Population density, development and behaviour of Diopsis longicornis and D. apicalis (Diptera: Diopsidae) on rice in the Republic of Guinée

• Published in: Bulletin of entomological research 1993-03, Vol.83 (1), p.5-13
• Main Authors: Chiasson, H., Hill, S.B.
• Format: Article
• Language: English
• Subjects: Biological and medical sciences; Diopsidae; Diptera; Fundamental and applied biological sciences. Psychology; Invertebrates; Phytopathology. Animal pests. Plant and forest protection; Protozoa. Invertebrates; Records, symptoms, damages, economic importance, population surveys
• ISSN: 0007-4853; 1475-2670
• DOI: 10.1017/S0007485300041729

The behaviour and pest status of the rice stem borers Diopsis longicornis Macquart and D. apicalis Dalman were investigated in the Republic of Guinée, particularly during the dry season. The variables were direct seeded and transplanted rice, and three (1988, 1989) and four (1987) planting dates. Transplanted rice was damaged nearly three times more than direct seeded rice in the dry season, but no significant difference was detected during the wet season. As previously observed in other West African countries, D.apicalis only occasionally damages rice in Guinée. Contrary to findings elsewhere, D. longicornis was not an important pest of Guinean rice, infesting only 5% and 3% of stems over the three dry and the two wet seasons, respectively. However, year round rice production could promote build up of the diopsid population if dry season planting is not sufficiently delayed (45 days) after the last rains of the wet season.