ISSN 1362-1971
An international journal of the Systematic and Applied Acarology Society, published since 1996
[Aims] [Editors] [Content] [Subscriptions] [Contact details] [Society Homepage]
|
|
ISSN 1362-1971 An international journal of the Systematic and Applied Acarology Society, published since 1996 [Aims] [Editors] [Content] [Subscriptions] [Contact details] [Society Homepage] |
Systematic & Applied Acarology (2003) 8, 13-24Biology and life table of the cassava mite, Tetranychus truncatus Ehara (Acari: Tetranychidae)
SUTHIDA SAKUNWARIN1, ANGSUMARN CHANDRAPATYA1 & GERALD T. BAKER2
1
Department of Entomology, Kasetsart University, Bangkok 10900, Thailand2
Department of Entomology & Plant Pathology, Box 9775, Mississippi State University, MS, USA 39762Abstract
The life history and life table of Tetranychus truncatus Ehara on mulberry leaflets were studied under laboratory conditions at 20, 24, 28, 31 and 35°C. Mites completed their development and produced offspring within this temperature range. The development time from egg to adult varied from 6.30 to 14.89 days. The highest immature mortality was 39.88% at 20°C followed by 30.70% at 35°C. The threshold temperatures of egg, larva, protonymph, deutonymph, and a generation were 11.38, 9.91, 10.67, 12.51 and 11.57°C whereas the day-degree requirement at each stage was 62.52, 15.38, 11.36, 11.76 and 142.83 Do, respectively. The highest number of eggs laid by fertilized females was 65.6 eggs at 24°C, followed by 64.78 eggs at 31°C. Fertilized females lived up to 28.41 days at 20°C and only 9.63 days at 35°C. Unfertilized females survived relatively longer at 24°C and produced slightly more eggs at 24 and 28°C. The net reproductive rate (Ro) was the highest (37.39) at 24°C, followed by 37.00 at 31°C. The innate capacity for increase (rm) and finite rate of increase (l) reached maximal values (0.321 and 1.378) at 31°C, whereas minimal values (0.134 and 1.143) were at 20°C. The mean generation time was the shortest at 35oC and the shortest time for a population to double was 2.16 days at 31°C. The highest population trend index (49.49) was obtained at 24°C, followed by 48.58 at 31°C. The overall results suggested that T. truncatus could develop and reproduce within a wide range of temperatures. The range 24-31°C was the most suitable for the development, survival rate and reproduction of this mite.
Key words: Tetranychus truncatus, spider mite, biology, life table, development, temperature
Copyright 1999-2003 Systematic and Applied Acarology Society
Last updated 20 Aug. 2003
Questions about this page should be directed to webmaster
Natural History Museum is acknowledged for hosting these pages. Please read the Disclaimer.