These small beetles feed on a wide range of animal and plant products, being severe pest problems in stored foods as well as on wool, hides, furs, feathers, or other materials with animal hair origins. They feed commonly on dead insects, and this may be the attraction to structures, where the beetles find leftovers in wasp nests, ant colonies, termite colonies, or bee hives, as well as accumulations in window sills. They are destructive to collections of insects or animals in museums. The length of time from egg to adult varies widely depending on temperature, humidity, and food quality, but appears to average around 275 days, extending to almost 2 years in some circumstances. Adults live for around 1 month.
Carpet beetles in general are patterned in mottled, checkerboard, or wavy lines with black, white, gray, brown, or orange colors. They are only around 2 to 3 mm long, flattened from top to bottom, oval in shape, and very compact, with no separation between the prothorax and the elytra. The Varied Carpet Beetle is the most common in the western U.S., and it has the typical coloration and a “checkerboard” pattern, and the elytra meet at the posterior end with a straight juncture. The Furniture Carpet Beetle is identical to the Varied, but where the elytra meet there is a small concave notch or “V” at the juncture. The larva of the Varied Carpet Beetle is brown, very hairy, with several enlarged tufts of hairs at its tail end, and is much wider at the tail end than at the front.
Control of carpet beetles begins with storing susceptible food or fabric materials in containers that exclude the adult insects. Prevention also centers around removal of abandoned insect, rodent, or bird nests that may contain leftover skins, feathers, or hairs that the carpet beetle larvae feed on. If the infestation is in progress a thorough inspection to determine the source is needed, prior to the application of any pesticides. Pheromone traps exist that may facilitate the inspection and monitoring process.
This beetle is found throughout the world, including in all of North America, where it is no longer found commonly as a food pest. This may be due partly to the better storage of meat products, which were often subjected to attack by this beetle.
Typical of the family Dermestidae, the Larder Beetle attacks a very wide variety of products, from meat to grain products, cheese, tobacco, cereal and pet food products, as well as scavenging on dead insects and animal byproducts such as hair or wool. Females lay around 150 eggs in the food material or in crevices nearby. The larvae feed until they have completed 5 to 6 molts and are ready to pupate, at which time they often move from the food and wander off to find a protected place to pupate, often boring into solid materials for this stage. Development from egg to adult normally takes about 45 days, and one generation per year is normal.
The Larder Beetle has distinct coloration on the adult, with the prothorax and posterior half of the elytra dark grayish brown, and the front half of the elytra yellow. Six dark spots appear on this yellow area. The shape is somewhat elongate and oval and around 8 mm long, fairly large for stored food pests.
The Larder Beetle has become less of a pest of importance with the proper storage of meat products, although it also feeds on dead insect accumulations in structures, and its presence may be linked to this type of a source. Inspection to determine the source of the beetles and disposal of the infested material are necessary.
Thought to be native to Egypt, where it was found in the tomb of King Tut, this beetle now is found throughout the world.
Closely related to the Drugstore Beetle, the Cigarette Beetle will infest virtually any food product of vegetable origin, including baked goods and spices. It also is a severe pest of stored tobacco or tobacco products. It will bore into books, objects stuffed with straw or flax, dried flower arrangements, and other odd materials. The adult beetles can fly well, but they do not feed. Each female beetle can lay about 30 eggs, and the time from egg to adult is about 2.5 months, with up to 6 generations in one year in warm climates, only 1 generation in colder climates. Adult beetles live about one month.
Like the Drugstore Beetle, the Cigarette Beetle has its head strongly deflexed, or hidden under the prothorax, and when not walking it assumes somewhat of a “C” position. It has a more reddish color and is shiny, due to the very small pores on its exoskeleton. It is a very small beetle, usually around 2 mm long or less. The antennae are very different from its cousin, in that they are serrate, with all the segments the same size and shape, and without an enlarged club at the end.
Preventing the pest from getting a foothold is extremely important, given the rapid reproductive rate and wide varieties of foods attacked. Proper stock rotation and storage practices are needed, including storage in a cool, dry condition if possible to slow down the reproductive rate of beetles that do enter.
There are 3 species of box elder bugs in the U.S., and they are common insects found throughout the U.S., feeding on various species of maple, ash, box elder, apple, grapes, and many other plants. They feed by inserting their long proboscis into the plant tissues and removing fluids, but are rarely present in such numbers as to cause any problems for the trees. The major issue with the BEB is its annoyance and presence inside structures, where it commonly seeks an over-wintering site and may occur in large numbers. It moves inside in the fall and returns to the outside in the warming months of spring, but often will become active on warm winter days as well, and be seen running around inside. It may attempt to bite if handled, but is not dangerous to people. In the fall the insects begin congregating on walls, fences, and other sunny locations. They then seek entry points to enter the structure where they settle within voids. They will not feed or reproduce indoors, but lay eggs only on the plants outside. Inside, however, they may leave stains from fecal droppings on surfaces, and if crushed will emit the same characteristic odor of other “true” bugs. Females deposit eggs in clusters of about a dozen eggs per placement, for a total of about 250 eggs. Development from egg to adult is about 2 months, and there are two generations per year.
The insects are about one half inch long and elongate oval in shape with the dorsal side flattened. Their color is dark, dull gray with red lines along the sides of the prothorax and along the veins of the wings. When at rest the wings are held flattened over the abdomen, with one wing crossing the other. Each forewing has the inner half distinctly different from the outer end, with the outer half more membranous, and with the wings folded a distinct “X” shows on the top. Nymphs begin as wingless, bright red insects, gradually turning to gray as they mature. The BEB is very similar to common “milkweed” bugs, which have broader red lines and often white spots on the thorax.
The BEB feeds primarily on the developing seed pods of the box elder and maple trees, and planting male box elder trees will eliminate this food resource and make the trees less attractive. Identifying entry points and permanently closing them will reduce the numbers that are able to enter and identifying harborage sites indoors and treating, if necessary, may kill them inside. The occasional insect found wandering in the winter should be vacuumed.
Species of powder-post beetles occur in many countries throughout the world, easily being transported in infested wood products.
It is believed that Lyctus species feed only on hardwoods and not softwoods such as the conifers. They feed primarily in the sapwood of the tree where the starch content is highest, and starch may be the principal food of the larvae. Adults do not feed. Bamboo and wicker products also are commonly attacked. Infested products within a structure may be re-infested for many generations of the beetles, eventually reducing the wood to little more than dust, and potentially moving into other susceptible wood products around them. In an outdoor environment the winter is passed in the larval stage, and as spring approaches it moves near the surface to pupate. Once the adult beetles emerge they mate almost immediately and lay eggs within only a few days, the female placing the eggs into pores in the wood or old emergence holes, using her long ovipositor. The time from egg to adult can range from 3 months to 1 year, depending on the species of the beetle and the environmental conditions.
The fecal material of Lyctus beetles often is diagnostic, as it falls freely from the emergence hole of the adult once it is exposed to the outside. This fecal material is extremely fine and powdery, having almost no grainy consistency to it. Feeding channels of the larvae tend to follow the grain of the wood without branching, and emergence holes of the adults are small and round. Adult beetles range from 2 to 7.5 mm in length, and colors from reddish to brown to almost black, depending on the species. They are very similar to flour beetles, but can be distinguished by the more elongate shape, the longer, thinner antennae with a distinct 2 or 3 segmented club, and by the prothorax which is wider at the front than at the back. In addition, the top of the prothorax has a concavity running front to back in the middle.
Control of most beetles that infest structural wood begins with using clean, un-infested wood so the insects are not built in. For beetles that can re-infest the wood they emerge from elimination usually relies on fumigation, although heating or freezing of smaller objects may be effective. Removal and replacement of the infested wood is also effective where it is practical.
If you have a beetle problem and would like to have a Craig Thomas Pest Control, in partnership with Orkin Pest Control, representative speak to you, give us a call! Contact us by phone 800-255-6777, email for your free inspection today!
We at Craig Thomas Pest Control, Inc. are grateful to Univar Profession Products and Services for pest information incorporated into this work.