When you ask a pest control professional what are some of the toughest pests to control inside a home, silverfish always seems to be on those lists.
Silverfish typically find their way inside a home from either the outside or are brought in via items like boxes, furniture, and other items that have been stored in infested areas. By the time silverfish are spotted by a homeowner, they have an infestation on their hands. That is because silverfish are nocturnal, so you usually won’t see them. They spend their days hiding in dark secluded places. You would typically only see them during the day if you disturb their hiding places. They move quickly. They reproduce quickly. And they can live for up to a year without food. Talk about a hardy pest!
Silverfish have a rather interesting life cycle. Females usually lay between seven to twelve eggs in clutches (small clusters), though it can go as high as 30 eggs. She typically produces about 100 eggs in her lifetime. The hatching of those eggs depends on the temperature. If it is below 71°F the eggs can take as long as 40 days to hatch. But when the temperature reaches 90°F the eggs can hatch in under 20 days. What makes their life cycle unique is that when the eggs hatch, the immatures resemble miniature versions of the adult (think “mini-me’s!) They molt six to seven times before reaching the sexually mature adult life stage. That process can take anywhere from three months to three years! Another interesting tidbit is that adults continue to molt throughout their entire adult life which can last as long as three years, making their total potential lifespan about six years. They are a long-lived insect!
Silverfish have a preference for starchy materials as their main food source, such as paper and wood. They also eat glue used on wallpaper, book bindings, curtains, and carpet. But pests are scavengers and will eat virtually anything available. Silverfish can adapt to a wide range of temperatures, but indoors they are typically found in moist, humid, temperature-controlled areas with temperatures between 72°F to 81°F, including bathrooms, kitchens, attics, and basements. They can become a serious problem in commercial buildings with strict climate control like museums and libraries. Outdoors they can be found in hidden, moist locations including under rocks, mulch, and leaf litter.
Controlling an active silverfish infestation may require the use of liquid and dust insecticides, or both, trying to target potential silverfish hiding places. But professionals should also include insect baits as part of their silverfish control program, since they are designed to attract the silverfish to them without the need to find the source of the infestation, or their hiding places, which can be challenging.
A boric acid granular bait is ideal for use in those non-living areas where silverfish are often found, such as attics, crawlspaces, and unfinished basements. Granular baits do not require precise placement, since the attractants used in the bait will have silverfish seeking it out in their search for food. Boric acid granular baits like InTice 10 hold up well in those less-than-optimal conditions with high heat and/or humidity, as it is mold and moisture resistant.
InTice 10 also provides long lasting protection, up to a year or longer when protected from the elements, since the active does not break down from heat. InTice 10 will also control other crawling insect pests as well. Another major plus of a boric acid granular bait is that it can be applied around the perimeter as it performs well in those hidden, high moisture areas where silverfish are often found outdoors. InTice 10 will last for up to 90 days outdoors, which is perfect for quarterly service programs!
While it can be difficult to find a gel bait that works well on silverfish (because most ant and roach gel baits are not formulated to attract silverfish and therefore, they do not feed on them), there are a few that work well, with one of the more highly effective gel baits called InVict AB. InVict AB is a multi-use gel bait with 0.05% Abamectin as the active ingredient, and it excels at attracting and controlling silverfish along with other crawling pests listed on the label. You only need to apply 5 to 10 pea-size bait placements per 100 square feet in and around areas where the silverfish have been seen. Silverfish will seek out the attractants used in the bait formula. It includes a range of sweet, oil, and protein attractants, and silverfish are known to feed on sugars, protein, and fat so they will feed on InVict AB. It is also a very slow drying bait that will remain palatable for three months or until eaten. InVict AB is labeled for indoor and outdoor use.
The next time you find yourself dealing with a silverfish infestation, make sure to include insect baits in your treatment plan (and not just any insect bait!). They are the perfect complement to both liquid or dust treatments. Just be sure not to apply any residual insecticides around those bait placements to allow the silverfish easy access to them. Don’t forget to tell your customers that they can be part of their own silverfish prevention program by keeping their basements, laundry rooms, and bathrooms dry, repair leaky pipes and drains, store items in plastic containers with lids vs. cardboard boxes, and keep food items like flour and sugar in tight containers in their pantry. Since silverfish require a lot of moisture, using dehumidifiers in closed spaces can also help. On the outside, make sure they look for and seal up all possible entry points into their home and move firewood away from the foundation