- Additional Plants: ornamentals
- Pest Management: biological control, integrated pest management
Aphids are one of the top five pests in floriculture today. Due to the aesthetic value of the crop, only non-detectable levels of pests are tolerated, and floriculture growers apply more pesticides than another other commodity. However, this method of pest control is not sustainable, as several common aphid species are highly pesticide resistant. The midge Aphidoletes aphidimyza is a generalist aphid predator which, in the larval stage, is capable of consuming ca. 25 aphids per day, and can feed on over 70 different aphid species. We will investigate the ability of Aphidoletes to be incorporated into a banker plant, or open rearing, system, in the greenhouse. A banker plant provides alternative food sources such as non-pest aphids to sustain natural enemies in the absence of the pest on the crop. Several different non-pest aphids – host plant combinations will be considered as possible banker plants. Studies will consist of lab trials to determine predation capacity on each of the candidate aphid species and its ability to establish and maintain a sustainable population on each of the candidate banker plants. We will then investigate the inclination of adult midges to disperse off the banker plant and forage for pest aphids within the greenhouse crops, and whether this can be increased with type of banker plant system used. Finally we will test the efficiency of Aphidoletes banker plants to control low-density aphid infestations in large-scale greenhouse trials. Information from these trials will be immediately passed along to growers through extension activities and IPM working groups.
Project objectives from proposal:
1. We will determine the relative preference of Aphidoletes for each of the aphid species, to be sure they are all sufficiently attacked (both the pest species and those to be used on the banker plant) as well as predation capacity.
2. We will investigate the ability of Aphidoletes to establish and sustainably reproduce on various aphid-banker plant candidate combinations.
3. We will investigate dispersal from the banker plant both in terms of pest control and banker plant management, i.e.:
a) the natural enemies must disperse from the banker system and discover and attack patches of pest aphids prior to the aphids becoming abundant,
b) but some adult Aphidoletes must either stay on or return to the banker plant in order to replenish the open-rearing system;
4. Finally, we will compare the effectiveness of at least two banker systems in controlling pest aphids in research greenhouses. Of these, using other funds, we will test the most successful system in a commercial greenhouse. Demonstration of effectiveness at a commercial scale is essential for adoption.