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Pill Bug

by Karen Miller, Master Gardener Entomology Specialist

Most of us consider the Pill bug, aka Rollie Pollie or woodlice, a pest especially in large numbers. Though they are associated with insects and are called “bugs”, they are really crustaceans and more closely related to the shrimp and crayfish than to insects. They breathe through gills like their marine cousins and are the only known crustacean that lives its entire life on land. They are found in many dark, moist environments feeding on decaying matter. Pill bugs live in wet locations, under damp decaying logs, in organic garbage and even under our flower pots, where it is nice and damp. All these places provide a humid retreat during the day. Pill bugs are nocturnal and can cover a considerable distance during the night. They feed on dead vegetation, such as leaf litter and decaying wood. They are also found in compost piles. I even have them in my worm compost. If the small pill bug gets into our home, it will most likely dry out and die. They rely on humid conditions for their survival, but will drown if submerged in water. They are also susceptible to temperatures below 21 degrees F. Pill bugs were given the name “Roly Poly” because of a unique way in which they are able to roll up into a ball when disturbed. This process is known as conglobation and is their key defense against predators. Conglobation is also used to reduce water loss through respiration. It can be triggered by vibrations or pressure when touched. Pill bugs play an important part in the cycle of healthy plant life. They are scavengers, eating decaying matter and returning the organic matter to the soil to be further digested by the fungus and bacteria there. This process produces natural supplies of nitrates, phosphates, and other important nutrients that plants need to thrive now and for future growing seasons. It has been found, that by releasing mass quantities of pill bugs in to a mature garden, you can be assured that dead plant matter is being broken down and returned to healthy soil. Pill bugs can literally speed up the process of decomposition by using a number of microbes found in their digestive system which help them feed on dead organic matter. NOTE: If you release the bugs to early they will most likely munch on tender plants also. Bottom line…There are so many benefits the pill bug provides to our garden. While doing my research I came across one unique quality I didn’t know about. The Pill bug has the ability to remove heavy metals from the soil. They can clean up soils that have been contaminated with lead, cadmium and arsenic. This process not only helps reestablish healthy soil, it prevents toxic metals from leaching into our groundwater, thus protecting our well water from becoming contaminated. Pill



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