Tischeria eckebladella Bjk. (= complanella Hb.), the oak leaf miner moth (Lepidoptera, Tischeriidae) is an insect pest, due to the damages caused by larva, which mines the leaves of some species of Quercus, which are living on. In the last twenty years it was producing very important attaques, both in our country and abroad. Heavy attaques we observed during the outbreaks from 1968-1969 and 1973-1974 in the ranger-districts Livada and Satu Mare, in north-west part of Romania. Because this insect was very few studied in Romania and other countries, we started special researches on biology, ecology and control of this insect pest, more deeply, particularly from ecological point of view, using the most modern nd appropriate methods. The adult of oak leaf miner moth is a microlepidopter having the width of wigs of 8-12 mm. The eggs are laid izolated on the upper face of the leaves in both generations. Larvae (caterpillar) develops in the mine which is forming during the process of feeding. Here it pupates in a (Formel) circle place delimited in a side of this, after passing of 4 ages. In western and north western zones of Romania and in the other regions with the same bioizoheats the insect is bivoltine. First generation, in the field, is developping from the first half of May to the first decade of August and second generation from the finish of July till the finish of May next ear. It is wintering in the mature larval stage in the mines on the leaves fallen upon the ground in autumn. The fly of moths hopes, in spring, when the leaves of host trees have the size of 2/3 from normal size. Generally, the fly is developing in a long period of time, depending on weather and the growth of the insect in previous stages. The scheme of biological cycle are showing that the emergency and the periods when the insect is developing in the field is different by regions. The time of developing of the stages and of generations, in laboratory breeding conditions (constant temperature and humidity) is 63 days at 20C, 37 days at 25C and 33 days at 32C, relative humidity being 75-80%. The biological constants established by laboratory rearing and the general equation of development of insects (Blunk, 1923, Savescu, 1960) are following: Biological threshold per generation is (Formel) . In the egg stage is 13,9C and in the adult stage 15C. Sume of effective temperatures (thermique constant K) is 447,3C per generation, and 284C in larval stage. Zone of biological activity is comprised between (Formel) and the upper threshold T = 34C. The underzones are delimited by biological constants as follow: cold underzone: 12,9 - 17,5C (prolificity threshold), optimum underzone: 17,5 - 28,5C (Optimum threshold), warm underzone (28,5 - 34C). The area of geographical spread and the number of generations per year, found out computing the bioizoheats for the main localities ...
