none The biology and interrelationships of A. olivierella Rag. were investigated. The moth is unvoltine; adults emerge about Nov. and oviposit. Larvae hatch in March and enter the branches where they develop, after forming a gall (in Tamarix nilotica, T. jordanis, T. aphylla and T. tetragyna trees), until Aug. when they pupate. Several parasite species were recovered, the most prominent being Eupelmus nr. spongipartus Foerster and Eurytoma sp. A new species of Hockeria, H. tamaricis Boucek appeared occasionally and 2 braconids, Apanteles oliverellae Wilk and Microdus sp. were rare. Overall percentage of parasitism varied from 77.8%-22.7%. Additional mortality factors included plant resistance, especially of T. aphylla, and predators such as ants. Larval mortality from unknown factors occurred along the Dead Sea Coast (of Israel). Most of the parasites probably are K-strategists, and the host parasite association probably is mature, though not necessarily stable.