Pestworld Magazine Focusing on the Business of Pest Management
BEETLES
Little beetles are coming out of a drop ceiling in a manufacturing firm’s administrative building that has been treated for rodent issues previously. Every morning they’re falling on to the office manager’s desk, keyboard, paperwork etc. Any ideas?
There is a good chance that there is some type of stored product beetle problem stemming from the use of rodent bait. I would investigate the drop ceiling thoroughly and see if the beetle infestation is coming from leftover rodent bait that was being used to mitigate earlier pest problems. Some rodent baits are grain based and will provide a food source for stored product pests, including beetles.
You may want to momentarily remove the rodent bait or even try replacing the bait with a new bait that is not primarily grain based if there is still a rodent issue in the building. If you are unsure of what bait to use as a replacement, contact your distributor and ask them about baits that do not contain grain as a main ingredient. Elimination of the food source for the beetles should help solve the issue and keep your customers happy when beetles are no longer raining from the ceiling.
I was working in a school today and came across an insect on the strap of a white bookbag on a shelf of books. It looks kind of like a bed bug, with the same body shape but a lot lighter in color, and no one has complained of bites. I also found several small, hairy larvae in the same area. Any ideas on what it is?
There are a few insects that can easily be misidentified as bed bugs to the untrained eye, and carpet beetles are one of the more common culprits. One dermestid beetle in particular, the odd beetle, is unique because the male and female both look very different. The male has hardened wings like most beetles, but the female form has no wings and looks very similar to a bed bug. The larvae look similar to other dermestid beetle species and have hairs covering their bodies.
Like other dermestid beetle species, finding the source of the infestation is imperative for control. Pay special attention to any carpets or rugs around the shelf, as well as items on the shelf—especially if there are any animal products on display. Removal of the source of the infestation should solve the problem.
I have a client who makes high-end guitars from special ordered wood. I found small exit holes in one of the guitars, but am concerned about applying any liquid insecticide. Are there other options for treatment?
It sounds like you may be dealing with powderpost beetles. Educating your customer on powderpost beetles and their treatment options will help guide your decision and will also make the customer more comfortable with treatment of such valuable items. They may have already told you they don’t want the wood treated with a liquid insecticide, so a fumigation chamber may be a viable option for killing any beetles in the guitar if the infestation is still active. It is possible that the wood your customer is ordering was already infested with beetles, so I would recommend the customer contact the wood manufacturing company. Also, do a thorough inspection of any unused wood, looking for more exit holes and frass. I would be concerned about potential infestations in the unused wood, so bringing it to the company’s attention may help the customer get the wood replaced. If the company doesn’t replace the wood, then the customer may also want to fumigate the unused wood to ensure future guitars do not end up with damage.
I collected a few adult beetles from a commercial food-handling facility that looks similar to the khapra beetle. I know the khapra beetle is a serious grain pest, but I am not able to make a positive identification of the specimens. What should I do?
If you ever collect specimens that you are not able to identify, there are several identification options available to you. First, specimens can be mailed into the National Pest Management Association headquarters at 10460 North Street, Fairfax, VA 22030, along with a description of where the specimens were collected and any other information that could be useful in identification. If you need a faster response, your local extension office is another valuable resource that can often provide species-level identification of specimens. However, when you encounter an insect that you believe to be an important invasive pest, such as the khapra beetle, then you should contact the United States Department of Agriculture’s Animal and Plant Health Inspection Service (USDA-APHIS). The khapra beetle is considered one of the world’s most destructive pests of grain products. For this reason, the USDA takes the detection and elimination of this pest very seriously. To ensure that the khapra beetle does not establish in the United States, the USDA has developed an emergency pest response program designed to detect, contain and eradicate an infestation of this beetle. Therefore, if you believe the specimens you collected could be the khapra beetle, then you should contact the USDA to determine how you should proceed.
My client is finding several adult wharf borer beetles per day inside their newly renovated single‑story home. There is no basement, but the house does have a crawl space. I have inspected the newly installed wood in the renovated rooms but cannot find frass or exit holes to indicate where the beetles may be coming from.
Narcerdes melanura prefer to infest wood that is very wet. This can include wood next to water leaks, buried lumber and wood that is in damp cellars and crawlspaces. Because the infested wood is often buried or inaccessible, the frass and exit holes are not easy to find. Therefore, finding damp wood will be the best way to identify the possible source of the infestation. Start by using a moisture meter to search for the presence of damp wood inside the home. If an interior inspection does not turn up anything, the crawlspace beneath your client’s home may be where the beetles are coming from. I would suggest checking the crawlspace for any exposed or buried wood that is damp. If the source of the infestation is found, treat the wood with an appropriately labeled product and correct the moisture issue to resolve the infestation.
My client has an infestation of confused flower beetles in their pantry, but they refuse to allow any pesticides in their kitchen. What other options do I have?
Confused flower beetles, like most pantry pests, can be frustrating to control. This difficulty can be compounded in some cases when a client limits your control options. Luckily, the key to eliminating most pantry pest problems is a non-chemical strategy: find and remove the source of the infestation. Confused flour beetles feed on stored grain products such as flour, cereals, corn meal, crackers, spices, beans, pasta, nuts, pet food and even dried flowers. Begin your search by looking through the kitchen for any evidence that the beetles are feeding on any of these items. If you don’t have any luck in the kitchen, check with your client to see if other items like decorative wreaths or flower arrangements are stored in any other location like the garage or a closet. Once the source (or sources) has been identified, contain it in a sealed trash bag and remove it from the property. Sanitation and storage are also critical steps to successfully controlling confused flower beetles. The infested site should be thoroughly vacuumed and cleaned, paying special attention to cracks and crevices. This eliminates any insects or spilled food that could sustain the beetles. Afterwards, recommend that your client store all remaining or future items in glass or plastic containers that have tight fitting lids. This serves to prevent contamination of existing items, and prevents a possible reinfestation when incoming items are unknowingly contaminated.
One of our commercial accounts is an office building that has had a reoccurring problem with little brown beetles. the adults are about 2.0 mm long with the head and thorax narrower than the abdomen. they only seem to show up on the top floor. i thought this may be a pantry pest, so I instructed the client to seal or remove all dried foods to eliminate potential breeding sites. however, the infestation has not gotten any better. Where should I go from here?
Your description of the adult beetle and its activity around the air conditioning vent suggests that this may be some species of minute brown scavenger beetle (Family Latridiidae). the presence of minute brown scavenger beetles indoors often indicates a moisture problem because both adults and larvae feed on fungi that grow under high moisture conditions. A common source of infestation for these beetles in commercial buildings is roof leaks. I would recommend visually inspecting the ceiling and walls for any signs of water intrusion. this could include staining, sagging roof tiles, and blistering paint. If no obvious signs of moisture damage are present, use a moisture meter to inspect around the air conditioning vents where beetles were previously found to identify any high‑moisture areas. I will point out, however, that a lack of pest activity on or around stored foods does not exclude the possibility that this could still be a stored product pest. Some beetle species that infest dried foods can also survive on non‑food goods such as dried flower arrangements, furniture stuffing, papier‑mâché and book bindings. therefore, you will need to identify the pest to determine the source of the infestation. If you are unable to identify the beetle on your own, the National pest management Association offers a pest identification service to all of our members at no additional cost. Information on where to send pest samples can be found here: npmapestworld.org/member‑center/membership.
I keep finding drugstore beetles in the light traps placed high above the floor in a food processing plant. The plant makes dried treats for pets. Can you explain this beetle and can you think of a source?
The Drugstore beetle, Stegobium paniceum (Linnaeus), most likely was named as such because it was commonly found infesting early pharmacies where dried herbs and other plants were used to compound medicines. Today, it is considered a stored product pest and, as you have noted, it can get into many areas since the adult does fly. You will find it in lights for two reasons. One possibility is that it was attracted to overhead lights or the light in the trap. The second reason is that the insect light trap tray might have a food source such as ingredient dust. These insects don’t feed on insects in the tray as readily as dermestids such as the warehouse beetle, but the tray can be attractive.
As far as sources, don’t expect that the beetles are infesting just the areas near the ceiling. In fact, that is probably not the case. Look for raw ingredient storage and seek out dried ingredients. Also, look for product spills and even food dust on the overhead areas. Don’t rule out minor ingredients such as spices. You can zoom in on an area by installing monitoring devices including pheromone traps. Then removal of the source can be done; if there is infestation on the outside of packaging but not inside, you can heat the material to at least 140° F for several hours. Don’t forget that animal food facilities must be maintained in the same fashion as plants that make human food, so any infestation must be addressed quickly.
I keep finding carpet adult carpet beetles near the windows at my client’s home. She has no carpets in the house, mostly hardwood and tile floors throughout their home with area rugs in some rooms, but I can’t find any signs of damage. Where they coming from and what are are they feeding on?
With the advent of synthetic carpet fibers, carpet beetles are rarely found feeding on carpets in modern homes. The preferred food sources for carpet beetles are natural animal fibers like wool. When carpet beetles earned their common name, many rugs and carpets were woven from wool, where the beetles were often found feeding on and damaging the fibers. With the exception of antique or specialty rugs, natural animal fibers are rarely encountered today.
Carpet beetles, which are members of the family Dermestidae, will feed on other animal products in structures, which is probably what’s going on in your case. Check the property for hunting trophies or animal hides, which may harbor an infestation. In pet supply stores, natural dog bones are often infested, so carefully inspect any treats that you bring home for your pets. Along those same lines, pet hair can also be a good food source carpet beetles. If your customer has pets, recommend that they perform a deep cleaning of the any areas where pet hair might have accumulated, like in the cracks and crevices around floor vents or baseboards. Finally, if the structure has a history of infestation by overwintering pests like, multi-colored Asian lady beetles, brown marmorated stink bugs, cluster flies or other pests, carpet beetles may be feeding on dead insects in the wall voids. It turns out that dead insects are a favorite food for carpet beetles, in fact, entomologists take care to keep them out of preserved insect collections where they can be extremely destructive.
I have a potential customer with a solid oak living room floor and it appears to have a powderpost beetle infestation. How can I tell if it is active and can I perform a topical treatment or do I have to ask them to strip the flooring?
It sounds like the floor has an infestation of Lyctid or Anobiid powderpost beetles. Lyctines prefer hardwoods while Anobiids will infest hardwoods or soft woods. The emergence holes look similar and if the frass and hole walls are light colored, that usually means that the wood particles have not oxidized into a darker color and thus would be considered fresh or active. You rarely see the actual insect. Pay careful attention, for if the holes appear to have any cross sections of galleries, that means that the damage was done by an insect prior to milling and then is not a concern. Some states do require determining if the infestation is active if this is a real estate transaction. If there is question or hesitance on the part of the homeowner, you can photo or mark the holes and return later in the season to see if there are new holes.
If you do decide to treat, most insecticides must penetrate the wood so the polyurethane must be removed for optimal effectiveness. Check the label and manufacturer’s information for more information on how to use specific products.
How do I distinguish between a cigarette and a drugstore beetle?
Cigarette and drugstore beetles are two of the most common stored product pests found in homes. Adults of both species are small (1/16 to 1/8”) and light-brown, they both have an oval shaped body, and their heads are concealed by a hood-like prothorax. They can even be found infesting several of the same foods including flours, dried fruits, herbs and spices.
Despite the many similarities between cigarette and drugstore beetles, there are three key features that can be used to distinguish between the two species. First, hairs covering the body of cigarette beetle larvae are comparably longer than the hairs found on drugstore beetle larvae. Second, the antennae of cigarette beetle adults are serrated, much like the teeth of a saw blade. However, drugstore beetle antennae are not serrated and end in a 3-segmented club. Lastly, the elytra of adult cigarette beetles are smooth, whereas drugstore beetle elytra have rows of pits, giving them a lined appearance.
