Sucking insects, which representatives are also aphids, can cause important economic damage on cultivated and wild-growing plants in vegetable ecosystems. Our research was based on the aim of ...biological control, which is to limit or to control the pests with the use of their natural enemies. From April to November 2006 living aphids and their mummies were sampled together with their host plants in four locations in Slovenia. The samples have been taken from vegetables, weeds, within-crops plants and from the plants in the field borders. The occurrence of 18 aphid species was confirmed - 14 of them were parasitised. In our research 365 parasitoid specimens (17 species from 8 genera - Aphidius, Binodoxys, Diaeretiella, Ephedrus, Lipolexis, Lysiphlebus, Monoctonus, and Praon - of the family Aphidiidae) were recorded and identified. The most abundant parasitoid species were Aphidius matricariae (32.2 %) and Lysiphlebus fabarum (29.3 %). Parasitoid L. fabarum had the widest range of hosts; it parasitised aphids on the plants from 7 different botanical families. Sex ratio in our research confirmed the known fact, that in natural ecosystems female parasitoids are more numerous than the male parasitoids; this ratio in our research was 71%: 29%.
Sesajoče žuželke, med katere spadajo tudi prave listne uši, lahko povzročajo pomembno gospodarsko škodo na gojenih in samoniklih rastlinah v vrtnarskih ekosistemih. V naši raziskavi smo se opirali na cilj biotičnega varstva rastlin, ki je z naravnimi sovražniki omejiti oziroma zatreti škodljivce. Od aprila do novembra 2006 smo na štirih lokacijah v Sloveniji vzorčili žive listne uši in ušje mumije na gostiteljskih rastlinah. Vzorce smo nabirali na vrtninah, plevelih, medsevkih in robnih posevkih. Ugotovili smo zastopanost 18 vrst pravih listnih uši, kar 14 vrst pa je bilo parazitiranih. V nabranih vzorcev smo identificirali 365 osebkov parazitoidov listnih uši, ki so pripadali 17 različnim vrstam iz 8 rodov (Aphidius, Binodoxys, Diaeretiella, Ephedrus, Lipolexis, Lysiphlebus, Monoctonus in Praon) družine Aphidiidae. Najbolj množično sta se pojavljali vrsti Aphidius matricariae (32,2 %) in Lysiphlebus fabarum (29,3 %). Vrsta L. fabarum je imela tudi najširši spekter gostiteljev in je parazitirala uši na rastlinskih vrstah iz 7 različnih botaničnih družin. Če številčno primerjamo zastopanost spolov, lahko potrdimo znano dejstvo, da je število samic v naravi večje od števila samcev; v naši raziskavi je bilo omenjeno razmerje 71%: 29%.
In 2008, massive population of parasitoid Encarsia formosa was found for the first time in the greenhouses on the Laboratory Field of Biotechnical Faculty in Ljubljana (Slovenia). This species is ...known for a long time as effective natural enemy of the greenhouse whitefly, Trialeurodes vaporariorum, and other whiteflies in different parts of the world. 1306 wasps from genus Encarsia were found in nymphs of greenhouse whitefly. The most numerous was E. formosa (934 individuals), following by 367 individuals of E. tricolor, 4 males of E. inaron and a male of E. longicornis. Greenhouse whitefly parasitoid was determined on 14 host plants in the greenhouse and E. tricolor on 11 host plants in the greenhouse and on one host plant in the field. E. inaron and E. longicornis appeared only on one host plant in a greenhouse. For the time being the use of wasp E. formosa is not yet permitted in controlling greenhouse whitefly in Slovenia, but there is possibility to include it in the programs of biological control of pests on ornamentals and vegetable plants in the greenhouses. Consequently, the use of chemical insecticides will be reduced.
V rastlinjakih na Laboratorijskem polju Biotehniške fakultete v Ljubljani smo v letu 2008 prvič našli številčnejšo populacijo parazitoida Encarsia formosa, ki je v svetu dobro znan naravni sovražnik rastlinjakovega ščitkarja, Trialeurodes vaporariorum, in nekaterih drugih vrst ščitkarjev. V ličinkah rastlinjakovega ščitkarja smo našli 1306 osic iz rodu Encarsia. Najbolj številčni so bili osebki vrste E. formosa (934 osebkov), našli pa smo še 367 osebkov vrste E. tricolor, 4 samce vrste E. inaron in enega samca vrste E. longicornis. Predstavnike vrste E. formosa smo našli na 14 gostiteljskih rastlinah v rastlinjakih, vrsto E. tricolor pa na 11 vrstah gostiteljskih rastlin v rastlinjakih in na eni rastlinski vrsti na prostem, medtem ko sta se vrsti E. inaron in E. longicornis pojavili le na eni rastlinski vrsti v rastlinjaku. V Sloveniji uporaba osice E. formosa za zatiranje rastlinjakovega ščitkarja še ni razširjena, vendar bi jo lahko vključili v programe biotičnega varstva okrasnih rastlin in vrtnin v zavarovanih prostorih in tako zmanjšali uporabo insekticidov.
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