Cockroach Research

Cockroaches have survived for millions of years in various forms, with species of roaches today numbering around 4,000. It should not be surprising then that scientists continue to study the resilient cockroach - a pest that seems to be able to adapt and live through whatever nature or humans throw at it. In fact, throwing things at cockroaches is at the core of a new study on how cockroaches keep their predators guessing.

According to a report in Science Daily, when roaches flee from predators they seem to run randomly along one of several preferred escape routes. Their very unpredictability aids their escape from harm. This alone seems intuitive - but these bugs have been studied for many years as a model for understanding animal escape responses. Apparently, cockroaches most often choose an escape path directed at a 90 to 180 degree angle from the attack. Trying to stomp on a fleeing cockroach? This only gives you a slight advantage - they are among the fastest of insects.

In another study, 50 roaches were placed in a situation where they had a choice of three hiding places, each with a capacity for 40 cockroaches. When startled, the bugs ran to two of the hiding places, leaving the third empty. If given a choice that included a shelter that would house them all, they preferred the one shelter and left the other two empty. They seem to use two pieces of information to decide on where to hide: (1) How dark is it? and (2) How many friends are there? We use the term "friends" loosely, as there is no evidence that cockroaches live in social groups.

If you are interested in knowing more about cockroaches and studies about these small creatures, click here for a bibliography of cockroach books and articles.

Preparation for Cockroach Control - or What not to do!

To the left you see an actual note left by one of our customers who was unable to be there when the technician arrived. She had a serious German cockroach infestation, and wanted us to just spray EVERYTHING! The problem was that she had not done the requisite preparation so that we COULD spray everything that needed to be treated. Dishes and food were in cabinets and in the sink, clutter was everywhere. Her hope was that we could blast the roaches with a magic killing force, and she would clean up afterward. Unfortunately, that is neither safe nor effective - nor legal!

In as effort to better communicate what needs to be done by homeowners and residents with bug problems preparatory to our treatment, here is the list for cockroach preparation and a few explanations.

1. Remove all contents of kitchen and bathroom cabinets. Stack contents in a room other than the kitchen and bathrooms and cover with a sheet, blanket, or similar material. This means the kitchen and bathroom cabinets need to be empty and clean. Food, dishes, pots and pans or other kitchen items should not be stacked on kitchen counters or on the floor of the kitchen. We need complete access to the empty and clean cabinets. Legally and professionally, we cannot spray food or dishes  - or anything left in a cabinet. If you decide to leave things in cabinets, there will be no protection against cockroaches in that area. Often customers believe the cockroaches are isolated to one area of the kitchen. This may be true. But to do the best job possible, please let us have access to all cabinet areas. 

2. Remove all kitchen drawers from the kitchen and cover. Please make sure that drawers and their contents are clean before returning them. Sanitation is one of the biggest items in cockroach control. Cockroaches can live off the crumbs in a drawer or the grease behind the stove. Thorough cleaning gives them less to eat and fewer places to hide.

3. If closets are infested, remove all items from the floors of closets and push clothes to the center. We will treat baseboards as available throughout the house.

4. If you have a fish tank, please cover it with a towel, sheet, or similar material, and turn off all aeration equipment until the pest control application has dried.

5. Please be prepared to vacate for at least four hours following treatment. Do not return materials to kitchen or bathroom cabinets until the application has completely dried. DO NOT clean out cabinets with wet materials until control has been established to ensure active material is not removed after treatment. You may use a brush or vacuum to remove dead cockroaches. Once the chemical is dry, it is safe to put food and dishes back in the cabinets.

6. Do not expect all roaches to die immediately. Cockroach control is a process. Even after thorough cleaning and pesticide application, you may expect to see live cockroaches for three weeks. Adult roaches will die within a few days, hatch-out will occur in 10-12 days. We use chemicals with excellent residual effect, which will continue to eliminate new hatches and eventually eradicate the problem. If you are still seeing live roaches at the three week point, please call for a follow-up service. 

 When chemicals are applied according to their label, risks are within limits found acceptable by state and federal government regulatory agencies. Working together, we can solve all kinds of pest problems!

Cockroach Quiz Answers

Here are the answers to yesterday's Cockroach Quiz. How did you do? Hopefully, the answers will help you understand some of the habits and control methods for cockroaches.

1. Cockroaches have (c) membranous wings, whereas beetles have hardened forewings (elytra). This does not mean that all cockroaches or all beetles can fly. If you want to see pictures of the various kinds of cockroaches most common in California, there are pictures and descriptions here. To the best of our knowledge, none of the cockroaches common to San Diego click when disturbed. Beetles, not cockroaches, are related to lady bugs, and feed on plants and fungi.

2. An adult German cockroach can fit through an opening as small as (b) 1/16th of an inch. An immature cockroach can fit through an even smaller opening. Part of exclusion involves sealing cracks and crevices in kitchens and bathrooms, where cockroaches can hide.

3. The egg cases of cockroaches are called (b) oothecae. HEPA (a) is an acronym for High Efficiency Particle Absorber - the kind of  vacuum filter suggested for use in vacuuming up roaches to avoid allergic reactions. The pronotum (d) is the shield-shaped section on most cockroaches located behind the head - another way to tell it is a cockroach and not a beetle.

4. German and Oriental cockroaches are the most common varieties seen in San Diego. Oriental cockroaches are (b) larger and darker in color than the German variety. Oriental cockroaches prefer cooler weather and survive well outdoors; American cockroaches can fly.

5. In controlling an infestation of cockroaches, (a) sanitation and exclusion are most critical. No amount of chemical treatment will eliminate a cockroach population without sanitation and exclusion. Keep food in tightly covered containers, clean kitchen and bathroom cabinets and walls, keep trash areas outside clean and garbage cans with tight fitting lids, eliminate piles of newspapers, paper bags, and boxes inside and outside the house, fix plumbing leaks, seal cracks to the outside, and check weather stripping on doors and windows.

6. Monitoring stations are helpful in identifying the origin of a cockroach infestation. It is wise o place monitoring stations in (d) the backs of kitchen cabinets, behind the refrigerator, and in corners of rooms.

7. One of the inherent problems with effective chemical control of cockroaches is (c) cockroaches can develop a resistance to chemicals used frequently or improperly. Cockroaches can actually pass along some resistance to their offspring if liquid chemicals are sprayed too frequently. Integrated pest management involves sanitation and exclusion, and the use of chemical applications used according to label directions.

8. The answer is (d) - all of the above. Cockroaches can carry salmonella, hepatitis or staphylococcus germs. Far from harmless, these invaders can put your family at risk for these and other diseases. If you have an existing problem which you cannot solve yourself, call your pest professional.

Cockroach Quiz

Today's Tuesday Quiz will test  your knowledge of one of our least welcome pests: Cockroaches. If you have been following this blog, you already know how quickly they can multiply.  Now try some cockroach questions that may help keep these common pests at bay.

1. Cockroaches and beetles may look alike, but they have different habits and attributes. Which of the following are common only to cockroaches?

a. Cockroaches make a clicking sound when disturbed.

b. Cockroaches are related to lady bugs.

c. Cockroaches have membranous wings.

d. Cockroaches feed on plants and fungi.

2. Cockroaches are nocturnal. They like to hide in narrow, warm, dark places. How small a hole can an adult German cockroach fit into?

a. 1/32 of an inch

b. 1/16 of an inch

c. 1/8 of an inch

d. 1/4 of an inch

3. Cockroaches sometimes glue their egg cases underneath furniture, in appliance motors, or under kitchen shelves or drawers. What is another name for cockroach egg cases?

a. hepa

b. oothecae

c. larvaettes

d. pronotum

4. The difference between German and Oriental cockroaches is:

a. German cockroaches prefer cooler weather and live mostly outdoors.

b. Oriental cockroaches are larger and darker in color.

c. German cockroaches can fly.

d. all of the above.

5. In controlling an infestation of cockroaches, which of these methods are most critical?

a. sanitation and exclusion

b. trapping and baiting

c. exclusion and spraying

d. spraying and baiting

6. Monitoring stations help identify where the origin of an infestation of cockroaches is located. Where is the best place to put monitoring stations?

a. in the backs of cabinets in the kitchen

b. behind refrigerator

c. all corners of rooms

d. all of the above

7. What is one of the inherent problems with effective chemical control of cockroaches?

a. not putting enough chemical in place

b. chemicals evaporate and become useless

c. cockroaches form a resistance to chemicals used frequently or improperly

d. chemicals can't sterilize cockroaches, so they continue to reproduce

8. Which of the following diseases can be spread by cockroaches?

a. Salmonella

b. Hepatitis

c. Staphylococcus

d. all of the above

Answers to today's quiz will be posted in tomorrow's blog.

The Great Race

Cockroaches were in the news again today, as a race between two giant Madagascar hissing cockroaches took place in New Brunswick, New Jersey yesterday. What made it newsworthy was how the roaches were named and how they finished. The New Jersey Pet Management Association included the race as part of their annual clinic and trade show. And the roaches were names John McCain and Barack Obama. According to one news release, McCain "sped to the finish while Barack Obama was reluctant to leave the starting point." There's no guarantee the race is a prediction of things to come in November, but you have to like their style. Madagascar hissing cockroaches get their name their place of origin, the island of Madagascar off the eastern coast of Africa, and from the loud hissing sound they make to scare away predators. They are large in the roach world, up to three inches long, and are sometimes kept as pets. Although they are not a pest control problem here in San Diego, we knew you'd want to know they are doing their part for national politics.

Doing the Math on German Cockroaches

As mentioned in a previous post, German cockroaches are not actually from Germany, but Asia. In fact, they are closely related to Oriental cockroaches. They are smaller (1/2-5/8 inch long) than some other species of cockroaches, and they live and hide easily indoors. But German roaches have an advantage over other varieties in their ability to reproduce in large numbers. Perhaps this is why they present such a challenge to homeowners and pest control management. In an effort to quantify the biological potential, lets do the math.

A basic formula for estimating how many roaches are produced per year from a pregnant female is to multiply the number of embryos per egg case by the number of egg cases produced per year. For instance, one pregnant American cockroach may have an average of 16 embryos in her egg capsule. If she lays 30 egg capsules, 16X30=480  mature adults in about a year. By contrast, if we start with one pregnant German cockroach that has an average of 30 embryos in her egg sack, and she lays 5 egg case, we would have 30X5=150 mature adults - in three months! If half the adults are female and they all mate, in 6 months we would have 75X30X5  mature adults. The number is now up to 11, 250, in half a year. If half those adults are female... you get the idea.  Saving you the math, one pregnant adult German cockroach could multiply into more than 63 million cockroaches in  a year, if left unchecked. Potentially, a German cockroach can out-produce an American cockroach by 131,000 times. 

Fortunately, we have management techniques to keep up with these common invaders. Insecticides that contain Insect Growth Regulators interrupt or inhibit the life cycle of the insect targeted. Sometimes called "birth control for roaches," these chemicals can be a valuable tool in limiting the biological potential of a cockroach population. If the bug can't reach adulthood, it can't reproduce. When combined with an adult cockroach killer, the results are significant. However, insecticides are most effective in controlling cockroaches when combined with sanitation and exclusion. Baits can also be useful, but are slow-acting and also require thorough cleaning to remove any other attractive food sources which may draw the bugs away from the bait. There is no easy or quick solution to a cockroach problem, but as the numbers indicate the best plan is to attack the problem before it becomes a nightmare - which in the case of German cockroaches, will happen quickly.

American Roaches

The summer of 2008 has brought the nationalistic fervor of the Olympic Games into our homes as we watch athletes from all over the world compete. But one American team we can't bring ourselves to cheer for is the American Roach - especially if the team shows up in our own home. Common cockroaches in San Diego County include the German cockroach (most common, also known as a "house roach"), the brownbanded cockroach, the oriental cockroach, the smokybrown cockroach, the Turkestan cockroach, and the American. We are highlighting the American Roach today, not because we're hoping he wins gold, but because we have had an increase in the number of calls reporting this particular variety. Pictured above are three stages of the American cockroach, (r-l) the adult, the nymph and the egg sack, or "ootheca." American roaches are larger than the common house roach, typically 1 to two inches in length, and brown in color.

We find more American roaches in downtown San Diego than in other areas - perhaps because the buildings are older or because of the higher concentration of commercial buildings. They are often associated with plumbing problems, as they favor warm, damp locations and are known to infest sewers, storm drains, basements and trash areas. Here are a few ways to limit their access to your home:

Have a plumber check to be sure pipes are in good repair throughout the house.

Check weather stripping around doors and windows, and seal any cracks or openings to the outside of the house.

Keep landscape bushes and vines trimmed, especially near vents. 

Store trash in covered containers well away from the house.

Where practical, use gravel around the perimeter of the house.

Store food in insect-proof containers.

Properly dispose of stacks of newspapers, magazines, bags and boxes.

If you find you have an infestation of American cockroaches, clean and dry out areas where they have been seen, and call a pest professional. Baits and insecticides are useful elements in an integrated pest management approach,  but must be used with the above suggestions to gain control. To view a video on exotic varieties of cockroaches, visit the Natural History Museum website, here. Or if the Olympics have put you in an international mood, click here to view a "Crazy Japanese Cockroach Commercial."

Cockroach Nation

A recent news story from  Turkmenistan reported that the country's president had fired thirty workers at the main state TV station after a cockroach was seen running across the news desk during a nightly news broadcast. People do get passionate about cockroaches - and not in a good way. The specimen we have pictured below is the  most common of roaches, the German cockroach, or Blattella germanica. Not much Germanic about them, these pests actually originated in Asia. They can enter your house in a bag or box from the grocery store, or ride along on a piece of borrowed furniture - and can be devilishly hard to get rid of, especially in multiple-unit complexes. But contrary to the message of this video, control can and should be achieved if pest management techniques and simple housekeeping are used. 

Many sprays and baits are labeled for use against cockroaches in California. If you opt for baiting, there are some facts you should keep in mind. Roach baits attract the pests, then feed them a poison which the insect takes back to the nest to share with his friends. Bait should be applied with caution so as not to come in contact with food or dishes. If there are other sources of food readily available to the cockroach, it may or may not eat the bait. And Cockroaches will eat just about anything - garbage, cooking spills, even the grease on a kitchen wall can support life. A more certain approach is to hire a pest professional to apply a contact spray in cracks and crevices in a clean kitchen environment. What this means is that homeowners need to empty and clean kitchen and bathroom cabinets, and remove or cover trash areas before the bug guy is called in. Residual insecticides last for up to two months, continuing to kill roaches as they hatch. Control can take three to four weeks in the case of a serious infestation. One more tip: setting off "bug bombs" is usually a bad idea. Some cockroaches may die, but the ones that survive will hide in unusual and hard-to-treat places. The best tip on cockroaches is to get rid of them before they take over the house!