There are good reasons to exclude cockroaches from your home. A cockroach will travel through many types of waste then walk over, and defecate on, your kitchen counters, plates, silverware, and any accessible food.
Finding even one roach warrants alertness. All roach problems start small, but roaches reproduce rapidly, so early intervention is highly recommended.
What Do Cockroaches Look Like?
Four species of cockroach are common pests in New York State, ranging in size from 3/8 inch to 1 5/8 inches. All cockroaches have flattened bodies (close to the ground), with an oval shaped shield-like structure (pronotum) that covers the head. Cockroaches have long antennae and thin ‘cursorial’ or running legs that often contain spines. Immature or young stages look like adult cockroaches, but are smaller and lack wings. The four species of concern in New York are:
Adults are tan or brown with two parallel black bands from front to back on the pronotum (behind the head); adults are ½ to 5/8 inch (13 to 16 mm).
They are easily spread with food items, including packaging or shipping materials made of cardboard or paper. Electronics, such as computers, cable boxes, modems and routers are attractive to cockroaches based on the heat generated. Used electronics, including those from major retailers and cable companies, can be a source of cockroaches when they are swapped from one account to another. Finally, German cockroaches can be transported on personal items from homes, where populations are high, to a place of work or school where they might transfer to another person’s belongings.
Reddish brown in color; adults measure an average of 1 to 1 5/8 inch (27 to 40 mm) in length.
Also commonly called “water bugs” and “palmetto bugs”, they are closely associated with sewer systems and drains. These cockroaches can move into buildings on the inside of waste pipes. American cockroaches can also be transferred on cardboard and other items stored near dumpsters. In multifamily housing, cockroaches in a basement can be transported up to individual units on personal items, including boxes and firewood.
Adults and nymphs have two horizontal bands from side to side across the body; similar size to German cockroach: males (1/2 to 5/8 inch; 13 to 15 mm) have wings that cover the body and females (3/8 to ½ inch; 10 to 12 mm) have wings that are short and do not cover the abdomen.
Brown-banded cockroaches prefer warm, high, and dry places. As a result, the brown-banded cockroach can be found throughout a living space, making inspection and treatment for this pest unique.
While this cockroach is not common in the Northeast, they are easily introduced on furniture and other
Adults are dark brown to black, ¾ to 1 1/8 inch (18 to 30 mm) long; male wings cover 3/4 of body, female wings are very short.
Like American cockroaches, this species can infest and move through sewer lines into new areas (including in storm drains during warmer weather). They show up around garbage cans, and may spread during refuse pickup. This cockroach is not capable of flight due to its small wing size.
Don’t see your cockroach?
Several other cockroach species may be found indoors, including the male Pennsylvania Wood Cockroach. The adult male wood cockroach is attracted to lights at night and can end up indoors. However, females do not fly and do not enter homes – making an infestation unlikely.
Accurate identification is needed to determine which cockroach species is present and why.
Should I Worry About Cockroaches?
Cockroaches pose a potential health threat because they can carry pathogens or disease agents on their bodies. If an American cockroach feeds on food residue in a dumpster or travels through a sewer, it may pick up bacteria at that site. If the cockroach then moves onto food preparation surfaces in a kitchen, it can transfer bacteria to food being prepared.
Cockroaches also impact human health in a known and significant way. Proteins found in cockroach feces are allergens that can cause and sustain allergic reactions, including asthma, in children and adults. Even small amounts of cockroach feces can lead to sensitization, while heavy cockroach infestations can and do lead to chronic asthma issues.
Why Do I Have Cockroaches?
Cockroaches are great hitchhikers, and arrive in a variety of ways. The source of a cockroach infestation can differ by each species’ biology:
German and Brownbanded Cockroaches
Cockroaches can be transferred from personal belongings stored in locker rooms.
American and Oriental Cockroaches
American cockroach at a floor drain. Photo: NYSIPM
How Do I Control Cockroaches?
The steps involved in a cockroach management plan depend on the severity of infestation and the species of cockroach. Pest populations are easiest to control when populations are small. The steps below walk through a cockroach management plan from beginning to end. Some steps are needed only when an infestation is present.
Correctly identify your pest
Identify the cockroach: Knowing the species of cockroach can help you figure out their preferred hiding place. German cockroaches, the most common cockroach pest, are often associated with food spillage and moisture in kitchens and, sometimes, bathrooms. American and Oriental cockroaches are associated with dark and damp locations such as basements, sewers and drains. The brownbanded cockroach can be found in dry locations, and may be located in bedrooms, living rooms, offices, and other areas where food crumbs are present.
White cockroaches are sometimes observed in infestations. These are not a unique species, but rather a cockroach that just shed its skin. The cuticle turns darker over the next few hours.
Collect a sample and bring it to a qualified, unbiased organization such as a Cornell University Cooperative Extension office located in each county. Samples can include cockroaches collected on a glue board, or evidence of a cockroach infestation such as droppings.
Look for egg cases: Cockroach egg cases, also known as ootheca, vary in appearance by species. Whereas German cockroach egg cases are tan and elongate, American cockroach egg cases are reddish-brown and bean-shaped.
Note: pest management companies, friends and social media such as Facebook may be unreliable sources of identification.
Look for cockroach parasites: Ensign wasps are egg parasites of American cockroaches. Finding these insects at a window or other light source indicate that cockroaches are reproducing in the facility.
Inspect for cockroach harborage
Cockroaches are cryptic insects that prefer to live in tight, dark spaces such as gaps, crevices and sometimes corners. There may be a few to hundreds of cockroaches in these spaces depending on the population size and the amount of available space. Start by looking close to where you saw cockroaches or their droppings. German cockroaches leave small black droppings on surfaces near a harborage area, while American cockroaches will leave larger droppings below harborage areas.
Use a bright flashlight to look into gaps for live cockroaches, which will likely move when the light shines on them. You can use a spatula or other thin item such as a business card to ‘flush’ cockroaches out from these hiding spaces. Flushed cockroaches can then be vacuumed. A mechanics mirror can be helpful to inspect hard to see places like the underside of heavy furniture and equipment. Keep in mind that cockroaches can move between rooms and floors using utility lines, so be sure to investigate where pipes and wires enter the room to see if the opening would be large enough to allow pests to enter.
Use monitors to document pest activity and reduce numbers
Insect sticky traps are a valuable tool for cockroach management. They can be used to determine what cockroach species is present, if cockroaches are reproducing (different life stages observed), the location of pest activity, and the success of a management program. Sticky trap monitors can be purchased online or in big box stores. They should be placed in enough locations that they provide complete coverage of the area.
Regularly spaced monitors can help identify the clumped distribution of pest populations, and this information can be used to hone in on pest activity and find breeding sites [Image: monitoring]. In addition to providing information, monitors are also a trap that reduce pest numbers. For detailed information on monitoring, see American Cockroach Monitoring.
Considerations: Monitors are useful in all environments to document the extent of a cockroach infestation. However, paper monitors can easily be damaged when used in locations where floors are ‘wet washed’ with a mop or water spray, such as commercial kitchens. In these settings, it is important to ensure monitors are picked while the floor is being washed.
Reduce Cockroach Habitat
Think of pest populations as an indicator of some underlying problem. If food, water and shelter are available, pests can survive. The most important long-term step for managing cockroaches is to remove their feeding and breeding sites, which is achieved through Sanitation and Exclusion, respectively.
- Sanitation can also be defined as good housekeeping. Implementing good sanitation means removing clutter that gives pests harborage and removing food items that sustain pests. Eliminating hiding places and food sources can result in more bait consumption, leading to better control of cockroaches.
- Exclusion seals the gaps that allow pest entry and harborage. There are numerous considerations to implementing an exclusion program, such as material selection, which you can learn about by visiting the Scientific Coalition of Pest Exclusion’s website.
Cockroach management is best achieved through an integrated pest management approach that uses multiple tactics. Methods available for cockroach management are described below.
Glue boards are an effective way to monitor pest populations, the success of treatments, and also reduce pest numbers.
Your vacuum can be used to dramatically reduce cockroach infestations if the harborage location is known. Use the crack and crevice applicator on a vacuum to suck up cockroaches. A knee-high stocking can be used to catch cockroaches and prevent infestations of the vacuum. However, when dealing with large size or large numbers of cockroaches, longer panty hose may be needed to capture the insects. Vacuuming can be combined with flushing (use of a probe or compressed air to ‘scare’ cockroaches out of hiding) to enhance the capture.
Baits are one of the most successful techniques for managing cockroach populations. When placed in the right location and in the right amount, cockroaches will feed on the bait and acquire a lethal dose of pesticide. They can also transfer this lethal dose to other cockroaches in their hiding place through oral and fecal secretions. This is an important consideration for cockroach infestations because reproductive females rarely leave the protection of harborage areas and are unlikely to consume baits. Therefore, transfer of active ingredients from foraging individuals to hidden females is one of the few ways to treat this important group.
- Monitoring is needed to determine how many insects are present and how much bait is needed. Recent research has documented that even with competing food resources, the appropriate amount of bait can control German cockroach populations.
- Baits should be rotated on a regular (three month) basis to products with different modes of action. Bait rotation is an effective way to slow the development of pesticide resistance. For more details, see this University of Florida Factsheet: Assessment-Based Management of Cockroaches, or this PCT Magazine article: Bait Rotation: Crucial to Control.
- Bait aversion is a phenomenon where certain cockroach populations avoid a bait due to the sugar base or flavor used. This is not pesticide resistance, but rather avoidance behavior. If cockroaches fail to eat a certain bait, consider trying a few different products and seeing which ones are fed upon.
Hiring a Professional
If cockroach populations are large and dispersed throughout the living space or apartment building. Professional pesticide applicators have access to a wider variety of products than those available in retail stores, and have more experience in applying these products. Professional applicators may use:
- Insect Growth Regulators (IGRs) that prevent insects from developing and reproducing.
- Crack and Crevice applicators to directly apply products to those tight spaces where cockroaches spend most of their time.
- Dusts applicators to apply insect-killing dusts into locations that stay dry, such as wall and equipment voids that are out of reach for people and pets.
- NOTE: Are pesticide sprays also being used to manage the cockroach population? Some sprays are repellant to cockroaches and can contaminate baits if the two come into contact.