Late each summer, in many areas, insects such as yellowjackets are out foraging for food. Unfortunately, more and more, these insects are entering areas where people are picnicking or playing. 

     Yellowjackets fall into the wasp family which includes insects such as hornets and paper wasps. The other major group of stinging insects, the bees, includes honey bees, bumble bees and carpenter bees. Though both groups have different characteristics, it is common for people to refer to all flying, stinging insects as "bees". 

     Not all bees nor all wasps are aggressive or likely to sting, but a healthy respect for these insects is recommended. Often, these insect sting simply because someone or their pet just happens to block the insect's normal flight pattern.   If you've never been stung, we urge caution:  a sting may be fatal for some hypersensitive individuals.

 

Location of Nests

     There are a number of areas around a structure where these stinging insects may enter to nest including wall voids on the outside of buildings, under siding or under shingles.  In other cases, they may build a visible nest that hangs from a tree, inside a shrub or bush or from a point on a structure.   Another common site for stinging insects to nest is an open made in the ground. 

 

Yellowjackets and other Related Stinging Insect Management

     Several steps may be taken to help manage yellowjacket problems.  Bottle traps may be very effective in reducing populations of stinging insects. These traps are baited with sweet liquids which will draw yellowjackets in. Once inside, they cannot find their way out.  The opening that they've entered through appears black and abundant light inside the bottle confuses them and obscures the holes that would allow them to escape.  The bottle trap we sell is the Victor Flying Insect Trap.  Black light electrocution type units are of little value because these insects are diurnal rather than nocturnal and are not normally attracted to such traps during the daylight hours.

     Lawn sprays can reduce the number of stinging insects around in general, but the risk to other non-target organisms is increased. Premise treatment along the outside of buildings such as along eaves and gutter areas may repel insects from these areas.

     In most cases, insects will enter through a small opening on a structure. Targeted application of known nesting sites with a insecticide dust is probably the most effective treatment and most ecologically sound. Dust formulations of insecticide, when applied at entry points, will be picked up by all incoming and outgoing insects, thus effectively eliminating the inhabitants. The Bug Clinic sells Apicide, an insecticide dust, which comes in a ready-to-use applicator canister with an attachable extension tube for this purpose.  Apicide contains 5% carbaryl (Sevin) which is very effective at killing bees and wasps due to their sensitivity to this product.

     In cases where there is a visible nest, an aerosol product such as Whitmire PT Wasp Freeze II may work well.  It shoots a stream of product ten feet or more.  It may be applied first to the openings at the bottom of the nest where insects enter and then used to soak down the outside of the nest to kill other insects inside. 

Because Whitmire PT Wasp Freeze II contain petroleum distillate to quickly disable flying insects, use caution if the nest in embedded within a shrub or bush or if applying to a nest adjacent to vinyl siding.  The liquid could burn surrounding leaves and may damage vinyl siding.

     The trick to this making applications of either type of product to kill stinging insects is to apply it at dusk (almost dark) and being sure not to block the flight path of insects entering the nest opening.  If you need to use a flashlight to see what you are doing at night, cover the lens with red plastic or cellophane.  Yellowjackets cannot see red light.

     To prevent wasps from reusing an opening year after year, when you are sure that there is no activity, seal the opening with caulking or other appropriate materials.

     Finally, there is also an insect repellant called Outlast NBS-30.  It contains variety of plant oils which can be mixed with water, paint or stain.  When applied with water, the product repels the insects for about a week.  If mixed into paint, stain, or sealant, its repelling properties last for two year or more.  Targeting the areas where insects return year after year may be a good control strategy. 

    For more information, you may call us at 800-433-1128 or 845-356-2837, fax us at 845-746-9018 or E-Mail us at drbugclinic@bugclinic.com.