Little fire ants, Wasmannia auropunctata, or the electric ant as they are called in Australia, can be extremely problematic for home owners, farmers, landscapers, pet owners and anyone with an affection for plants and the outdoors. You may be in for a nasty surprise if you harvest fruit and coffee, prune or climb trees or even lie on your lawn, floor or carpet. Little fire ants easily fall from plants when disturbed and despite their small size have a very nasty bite which can cause scarring on people and blindness to animals. At barely 1⁄16 inch, they will invade anything that can serve as a home. Only you can stop this pest from spreading to your residence or farm.
How can you avoid inviting little fire ants to your property?
▶ Get educated. There are many sources, but one of the best is the Big Island’s own ant specialist, Cas Vanderwoude of the Hawaii Ant Lab. Vanderwoude will lead a free little fire ant workshop from 5:30 to 7:30 p.m. Nov. 27 at the Kona Imin Center in Holualoa. Additional speakers include Hawaii Department of Agriculture’s Derek Shigematsu, who will discuss proper pesticide use, handling and application, and Kona coffee farmer Kim Johnson who will speak about her personal experiences with the pest on her property, in her coffee farm and in her mill. A question and answer session will follow. Register by calling Gina Bagarino at 322-4892 or emailing Andrea Kawabata at email@example.com.
▶ Avoid purchasing or accepting potted plants, propagative plant materials, fresh fruits, cut flowers and foliage, lumber or any other questionable materials from areas known to harbor little fire ants..
▶ If you must bring new plant material, such as potted plants, cuttings, and air-layers onto your property, quarantine upon arrival and conduct an ant survey — directions follow.
▶ Closely inspect fresh fruits with hiding places for little critters. Completely soak fruits in mild soapy water and agitate or scrub them to unlock air pockets and dislodge and destroy ants.
▶ Mulch is a great addition to gardens and farms, but unless you are certain of a clean source, there is a chance that these ants will be in the material you take home. Remember, anyone can add to the green waste mulch pile, and this means that someone with fire ants on their property could share them with you. It is highly recommended that you survey for ants before and after collecting mulch at the green waste station.
▶ Talk to your neighbors, friends, family and co-workers, and make them aware of this little ant — one of the world’s worst invasive species. Share as much information as possible. Little fire ants are everyone’s problem, but it is your responsibility to protect your family, pets, property, home, garden, orchard, farm, business and livestock.
How do you survey or bait for little fire ants?
Coat the end of a chopstick or Popsicle stick with a thin layer of creamy peanut butter, and then place the stick flat on the cutting or air-layer or on the soil in the pot. Be sure that the peanut butter contacts the plant or soil. After 30 minutes, check for ants congregating at the peanut butter. If you see small red ants, collect them in a covered jar or Ziploc bag.
If you are unsure of the species of ant, freeze your sample and immediately call the Hawaii Ant Lab at 315-5656, your local Hawaii Department of Agriculture Plant Quarantine Department at 326-1077 or a local HDOA entomologist at 323-7594. The University of Hawaii College of Tropical Agriculture and Human Resources Cooperative Extension Service at 322-4892 and UH master gardeners at 322-4884 may also be of assistance.
Your awareness and vigilance is the best protection against ant infestation.
Andrea Kawabata is the UH Cooperative Extension Agent in Kona. Robert Curtiss works for the Hawaii Department of Agriculture.
Tropical gardening helpline
Mark asks: We want to landscape our half-acre site in Waikoloa with fruit and vegetable plants. We have some raised beds and lots of wind. Our bananas and citrus seem to be struggling, but the pineapples are doing better. Any advice?
Answer: Windy Waikoloa presents a challenge to gardeners. As usual, the best cure is prevention. Planting windbreak plants to diminish the wind’s disturbing and drying effects can help a lot.
Though most fruit and nut trees in the tropics are not highly wind tolerant, guava and mango are among those with tough leaves that can tolerate moderate winds. These trees can also provide some wind protection as they grow. You may want to plant these between the wind and your bananas and citrus trees to reduce damage.
Wind and drought tolerant shrubs like rosemary, natal plum or poha can also help shield smaller, more vulnerable plants from the wind. Flowering hedges of hibiscus or bougainvillea may grow faster and provide additional windbreaks. While your windbreak plants are growing, you may want to install a physical barrier by staking some shade cloth protection between your plants and the wind. This is a very effective way to prevent wind damage to your seedlings.
Once you have some kind of wind break in place, you can start planting. A general rule for windy, hot and dry locations like Waikoloa is to choose plants that are low to the ground and keep them well mulched. Carrots, beets, radishes and turnips should do well in your raised beds. You might also want to consider potatoes including the Hawaiian heritage sweet potatoes or yams. Varieties abound, check seed catalogs for ones you prefer. Squash and bush beans are low-growing and should do well. Again, make varietal choices based on your personal taste.
Additional suggestions from the master gardeners include dragon fruit, avocado, lychee, coconut, sapote and jackfruit. These plants are listed as somewhat wind tolerant to very wind tolerant. Pineapples should do okay as well if you plant them close together. They don’t mind being a little crowded and that way they provide support for each other. Passion fruit may do okay as well, provided the vine has a sturdy structure or tree to grow on.
These websites list drought, wind and salt tolerant plants. Most of these plants are landscaping plants, rather than food plants, but they may be useful in providing wind breaks and shade areas: ctahr.hawaii.edu/oc/freepubs/pdf/L-13.pdf and waikoloa.org/talkstory/download.php?id=608.
Email plant questions to firstname.lastname@example.org for answers by certified master gardeners. Some questions will be chosen for inclusion in this column.
This column is produced by Diana Duff, a consultant, plant adviser and organic farmer in Captain Cook.