Wednesday, June 13, 2018

Conglobation (Think Pillbugs): June Word of the Month

Armadillidium vulgate, common pillbug, photo courtesy

Conglobation is a term often associated with the common pillbug because of the way they roll up into a ball. This is called conglobation. Rolling into a ball is why many people call them 'roly-polies'. When pillbugs are threatened or bothered, they roll into a ball, likely to protect their soft inner body. Rolling into a ball could also limit water loss. When moving, they alternate between gradual right and left turns so that they end up moving straight forward.

Here are some additional interesting facts about pillbugs.

Armadillidium vulgare, the common pillbug, is originally from the Mediterranean. It has been brought by people to almost all other areas of the world. It is most common in temperate climates. Common pillbugs, also called roly polies, are found throughout the United States, as well as Madagascar, Australia, South Africa, India, Japan, France, Canada, the Czech Republic, and western Romania, among many other places. 

In most years pillbugs content themselves in feeding harmlessly on decaying vegetable matter in and on the soil. However when abundant–as in years of high rainfall–they can become a significant pest of landscape plants. Most feeding takes place in the evening or at night. Feeding pillbugs readily feed on small garden plants, and new transplants can be eaten to the ground overnight. Some of the plants attacked include hosta, pansies, blue lobelia, cardinal flower, English primrose, Allyssum, Dahlberg daisy, zinnia, verbena, and blackfoot daisy. Garden vegetables are also susceptible, especially strawberries and other plants with fruits that contact the soil. During the day, pillbugs can be found in moist areas under mulch or leaves and vegetable debris of all kinds. Cooler portions of compost piles can also harbor large numbers of pillbugs. Pillbugs often bury themselves several inches beneath the soil surface to avoid hot, dry conditions. Pillbugs are prolific, giving birth to 30-80 young per brood. 

The best way to eliminate pillbugs is to destroy their breeding and hiding sites. Eliminate unnecessary piles of leaves, grass clippings and mulch. Flower pots, planters, dog houses, firewood, bricks or other objects that sit directly on the ground should be elevated to allow air-flow and drying underneath. Adjust irrigation systems so that the soil around your home has a chance to dry between irrigations. When abundant, pillbugs can enter homes and become a nuisance. Pillbugs are harmless and can be removed by hand, or by vacuuming. They rarely survive more than one or two days indoors, due to lack of moisture.

For more information:
Insects in the City, Texas A&M AgriLife Extension
Pillbug, Kids Inquiry of Diverse Species