2. Lawrence, J.F., Newton, A.F. Families and subfamilies of Coleoptera (with selected genera, notes, references and data on family-group names). In: Pakaluk, J., Slipinski, S. A. (Eds.), Biology, phylogeny and classification of Coleoptera: papers celebrating the 80th birthday of Roy A. Crowson. 1995. Vol. 2. Museum i Instytut Zoologii PAN, Warsaw, pp. 779-1006 3. Majerus, M.E.N. Ladybirds. London: Harper Collins, 1994. 359 p. ISBN 0-00-219935 - 1 4. MКУФКăC.G.ăТă MМCШЫqЮШНКХОăD.B.ă – Ladybird beetles (Coleoptera: Coccinellidae) of the Atlantic Maritime Ecozone. In: Assessment of Species Diversity in the Atlantic Maritime Ecozone. Canada, Ottawa: D.F. McAlpine and I.M. Smith. NRC Research Press, 2010. pp. 436 – 452, 5. Thalji R. Composition of Coccinellid Comunities in Suger Beet Fields in Vojvidina. In: Proc. Nat. Sci., Matica Srpska Novi Sad. 2006. no. 110, pp. 267 – 273 6. Vandenberg N.J. Coccinellidae Latreille 1807. In: Arnett, R.H., Jr., Thomas, M.C., Skelley, P.E., Frank, J.H. (Eds.), American Beetles. CRC Press, Boca Raton, 2002. pp. 371-389 7. VьЫЭОТЮă AЧКă – Maria, Grozea IШКЧК,ă ЭОПă RКЦШЧК,ă VХКНă M.,ă DШЛЫТЧă IШЧОХК. Faunistic study of ladybirds (Coleoptera: Coccinellidae) in the Banat region, Romania. In: Bulletin of University of Agricultural Sciences and Veterinary Medicine Cluj-Napoca Agriculture, 2015. vol. 72 (ьЧăМЮЫЬăНОăКЩКЫТТО) CZU 632.78(498) CONTRIBUTION TO THE KNOWLEDGE OF INVASIVE SPECIES OXYCARENUS LAVATERAE (FABRICIUS, 1787) (INSECTA: HETEROPTERA) IN THE TOWN OF PITESTI (ROMANIA) BRBUCEANUăDANIELA,ăBRBUCEANUăM. UЧТЯОrЬТЭвăШПăPТЭОşЭТ,ăRШЦКЧТК Abstract. The observations carried out in the winter of 2008/2009 reveal invasive species Oxycarenus lavaterae ШЧă ХТЧНОЧă ЬЩОМТОЬă ТЧă ЭСОă ЭШаЧă ШПă PТЭОşЭТă КЧНă ПШЫă ЭСОă ПТЫЬЭă ЭТЦОă ТЧă RШЦКЧТК.ă TСОă evidence suggests a western route of entering Romania. O. lavaterae overwinters in aggregations containing approximately equal numbers of females and males. Out of 1,254 individuals observed, the males accounted for 50.8%, and the females for 49.2%. The average value of the density of individuals in the collected samples is of 62 specimens/ cm3, so, the size of the aggregations ranges from a few thousand ЭШăЭОЧЬăШПăЭСШЮЬКЧНЬăШПăТЧНТЯТНЮКХЬ.ăUЧНОЫăЭСОăЬЩОМТПТМăМШЧНТЭТШЧЬăШПăЭСОăвОКЫЬă2010ăКЧНă2011ăТЧăPТЭОşЭТ,ă our observations lead us to consider that the species had only one annual generation. The local administrative authorities monitor this species, and insecticide treatments are applied when appropriate. Keywords: Migration route, Sex ratio, Size aggregations, Life cycle INTRODUCTION Oxycarenus lavaterae (Fabricius, 1787), known by the name of Mediterranean bug, due to its preference for the areas of a Mediterranean climate is added to approximately 1,000 species of Heteroptera of Romanian fauna. This invasive species is spread in many European countries, including those neighborТЧРă RШЦКЧТК:ă BЮХРКЫТК,ă SОЫЛТКă КЧНă HЮЧРКЫвă (PЫШЭТć,ă LУ.ă ОЭă КХ.ă 2001;ă Kalushkov, P. et al. 2007). Global warming causes this gregarious species to gradually extend its habitat from the Southern regions of Europe towards the central ones; over the past few years, it has been mentioned in Austria and Switzerland (Wittenberg, R. 2005). The species lives in huge spectacular crowds consisting of millions of individuals. They may disturb especially the urban areas, rather from aesthetic reasons. In Switzerland, for 465 ОбКЦЩХО,ă ЭСОЫОă КЫОă ЫОЩШЫЭОНă ЬТЭЮКЭТШЧЬă аСОЫОă ЭСОвă ЛЫШФОă ТЧЭШă ЩОШЩХО’Ьă СШЮЬОЬă ЭСЫШЮРСă ЭСОă windows causing entomophobe reactions (Wermelinger, B. et al. 2005). In the literature, such host species have been cited as Tiliaceae and Malvaceae. It seems that the individuals feed rather on linden fruit than leaves as previously believed. In Romania, the first published recording of the species was in Banat, the species being ШЛЬОЫЯОНăТЧăЭСОăПКХХăШПă2009ă(KЦОЧЭ,ăP.ă2009),ăаСТХОăBЫЛЮМОКЧЮ,ăD.ăОЭăКХ.ă(2010)ăШЛЬОЫЯed it for the first time in the winter of 2008-2009ăТЧăPТЭОşЭТ.ăRНКМ,ăI.ăAХ.ăОЭăКХ.ă(2015)ăЦОЧЭТШЧăЧОаăНКЭКă about biology and spread of the species in our country. These recordings attest a future expansion of the habitat to the North and East of Europe. The purpose of this paper is to bring new data about the spread, biology and ecology of this ЬЩОМТОЬăТЧăЭСОăХШМКХăКЧНăКЧЧЮКХăМХТЦКЭОăМШЧНТЭТШЧЬăШПăPТЭОşЭТ. MATERIAL AND METHODS PТЭОşЭТăТЬăХШМКЭОНăТЧăЭСОăМОЧЭЫКХăЬШЮЭСОЫЧăЫОРТШЧăШПăЭСОăАКХХКМСТКЧăСТХХЬăШПăRomania at 280 ЦОЭОЫЬăКХЭТЭЮНО.ăAЯОЫКРОăКЧЧЮКХăЭОЦЩОЫКЭЮЫОЬăЫКЧРОăЛОЭаООЧă9ă°CăКЧНă10ă°CăКЧНăТЧăЭСОăХКЬЭăвОКЫЬ,ă the climate is more warmly, with gentle winters. The observations were carried out in the winter of 2008/2009, and during de years 2010 and 2011, on individuals located on two linden species, Tilia cordata and Tilia polyphyllos, from different areas of the city. For the assessment of certain structural of populations of Q. lavaterae, on 26.03.2009, during the hibernal diapause, were collected 20 samples, each sample consisting of individuals taken from different points of the in aggregations, using a cubic device with the side of 1 cm. The sex ratio and density of individuals forming a sample was taken into account. There were also traced aspects regarding the biological cycle of the species under the conditions of the 2010-2011 period and the preference for the Tilia species. It is to be noted that the samples taken during the hibernal diapause were composed only of living individuals, the viability of each sample being of 100%, due to mild winter. RESULTS AND DISCUSSIONS Migration route Oxycarenus lavaterae, was observed for the first time in Romania, in the 2008/2009 winter on specimens of Tilia ЬЩ.ăТЧăЭСОăЩКЫФЬăШПăЭСОăМТЭвăШПăPТЭОşЭТ.ăAЭăЭСКЭădate there was no information on the presence of the species in Romania (Figure 1). Considering the current spreading of this species, it seemed likely that its migration might have taken place through the western or southern part of this country (Figure 1). In the fall of 2009, Kment, P. (2009) signal it in Banat, КЧНă RНКМ,ă I. Al. et al. (2015) recently mention 56 new locations in Romania, mostly in Transylvania. Observations carried out by the authors of this paper in 2010-2011 on linden trees in Craiova and Bucharest have not revealed this species. In this context, it is undisputed that the migration of the species in our country took place through the western route. 466 Figure 1. Distribution of Oxycarenus lavaterae (Fabricius, 1787) in Europa, in 2009 and potential migration routes in Romania (www.faunaeuropaea). Sex ratio The balanced sex ratio in this species is suggested by the behavior during the mating period, when the insects walk coupled two by two, male and female. In spring, when temperatures rise, insects start to migrate from one aggregation to another or aggregations begin to segment giving birth to new ones, consisting only of immigrants. Thus, it is very difficult to calculate the sex ratio due to intense emigration and immigration. In this study, the sex ratio was calculated during the period of hibernal diapause when the individuals form aggregations in the wintering places to determine the percentages of wintering of the two sexes. The sex structure of the samples collected from the wintering aggregations is highlighted in Figure 2. It is interesting to note that, even though the samples come from populations with different disposal and location, they are made up of roughly equal numbers of male and female individuals. Overall, out of 1,254 individuals observed, males accounted for 50.8%, and females for 49.2%. Only two samples, i.e. samples XI and XII contain a greater number of females, with 24%, respectively 16% more than males, five samples have a 1:1 ratio, and for the rest of the samples, males presented a slight domination. The results confirm the data from the literature of specialty. Thus, O. lavaterae hibernates in aggregations containing approximately equal numbers of females and males which ensures the survival and perpetuation of the species in the following year. Even if aggregation mortality may reach critical values during very harsh winters, due to the balanced sex ratio, the survivors will rebuild the population. Size of aggregations Each of the 20 collected samples consisted of a certain number of individuals, the minimum value being of 30 specimens/ cm3, and the maximum value of 117 specimens/ cm3 (Fig. 3). The average value of the density of individuals in the collected samples is of 62 specimens/ cm3. Using the average density we can estimate the relative number of individuals composing the hibernation aggregations from a linden tree, regardless of their shaper. TСЮЬ,ăКЧăКРРЫОРКЭТШЧăНТЬЩШЬОНăШЧăКЧăКЫОКăШПăКЩЩЫШб.ă45ăМЦ²ăМШЧЭКТns approximately 2,790 individuals, while an aggregations МШЯОЫТЧРăКЧăКЫОКăШПăНОăКЩЩЫШб.ă1,500ăМЦ²ă(ЬТЭЮКЭТШЧăШЛЬОЫЯОНă in the field), up to 93,000 individuals may be found. Thus, the size of the aggregations ranges 467 from a few thousand to tens of thousands of individuals. On a linden tree with several aggregations hundreds of thousands or even millions of individuals may be found. 100 90 41 46 45 45 42 46 80 50 49 49 50 48 49 47 50 50 47 47 50 49.2 62 58 70 60 50 40 59 54 55 55 58 54 30 50 51 51 50 52 51 53 50 50 53 53 50 50.8 38 42 20 10 0 I sample II sampleIII sample IV sampleV sampleVI sample IX sampleX sampleXI sample VII sample XII sampleXIII sample VIII sample XIV sampleXV sampleXVI sample XIX sampleXX sampleglobal ratio XVII sampleXVIII sample male (%) female (%) Figure 2. Sex-rКЭТШăЭШăOбвМКrОЧЮЬăХКЯКЭОrКО,ă26.03.2009,ăPТЭОşЭТ