People sometimes struggle to find something positive to say about organisms such as bedbugs and rats. I recently posted that bedbugs are valuable because they provide food for Pharoah ants. In yesterday’s New York Times, there was an article about the value of rats. Gambian pouched rats have been trained to do valuable tasks for humans. In the first case, the rats have been trained to detect land mines. According to the article, “Rats are abundant, cheap and easily transported. At three pounds, they are too light to detonate mines accidentally. They can sift the bouquet of land-mine aromas far better than any machine. Unlike even the best mine-detecting dog or human, they are relentlessly single-minded.” In the second case, researchers found that Gambian pouched rats can smell the difference between tuberculosis bacilli and all the other germs in a human sputum sample. In the American Journal of Tropical Medicine and Hygiene, Dr. Alan Poling (Western Michigan University), conceded that research on the rats was still preliminary. But he said, “We think that eventually there will be a place for them in first-line screening.” Dr. Poling says he likes Gambian pouched rats. “They’re handsome animals, they follow you around, come when you call them,” he said. “If they didn’t have those long, scaly tails,” he added wistfully, “they’d be lovable.”
“Few groups of animals are more feared, and few deserve it less.” (The Spider Book, John Henry Comstock, 1913). Last week, Dr. Paula Cushing, spider expert from the Denver Museum of Nature and Science, speaking to a group of public health specialists, confirmed this opinion. Among the spiders that are native to Colorado, the one having the worst reputation is the black widow. Dr. Cushing brought a “pet” black widow with her (it was in a glass jar), and proceeded to demonstrate just how docile the animal is. You can feed your pet black widow almost any other invertebrate.
The black widow will bite when she is disturbed or threatened, especially if she is within a web. In fact, all spiders are venomous. Spiders bite to deliver their venom. Two criteria are considered when determining whether a species of spider is dangerous to humans: “Are its jaws strong enough to penetrate human skin?”, and “Is the venom virulent enough to cause any serious effects on humans?”
Black widows produce a toxin that affects the nervous system. Common reactions include muscle and chest pain or tightness, restlessness, anxiety, breathing and speech difficulty, and sweating. The pain may also spread to the abdomen, producing stomach cramping and nausea. Swelling may be noticed in extremities and eyelids, but rarely at the bite site. A sense of burning in the soles of the feet is often noted.
Dr. Cushing described how each female black widow spider produces 5 or more egg cases (wrapped in silk to protect them), with up to 300 eggs in each case. This demonstrates that, if your pet widow dies, there will always be another one to replace it.
If you are not convinced that you want black widows around your home or work, the best control is prevention. Periodically check areas where black widows may likely occur. Look near the ground and in dark, undisturbed areas, such as near holes produced by small animals, around low shrubs or around construction openings and woodpiles. Indoors, widows similarly occur in dark areas such as behind furniture, under desks, in undisturbed basement areas and crawl spaces. When discovered spiders can be destroyed by crushing or vacuuming the web and spider. Even though Dr. Cushing did not wear heavy leather gloves, we recommend you do so when looking for spiders!
Today is National Healthy Schools Day, promoting the goal of every child and school employee having a school that is environmentally safe. The Healthy School Network can help parents and others find answers to questions such as these: How do you promote good indoor air quality? Do you tell parents and employees in advance of hazards, such as renovation or pesticide application? How do you respond to complaints? Are the heating, lighting, ventilation, windows, doors, and buses energy efficient? Do you prevent pests without the use of chemicals?
The Colorado Coalition for School IPM help schools use common-sense methods to manage pests. Using Integrated Pest Management, coalition members help prevent pests from becoming a problem in the first place, reducing the need for pesticides. Pesticides (insecticides, fungicides, herbicides, rodenticides) are valuable tools, but are never intended to be a substitute for preventative measures such as sanitation and exclusion.
I have been talking with school district facility managers across the state and am surprised by how many listed termites as a pest problem. While our native species of termite, the arid lands subterranean termite, usually doesn’t cause many problems, the introduced eastern subterranean termite is reported to be increasing along the Front Range, especially in Colorado Springs. There is also a small area in Grand Junction affected by drywood termites that require different management tactics.
Use preventive measures to protect wooden structures against the eastern subterranean termite. These termites usually maintain contact with the soil in which the main nest is found. They construct earthen tubes from the nest to the food source. There should be no contact between wood and the soil. Remove all waste wood from the building site. Move or cap shut with reinforced concrete any cinder blocks, bricks or other hollow masonry in contact with wood and soil. Seal any crack or gap in the foundation or plumbing; these are potential points of entry. Wooden shingles or supports should have at least 8 inches of clearance above the soil or the termites may construct connecting tubes above ground for a short distance. Use pressured-treated lumber in termite-prone areas. “Termite sand” (10-16 mesh sand) has been used as an effective termite barrier under buildings in other parts of the country.
Eastern subterranean termites (USDA, ARS)
If an infestation is discovered, don’t panic. In addition to conventional chemical barrier treatments, existing infestations can be eliminated using a combination of bait stations and low toxicity termiticides. Locate the point of entry and contact a reliable pest control operator. Once an existing infestation has been treated and eliminated, identify and correct conditions in the structure that may have contributed to the problem.
Bed bugs use humans (and a few other critters) for food. Have you ever wondered what eats bed bugs? Dr. G. Buczkowski from Purdue University is finding out. He designed experiments where he placed bed bugs with pharaoh ants and watched the predation. In a scary video, he shows the pharaoh worker ants swarming the bed bugs, feeding off their stored blood and tearing pieces of them off to take back to the nest. The ants especially liked freshly fed bed bugs, but they were willing to eat bugs that had not recently fed, nymphs and even eggs. Now he needs to figure out how to use them effectively as a biological control, and not have the ants become pest problems in homes.
As spring slowly approaches, weeds seem to be the first plants to turn green. If you are practicing integrated weed management, some of the most useful tools are “mechanical” and “cultural” controls. To gardeners and landscapers, this means hand-weeding and the use of mulches. Organic mulches in landscape planting beds not only control some weeds, but also improve soil characteristics, provide nutrients, and enhance property aesthetics. Landscape maintenance professionals sometimes apply a combination of mulch and herbicides to landscape beds in order to provide long-term weed broad-spectrum weed control. However, there are concerns that these herbicides may leach and runoff into urban and suburban streams, lakes and rivers. A recent article (Chris Marble, 2015, Herbicide and Mulch Interactions: A Review of the Literature and Implications for the Landscape Maintenance Industry, Weed Technology In-Press) suggests satisfactory weed control can be achieved with high mulch depths (>7 cm) regardless of herbicide use. Research is needed to determine which herbicides are best suited for different mulch types to improve weed control and reduce environmental impacts.
If you have ever watched CSI on TV, you know that you can use a black light to detect body fluids. This may be helpful if you are investigating a crime scene – or a pest situation. If you have found mouse feces, but have been unsuccessful in catching the mice, you can use a black light to find their trails. Mice mark their trails, and communicate with each other, by excreting small droplets of urine. Mouse urine is full of information about the mouse that produced it: its species, sex, age, reproductive status, sexual availability, social status, individual identity, and current stress level, as well as the age of the scent mark itself. Urine glows under a black light (primarily because it contains the element phosphorus). Setting numerous traps along the favorite routes of mice, as indicated by their urine trails, will increase your trapping success.
Many everyday materials fluoresce when placed under a black light. Fluorescent substances absorb the UV and then re-emit it almost instantaneously. Some energy gets lost in the process, so the emitted light has a longer wavelength than the absorbed radiation, which makes this light visible and causes the material to appear to glow.
Here are some common items that fluoresce: tonic water (actually it’s the quinine), vitamin B-12, some species of scorpions (if you live in the southwest, look for bark scorpions under rocks at night), antifreeze, and some laundry detergents.