none Searching behaviour in Agathis sp., and undescribed species of braconid was studied in the field during 3 years and compared with the oviposition behaviour of its host, Greya subalba (Lepidoptera, Incurvariidae). The larvae of G. subalba feed within the schizocarps (seed-pairs) of Lomatium dissectum (Umbelliferae), and Agathis females must search among the umbellets on each umbel to find the minority of schizocarps that contain larvae. The number of schizocarps probed per umbellet by Agathis females closely fit a truncated geometric distribution, which is the distribution that also accurately fits the oviposition behavior in G. subalba . This distribution, based upon the Shannon-Wiener information index, minimizes information on larval distribution to a searching parasitoid. The means of the distributions were also similar in the parasitoid and the moth.