Effect of temperature on the survival and infectivity of Pseudotheraptus devastans vector.
The aim of this study was to investigate under a controlled environment, the effect of temperature on the survival and infectivity of Pseudotheraptus devastans Distant, a cassava anthracnose disease vector. The insect P. devastans was collected from young cassava (Manihot esculenta Crantz) field plots, at the International Institute of Tropical Agriculture, (IITA), Ibadan, Nigeria. A mixture of the different developmental stages of eggs, first to fifth instar nymphs, and adults, were incubated in controlled environment chambers, under various constant temperatures of: 15, 17, 22, 25, 27, 30, and 35 degrees C. Relative humidity at different temperature conditions were recorded and maintained at 90%, 85%, 80%, 75%, 70%, 65%, and 60%, respectively. A significant increase in insect survival was observed between 22 and 27 degrees C temperature conditions while a significant decrease in survival was observed at 15 degrees C and above 30 degrees C. Lesion number, lesion diameter and infectivity among the insect stages varied as a function of temperature and relative humidity. Infectivity was highest at 22-25 degrees C maintained at 75-80% RH and lowest at 15 degrees C and above 30 degrees C maintained respectively, at 65% RH and 90% RH. There was considerable low vector infectivity due to low survival of the insects at extreme temperatures.
Fokunang
C N
CN
Department of Crop Protection and Environmental Biology, University of Ibadan, Nigeria.
Dixon
A G O
AG
Ikotun
T
T
D000818:Animals; D004199:Disease Vectors; D020062:Heteroptera / Q000472:pathogenicity* / Q000502:physiology*; D006813:Humidity; D007313:Insecta; D007814:Larva / Q000254:growth & development; D002365:Manihot / Q000469:parasitology*; D013696:Temperature