Bulletin UASVM Horticulture, 67(1)/2010 Print ISSN 1843-5254; Electronic ISSN 1843-5394

Detection and Prognosis Defoliators Present in Deciduous Forests of Northwestern Transylvania

Ioan TAUT, Vasile SIMONCA

University of Agricultural Sciences and Veterinary Medicine, Faculty of Horticulture, Forestry Departament, 3-5 Manastur Street, Cluj-Napoca, Romania; [email protected]

Abstract . Studies, analysis and control measures presented in this paper which we have made in the years 2008-2009 and found mainly of oak stands in Forestry Department of Oradea and Satu Mare and to a lesser extent the framework of Cluj, and Mures Forest District. The stability of the stand is strongly affected, first of all by is stationary conditions which are not always the best opportunities, it is also affected by way of leadership and management and last but not least this biotic factors, especially defoliation. On the latter are screening each year and forecasts in order to establish concrete measures to combat healing using aircraft or ground equipment. The dates obtained by analyzing samples which were taken from different stands of quercus species showed that the most dangerous defoliation which we studied were Lymantria dispar, Tortrix viridana, nipped, and Eranis defoliaria, Eranis aurantiaria and against them were recommended controls, obtaining efficiency between 95-98%. In latent conditions we find no less dangerous defoliators which can create damage as: Operophtera brumata , Euprochtis chrysorrhoea respectively the Malacosoma neustria .

Keywords: prognosis, stands, oak, defoliation, treatment, control

INTRODUCTION

In the forestry found of Romania, the forests of broadleaves hold weighted importance so that the area (69.6 percent) and volume (61 percent). As regards the allocation on species by class, preponderant species its beech (32.1 percent of the area of Romania's forests) being the most widespread species and forming the most valuable stands pure or mixed and the wilt (oak species), which are well represented in the area totala.17, 7% when constitute bodies forest too fragmentation. Of these add various species countries (15 percent) and various species soft (5 percent). In the studied area, the North-West of Transylvania is about 983642 ha forests deciduous (52%) mainly as oaks species, which is why were taken to study these forest formations.

MATERIALS AND METHODS

Forest pest detection and prognosis are important works on forest protection activities, these can be known because the health of forests at any time of year. Establishing prognosis that reflects the real situation of forest sampling of surfaces requires control data referring to quantity, quality and probably percentage of the damage. Quantitative data refers to population density, the ratio of the number of insects to the unit as the case may be that tree, branch, bud or surface. Here we discuss by population growth rate R, which represents the value of density ratio current population ( D1 ) and population of the previous year beginning density mass multiplication ( D2 ). Finally, all

458 quantitative data discuss its the frequency, this is the ratio between the total number of trees attacked and control trees. The quantitative data relates to population density are represented by fecundity, depending on which stage sets graduation and sex index (I), the ratio between the number of females ( F) and total number of insects (F + M); I = F / F + M Depending on these factors probably to determine the percentage of defoliation as the ratio of population density (d) and critical number (n). These elements were sampling away and for defoliators Lymantria dispar and Tortrix viridana .

RESULTS AND DISCUSSION

The studies were located in the oak forests, in County Forest Administration located in Northwestern Transylvania where appear major defoliation, Lymantria dispar and Tortrix viridana. Detection and prognosis Lymantria dispar defoliator The gypsy moyh (Lymantria dispar) is the defoliators with highest potential for reproduction. In over time t his harmful has formed a large-scale up, especially in forest with different species of oak. The harmful reporting this was done in all development stage and detection areas infested was made after deposits of eggs in the months September and October, 2008 of infected areas was made deposits eggs in September-October, 2008 (Tab. 1). Tab. 1 The situation analyses carried out on Lymantria dispar harmful

County Forest Analysis Report Graduation Perhaps Degrees of Forest District Administration phase defoliation Aiud 36 I-II-III Low 7 I-II Very low Alba Iulia 34 I-II Very low 1 I-II Low Blaj Alba Iulia 43 I-II Very low Petre şti 9 I-II Very low 8 I-II Low Valea Ampoiului 35 I-II-III Low Somcuta Mare 44 I-II-III Very low Baia Mare Tăuţii M ăgheru ş 14 I-II Middle Cluj Gherla 12 III Very low Oradea Oradea 10 I-II Middle 2 I-II Middle Carei 27 I-II Middle Satu Mare 5 I-II Very low Livada 29 I-II Middle Satu Mare 28 I-II Very low Tăş nad 31 I-II Low

The data presented in Table 1 shows that of the 18 samples analyzed from the five forest region and 13 forest districts, only 4 to provide a likely degree of defoliation middle, meaning a likely defoliation up to 25%, others are provided with degrees of defoliation its low and very low. The graduation stage was determined by the formula: f = 1204.56 x g 40.89, where g is the average weight of a deposits.

459 In the Forest District Livada and Carei, degree perhaps shall is middle, corresponding to a percentage probably shall the 19.4% and 21.2, as a result of average diameters of 16cm, the bone which, according to a critical number 780 at Carei of 20 and cm corresponding to a critical number of 1100 at Livada. The analyses result that harmfull Lymantria dispar will not damage dishes in the spring of 2009 in the forests of north-western Transylvania, and the areas assessed, will be introduced in the surveillance zone . Detection and prognosis Tortrix viridana defoliator Tortrix viridana (green oak moth) is the largest defoliator spread in the area in the oak forest area, a fact confirmed by studies and our analysis. As with previous harmful, detection and prognosis can be made in all stages of development, but its accuracy is the highest forecast by egg. This analysis consists of six branches from a tree at least a meter long each, each two branches at the base, middle and far right trees crow. These trees to be the 3 in a plot and must be uniform assigned to the forest. On each branch count buds well developed and using his shall identify eggs. The percentage of shall presented in Table 2, resulting from the ratio between the number of viable eggs and the number of so controlled. Tab. 2

The situation analyses carried out on Tortrix viridana harmful

County Forest Analysis Report Forest District Perhaps Degrees of defoliation Administration Aiud 46 Very low Alba Iulia Municipal Sebe ş 52 Very low Beclean 49 Very low Bistri ţa-Năsăud Lechin ţa 48 Very low Cluj 32,39 Very low Gherla 33 Very low- Low Cluj Dej 68 Very low Turda 67 Very low Oradea Oradea 47 Low, Middle Ludu ş 45 Very low Târgu Mure ş Sighi şoara 60 Very low 3 Low, Very low, Strong Carei 37 Very low, Low, Middle 4 Middle, Strong Livada 38 Very low Satu Mare 6 Middle Satu Mare 42 Low, Middle Alma ş 65 Very low Cehu Silvaniei 61 Very low Ileanda 62 Very low Zal ău Jibou 63 Very low Şimleu Silvaniei 64 Very low Zal ău 66 Very low

From the above table we see that in the 25 samples analyzed, in only two situation, in the County Forest Satu Mare, Carei and Livada Forest districts, degree shall probably is middle and strongly, situation in which these areas will be proposed in the area of combat, in other cases of probable degree shall is low and very low.

460 CONCLUSIONS

The studies and analyses carried out in forests of the north-western Transylvania broadleaves showed the most affected stands its those that are based on Quercus species The forest composed especially of beech are rarely affected by pests and insects much less defoliators harmful. It can be noted however that in the Forest District Ulmeni, was a gradation of Lymantria dispar in pure beech stands in the spring of 2007, but stopped after applying avio treatment. Lymantria dispar and Tortrix viridana , are the gradation in all forest location studied, in most cases but without producing significant defoliation, except stands located in Carei and Livada. In Carei Forest District, in Craidorolt forest, which has a 250 ha area, has forecast a strong defoliation - the 76.7 percent to produced by harmful Tortrix viridana , and has proposed applied of a treatment avio with insecticide DIMILIN, 75 g/ha + 3, 0 L diesel. A similar situation was encountered in Livada Forest District, in Tilos forest, which has 200 ha area, and have been proposed similar measures. It was established during the implementation of optimal treatment depending on defoliation stands read in conjunction with their velopmentstage of harmful. Their application was successful make it an efficiency of 96% Craidorolt forest respectively 98% in the Tilos f orest. The studies and analyses carried out at the laboratory resort ICAS Cluj, shows that making forecast for major defoliators from forest fund is absolutely necessary, and must be carried out every year, and the proposed measures to maintain the forests integrity and stability.

REFERENCE

1. Dissescu, G. (1966). Contribu ţii la prognoza principalilor defoliatori din p ădurile de foioase ale României. Revista P ădurilor no. 5. 2. Marcu, O. and S. Dieter (1995). Entomologie forestier ă. Editura Ceres Bucure şti, 284. 3. Meijerman, L. and S. A. Ulenberg (2004). Artropod of economic importance – Eurasian Tortricidae. Site web, http://nlbif.eti.uva.nl/bis/tortricidae.php. Accesat octombrie 2009. 4. Netoiu, C. And I. Taut (2006). Cercet ări privind depistarea, prognoza şi combaterea defoliatorului Lymantria dispar în arborete cu fag. Referat ştiin ţific par ţial, Manuscris ICAS. 5. Tomescu, R. and C. Ne ţoiu (2006). Control of the broad leav’s mains defoliators in Romania in 2005. Proceedings of IUFRO Working Party 7.03.10 Workshop on “Metodology of Forest Insect and Disease Survey in Central Europe”, (CD), Federal Research & Training Centre for Forests, Natural Hayards & Landscape, Gmunden – Austria, p: 263-270. 6. ***Ordin nr. 454 din 07/14/2003 Privind aprobarea Normelor tehnice pentru protectia padurilor si a Indrumarilor privind aplicarea Normelor tehnice pentru protectia padurilorMonitorul Oficial nr. 564 din 08/06/2003

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