Potential of an annual hemiparasitic plant as a biological control agent against Solidago gigantea and Symphyotrichum lanceolatum
Melampyrum arvense (Orobanchaceae) is an annual hemiparasitic species native to the EPPO region. It obtains nutrients from host plants by attaching to their root system. The potential of M. arvense as a biological control agent against two North American plant species present in the EPPO region, Solidago gigantea (Asteraceae: EPPO List of Invasive Alien Plants) and Symphyotrichum lanceolatum (Asteraceae), was assessed. An experiment was established at six sites in the Czech Republic where S. gigantea and S. lanceolatum were dominant. At each site, two treatments and a control were carried out in different plots: mowing with biomass removal twice a year—in late July and October, mowing twice a year plus sowing of M. arvense in the first autumn. Throughout the experiment growth parameters of the two alien plant species were measured (percentage cover, height and below-ground biomass). Mowing alone reduced the growth of both alien plants. Mowing plus the addition of M. arvense had a greater effect reducing the cover of S. gigantea from 90 to 8 % and the cover of S. lanceolatum from 78 to 12 %. M. arvense reduced the below-ground biomass of both hosts by more than 80 %. The study shows the potential of using M. arvense as a biological control agent which can also help to facilitate restoration of the invaded area.
Sources
Knotková K, Tĕšitelová T, Knotek A, Axmanová I, Chytry H, Pleskoná Z, Preislerová Z, Tĕšitel J (2025) Biocontrol by a native hemiparasite: rapid suppression of noxious invasive plants in a field experiment. Journal of Applied Ecology 62(12), 3514-3524. https://doi.org/10.1111/1365-2664.70183