The potential of entomopathogenic nematodes to control moth pests of ornamental plantings

Worldwide biodiversity decline is caused by multiple factors, including pesticides. Aside from their applications in agriculture, the uptake of pesticides in urban gardens is widespread. Here, we review the potential of controlling pests of ornamental garden plants, like the boxtree moth Cydalima perspectalis Walker, 1859 (Lepidoptera: Crambidae), using entomopathogenic nematodes (Heterorhabdidae & Steinernematidae). Nematode biocontrol is highly suitable, particularly for small-scale control such as in boxtree plantings. Boxtree (Buxus spp.) is an ornamental shrub widely used in public and private grounds across Europe. Over the past decade boxtree has suffered heavily from the destructive boxtree moth, an invasive and persistent pest species of East-Asian origin. Widespread application of insecticides has been effective, yet resistance to these compounds is accumulating. The dense foliage of boxtree shrubs facilitates the correct tuning of moisture and temperature conditions required for nematode mediated pest control. Warm weather, without direct sunlight, on moist to wet foliage appear to be the most suitable conditions. We conclude that the use of entomopathogenic nematodes for controlling pests, such as the boxtree moth, may limit damage to horticulture and provide a safe and environmentally friendly form of control in urban spaces.