Marion County Weed Control DistrictHot Topics and Watch List 2015
This list is intended to keep attention on new or increasing threats that have not yet been targeted. This list will also include items of current interest as they relate to specific noxious weeds.
Worst offender: Tansy ragwort! (Senecio jacobea): This weed is overtaking pastures, tree farms, fields, and unmanaged or fallow properties. This weed has the ability to kill livestock, particularly horses and cattle. Improved stewardship would address this problem—land management changes such as rotating grazing areas and early detection and control, are the solution. The biological controls are effective under certain conditions, but should not be relied on to solve the population problems in pastures. BE A GOOD NEIGHBOR! Control tansy!
Italian arum (Arum italicum): This hardy invasive plant grows from a corm, an underground structure similar to a bulb. It is common in gardens and landscapes, and was frequently used as an ornamental. It is recognizable by its arrowhead-shaped leaves on long stalks, and the small blooms (in the form of spathes) that look similar to a calla lily blossom but are usually pale green.
Lesser celandine (Ficaria verna, formerly Ranunculus ficaria): This buttercup family plant poses a serious concern with regard to spring ephemerals (plants that grow and flower in the late winter and early spring, and then go dormant for the dry season). Because celandine begins its life cycle even earlier than our natives, it has a definite advantage, and can quickly populate an area to the detriment of the indigenous species.
Spotted-wing fruit fly (Drosophila suzukii): This insect poses a serious threat to all fruit growers and backyard gardeners. Instead of laying eggs only in ripened fruit, it has the ability to lay into fruit still entering the ripening process. Additionally, it uses invasive blackberry as an alternate host.
Brown marmorated stink bug (Halyomorpha halys): This insect is a pest for fruit and vegetables and can cause major economic damage. Fruit trees are of primary concern. Affects interstate movement of crops. Identification is challenging, as this stink bug looks very similar to other stink bugs.