Friday, December 21, 2012


Silverfish in the order Thysanura are one of the most common household pests found in North America. They are considered cosmopolitan which means they are found nearly Worldwide. Unmistakable in appearance with a teardrop-shaped wingless body, three long projections coming from their posterior end and two long antennae located on their head. Silverfish reach lengths up to 3/4 of an inch, and are covered in tiny scales and usually soft bodied. Their common name of silverfish comes from the silvery-blue coloration and their fish-like movements. These are incredibly fast insects capable of extreme short bursts of speed. They typically hang out in areas of high humidity including basements, bathrooms, garages and closets, but may also be found in attics, bedrooms and other parts of your home. They are nocturnal and prefer to remain hidden from humans, therefore infestations are rarely noticed until they are large in number. Humidity levels between 75% and 95% seem to be ideal for optimum population growth and survival.

They feed on a wide variety of substances but prefer carbohydrates in the form of sugars and starches. Diet may consist of glue, book bindings, plaster, photos, paper, sugar, coffee, carpet, clothing and even dandruff. But they will also consume proteins, silk, cotton and synthetic fibers. It is this feeding preference that gives them pest status as they can cause damage to many of our valuable items. They are capable of living up to a year or possibly longer without eating, and in times of famine may turn to other forms of food for sustenance such as meat. If you discover an infestation of silverfish you will need to contact a pest control agent to treat your home in order to get rid of them. Some claim to have good luck with using cinnamon or nutmeg as a repellent to keep them away from certain areas of your home. Although these household spices will not kill them, it may afford you some comfort in keeping them at bay. Silverfish are also prey for arthropods such as earwigs, house centipedes and spiders.

Other methods that may help prevent or control silverfish infestations are:

  • Keep bookcases clean by vacuuming and shaking out books occasionally
  • Prevent the stockpiling of newspapers
  • Reduce the humidity in the basement and laundry room with a dehumidifier
  • Store starched linens in sealed plastic bags
  • Repair leaky pipes and patch openings around pipes and conduit
  • Periodically clean out closets, cabinets, and storage containers
  • Keep dry processed foods in containers with tight lids

Silverfish are one of the longest lived insects, living from 2 to 8 years and are capable of producing up to 100 offspring in their lifetime. Reproduction is an elaborate affair that consists of a mating dance where the male will approach the female and they will face each other touching antennae. The male will back away and return and once again touch antennae. This may be repeated numerous times. Then the male will run away from the female and the female will pursue him. Once she catches up to him the male will line himself up beside the female so that their tails touch. He will begin vibrating his tail against the female. This stimulates the male to release a spermatophore and stimulates the female to take the spermatophore up into her body. Once the eggs are fertilized she will lay them from one to 60 at a time in small clusters hidden away in tiny cracks or crevices. It takes the eggs from two weeks to two months to hatch.

They will be born looking nearly identical to the adults in appearance, except they will be white instead of silvery-blue. They gain the silver coloration as they age and molt. From 3 months to 3 years they will reach adulthood and will continue to molt even after reaching adult age. They may molt up to 66 times in their lifetime, and some specimens have been documented molting 30 times in a single year! That is highly unusual for an insect.

Even though they are not known to bite humans or carry diseases that can be spread to humans I still kill them each time I find them. I normally let all bugs live, and even if I don't want them in my home I just take them outside and turn them loose. But I have a huge book collection and cannot risk the silverfish damaging them. 

Monday, December 3, 2012

Silver-Spotted Skipper

With the unseasonably warm weather we've been experiencing here in NW Missouri it puts me in mind of spring and butterflies. One of my favorites is the very common, yet beautiful Silver-Spotted Skipper (Epargyreus clarus). When I say common, I literally mean dirt common, they are everywhere in the spring and summer all over Missouri. They can be found in backyard gardens, open fields, prairies, parks, you name the place and these butterflies are sure to be there.These butterflies belong to the family Hesperiidae, which are the skippers. Silver-spotted skippers are the largest skipper in North America with a wingspan up to 2 5/8 inches. This may not seem large, but by skipper standards it is quite huge. Most skippers have a wingspan of one inch or a bit more.

Identifying them is much easier than other skippers which can be confusing even to the experts. Silver-spotted skippers are chocolate brown with orangish blocky spots on the forewings and silvery-white spots on the underwings. It is this silvery-white spot that earned them their common name.

Like all butterflies they are diurnal, flying about during the day nectaring at a wide variety of flowers, including clover, coneflowers, thistles, blazing star and others. They seem to prefer flowers that are red, pink, purple, blue or white. At night they rest underneath leaves of plants or trees which effectively hides them from night creatures that may want to dine on them. It will also shield them from heavy overnight dew.

With few exceptions, butterflies are often part of the diet of many predators including birds, frogs, small mammals, and spiders. Exceptions would be monarchs, pipevine swallowtails, etc. that glean toxins from the plants they consume as caterpillars. Skippers have no such toxins and therefore fall victim to many predators. Spiders in particular are excellent at capturing these butterflies as they hide on flowers waiting for passing butterflies to alight and begin nectaring. The spider will very stealthily approach the butterfly, unseen, and reach out with their front legs and sink their fangs in and give a venomous bite, This bite is designed to subdue the prey and turn the insides of their prey into a nutritious, liquidy, buggy milkshake that the spider will slurp up with relish.

(Flower crab spider feeding on silver-spotted skipper)

Males will perch on branches of low lying bushes or on tall plants to wait for females to fly by. Once a receptive female has been mated, she will lay eggs one at a time on the leaves of the host plant which are black locust, honey locust, and false indigo. With all the honey and black locust trees found throughout the state it explains why these butterflies are so prolific in our state. They certainly have plenty for them to eat. Even the drought we have been experiencing since June did not affect them to the degree it did other butterflies and insects. For obvious reasons, droughts are hard on all animals, even insects. With no rain, plants cannot grow or continue to produce. This causes a lack of food sources available to the females, so therefore there will be no subsequent generations until the rain returns. 

Who knows with the 65 and 70 degree weather we've been having, I might not have to wait until spring to see a butterfly.