Fecundity and longevity of individual Xiphinema ifacolum (Nematoda: Dorylaimidae) on tomato

Female Xiphinema ifacolum from a population From Sierra Leone had a longevity of c. 34 wk on tomato, Lycopersicon esculentum cv. Roma, in a laboratory study done at 25 degrees C. This result was equivalent to c. 1190 day degrees above a basal temperature of 20 degrees C. The nematodes had a reproductive span of only c. 20 wk, equivalent to 700 day degrees, and their total reproductive capacity was 82-90 progeny with an egg produced every 10.3 day degrees. This tropical Xiphinema species appears to have adopted a ''k'' survival strategy like X. index and X, diversicaudatum, and as with almost all tylenchs, longidorids and trichodorids. However, the relationship between mean cumulative total reproductive capacity and day degrees requirement for all three species closely fits (r = 0.943) a logarithmic curve.