Holy Moley

by Andrea Laine, EMGV

A mole has taken up residence in my yard and, seemingly overnight, disrupted a couple of landscaped ornamental beds and killed two biennials. Well, it’s time to send that critter an eviction notice!

I immediately installed a spike as I’ve experienced good results with them in the past. These low-tech devices periodically emit a sonic vibration that supposedly moles find irritating. It worked, somewhat; The critter vacated the one bed, waddled (I imagine) across the walkway leading to my front door and dove into the next nearest bed to begin again. Aargh.

So, I poked another spike into the soil thinking, “can’t hurt, might help.”  True enough–no moles were hurt. Extension resources say my go-to solution has not been scientifically proven effective.

Know thy enemy
Solving a problem is more difficult when you know next to nothing about its cause. It was time for me to do some reading and uncover a few facts about moles:

  • Moles are solitary animals and, since they live underground, have few predators (snakes and foxes are two). Three to five moles per acre are considered a high population for most areas.
  • Moles are carnivores; they prefer to eat insects and grubs. They eat 70% or more of their body weight each day. With an appetite like that it is no wonder they cover so much (under)ground.
  • Moles are very efficient at tunneling. Observe their front feet in the accompanying photo and you can see why. The feet are broad and flat with long, protruding claws to help toss soil aside. They “swim” through the soil. They can tunnel forwards or backwards. Their deep (10 to 18 inches) and wide tunnels can destroy plant roots in their path, which is likely what happened to my biennials. get-rid-of-moles
  • Moles do not eat plants. If you notice plants or their roots suddenly vanishing, that is the work of white-footed mice or voles who are opportunistic herbivores – they make use of a mole tunnel to reach their food source.
  • In addition to grubs and insects, moles eat earthworms, spiders and other beneficial soil microorganisms. Moles like shaded, moist, cool loamy soil. No one warned me that a reward for improving my clayey soil would be moles. They also enjoy mulched areas and compost piles.
  • North Carolina is home to two species of mole: the Eastern mole and the star-nosed mole. The latter is a rare species and thus, moles are a protected species in this state.


Actions that may solve a mole problem
A 24-inch square piece of hardware cloth, bent in half and buried in the soil may work to protect a small area or a treasured plant. This option is hardly practical for my larger landscape and besides, I treasure all my plants.

Chemical repellents, toxicants and fumigants are not recommended as their effectiveness is limited at best and potentially dangerous to humans, pets and other wildlife. Extension also recommends not planting Euphorbia latharis (mole plant) nor Ricinus communis (castor bean plant) for similar reasons.

The most effective way to control moles is to trap them. Since moles are a protected species in N.C., you need a depredation permit to trap them. Depredation refers to wildlife causing property damage.

Benefits moles bring to nature
I am highly unlikely to experiment with trapping a mole, permit or not. And the problem would have to get pretty bad before I paid someone to trap a mole for me. So, it is time to consider what benefits moles bring to nature. Maybe we can coexist.

  • For starters, moles eat white grubs and the larvae of pest insects. Grubs become Japanese beetles so hooray for moles.
  • Tunneling loosens and aerates the soil. It also mixes the soil near the ground surface with deeper subsoil.
  • Borders of marigolds may repel moles from gardens. This method has not been scientifically tested but who would object to planting marigolds? Thus, I am counting it as a benefit.

Alas, there are just too few benefits of moles in the landscape. Sigh.

640px-Marigold_Flower

Drawing a conclusion
I might have won the battle, after all. One source noted that spring floods are probably the greatest danger to adult moles and their young. I know it’s not spring, but Hurricane Flo just dropped several inches of rain on Durham. Maybe the two inches of water that seeped from the over-saturated soil into my basement was also enough to wash away the smorgasbord that my resident mole was enjoying and he will soon pack up for new digs. Wishful thinking? Can’t hurt, might help me feel better.

Further Reading:

Find lots more detail about moles and trapping them at this resource from Penn State Extension:  https://extension.psu.edu/moles

https://wayne.ces.ncsu.edu/2015/12/moles-or-voles/

https://extension2.missouri.edu/G9440

https://www.ncwildlife.org/Licensing/Regulations/Nongame-and-Other-Regulations/Wildlife-Depredation

http://www.metromastergardeners.org/faq/index.php?action=artikel&cat=9&id=20&artlang=en

Photo credits:
Mole: https://www.almanac.com/pest/moles
Marigold:  Sarbast.T.Hameed [GFDL (http://www.gnu.org/copyleft/fdl.html) or CC BY-SA 4.0  (https://creativecommons.org/licenses/by-sa/4.0)%5D, from Wikimedia Commons

 

Coping During Japanese Beetle “Season”

by Kathryn Hamilton, EMGV

At this time of year, Japanese Beetle “Season,” my favorite gardening tool

P1000072
Beetles are most sluggish in early morning.

is a plastic fork.

When disrupted, beetles are supposed to fold their hind legs and fall. You are supposed to be able catch them with a container of soapy water. In my experience that’s true only about half the time. Sometimes they must be pointed in the right direction; other times they need to be fished out from between the layers of a rose petal, and at still other times, they must literally be pried off the flower. Apparently, even Japanese beetles have a survival instinct!

Japanese beetles (Popilla japonica) are attracted to the foliage, fruits, and flowers of nearly 300 different plants, among them: roses, crape myrtle, hibiscus, purple-leafed plums, grape leaves, and geraniums.  If you are a Piedmont gardener, chances are very good that you have encountered these pests in recent weeks.

skeletonized squash leaf
A skeletonized rhubarb leaf.

The good news is that Japanese beetles are unlikely to destroy established trees or shrubs. Skeletonized leaves and flowers will grow back once the beetles disappear. The better news is that within 30 – 45 days of their onset they will be gone.

Here are some takeaways to help you cope with Japanese Beetle “Season.”
1. Only one generation occurs each year. They typically emerge in early June and are gone by mid-July. You may see an isolated beetle during the rest of the year but ground zero is late May until early July.

2. Beetles emerge when the temperature is “just right.” Scientifically this equates to approximately 1,000 growing degree days. (Here’s a scientific explanation of growing degree days.)  If the weather heats up faster beetles are likely to appear sooner. Weather conditions also determine the grub population, their larval stage. Damper weather typically means more grubs. More grubs mean more beetles.

3. Japanese beetle traps should not be considered control devices. Designed to attract beetles, rather than trap them, they can increase the beetle population in your back yard. Furthermore, if not emptied every couple of days, the beetles will rot inside, releasing an ammonia which repels them. Instead of going into the trap, they are likely to tap your hibiscus.

4. Where practical, cover the plant with light netting.

5. Just say “no” to things they don’t like. But who could imagine a garden without roses?

6. Rose experts advise picking your roses and bringing them inside. They can beautify your property the rest of the year.

7. Japanese beetles aggregate in response to odor released by damaged plants and a pheromone released by female beetles. I usually cut the least-damaged roses and leave one or two that have been attacked. They are always one of my best beetle-harvest sites.

Beetles in every corner of beat up rose
There are at least eight beetles in this “trap.”

8. Another tip, before cutting a rose to bring inside,

Rose closed sepals
Because the sepals haven’t fallen, this rose, if cut, will not open.

be sure the sepals have fallen or the rose will not bloom.

9. You can, of course use insecticides, a discussion of which is outside of this posting. However, any insecticide will have some negative effect on other insects, including those which are beneficial. The North Carolina Agricultural Chemicals Manual lists pesticides and their relative safety for bees. Should you opt for an insecticide, prune all the flowers first. There are label restrictions against using most insecticides on flowering plants and when pollinators are present. Read the label for detailed restrictions.

10. Insecticides only treat the exposed petals. So, if a bud opens throughout the day, the unprotected petals are just another meal. And, unless they are systemic, insecticides must be reapplied after a rain.

My bottom line strategy: I cut my best roses and leave a few that have already been attacked as traps. Several times a day, I am single-mindedly devoted to search and destroy missions, first dumping the beetles into a container of water soapy water then  finishing with a flush down the toilet.

Further Reading:

Japanese Beetles on Ornamental Landscape Plants

Japanese Beetles

Insects: Japanese Beetles

 

 

Fired Up About Imported Ants

By Carl J. Boxberger, EMGV

Fire ants are a serious nuisance pest in home lawns. They form unsightly mounds in sunny areas in lawns or next to sidewalks and driveways where soil temperatures are greater.

When their mounds are disrupted, their bites and stings can cause pain and serious injury to people or pets they land on.

Description and Biology

Red fire ants are about a quarter-inch long, red-brown, with shiny black abdomens. They are native to South America and, having escaped their natural enemies, thrive in our southern landscapes.

There are three types of adults in a fire ant colony:  winged males, reproductive females and worker ants. Queen fire ants can lay 800 or more eggs per day. Worker ants are sterile females, wingless and protect the colony by feeding the queen, defending the nest, and foraging for food.

As the ant population grows new mounds will pop up to support the growing population. Also, if a mound is disturbed, the queen will be moved and a new mound will surface.

Control

Drenching the mound with greater than two gallons of hot water or mechanical disruption of the mound can reduce fire ant activity, however, fire ants will form new mounds a few feet from the original mound. Do not pour gasoline, diesel fuel, ammonia or chlorine on the mounds as these are dangerous and will contaminate the soil and ground water.

Broadcast pesticides applied over the entire lawn will only control ants on the surface and will not kill the colony deeper in the soil. It may kill beneficial insects as well.

Individual mound treatment is probably the best option for home lawns. Commercially purchased baits should not be placed on top of the mound but placed within a two-foot radius around the mound. The ants will take this bait into the mound and feed the queen and kill the colony.

As with all pesticides read and carefully follow all label directions.

Conclusion

Nest building by fire ants, like common ants, will reduce soil compaction and help aerate the soil. Fire ant diet includes other arthropods including insects, ticks and mites. So, fire ants can be beneficial to the environment.

Today, there are five times more ants per acre in the United States than in their native South America.

Resources 

NCSU Turf Files – Fire Ants in Commercial Turfgrass, Home Lawns and Landscapes by Dr. Terri Billeisen , Extension Associate, Entomology and Plant Pathology – NCSU

Center for Disease Control: https://www.cdc.gov/niosh/topics/insects/fireants.html

Medical problems and treatment considerations: http://fireant.tamu.edu/files/2011/12/FAPFS023_2002rev_Medical.pdf

OSHA Factsheet: https://www.osha.gov/OshDoc/data_Hurricane_Facts/fire_ants.pdf