Biology and harmfulness of Planococcus vovae (Nassonov) (Hemiptera: Pseudococcidae) in Belgrade area

Abstract

Planococcus vovae (Nassonov) (Hemiptera: Pseudococcidae) is an important pest on plants of the family Cupressaceae. Its numerous populations have been present in recent years on Juniperus spp. in Belgrade. Feeding by sap-sucking on all aboveground plant organs, it causes growth stagnation, chlorosis, drying of needles and branches, and even of entire plants under heavy infestation. Additionally, the scale excretes large quantities of honeydew, on which sooty mold develops, reducing photosynthesis and causing faster plant deterioration. Throughout 2007 and 2008, P. vovae was recorded on Juniperus spp. in 12 localities in Belgrade, and on Thuja sp. in a single locality. The pest was found to develop three generations per year and overwinter on branches at the egg or second instar stages. The first generation adults were observed at the end of May, the second generation at the beginning of August, while the third generation was recorded at the beginning of October. Different overwintering modes, and variable oviposition, embryonic and larval development periods led to an overlapping of generations and continuous presence of all developmental stages on plants. In different localities the infestation of plants varied in abundance from a few individual specimens to very large colonies. The highest infestation intensity was recorded in the localities Bežanija, Doræol and Voždovac. The predatory species Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) and Nephus bipunctatus (Kugelann) (Coleoptera: Coccinelidae) were found in the scale colonies. Regarding N. bipunctatus, this was its first record as a new species in the Serbian fauna.

Planococcus vovae (Nassonov) (Hemiptera: Pseudococcidae) je značajna štetočina na biljkama iz familije Cupressaceae. Poslednjih godina je na području Beograda prisutna u brojnim populacijama na Juniperus spp. Hraneći se na svim nadzemnim delovima biljaka dovodi do zastoja u porastu, hloroze i sušenja četina, sušenja grana, a pri jakoj infestaciji i celih biljaka. Osim toga, vaš izlučuje velike količine medne rose na kojoj se razvijaju gljive čađavice koje utiču na smanjenje fotosinteze i brže propadanje biljaka. Na teritoriji Beograda P. vovae je tokom 2007. i 2008. godine utvrđena na Juniperus spp. na 12 lokacija i na Thuja sp. na samo jednoj lokaciji. Ustanovljeno je da razvija tri generacije godišnje i da prezimljava u stadijumu jajeta i larve drugog stupnja na granama biljaka. Imaga prve generacije registrovana su krajem maja, druge generacije početkom avgusta, a treće početkom oktobra. Različit način prezimljavanja, neujednačen period ovipozicije, kao i embrionalnog i larvenog razvića, dovode do preklapanja generacija i stalnog prisustvo svih razvojnih stadijuma na biljkama. Na različitim lokacijama, naseljenost biljaka vašima kretala se od pojedinačnih jedinki do veoma brojnih kolonija, pri čemu je najjači intenzitet napada zabeležen na lokacijama Bežanija, Dorćol i Voždovac. U kolonijama vaši registrovane su predatorske vrste Chrysoperla carnea (Stephens) (Neuroptera, Chrysopidae) i Nephus bipunctatus (Kugelann) (Coleoptera, Coccinelidae), pri čemu je N. bipunctatus nova vrsta za faunu Srbije.