Drugstore Beetle (Stegobium paniceum) Integrated Pest Management Plan
This document contains information about the biology and management of the drugstore beetle. A range of management options is listed. From this list, the IPM Practitioner can choose options to develop a unique management plan for each particular customer site.
Management Objectives for the Pest at the Particular Site
What do you want/need to accomplish at the site in regard to the drugstore beetle?
The answer to this question will vary, depending on the site and the customer. Some examples are:
- Prevent or minimize drugstore beetle damage to food.
- Eliminate drugstore beetles from the site.
- Help the customer comply with Health Department regulations.
Drugstore Beetle Identification
- The drugstore beetle is superficially similar to the cigarette beetle in appearance.
- The adult drugstore beetle is about 1/10” long and reddish brown. Its head is somewhat bent down; however, it does not have a humpbacked appearance of the cigarette beetle.
- The drugstore beetle is more elongated than the cigarette beetle.
- The wing covers (elytra) on the drugstore beetle have faint lines running down them, whereas the cigarette beetle’s wing covers are smooth.
- The antennae of the drugstore beetle end with 3 enlarged segments near the tip. Cigarette beetle antennae have the appearance of a saw blade.
- Mature larvae of the drugstore beetle are C-shaped, about 3/16”, creamy white, but do not have the fuzzy appearance of the cigarette beetle.
- Larvae have brown heads and 3 pairs of legs.
Why the Drugstore Beetle is Considered a Pest
- The larvae and adults of this beetle feed on a wide variety of stored food products and drugs.
- They contaminate far more food than they actually consume.
- Many people are unnerved by the thought or actual presence of insects in their food
Special Regulatory Conditions
California Health and Safety Code Sections that relate to cleanliness in food establishments:
114010. “All food shall be prepared, stored, displayed, dispensed, placed, transported, sold, and served as to be protected from dirt, vermin, unnecessary handling, droplet contamination, overhead leakage, or other contamination.”
114030. “A food facility shall at all times be so constructed, equipped, maintained, and operated as to prevent the entrance and harborage of animals, birds, and vermin, including, but not limited to, rodents and insects.”
114040. “The premises of each food facility shall be kept clean and free of litter, rubbish, and vermin.”
114050. “All food facilities and all equipment, utensils, and facilities shall be kept clean, fully operative, and in good repair.”
Biology and Behavior of the Drugstore Beetle
To be successful, management strategies must take into consideration the biology and behavior of the pest. Understanding the biology of a pest can reveal weaknesses and vulnerabilities that can be exploited when trying to manage the pest.
- Drugstore beetles go through 4 distinct stages of growth: egg, larva, pupa, and adult.
- The adult female can lay up to 75 eggs in the larval food.
- The larvae feed and when mature, make a little round cell in which they pupate.
- Inside the cell, the larva transforms into an adult.
- The life cycle takes from 2 to 7 weeks to complete and is affected by both temperature and the food source.
- Adults can fly and therefore can infest materials at a distance from the original infestation.
- These beetles are capable of chewing through paper, cardboard, plastic, wood, and even lead sheets.
- The drugstore beetles harbors symbiotic yeasts in its body that produce B vitamins. This enables the insect to subsist on many foods of low nutritional quality.
- Larvae and adults feed on
- Prescription drugs
- Grain and grain products such as flour, meals, cereals crackers, cookies, bread, cake mixes, pasta
- Beans and peanuts
- Coffee beans
- Nuts and seeds, including birdseed
- Dries herbs and spices
- Powdered milk
- Chocolate and other sweets
- Herbarium specimens
- Dried flowers
- Dry pet foods
- Dried fruits
- Fish meal
- Dried insects
- Books and manuscripts
- Leather, wool, horn, and hair
- This beetle is found in pigeon nests.
Factors that Favor the Drugstore Beetle
- Improper storage of food products that leaves these materials vulnerable to infestation
- Failure to inspect food products and their packaging before storing
- Storing food items for lengthy periods of time
- Poor sanitation in food storage areas
Monitoring and Record Keeping
The purpose of monitoring is to track pest activity in order to catch small problems before they become overwhelming. Monitoring makes it possible to pinpoint pest activity so treatments can be targeted. Monitoring also makes it possible to properly time pest management actions and to evaluate the effectiveness of those actions. Records are kept to document the methods and products used and to record information that can be used to fine-tune pest management methods and plan future actions.
A commercially available sticky trap that is baited with a pheromone will capture male beetles. This can be used to monitor for the presence of this pest.
Supplies should be stored up off the floor on pallets or shelves and away from the wall at least 18” to allow for thorough inspections.
The “tolerance level” is the number of beetles that triggers action to control the pest. The tolerance level is site-specific and differs depending on the customer, the location, and other factors.
Determining the tolerance levels for a site helps prioritize work that must be done to control the pest.
Management of drugstore beetles is largely a matter of sanitation. Heat and cold can be used to kill the insects directly.
To limit availability of food
- Immediately clean up and dispose any spilled food or other items attractive to stored product pests. This is important in storage areas as well as loading docks and other transportation areas.
- Keep food storage areas clean. This includes areas where pet food or birdseed is stored. Regularly vacuum shelves, floors, baseboards, etc. to remove whole grains, grain fragments, flour, seeds, crumbs, and other debris. Pay careful attention to all cracks and crevices.
- Thoroughly clean food preparation and eating areas daily, paying special attention to crumbs and other susceptible foods that may fall behind or under appliances or into cracks and crevices in workspaces.
- Dispose of or treat (see below) infested items immediately.
- Throw away or treat (see below) infested decorative items.
- Store food products in insect-proof containers, such as metal, glass, or heavy plastic. The containers must have tight-fitting lids, preferably with rubber gaskets. This is especially important once packages are opened; however, these beetles can chew through many kinds of packaging, so unopened packages may not be pest-proof.
- Store food items in a cool, dry location.
- Date incoming supplies and use the oldest first.
- Buy supplies in quantities that can easily be used in less than 2 or 3 months, unless they can and will be stored in a freezer.
To limit shelter/harborage
- Inspect incoming supplies:
- Check packages for damage and a tight seal
- Check package due date for freshness
- Check packages for insect evidence such as webbing or cocoons
- Remove food packages from their cardboard shipping containers before storing, to eliminate hiding places.
- Caulk or otherwise seal cracks and crevices in food storage areas, in cabinets, walls, floors, baseboards, etc.
Physical controls employ physical means to remove beetles from the structure or to kill them directly.
- Vacuum regularly to remove potential food, infested material, and stray insects
- Treat infested materials with cold or heat. Spread material in shallow pans to make sure all of it is thoroughly heated or cooled:
- 4 to 7 days in a freezer at 0°F
- 5 minutes in a microwave
- 2 to 3 hours in an oven at 120°F to 130°F
- At 180°F death is rapid
- Pheromone traps can be used for monitoring and pinpointing the infestation, but not control.
Chemical controls are not recommended for drugstore beetles.
The IPM Partnership
The PCO-Customer Partnership is Very Important
IPM works best when the customer and Pestec form a partnership to tackle the pest problem. Drugstore beetles cannot be managed satisfactorily without the cooperation of the customer, especially in the area of sanitation. Pestec will discuss the findings of the initial inspection and any subsequent monitoring sessions with the customer to determine which issues and tasks will be the responsibility of Pestec and which will be the responsibility of the customer.
Information is a powerful tool in IPM. Information can help change people’s behavior, particularly in how they store food and dispose of waste. Changing these behaviors is a necessary part of managing stored product pests. Occupants of buildings and homeowners can also help in the early detection of pests so that Pestec can be alerted before the problem is severe.
Pestec’s highly trained and knowledgeable staff can provide pest management education or training sessions for facilities managers, risk managers, building occupants, homeowner associations, and others.