406 Bulletin UASVM Agriculture, 68(1)/2011 Print ISSN 1843-5246; Electronic ISSN 1843-5386 Monitoring the Attack by Parectopa Robiniella and Phyllonorycter Robiniella on Trees From the City of Tg. Secuiesc Örs Pál DOMBI 1) , Ion OLTEAN 2) , Teodora FLORIAN 2) , Mircea VARGA 2) 1) LAM Foundation, 222 Principala Street, 527105, Ilieni, email:dombi.ors@gmail.com 2) University of Agricultural Sciences and Veterinary Medicine, Faculty of Agriculture, 3-5 Mănăştur Street, 3400, Cluj-Napoca, Romania, email: ion.oltean@personal.ro SUMMARY The black locust leaf miners, recently permeated in the territory of Covasna County, are found in all locations where the host plant is present. The attack value (frequency and intensity) differs from an area to another in the county, which is determined by climatic conditions characteristic of each area of the county (Dombi Pal Ors şi colab. 2010). This species have two generations in a year (Neţoiu and Tomescu, 2006). In the period the two species were monitored in the city of Târgu Secuiesc. In July 2008, Phyllonorycter robiniella had an attack frequency of 1,4%, and the average number of mines was 1,3 mines/leaf. Parectopa robiniella attacked 0,8 % of the leaves, developing an average of 1,1 % mines/leaf. From this date increased both the frequency of the attack and the number of mines/leaves, at both species, that the final attack frequency reached 5,4% to Phyllonorycter robiniella and with 2 mines/leaf, and the attack frequency for Parectopa robiniella was 2,7 % and an average of 1,8 mines/leaf. In 2009 at first observation, Phyllonorycter robiniella had an attack frequency of 2%, and the average mine number was 1,8 mines/leaf, and Parectopa robiniella attacked 1,5 % of the leaves, developing on average 1,5 mines/leaf. In September, at the final assessment it was reported a frequency of 6,1 % to Phyllonorycter robiniella and with 3,2 mines/leaf, and for Parectopa robiniella the attack frequency was of 3,9 % and an average of 2,1 mines/leaf. In July 2010, Phyllonorycter robiniella had an attack frequency of 2,2 %, and the average number of the mines was 2,18 mines/leaf, and Parectopa robiniella attacked 1,8 % of the leaves, developing on average 1,7 mines/leaf. In September, at the final evaluation was reported an attack frequency of 9,8 % to Phyllonorycter robiniella and 3,3 mines/leaf, and to Parectopa robiniella the attack frequency was 5,9 % and an average of 2,9 mines/leaf. From year to year was reported on black locust trees from Târgu Secuiesc a growth of attack frequency and average number of mines/leaf for both species of leaf miners Phyllonorycter robiniella and Parectopa robiniella. Keywords: Parectopa robiniella, Phyllonorycter robiniella, attack frequency. REFERENCES 1. Dombi Pal Ors, I. Oltean, Florian Teodora, Bodiş Ilonka, M. Varga (2010). Moliile miniere ale salcâmului semnalate în localitatea Covasna, Agrobuletin AGIR, nr.6/2010, Timişoara, pag. 43-47. 2. Neţoiu C., Tomescu R. (2006). The leaf miners of black locust (Parectopa robiniella Clemens - 1863 and Phyllonorycter robiniella Clemens 1859, Lepidoptera, Gracillariidae, Analele ICAS, 49: 119-131.