Liquid Nitrogen Sprays Freeze Bed Bugs in Italy

THE WORLDWIDE BED BUG infestation, with all its miseries and desperation, has given rise to innovations from common molecules like cold liquid nitrogen gas (N2). Being 78% of planet Earth’s atmosphere and the air we breathe, liquid nitrogen gas is considered by some an ecological bed bug remedy. As John Emsley points out in his book, Nature’s Building Blocks, a copy of which I stumbled upon in Century Books near Pasadena’s Caltech: A bit over 78% N2 gas and the atmosphere goes from breathable to death by asphyxiation. Not that you would breathe better on Mars with its 2.6% nitrogen atmosphere; though neither would bed bugs survive, if leaving the planet to escape the plague were an option.

In its freezing cold liquid form, nitrogen gas freezes bed bugs and most everything else. Besides freezing and preserving genetic materials, liquid nitrogen is used in dermatology to freeze and excise warts, small lesions, early-stage skin cancers, and actinic keratosis. Liquid nitrogen treatments are called cryotherapy or cryosurgery, not because it makes you want to cry out in pain. But rather because cryogenics (physics) is the study of low temperatures. According to the National Cancer Institute, the extreme cold of liquid nitrogen is even used inside the body to freeze and excise cancerous pancreatic and liver cells, childhood retinoblastoma, precancerous cervix disorders (cervical intraepithelial neoplasia) and noncancerous bone tumors.

Italy, which has 400 pest control operators (PCOs) specializing in bed bugs, is the meeting ground for liquid nitrogen and bed bugs, reported Riccardo Biancolini and Guglielmo Pampiglione of the Istituto G. Caporale (Teramo, Italy) at the Entomological Society of America (ESA) annual meeting in Reno, Nevada. As people travel from north to south on trains and buses and stay at hotels or hospitals, Italy’s 21 regions and 50 million people have been exposed to the modern day bed bug resurgence.

The liquid nitrogen spray method developed by Ecotrade(R) (Roma, Italy) is called the Criopest method. Ecotrade’s Criopest method sprays liquid nitrogen at -196 C (-320 F) to freeze bed bugs and other pests. Liquid nitrogen has percolation effects, penetrating pillows and carpets to kill bed bugs. Italian hotels hire specialist PCOs who guarantee 100% results, and like the fact that after 1-2 liquid nitrogen treatments hotel rooms can be immediately rented again. The cost in 2011 was $400-600 euros per room. Well worth it if you are in the room rental business; and less costly than conventional bed bug treatments. The Italians told the ESA that 80% of their clients choose the Criopest liquid nitrogen option.

Liquid nitrogen is usually combined with other methods, as bed bugs are a tough pest to ferret out. As part of IPM (Integrated Pest Management) programs, the cold liquid nitrogen treatment of carpets and bedding might be combined with heat (hot dry air) to kill bed bugs on textiles. Also items to be disinfested are placed in bags with pyrethrin gels for 210 minutes. As part of the multi-modality IPM approach, pesticide treatments (only about 75% effective in 5 days) are also used to leave behind chemical residues in places like electrical sockets where bed bugs, cockroaches, and other pests might hide.

Hotels & Rooms Too Hot for Bed Bugs

HOT HOTEL ROOMS and hot dorm rooms are part of the bedbug buzz at the Entomological Society of America (ESA) annual meetings. There are even indications that hot air remedies can work well in combination with other bedbug control methods, including pesticides and dogs that sniff out bedbugs.

More companies are getting into commercial heat treatments for bed bugs. It seems a matter of practical application of the scientific data that heat can kill bedbugs, if you can figure out how to get the heat to where the bedbugs are hiding. Check out You Tube to see some companies in action using heat treatments against bedbugs, and read the comments (not everyone is convinced).

It is called integrated pest management (IPM) when you combine methods. KTLA News in Los Angeles has an amusing You Tube video combining dogs to sniff out bedbug pheromones with a propane heating device with a fan to cook cockroaches and bedbugs hiding out in rooms. Bed Bug Central TV (BBCTV) is also turning up the heat on bedbugs on You Tube. ThermaPureHeat has one of the best videos, with a Bakersfield heat fumigation job followed by a jazzy closing chorus of “don’t let the bed bugs bite ya.”

Roberto Pereira has been working on hot air fumigation treatments to kill bedbugs in University of Florida dorm rooms during the summer breaks between school years. Heat treatments have a long history of use in entomology (e.g. termites, stored product pests), but it takes some air circulation knowledge and skill.

Pereira and the University of Florida have come up with a short video of their heat chamber idea to disinfest furnishings: “Basically, we put all the furniture of the room at the center of the room, we create an oven around it by using insulation boards, and then inside the box, we put two heaters and fans so that the air is heated and it’s circulated within the box.”

Pereira also tested the combination of hot air fumigation plus “pest strips,” like what you find for sale in supermarkets and hardware stores, for use in EMPTY dorm rooms after all the students have gone home for the summer. You definitely do not want to breathe in the dichlorvos fumes from “DDVP Pest Strips,” particularly when the heat speeds up the chemical release. Though labeled for use at the rate of 1 strip per 900-1,200 cubic feet (25.5-34.0 m3) or no more than 2 strips per room, Pereira cautions that this treatment is for EMPTY rooms in which no one will be living for several weeks.

“DDVP is not something you should be breathing,” said Pereira, who noted that there is a 4-hour per day exposure limit. Indeed, buried in the pest strip label is the following warning: “HOUSEHOLD USES: Use only in Closets, Wardrobes, Cupboards and Storage Spaces. DO NOT USE IN AREAS OF A HOME WHERE PEOPLE WILL BE PRESENT FOR AN EXTENDED PERIOD OF TIME (e.g. Living Room, Family Room).”

Pereira’s work with the easily available pest strips was what is known in science as a “proof of concept” experiment. The idea being that if pest strips worked well with heat, a “softer” chemical, perhaps a botanical or herbal product, could be then be substituted. For scientific experiments, dorm rooms are ideal because they are identical modules. When you start getting into homes with furniture, where every room is slightly different, circulating hot air to kill bedbugs gets trickier.

Box fans placed behind space heaters were used in the Florida dorm room experiments. At 95-97 F (35-36 C), heat killed exposed bed bugs, but bed bugs in hiding (insulated vials) continued living and laying eggs. DDVP pest strips alone, with no heat, took 7 days to kill 100% of bed bugs. With fans circulating heat and pest strip poisons, bed bugs were killed in one day.

Thomas Jarzynka of Massey Services in Orlando, Florida, told the ESA that heat can penetrate walls to kill bedbugs missed by chemical treatments. Two 1,500-watt heaters were inadequate for a hotel room. Jarzynka recommends three 18,000-watt heaters. Besides being energy intensive, temperatures have to be monitored closely to avoid burning furnishings or surfaces. Heat treatments of hotel rooms are started at 7-8 a.m., and temperatures held at 120 F (49 C) for at least 4 hours (sometimes up to 8 hours). Wallboard probes are used to measure temperatures, as it is especially tough to circulate heat to kill bedbugs at carpet level in wall-floor junctions.

Heating a room to kill bedbugs is a bit of an art, combined with some knowledge of engineering and construction materials. Arrangement of room furnishings is critical to heat circulation by fans, said Jarzynka. Fans can be arranged to move hot air along an outer circle, direct heat to a central area, leave cool spots, etc. Rooms can be heated one section at a time, and furnishings can be moved or turned 360 degrees to avoid being burned by heaters.

Bedbugs are tough to get in their hiding places, even with chemicals. So heat treatments, if done right, make good sense. But you need to do your homework, if you want to make life too hot for bedbugs to bite.

Pirate Ships & Trojan-Horse Bed Bugs

BED BUGS PLAGUE houses, apartments, hostels, hotels, motels, barns, caves, and even ships on the high seas. There is no escaping bed bugs, even for frigates, warships, passenger ships and pirate boats plying the world’s oceans. If you doubt it, just talk to U.S. Navy entomologists like David Claborn at the Entomological Society of America (ESA) meetings.

Cockroaches, rats, lice and bed bugs sometimes outnumber sailors on ships at sea. About the time of the American Revolution, in the 1770s, ships were often such damp, putrid, scurvy-ridden pest-holes that half the crew would be sick during the voyage. And mortality was high. Captain James Cook of Great Britain’s Royal Navy was one of the early advocates for bringing ship hygiene up to modern standards.

Scrubbing decks with dilute solutions of sweet-smelling vinegar was one of Captain Cook’s practices to keep rats, lice, bed bugs and cockroaches at tolerably low levels. Caribbean pirate ships, a less sanitary lot, used “primitive fumigation techniques” like placing “tubs full of flaming tar and sulfur inside the hulls to kill the vermin and improve the odor,” said Claborn. Infestations were sometimes so bad that brandy casks were poured onto the decks as mop water and scrubbed into the wood.

In the modern world of asymmetrical warfare in the pirate-ridden waters off the coast of East Africa, bed bugs and other vermin have been used like weapons by the pirates. When a small pirate boat fired a rocket on a U.S. Navy ship, the U.S.S. Fearless, a wooden minesweeper, took action. The Fearless scooped up the pirate boat into its well deck. The well deck, a dock for floating military equipment, was raised up and the pirate ship came to rest high and dry.

“That’s when the insects and the rats started leaving the boat, perhaps lonely for the recently incarcerated pirates,” said Claborn. “When the corpsmen called me from the ship they reported, and I quote this: ‘at least three species of cockroaches, bed bugs, spiders, rats and some really scary things that we don’t recognize’. Our immaculately clean warship now has a Trojan horse populated not with Greek warriors, but with bed bugs, cockroaches and rats.”

Just like on land, the bed bugs and their harborages were hard to find and hard to disinfest. A minor victory for the pirates. All infested shipboard items had to be discarded, all the fabrics washed, and crack and crevice residuals were sprayed to stop the bed bugs from biting.

Bed Bugs, Turning Up the Heat

PESTICIDE RESISTANCE and bedbugs’ innate ability to avoid toxicant contact by hiding in cracks and crevices during daylight hours make alternatives like traps and heat hot topics at Entomological Society of America annual meetings. In contrast to ticks, where researchers have at least investigated biocontrols like micro-wasps, insect-killing nematodes and fungi, bedbug natural enemies have mostly escaped scientific scrutiny and testing.

Rutgers University’s Changlu Wang, an IPM (Integrated Pest Management; using multiple techniques) expert, is better known for his cockroach trapping skills in large public housing and apartment complexes in Indiana. Against bedbugs, Wang uses natural diatomaceous earth in bedbug interceptor traps (Climbup(TM); Susan McKnight, Inc.). This is in addition to clutter removal, bagging and washing infested belongings, new encased mattresses, and steam treatment (vaporized hot water) of floors, drapes and sofas.

Interceptor traps are designed to monitor bedbug infestations, and provide researchers population data. But these bedpost traps are also good control tools: In 10 weeks capturing 50% of the 8 to 1,103 bedbugs per one-bedroom apartment in Indiana. Though bedbugs can still crawl up from walls or behind headboards if a bed is flush against them, or even drop from ceilings.

Unlike “moat” traps surrounding bedposts, interceptor traps have a small container (which Wang fills with 20 ml of antifreeze for insect collection) inside of a larger container that Wang fills with an insecticidal formulation of diatomaceous earth. Future bedbug traps may also be able to take advantage of recently discovered airborne bedbug aggregation pheromones.

At the University of Florida Institute of Food and Agricultural Sciences, Roberto Pereira and others are working on heat fumigation to kill bedbugs. When test tubes containing bedbugs are placed in 111-113 F (44-45 C) hot tubs, these hardy insects survive an amazing 2 to 6 hours.

However, specialized pest control companies in the southern California counties of San Diego and Orange routinely use heat (hot air) fumigation instead of chemical pesticides against drywood termites embedded deep in wooden structures. It requires skill to arrange fans to circulate hot air in buildings. Temperature readings inside the wood are needed every half hour or so to calculate the heat dose needed to cook the insects. If it can be done economically with termites living in walls, heat fumigation can also be done with bedbugs. But expect stiff resistance to heat technologies from established companies with large fixed investments in traditional chemical fumigation skills and equipment.

A cheaper alternative to whole room or whole building heat fumigation is relatively low-cost portable heat chambers. Small heat chambers (e.g. constructed of foam boards) costing $400 or less are already used by the hotel industry, shelters and others to disinfest furnishings. In Florida, portable heat chambers stop the annual spread of bedbugs on preowned beds and furnishings purchased by students. Hospitals have used heat to disinfest wheelchairs of patients too sensitive for pesticide treatments.

Beating the Bed Bug Blues

“SUCH BUGS and goblins in my life,” said Shakespeare’s Hamlet during the medieval era when “bug” meant bed bug. Indeed, bedbugs have been part of the human condition from prehistoric times. By 400 B.C. the ancient Greeks were scratching bedbug bites and singing the Big Bed Bug Blues. Bat caves, bird nests and animal barns are the natural habitats supporting bed bugs and their goblin-like natural enemies like itch mites, assassin bugs, assorted ants, centipedes, and spiders.

Though bedbug biocontrol by the currently-known crop of natural enemies seems better left to the Batcave and more rustic outdoorsy habitats, natural ecological principles still apply in human dwellings. Contrary to the DDT-nostalgia (interestingly, lacking scientific citations) infesting Wikipedia, pesticides cannot substitute for human smarts in fighting bedbugs. Even in the heyday of DDT bed bugs were hard to kill and there was pesticide resistance, Clemson University urban entomologist Eric Benson told an Entomological Society of America (ESA) annual meeting. Indeed, overdoing pesticides is likely to kill natural enemies and stimulate outbreaks of new indoor pests (e.g. rat mites).

An integrated pest management (IPM) approach pits human ingenuity and a multiplicity of tactics against bedbugs. Shripat Kamble of the University of Nebraska told an ESA annual meeting of traditional bedbug remedies rememebered from a childhood in India: “People commonly used in the summertime heat treatment. Keeping the cot outside in the hot sun,” and shaking the bed so the bugs spilled onto bare ground hot enough to kill. “Another treatment that was commonly done was boiling water, and then pouring boiling water through all the hiding areas of the bed bugs…A lot of times it worked, and sometimes we still had problems.”

Nobody, not even the professionals, has a surefire remedy guaranteed to work against bedbugs every time in every household. Like Shakespeare and the ancient Greeks, bedbugs are likely to remain a part of the modern human condition.