Abstract: | Analysis of the searching behaviour ofEncarsia formosa showed that this parasite was not able to locate its individual hosts (Trialeurodes vaporariorum) from a certain distance. In addition, quantitative data on sizes and numbers of hosts of each stage present on the leaf
parts under observation, and the number of contacts the wasp made with these showed that the host-searching behaviour ofE. formosa on a leaf is random. Since, moreover, the distribution of the hosts over the leaf is random too, the number of hosts parasitized
per unit of time is entirely dependent on the walking speed of the parasite and the number and sizes of the hosts present. |