[Occational Invaders] Spotlight on Springtails

Despite their tiny size, springtails are growing nuisance pests in and around structures throughout the United States and the world. Some entomologists consider springtails to be separated from insects and have elevated them to the class Collembola ("the largest of the three lineages of modern hexapods").

IDENTIFICATION. Springtails have a pair of fork-like appendages (furcula) at the end of their abdomens. The common name springtail is derived from its behavior of springing (jumping) away by snapping its tail-like structures against the ground when disturbed.

Springtails are usually light brown to cream in color. They are tiny (1⁄16 to 1⁄8 inch in length), wingless and require very moist conditions for survival. They have oval heads with four-segmented antennae.

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Fun Facts

• Springtails are among the most interesting of all occasional invaders. If you don’t believe it, consider the following "fun facts" about these moisture-loving insects:
• Springtails are the most abundant microscopic animals in the world, and are found in huge numbers in nearly every habitat. There are approximately 700 species of springtails in North America and more than 6,000 worldwide.
• Springtails from the class Collembola have a tube beneath the abdomen, which secretes "glue"; this tube is important in grooming and allows the insects to adhere onto smooth surfaces. Thus, the name Collembola is from the Greek words "cole," meaning glue and "embolon," meaning piston.
• Springtails can be a problem in newly built structures because of damp building materials and wet plaster. In older homes they will usually be found in the kitchen, bathrooms, basement, or other areas where moisture is present.
• Springtails cause no damage to buildings and cannot bite or sting humans.
• Springtails are attracted to light and may be found in lighted areas at night.
• Springtails can jump up to 100 times their body length. They have been known to jump over 30 cm into the air at an initial velocity of 1.4 meters per second.
• Springtails have "mandibulate" mouthparts (adapted for chewing), which are withdrawn into the head when not in use.
• Some springtail species can live without food for up to three years by recycling their own waste, while others can also go into a form of dormancy.
• Species of the Collembola can be found above 21,000 feet on Mount Everest, in volcanic vents along Hawaii's Kilauea, near the North and South Poles, and from the tops of the tallest trees to the deepest soil layers.
• Most springtails breathe through their skin or cuticle, which is very permeable to water; therefore, these insects must spend most of their time in very damp locations.

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BIOLOGY. Springtails have an "ametabolous" life cycle, meaning that they DO NOT undergo metamorphosis. As a result, they do not have nymphal, larval or pupal stages. Instead, springtails develop by going through a number of molts (shedding their exoskeleton) as their body size is growing. Unlike other hexapods, springtails perform additional molts after reaching adulthood.

Reproduction can be complicated, depending on the species. For example, while parthenogenesis (reproduction without males) is common among females of some species, females of other species require mating in order to lay eggs, and they can be quite picky about which males they decide with whom to mate. These females desire the males to dance for them before they actually mate. On the contrary, many males of other species leave a sperm packet on the ground that is later picked up by the female. Others place sperm with their hind legs directly into the female’s reproductive organs.

Females usually lay up to 400 eggs during their life span. Eggs can be laid singly or in large masses. It takes about 10 days for eggs to hatch, and the immature springtails go through three successive molts lasting 7 to 10 days before they become adults. The number of generations per year, the longevity of springtails, and preferred temperatures are species-dependent topics, and are beyond the scope of this article. However, depending on the species, springtails can live from one week to three years. In general, they survive low temperatures and can appear in large numbers on snow surfaces (hence their nickname "snow fleas").

HABITS. Due to their breathing system, soft bodies and small size, springtails rapidly lose water through their cuticle. Therefore, they usually live in moist, cool, concealed places, such as in mulch around homes, rotted logs and moss, as well as in ant and termite nests. Some species occur on the surface of pools, snowfields, and other similar habitats.

Springtails feed on leaf litter, decaying plant materials, bacteria and fungi. Additionally, their diet may include fine roots in wet to damp soils.

Springtail populations can reach huge numbers, up to 50,000 per cubic foot of forest litter or up to 2,800 per square foot in planted fields, as well as around structures. When they reach a high population density up to 100,000 insects per cubic yard, they search for new habitats. They often invade structures during the hot, dry summer in search of moisture. Home-owners usually encounter springtails in large numbers and they become an irritation factor in damp basements, kitchens, bathrooms, and garages. Others are found on surfaces of water, on soil of potted plants and in other moist habitats.

CONTROL. Because there is little known about springtail habits and behaviors inside a structure, these bothersome pests have created big concerns among pest management professionals for a long time. Usually, repeated pesticide treatments in and around homes are performed to achieve an acceptable level of management. But to successfully eradicate springtail problems and prevent future infestation, it’s critical to eliminate their entryways, find the source of the infestation and remove it. This can be achieved by implementing the following practices:

• Fix moisture problems inside the house. Pay particular attention to the wood window and doorsills with water damage.
• Repair leaking and dripping pipes.
• Remove mold related to water leaks.
• Clean up loose materials from damp floors.
• Eliminate any moist or organic matters.
• Avoid over-watering and allow the soil to dry between watering.
• Increase ventilation, artificial air movement from fans or use a dehumidifier.
• Permit proper air circulation around the foundation of the structure.
• Remove moist leaves, moldy wood items, compost piles and decaying vegetable matter.
• Remove excessive mulch. Mulch only should be 2-4 inches deep so it remains dry most of the time.
• Clip bushes and ground cover.
• Seal cracks and crevices with caulk.

When pesticide applications are justified, perimeter, crack, crevice and spot treatments should be applied to the exterior and interior parts of a structure using EPA-approved residual pesticides. Depending on the pesticide, nature of the outdoor area and the level of infestation, exterior treatments should be made several feet out from the structure where springtails can be found. In order to cut callback and treatment costs, follow all instructions noted on the product labels, and carefully target springtail sources of infestation previously mentioned.

From a practical experience, wettable powder formulations (WP) seem to provide better springtail management results than other formulations, especially when they are used as barrier/perimeter treatments. A desiccant dust (silica gel or diatomaceous earth) can be used to treat voids around bathtubs, showers, along plumbing and water pipes. However, where mulch and wood chips are present, it is recommended to use granules, as they release slowly into treated areas. Depending on the product selected for this purpose, granules can provide more than two months of residual effects.

The frequent migrations of springtails from outdoors can involve continuous movement of new individuals into the structure. However, using the right type of pesticide applications and formulations at the right time can deliver successful management of these pests.

The author is technical and training director for Adam’s Pest Control, Minneapolis, Minn. He earned his Ph.D. in entomology from the University of Vermont. Contact him via e-mail at meldamir@giemedia.com.