Ants

ANTS

I have been servicing a home in West Hollywood, California, and have been having an issue with ants underneath the front steps for months. The sprinklers have been heavily watering the outside lawn, and the ants seem to be in areas with a lot of water. Any advice on this ant issue?

It sounds like you may be dealing with moisture ants, which can be a problem in the Pacific Northwest, including California. There are two main groups of ants that fall within the moisture ant category, Lasius spp. and citronella ants (Acanthomyops spp.)—both genera are much smaller than carpenter ants, which also will infest wood. The telltale sign of moisture ants is going to be nest location near damp wood and moisture. If it is moisture ants, you should be able to find wet, decayed wood—typically in a bathroom, bath trap or basement. They aren’t necessarily structural pests because they only infest wood that already has moisture damage and decay—they don’t eat the wood, just nest in it.

Eliminating the moisture problem will be the key to eradicating moisture ants. Thoroughly inspect around the home’s foundation and make sure there are not any areas that have decayed wood or excessive moisture problems. Correct any areas that are creating conducive conditions for moisture ants, such as leaking gutters, cracks around windows, improper soil grade, etc. Also, communicate with your customer about their sprinkler habits. Walk around with them and make sure the sprinklers are not directed towards the house or causing water to pool around the foundation. If you do find damaged wood, advise customers to have the wood replaced. You may use appropriately labeled insecticides; however, this would be a short-term solution until the moisture problem is fixed.

The tawny crazy ant, Nyla nderia fulva, is considered an extremely difficult ant to control and still gets misidentified. How can I tell if a customer has tawny crazy ants?

Males are required to properly identify the tawny crazy ant species. Under a microscope, the ants have 12-segmented antennae, a 1-node petiole, and are covered with many tiny hairs. Behaviorally, the ants move erratically (hence the name “crazy” ant) and tend to forage in random patterns and not tight trails like other pest ant species. This species will build nests underneath landscape debris and objects and does not build beds or mounds with a central opening. Insecticide sprays can be helpful to knock down tawny crazy ant populations immediately. Long-term control and population suppression is advised with the use of granular and liquid bait products. The time of application of the product you choose is extremely important for success. Tawny crazy ants can have hundreds of queens and extremely large colonies, so baiting early in the season is critical for control. Lastly, it’s important to communicate to your customer that they should help eliminate harborage areas in landscaping and reduce conducive conditions.

I was told that some residual pest control products could cause ants to bud. What is budding, and why does it occur in ants? 

Budding is one form of colony reproduction exhibited by ants whereby a small number of workers depart from the main nest with one or more reproductives to establish a new nest. Not all species of ants are capable of budding. This behavior is most often seen in polygynous (multiple queens) and polydomous (multiple nests) tramp ant species, such as the Pharaoh ant Monomorium pharaonis, that do not invest a great deal in nest construction. For those that can, there are few reasons why budding may occur. Ant colonies may bud to escape predators, to avoid overcrowding, or in response to a disturbance such flooding or extreme temperatures. Similarly, the application of a repellent insecticide could act as a disturbance to some ants, worsening the infestation by causing the colony to fracture and bud. This is why it is often recommended to use non-repellent products in combination with baits when managing ants. Although, different ant species may require different application strategies to eliminate the colony, always make sure you have identified the target pest to determine the best course of treatment, and that all products are used in accordance the manufacturer’s label.

When is the best time to start managing for pest ants?

For most ants, foraging activity usually declines in late fall when temperatures cool, and picks back up again in early spring as days get warmer. Timing your management strategies to coincide with these seasonal changes in activity can improve management success, particularly into the summer months when ants are most problematic. First, communicate the need to eliminate conducive conditions with your clients before ant activity picks up in the spring. Towards the end of winter, begin educating your customers on the importance of removing possible harborage sites outside the home. These can include firewood stored within 20 feet of the house, brush piles or excess mulch against the foundation. Also, make sure all foliage is trimmed back and kept from contacting the structure. Lastly, reduce or eliminate populations of aphids, scales and other plant feeding insects that are known to attract ants. Timing these proactive management efforts correctly can reduce the abundance of pest ants around your accounts in the spring, setting you up for an easier summer.

I’ve read that pavement ants have a stinger, but I’ve never been stung by one.  Can they sting and should my customer’s be concerned about it?

It’s true, pavement ants (Tetramorium caespitum) have a stinger, but they rarely use it.  Found throughout most of the United States, the pavement ant is one of the most common nuisance ant species in the Northeast and Midwest.  Winged reproductive ants are often seen during their mating flights in the spring and are sometimes confused with termites by consumers.  Pavement ants often nest under slabs, patios or landscaping features. Pavement ant stingers are so small that they generally cannot penetrate human skin and are not considered a threat to human health, so your customers don’t need to worry about getting stung by these pests.

I recently found velvet ant in my customer’s yard while performing a perimeter pest control inspection, how can I manage them for my customer?

Contrary to their name, velvet ants aren’t actually ants at all.  They belong to the family Mutildae (ants are in the family Formicidae).  Mutilids are a family of solitary wasps.  The females, which are what you mostly observed, are wingless and almost always hairy and brightly colored.  Velvet ants may be found with bright red, purple or orange and black markings.  Like many other venomous animals, the bright coloration is a warning to stay away; the females have an extremely painful sting, earning them the nickname “cow killers”.  Males have wings but are stingless and rarely encountered.

Velvet ants are parasites of other insects, most commonly ground nesting bees and wasps like bumble bees and cicada killer wasps.  The females locate the nest of the host (sometimes through use of force) and lay eggs in the brood chamber.  When the larvae hatch, they consume the eggs and larvae of the host.  Adult velvet ants typically feed on nectar.

Velvet ants aren’t pests, but since they can deliver an extremely painful sting, you should encourage your client to make the yard less inviting to the host species that females are searching for.   Bare patches in grass are often an inviting place for cicada killers, so they should be repaired, especially if cicada killers have been sighted in the past.  Luckily, unlike hornets, and yellow jackets, velvet ants are not social insects, so there is no nest to be concerned about and typically the sightings are few and far between.