Bumble Bee (Bombus terrestris L.) Pollen Forage on Strawberry (Fragaria x ananassa DUCH.) Open Field and PlasticTunnel

Aedmaasikas on levinud marjakultuur, mille viljade suurus ja kvaliteet sõltub sageli nende tolmeldamise tasemest. Aedmaasika kasvatamine kiletunnelites vajab aga sageli lisatolmeldajaid. Käesolev uurimistöö eesmärgiks on välja selgitada, kas kiletunnelitesse viidud kimalased korjavad aedmaasika õietolmu rohkem kui avamaale paigutatud kimalased. Uurimistöö tulemusel leiti, et: 1.) karukimalased on aedmaasika õietolmu korjanud rohkem kiletunnelis, hoolimata sellest, et see on poolavatud ning toidutaimede valik avamaal laialdasem; 2.) karukimalaste tarru toodud aedmaasika õietolmu osakaal ei erinenud oluliselt kahe vaatluspäeva vahel, samas kui talirapsi õietolmu korje vähenes 16.juunil kiletunnelis. Põhjuseks oli ilmselt selle vaatluspäeva madalam temperatuur; 3.) ühe korjelennu jooksul tarru toodud õietolmu liikide/taksonite arv avamaal ja kiletunnelis paiknenud kimalastel ei erinenud oluliselt.The strawberry is a commonly grown soft fruit culture, which yield and fruit size depend on adequate pollination. Growing strawberries in plastic tunnels needs additional pollinators. The aim of the present study is to explore whether bumble bees taken into plastic tunnels or open field forage for strawberry pollen at the same rate. The results of the thesis show that: 1.) bumble bees in plastic tunnel forage for strawberry pollen at higher rate than those in open field; 2.) there were no difference in the proportion of strawberry pollen brought into the hives between the two observation days. The proportion of winter oilseed rape pollen was significantly lower at the second observation day in plastic tunnel, whereas no difference was found in open filed. Probably the reason for that was cooler weather on that day and bumble bees from tunnels preferred to forage inside; 3.) the mean number of different pollens collected during one foraging trip did not differ between plastic tunnel and open field