444 Bulletin UASVM Horticulture, 67(1)/2010 Print ISSN 1843-5254; Electronic ISSN 1843-5394 Research Regarding the Knowledge of Biology and Ecology and Development of some Methods for Detecting, Forecasting and Control of Noctuide Defoliator Species Present in Oak Forests of Northwestern Transylvania Vasile SIMONCA, Ioan TAUT University of Agricultural Sciences and Veterinary Medicine, Horticulture Faculty, Forestry Department, 3-5 Manastur Street, Cluj-Napoca, Romania; simoncavasile@gmail.com, ioan_taut90@yahoo.com Abstract. The Noctuidae Family (ord. Lepidoptera, fam. Noctuidae) includes a large number of species, butterflies with different class, with very variable appearance, making it difficult to identify species. The activity of most species is nocturnal, rarely daytime. Research has considered the detection and understanding of Noctuidae species (moth), which together defoliated best known and most frequent cause of quercus species damage in these stands. The research sought to determine the most appropriate method for detecting the stages of caterpillar, pupa and butterfly. Laboratory work consisted of literature documenting both written form and electronic manufacturing equipment necessary collection of biological material (light trap, trap type Barber, sieve to pupa etc.), analysis and conservation of biological material collected (stalk, larvae, pupa, butterfly), interpreting the results. Field work was carried out between October-May in 2008 and 2009 and was located in the Forestry Department Cluj - (Baciu forest and Suceag forest), the Forestry Department Satu Mare (Noroieni forest) and Şomcuta Mare Forest District (Fersig forest). Within these forest bodies, chosen on the structure of older experimental blocks, we placed the experimental areas within basic stand oak (sessile and common oak), on stand age criterion, considering that according to the criterion variable and other stand fundamental characteristics (texture, composition, crown projection etc.) which could be affected the population dynamic of pests in general and particularly those of fam. Noctuidae. Keywords: Noctuidae, pupa, larvae, butterflies, defoliation, stand, oak INTRODUCTION Romanian oak forests in general, mostly the southern and western forests, are periodically affected by insect populations which produce partial or total defoliation. The most frequent attacks are those of the families Lymantriidae caterpillars (Lymantria dispar, Tortrix viridana), Lasiocampidae (Malacosoma neustria) and Geometridae (Operophtera brumata, Eranis defoliaria), but along with these other populations come up such as Lepidoptera’s order, as Noctuidae family, whose action is often transferred to the pests mentioned above. Noctuidae family (Lepidoptera, Noctuidae) includes a large number of species, butterflies with different sizes, very variable appearance, making it difficult to identify the species. The activity of most species is nocturnal, rarely diurnal In night butterflies family there are more species whom caterpillars feed on young plants. For forestry, the defoliating caterpillars have a higher importance, which along with other recognized species as pests of deciduous stands and