Question: There are tiny insects that crawl through our screen doors and bite or irritate my arms and legs. What are they and how can I control them?
Answer: I looked under the dissecting scope at these insects and saw a piece of dirt. It looked like the smashed body and leg of a flea-like creature but was unidentifiable because of the poor specimen. Later a local pest control operator was called out to the home. He sprayed indoors and around the house. After a week the gentleman was still "affected" by these insects. The pest control man was disappointed because he said this was the first time he had ever failed to control the target pest. I explained to him that in these types of cases there are not any insects involved. No insects are found in Arizona that feed on living human flesh. Mosquitos, ticks, fleas, lice, kissing bugs, and others feed on mammalian blood. What occurs, primarily in the elderly, is the skin becomes dry, because of reduced skin oil production. Low relative humidity can also cause dry skin. With the onset of winter forced-air and other types of heaters are used, further drying out the air.
Control: Liberal use of your favorite lotion, moisturizing bath soaps, and lip balm are advised to alleviate dry skin.
Question: My wife and I have several bites on our arms and legs. I have a sample of the insects that I think caused these irritations. Could you please tell me what they are and how to control them?
Answer: After examination under a dissecting microscope it was determined that they were insects from the Dermestidae Family. There are several species known as carpet beetles and furniture beetles. They can do great damage to home furnishings and clothes containing wool, hair, fur, feathers, or other animal products. They can also survive on dead insects and food products such as cereals. The adult insects are rarely more than 6 millimeters long except the black carpet beetle, which can be 12 millimeters long and are broad or an elongated oval in shape. When they are disturbed they play dead. The adult black carpet beetle is black with brown legs, but other species can be black to brown in color and may have a dull red band running down the center of the back. Others may be mottled with patches of white, yellow, and black and are light colored underneath. The larvae of all species are oval except the black carpet beetle, which is elongated with long tufts of golden to chocolate brown colored hairs at the end of the body. Other species are covered with black, brown, or tawny hairs and three tufts of bristles on each side of the posterior end. Adult beetles can fly and are attracted to light and are often found crawling on curtains and windows. On warm spring days they will feed on pollen of flowers and may fly from house to house. Females will lay up to 100 eggs which will hatch normally in 8 to 15 days. Larval growth depends on temperature and food supply and molt 6 to 10 times or more. The old exoskeletons are often seen on clothing and furniture and may cause itching in sensitive people. The pupal stage may last almost 2 weeks. The life span period from egg to adult depends on environmental conditions and species, but can be from 126 to 657 days. Usually there are only 1 to 2 generations per year.
Control: Remove or cover food sources like grain or animal food. In this case open dog food was the insects feeding source. If infestations are severe then treatment with residual pesticides may be necessary, but carpet beetles may be difficult to kill. Treat only the edges or under carpets and around baseboards and floor moldings. Tank-type vacuum cleaners may be helpful in reaching cracks and crevices to eliminate sources of food and developing life stages. Source: Insect Pests of Farm, Garden, and Orchard, 7th Ed. Ralph H. Davidson and William F. Lyon. 1979. pp.518-520.