Getting to know the Turkestan cockroach

Cockroaches have historically been a top pest and reliable source of business for PMPs.  Indeed, from day one most new technicians are taught to recognize the four most commonly encountered species:

• the German cockroach--one of our smaller cockroaches, bane of restaurants and homes
• the American cockroach (a fast and intimidating insect that looks twice as big as it really is when running across a floor or flying)
• the black, rather nasty Oriental cockroach--pest of sewers and the grounds around buildings
• the smoky brown cockroach, an outdoor cockroach unafraid to venture into homes. 

Other common species, depending on your part of the country, include the Australian, brown, brown-banded, Asian and field cockroaches.

Figure 1. The adult female S. lateralis (A) and adult female Oriental
cockroach (B) are similar in size and color. Arrow points
to the distinguishing light marking on the forewing margin
of the Turkestan cockroach. Photo modified from Kim and
Rust (2013).

In many parts of the country pest management professionals need to add the invasive Turkestan cockroach (Shelfordella lateralis Walker) to their watch list. This Asian invader is quickly making a name for itself and moving through Texas and other states.

Because the Turkestan cockroach looks similar to other species, you may already have seen it and not realized it was something new. Female Turkestans look like Oriental cockroaches. Male Turkestans look like small American cockroaches or perhaps an innocuous field roach.

Spread

The Turkestan cockroach has becoming a significant new pest since it was first reported in Shelford, California in 1978 and El Paso, Texas in 1979.  It has since spread through Arizona and New Mexico, across Texas and even to Georgia.  This week I got my first north Texas specimen, and tentatively identified an emailed photo from Tennessee as a Turkestan cockroach.

Figure 2. To my knowledge, this is the first Turkestan cockroach
recorded from north Texas. Collected from a hotel in Frisco,
TX (VII-29-2019). Note the pale, almost transparent border
at the margin of the forewing, and the size (28 mm/one inch),
which is smaller than a typical American cockroach. Photo
M. Merchant.

If you think this pest won't reach your area soon, think again. Internet commerce is also at work. Turkestan cockroaches are commonly sold online where they are well known in the pet trade as "red runners." They provide food for reptile, amphibian and small mammals. Pet owners like the fact that Turkestan cockroaches breed quickly, do well in captivity and don't climb glass (so are easy to keep in aquaria).

My first North Texas specimen of a Turkestan cockroach came this week courtesy of Emory Matts, with Rentokil Steritech.  Guests at a local hotel recently started complaining of roaches on several floors. Whether this was an invasion from outdoors (males can fly and are attracted to lights at night), or represented an indoor infestation could not be determined.  Though it's often referred to as an "outdoor" insect, the Turkestan is capable of establishing itself indoors, similar to Oriental and American cockroaches.

Competition

Figure 3. Turkestan (A) and Oriental cockroach nymphs.
Notice the reddish-brown thorax and dark abdomen of
the Turkestan nymph compared to the uniform brown color
of the Oriental. Photo from Kim and Rust (2013).

According to Kim and Rust (2013), the Turkestan is replacing the Oriental cockroach throughout much of the Southwest as the most important cockroach pest around the outsides of structures.  Common breeding sites are similar to those of Oriental cockroaches, including water meter and irrigation boxes, electrical boxes, hollow block walls, cracks and crevices in concrete, compost piles and potted plants.  However, it appears that in the warm climates of the Southwest, Turkestan cockroaches rush through their 5 nymph stages faster than the Oriental with its 7-10 nymph stages.  A female Turkestan cockroach will produce about 25 oothecae (egg cases) in her lifetime compared to 5-10 oothecae for an Oriental cockroach.  The numbers tell the story as to why Turkestan cockroaches are taking over.

Distinguishing Turkestan cockroaches

The immature Turkestan roach resembles both Oriental and American nymphs in general appearance (Fig. 3).  The Oriental cockroach, however, is uniformly dark-brown and the American cockroach is uniformly reddish brown.  The Turkestan, in contrast, is reddish-brown on the head and  thorax (pro- and meso-thorax) and dark-brown only on the rear of the body.

Figure 4. American (top) and Australian cockroaches. 
Note the bold markings on pronotum and the
forewings of the Australian cockroach, in contrast
with the American, which lacks forewing markings.
Photos, M. Merchant.

Besides size (the male Turkestan cockroach is smaller), American and Australian cockroaches can be distinguished by both the wing borders and markings on the prothorax (shield behind the head)(Fig. 4).  Forewing margins of the Turkestan cockroach are pale and almost transparent compared to the uniform-colored wings of the American, and the bold yellow margins of the Australian. Click here for another image of male and female Turkestans.

Control

Research on control methods for the Turkestan cockroach is still limited; however control methods should be similar as for the Oriental cockroach. Granular cockroach baits can be effective; however, Kim and Rust suggest that higher reproductive and growth rates for the Turkestan cockroach could mean that technicians should need more bait when treating.  Special attention should be paid to pest proofing doors and other building entry points to keep cockroaches outdoors where they pose the least trouble.

Reference:

Kim, T. and M. Rust. 2013. Life history and biology of the invasive Turkestan cockroach (Dictyoptera: Blattidae). J. Econ. Entomol. 106(6): 2428-2432.

Cockroach webinar worth your time

In case you've never heard of him, Dr. Coby Schal is the Blanton J. Whitmire Distinguished Professor of Urban Entomology at North Carolina State University. As one of the most respected researchers in cockroach biology and management, Dr. Schal is a friend of the pest control industry, and a talented communicator to boot. All this to say that if you ever have a chance to hear Coby talk about cockroaches, you should take advantage.

So here's the good news. On March 2, Cornell University's StopPest program will host Dr. Schal for a cockroach control webinar specifically designed for people working in multifamily housing.  While designed for multifamily apartment managers, this session should also be useful for pest management professionals.

Topics covered will include his research on effective baiting techniques, and ineffective controls like total release foggers (bug bombs).

Schal will talk about how cockroach allergens have been linked to the development and increase in symptoms of allergies and asthma in cockroach sensitive individuals. You'll learn how allergen levels can be significantly reduced with good pest control alone, and how gel bait treatments have revolutionized cockroach management (all good selling points when talking with apartment managers about their need for pest control).

Dr. Schal's work shows how an integrated pest management (IPM) approach with intensive, targeted cockroach control can lead to both dramatic reductions in cockroaches and clinically significant declines in cockroach allergens.

You can register for the webinar at the StopPests Now website. Email instructions will follow after you register.

Flag waving for Americans

I never get tired of reminding PMPs that professionalism starts with good identification skills. One insect that is just rare enough to puzzle most pest control technicians is the ensign wasp.  It is also one of the odder insects found in homes and businesses.

The ensign wasp, Evania appendigaster may be one of the
oddest  looking insects in pest control. Its name comes from
the flag-shaped abdomen that it waves while searching
for its cockroach prey.

The ensign wasp is a quick and nervous little insect.  Black and 5-7 mm long, it is usually found one at a time. Though it might look intimidating with its quick actions and an abdomen bobbing up and down, it does not sting or bite.  It is, in fact, a beneficial parasite that helps control at least three household cockroaches, the American cockroach being the most common.

Ensign wasps are cockroach egg parasites. They are experts at locating cockroach egg cases (oothecae).  According to one account, when the female ensign wasp encounters a cockroach egg case, she first taps it with her antennae, presumably to confirm that it is an acceptable host for her egg.  Then she lies down beside it (I have never heard of an insect voluntarily lying on its side before!) and braces her legs against the ootheca.  After much labor she inserts her slender ovipositor into the tough ootheca and lays a single egg.  After hatching, the wasp larva matures while feeding on the dozen or more cockroach eggs inside each ootheca.  No cockroaches will hatch from an egg case that has been parasitized by an ensign wasp.

The name ensign wasp comes from the unique, stalked abdomen.  Shaped like a sailor's signal flag, the wasp frequently waves her abdomen up and down while stalking her prey as if to say, "Here I am!  Look out cockroaches!"

The oothecae of  American cockroaches are glued in out of
the way locations in walls, attics and other places. A single
egg inserted by an ensign wasp inside the ootheca will prevent
hatching.  Bugwood photo by Gary Alpert, Harvard Univ.

So what does it mean finding an ensign wasp in an account?  It means cockroaches are around. Not just any cockroaches, but one of the larger species of cockroaches (American, Smoky brown, or Oriental cockroaches).  I see one or two of these wasps in my office building every year.  I know they come from the rarely seen population of American cockroaches lurking in the walls and ceilings of our office building--something found in nearly every commercial building.  I like to think that we don't see a lot of cockroaches because we have these little wasps keeping watch.

Nevertheless if you or your customer are seeing these wasps on a regular basis, it might mean there are more cockroaches around than you suspect. Check the crawl space, attic and utility areas.  Make sure that p-traps in the floor drains are being filled with water on a regular basis.  Consider setting out sticky traps and baiting suspected harborage areas such as garages, attics, pantries or utility rooms.

If you are looking for more information to provide your customers about cockroach control, check out the Extension fact sheet Cockroaches and Their Control.

Entomology in Knoxville: Bed bugs, Ants and Others

Bed bugs remained one of the most frequent subjects of
new research reports at the annual ESA meetings.

Continuing my earlier report on goings on at the Entomological Society of America's annual conference...

Total release foggers

In addition to health-related papers, urban entomology sessions covered many practical aspects of pest control. North Carolina State's Coby Schal, one of the top guns in urban entomology, reported on the first field study of total release foggers (bug bombs) for cockroach control. You may have heard of a parallel study done this year by Susan Jones at Ohio State University. She conducted a set of laboratory experiments with total release foggers (TRFs) against bed bugs, the results of which she recently spoke about on PCT's multimedia website.  She found that field collected strains of bed bugs were essentially immune to three common over-the-counter pyrethroid TRFs, and that even highly pesticide susceptible lab strains were largely able to survive when give basic cover as simple as a piece of paper.

Schal pointed out that TRFs are frequently misused by the public, causing four to eight home explosions per year in New York City alone. His lab looked at the impact of two TRFs on both naturally occurring cockroach populations and on "sentinel" cockroaches (lab reared cockroaches contained in open, escape-proof containers) placed in multiple locations in the treated apartments.  While the foggers did kill the pesticide-susceptible, lab-reared cockroaches, they provided little to no control of wild cockroaches (with 200-fold resistance to pyrethroids). In some treated apartments wild cockroach populations actually increased during the test. It will be interesting to see if the U.S. reevaluates registrations for TRFs in the next few years given the safety issues and dismal data coming out of university labs around the country concerning their use.

Bed bug repellents?

Conventional wisdom suggests that there are no repellents that can be sprayed on the skin to prevent bed bugs from taking a blood meal. However Changlu Wang, of Rutgers University, says "not so fast". He looked at the problem from a different angle, pointing out that there are two possible uses for repellents. Besides the traditional use of repellents applied to the skin to keep insects from biting, repellents may also be used off-host to keep bed bugs from climbing onto beds, suitcases, or other inanimate objects.  

Wang and colleagues looked at this second use. They chose several repellents including DEET, permethrin, picaridin, isolongifolenone, and other potential repellents. Although several products showed repellency, DEET was the overall winner. At 10% and 25% concentration, bed bugs were repelled from Climbup Interceptors (guarding a table with a CO2 lure) for 9 hours and 2 weeks, respectively.  While the practical use of repellents in the real world needs more experimentation, this is useful information.  DEET could conceivably be used as a repellent on some shoes (it does dissolve some plastics, so user beware) or booties to reduce the risk of hitchhiking bed bugs being picked up by technicians (or researchers!).  I expect that eventually bed bug control will be supplemented by the use of repellents as a quarantine tool or for "push-pull" tactics to get bed bugs to go where we want them to go (say, to treated harborages).  Wang cautioned that bed bug behavior may be different around a host where attraction to a live host may overcome the repellent effects he saw.

Standardized bed bug testing

One of the biggest applied bed bug research challenges today is how to standardize insecticide testing. It is common knowledge that results for nearly any insecticide can be fairly easily manipulated by selecting the right strains and using protocols that show more or less bed bug mortality. The challenge is to find protocols that are more or less predictive of a product's performance in the field. Mark Feldlaufer, with the U.S. Department of Agriculture/ARS, reported on progress being made to verify fair, standardized testing methods. This research will support the EPA in its efforts to develop standardized test protocols.

He noted that there are currently 318 insecticide formulations registered for bed bug control, 90% of which include pyrethroid insecticides. He noted that not all pyrethroids are equal, and cited as an example transfluthrin (currently unregistered in the U.S.). Transfluthrin has a high vapor pressure, which most PMP realize is likely to provide better control in difficult to reach areas like voids and crevices.  He also noted that a new combination product (metofluthrin plus clothianidin) is in the insecticide pipeline for bed bugs.

Among the USDA findings were that male and female bed bugs are approximately equal in insecticide susceptibility. This finding could allow researchers to use only one sex in tests (avoiding mortality problems with  traumatic insemination by males on females) rather than the 50/50 ratio currently recommended. Also, test results did not significantly change after seven days, suggesting that tests could be terminated after this time.

How to classify and handle insecticide exposed bed bugs is an issue for anyone who has conducted bed bug trials. USDA classified insecticide-exposed bed bugs as alive (A), dead (D), or morbid/moribund (M/M).  The latter group consisted of bed bugs that were not completely dead, but did not behave normally or respond normally to probing. They found that if placed on untreated surfaces after exposure, between 7 and 77% of the moribund bed bugs recovered compared to 100% mortality of M/M bed bugs left on treated surfaces. This information should be useful in helping EPA decide how to require M/M to be handled. It is fascinating, and alarming, how slight differences in the way test subjects are handled and classified can dramatically influence test results.

Other interesting reports

• Susan Jones (Ohio State) reported positive results controlling bed bugs with a new neem formulation (CIRKIL), which, PCT magazine reports, will be available in the U.S. this fall.
• Joe DeMark (Dow AgroScience) reported on field testing of a new Recruit AG above ground bait station for termites. This product will carry 254 grams (one pound) of bait matrix per station. Of nine sites on which it was tested, all termite colonies were determined to be eliminated within four months.
• Mike Rust (University of California, Riverside) reported on studies with the Turkestan cockroach, a species spreading throughout the southwestern states (CA to TX). They found that the Turkestan cockroach is better adapted to dry situations than the oriental cockroach, especially at higher temperatures, and may be expected to displace Oriental cockroaches in hot, dry situations.
• Karen Vail (University of Tennessee) tested insecticides on odorous house ant.  She found fipronil provided slightly superior control to Talstar, and she observed 2-4 weeks control with the new Arilon insecticide (indoxacarb).  She also found that sprays applied with backpack sprayers targeting ant trails and structural guidelines (gutters, ledges, etc.) were as effective in controlling ants as high-volume power sprays.
• Dini Miller (Virginia Tech) reported that a 2011 National Apartment Association survey found bed bugs as the number one concern among apartment owners (beating out concerns over property taxes). Besides control expenses, additional costs due to bed bugs include carpet wraps (to contain bed bugs on infested carpets during removal), need for heavier duty paint (to better cover fecal spots on walls), delays in rental payments, increased evictions, more abuse from residents, and loss of reputation in the community. Twenty states now have laws addressing responsibility for treatment costs for bed bugs.
• In a study reported in the May 2012 issue of Infection Control and Hospital Epidemiology, researchers from Nebraska tested the effectiveness of chlorine dioxide gas as a fumigant for bed bugs. You may remember chlorine dioxide as the gas used in US governmental facilities after the 2001 anthrax attacks. It proved to penetrate cracks and crevices well and kill bed bugs effectively. Chlorine dioxide is used in hospitals for germ control and might find a niche use for battling bed bug infestations in medical settings.
• Margie Lehnert, Clemson University, described a simple but (I thought) ingenious technique for studying bed bug population dynamics. She used nylon stockings inside a HEPA vacuum hose attachment to collect small bed bug aggregations in infested apartments. Once an aggregation is sucked up, the stocking can be removed and tied off and returned to the lab for counting. In this way Lehnert has developed a powerful tool to study population patterns and, perhaps, better infer reasons for bed bug dispersal away from beds. 
• Chris Keefer, Texas A&M University, presented some of the first data I've seen on the invasive, and difficult to control, dark rover ant. This ant is thought to have entered the U.S. from Argentina in Louisiana in 1978. It is now common through most of the southern states.  Keefer, after some difficulty,  has figured out how to colonize these ants in the lab. Using his lab ants he was able to compare the effectiveness of three baits: Terro PCO gel (98% control), Advance Ant Gel (88% control) and Advance Granular Bait (large granules) (58.81% control). The best residual insecticide treatments he found during an outdoor field trial were Demand CS and Temprid, which gave 84% and 82% control, respectively. This confirms what I've heard some PMPs say about effective treatments for these ants.

Of course much more went on in Knoxville than I can report (curse those concurrent sessions!). If I've done no more than convey how exhausting it is to sit for 50 paper sessions (my count), I've given you a taste of what it's like to be there.  Next year's meetings are scheduled to be in Austin, TX, so I encourage some of my Texas colleagues to consider attending. This year the ESA planned a special event for PMPs, including an ACE prep class. Stay tuned for PMP programs for 2013.

Are your customers' kitchens...kosher?

An article in the Wall Street Journal caught my eye last week.  The story follows Rabbi Naftali Marrus, in his duties as a certifying rabbi for OK Kosher Certification, a Brooklyn agency that certifies restaurants, caterers, cafés, industrial kitchens and food manufacturers.OK Kosher Certification is one of a number of agencies that certify foods and food servers follow strict Jewish food laws.

One of Rabbi Marrus' tools is THE INFERNO, a three-and-a-half-foot-long propane torch that produces a flame at least half as long, according to the article photo above.  Rabbi Marrus and his fellow rabbis use the Inferno to burn off the smallest impurities, yeast, leaven and other crumbs, to ensure a kosher Passover meal in certified restaurants.

To restaurant owner Doris Schecter, it's a renewal, "a chance to start over again."  To me it looks like pretty decent pest control. Imagine using one of these babies to rid stainless steel kitchen furniture of cockroaches. Of course one wouldn't want to get too close to a grease-covered wall.