It is well known that several common insect pests of homes have developed a resistance to insecticides, as well as other pest extermination agents. However, the problems posed by the eggs of insect pests are not often discussed in pest control literature published by extension agencies and pest control companies. This is surprising considering that insect pests are most difficult to kill during the egg stage. Insect egg’s shells are composed of many layers that keep embryos safe from environmental threats while also allowing embryos to breath and retain water. Because of this, insecticides, fungal pathogens and many fumigants are unable to penetrate the insect eggs of most insect pest species.

There are very few spots on an insect egg where insecticides could penetrate to kill the developing embryo. An aeropyle is a system of small openings on an egg shell that allows for oxygen exchange with the outside environment, and a micropyle is an opening on an egg shell that allows spermatozoa to enter. Unfortunately, when it comes to insect eggs, these holes are too small and/or too few in number to allow for the intrusion of insecticides. While the natural structure of insect eggs allows them to withstand insecticides and other extermination agents, the eggs of many insect pest species have evolved special mechanisms to resist the toxic effects of insecticide exposure. For instance, the eggs of multiple insect pest species have evolved to produce a greater amount of enzymes that break down insecticides.

Since very few pest control methods have been developed to kill insect eggs, it has become standard for urban pest control professionals to ignore eggs during the initial infestation treatment. In many cases, pest control professionals wait for insect eggs to hatch larvae before performing a second treatment. However, since most insect pests hide their eggs within concealed indoor locations where they are well protected, and since the eggs themselves do not annoy or harm humans, they are sometimes ignored entirely. In these cases, eggs can hatch and reinfest homes after all larvae and adults are successfully eliminated. The eggs of bed bugs and most cockroach pests are among the most difficult to eliminate with insecticides and other extermination methods.

Have you ever stumbled upon insect eggs within your home?