Ask a Master Gardener: Be On the Lookout-BOLO-These Garden Pests
BY: Barbara Boone, Mobile County Master Gardener I www.mobilecountymastergardeners.org
If you’re like me, you love a good mystery. I read mysteries, watch police procedurals, and stream mystery/thrillers. I am hooked. That is where I became acquainted with the acronym BOLO: BE ON THE LOOKOUT. Like police detectives in the gardening world, we need to BOLO new pests, identify, prove the “perp’s” guilt and apply justice or determine TOD (Time of Death) or exonerate the innocent. So, let’s go sleuthing!
#1: Asian Jumping Worm
Asian jumping worms, which include 51 species in the genus Amynthas including Amynthas agrestis and Amynthas tokioensis, are non-native to the United States. It is unclear how the worm, which is native to Southeast Asia came to the US. Many believe that they arrived by boat in plant shipments. Unbeknownst to customers, they have since been sold as bait and marketed for use in compost.
This worm feeds on leafy litter and mulch, leaving the soil dry and grainy like coffee grounds so that trees and plants are deprived of essential nutrients. Because the leaf litter is consumed in such large amounts, many of the microbial inhabitants of this layer are destroyed. In addition to depleted nutrients, plant roots can be damaged and the soil’s water holding capacity altered in the 10 acres that these worms can invade in a year. Their impact is so great that the ecosystems around them are reengineered.
By the way, Asian jumping worms do not need a mate, as they reproduce asexually. They can cause other invertebrates in the soil such as centipedes, salamanders, and even ground-nesting birds to die, which can impact species that feed on them. They can also change the carbon/nitrogen ratio in soil which can impact the efficacy of pesticides used in larger farming operations. Home gardens are not exempt, as the worms have been identified in 37 states so far, including several states in the South: Texas, Louisiana, Kentucky, Tennessee, and Georgia. Could jumping worms be headed our way, especially since their thrashing jumping behavior has given them other labels such as “Alabama Jumper”?
Asian jumpers can be confused with the European earthworm (also known as nightcrawlers). Asian jumping worms are smooth, glossy gray or brown and 1.5 to 8 inches long. They are relatively easy to identify if you take a look at their clitellum (the band around the body of a worm). The clitellum on a jumping worm is milky white to gray-colored, smooth and completely encircles the body of the worm. In contrast, the clitellum of European earthworms does not wrap entirely around the worm. Also, the European earthworm's clitellum is raised above the body of the worm, not smooth.
· Clean shoes and equipment.
· In a small population, hand pick and destroy.
· Purchase heat-treated mulch which destroys worm cocoons.
Text References: Nebraska Fish and Wildlife. U of Wisconsin-Madison Arboretum.
#2: Brown Marmorated Stink Bug
Another invasive pest also thought to originate from Asia in shipping material is the brown marmorated stink bug (BMSB), Halyomorpha halys, which is shield-shaped with brown mottling. It is between 14 and 17 millimeters long and about the size of a dime. Its abdominal edges and last two antennal segments have alternating light and dark bands. From May through August females lay clusters of 20-30 elliptical eggs on the underside of leaves. Newly hatched nymphs have dark red eyes and yellowish abdomens.
The nymphs and adults of the brown marmorated stink bug feed on over 100 species of plants, including many agricultural crops. A combination of neem and pyrethrins can be used in organic agriculture to reduce the numbers and discourage it feeding. This bug is a nuisance for homeowners as it is attracted to the outside of houses in search of inside entry for warmth during colder temps. They congregate in attics and basements during the cold months and can be removed with a vacuum cleaner. The concern is that with climate changing to warmer temps, BMSB will be on the rise.
Text References: USDA. IPMC-Stop BMSB.
Invasive pests like these are increasing their footprint due to factors like climate change and transport by human activities. Gardeners should be on the lookout for invasives that compete with native organisms for resources or alter habitats. If you have any questions about invasives, please call the Master Gardener Helpline for answers (1-877-252-4769).