae presents a well-defined sexual dimorphism, with females being larger than males (3.44 mm and 2.85 mm, respectively). Morphological characteristics are evident on the ventral side of the insect. The oviposition takes place on the rice plants sheath, preferably in the submersed parts. The eggs, white and slightly curved, are 0.88 mm long and 0.23 mm wide, and are located in each aerenchyma of the sheath. The average incubation period is 6.5 days inside the sheath, feeding on the divisory membranes of aerenchyma. They leave the sheath through a circular orifice at 6-10 days after oviposition. The larvae are white almost transparent in the first instar, and yellowish white in the subsequent instar. They are apodal, have six pairs of spiracles on the dorsal abdomen, which bears strongly sclerotized hook-like structures. Head capsules measurements evidence five larval instars: I (0.18 mm), II (0.24 mm), III (0.31 mm), IV (0.37 mm) and V (0.46 mm). The cocoons are impermeable, made of clay and plant residues. The attach firmly to young roots, from where the pupa removes its O2 supply. Inside the cocoon, the rostrum of the pupa is always turned to the fixation root.
Palavras-Chave: | Behaviour; Brasil; Comportamento; Inseto praga; Morfologia; Morphology; Ovoposicao; Pest insects.
Thesagro: | Arroz; Oryzophagus Oryzae.
Thesaurus Nal: | Brazil; Insecta; oviposition; rice.
Categoria do assunto: | --
Registro original: | Embrapa Soja (CNPSO)
Exemplares: | CNPSO - (18138-1) - UMT - PL - -- - RF 339 -  -  - DIS