Essential Oil for Roly Poly Pests

D. J. Bradford

Touch a roly-poly bug (Armadillilium vulgare) and you’ll know why it’s called a roly-poly. When threatened, these bugs role themselves into balls resembling little pills, which also gives them the moniker, pill bug.

Roly-polies, terrestrial crustraceans, prefer moisture like their sea-going relatives.

These entertaining bugs, called doodlebugs in some regions, are usually not a problem for gardeners -- unless they show up in large numbers after a good rain. Enough of them can do considerable damage to flowers, seedlings and tender plants. But gardeners can rest in the fact that there are natural ways to keep the little buggers at bay.

An Oil a Day Keeps the Roly-Polies Away

A number of essential oils have proven themselves to be effective against a number of different arthropods, animals with exoskeletons and jointed appendages. Some of the essential oils that have shown to be effective against troublesome arthropods like roly-polies include pennyroyal oil, peppermint oil, eucalyptus oil, citrus oil, citronella oil, rosemary oil, clove oil, cinnamon oil, oregano oil and tea tree oil. Most of these can both kill and repel, while citronella just repels and often confuses insects. Cinnamon oil is also primarily a repellent. Although research is ongoing, the "Journal of Pharmacognosy and Phytotherapy" reports that essential oils are believed to have a neurotoxic effect on insects.

Applying Essential Oils

Essential oils are best applied as sprays when mixed with natural biodegradable soap. Begin by using approximately 4 drops of oil per gallon of soapy water. The number of drops may be increased to reach the effective concentration. If using pennyroyal oil, only 1 drop may be necessary. Remember that essential oils can cause problems for beneficial insects as well, so be careful where you spray. Some essential oils such as peppermint, cinnamon and oregano can burn your skin. Do not get any of the oils in your eyes. For best results, use therapeutic grade oils only.

Other Oils for the Roly-Poly Arsenal

Coconut oil can be used as well on roly-polies. This oil clogs the gill-like structures that the roly-poly breathes through, suffocating it. Coconut oil may be used straight or may be mixed with water containing natural biodegradable soap. Combine with essential oils for added effectiveness. Make sure to use only 100 percent pure coconut oil for best results. Other oils including cottonseed, canola, olive, soybean and palm, will also work.

Alternative Natural Repellents

Many other natural solutions exist for the roly-poly bug. They can be trapped using rocks under which the soil is moist, and from there, handpicked and removed. Bugs such as the roly-poly can be easily repelled using cayenne pepper sauce, chili pepper oil and garlic spray. Make garlic spray by adding 1 tablespoon of crushed garlic to a quart of water. Adding Diatomaceous Earth to pepper sauce or garlic spray enhances their effectiveness.