If you’re battling infestations of bed bugs, you may think you’re saving money with do-it-yourself bug bombs, but you may actually making the problem worse. According to a study published in the June issue of the Journal of Economic Entomology, total-release foggers, otherwise known as bug bombs, are ineffective at killing bed bugs and fleas and can actually increase the number of cockroaches in your home.
Drs. Susan Jones and Joshua Bryant from the Ohio State University tested the effectiveness of three commercially-available foggers on five bed bug populations collected from homes in addition to one bed bug strain reared in a laboratory to be susceptible to pyrethroids. Foggers included Hotshot Bedbug and Flea Fogger, Spectracide Bug Stop Indoor Fogger and Eliminator Indoor Fogger.
Before this test, little was known about how effective foggers were at controlling insect populations. Most of the data on foggers concerns reasons for insecticide exposure, most of which include the homeowners’ failure to follow the label instructions. This experiment tested the effectiveness of the insecticide to manage the population, particularly in cases where the insect populations may be in hiding.
Bed bugs were placed in Petrie dishes, and each fogger was tested on two Petrie dishes. In one dish, bed bugs received direct exposure, and in the other dish, a paper disc was placed over the bugs to mimic the natural act of “harborage.” In their natural habitat, bed bugs typically come out of hiding at night to feed and then go back to hiding during the day. In addition, bed bugs usually come out of hiding when they sense an opportunity for feeding, so if there are no people or animals in the home at night (if the fogger is deployed at night), bed bugs would stay in their inaccessible spaces while the fogger was running.
Of the six bed bug populations exposed to the foggers, the laboratory-reared Harlan strain was the only one that was affected by the insecticide. With no cover, the Harlan strain died almost immediately after exposure. With the disc cover, mortality of the total population was slower, but all bugs were dead in about a week. The bed bugs collected from residences, on the other hand, had very low mortality, regardless of cover. One of the populations had higher mortality when exposed to the Spectracide fogger, but only when they were directly exposed and had no cover.
The research team concluded that pyrethroid resistance played a role in the foggers’ failure to kill bed bugs. In fact, after studying the genotype on all of the field-collected bed bug populations, the scientists discovered that all five field-collected populations had a mutation for pyrethroid resistance. Pyrethroids are the main active ingredient in most insecticides for bed bugs, whether they are sold over-the-counter or applied by a pest control professional. However, professional mixtures are far more potent than are the cans of insecticide sold at hardware stores, so homeowners who use several applications of an over-the-counter insecticide are usually just creating a more resistant population of pest.
Foggers also don’t penetrate into the cracks and crevices that most pests retreat to. Researchers also tested foggers’ effectiveness at killing cat fleas in carpet and discovered that fleas were less likely to die if they stayed hidden than if they were directly exposed.
In addition to being ineffective at killing bed bugs and fleas, foggers can actually exacerbate other pest issues. German cockroaches, for instance, prematurely released their eggs in response to fogging and, in multi-family housing units, often moved from the unit being fogged to an adjacent unit. Bed bugs and fleas did the same.
Because they bite at night, bed bugs have become one of the most hated and feared household pests. The strong desire to rid the home of the bugs often leads homeowners to use methods that can be ineffective, dangerous and only postpone the desired outcome. The authors’ opinion of the wisdom of purchasing these products is clear:
“The public is ill-served when products do not perform in accordance with labeling and use directions claims. The use of ineffective insecticide products means that people are wasting money, and they are delaying effective treatment of insect pests whose populations are ever increasing in their residence and likely spreading to others. Furthermore, insecticides are unnecessarily being introduced into the environment, and people and insects are being exposed to insecticide residues, while further reinforcing insecticide resistance in insects.”
Source: Jones, S.C. and Bryant, J.L. 2012. Ineffectiveness of over-the-counter total-release foggers against the bud bug (Heteroptera: Cimicidae). J. Economic Entomology. 105:957-963.
Filed under: Insects, Pesticides, Urban IPM Tagged: | bug bombs, do foggers work?, eliminator fogger, getting rid of bed bugs, hotshot bedbug fogger, over-the-counter insecticides, Spectracide fogger, total release foggers