Editor’s Note: This article originally appeared in Entomology Today, a project of the Entomological Society of America with the goal of reporting interesting discoveries in the world of insect science and news from various entomological societies. To learn more, visit www.entomologytoday.org.
We know the moon can do it, but what about a swarm of locusts?
On Monday, Aug. 21, 2017, denizens of North America looked skyward to witness a solar eclipse — the first in which the path of totality would cross the contiguous United States since 1979. Those who have witnessed a full solar eclipse say it defies description.
Likewise, those who have witnessed a swarm of locusts say it is also a bewildering sight — deemed a “plague” since biblical times — and popular descriptions often allude to the darkening of the sun in the midst of such a swarm.
So, is it true, or just hyperbole? We turned to an expert entomologist to try to find out.
Hojun Song, Ph.D., is an associate professor of entomology, specializing in arthropod systematics and biodiversity, at Texas A&M University. Among his current research portfolio is a National Science Foundation-funded project examining the evolution of locust species to understand why some form large swarms and others do not. Locusts are a type of grasshopper species that, under the right conditions, shift from a typically solitary lifestyle to a “gregarious” one, in which they gather, breed prolifically and migrate en masse. Two widely studied species are the desert locust (Schistocerca gregaria) and the migratory locust (Locusta migratoria).
In the course of that work, Song has seen one locust swarm with his own eyes, on Socorro Island in Mexico.
“It was a rather small swarm, but enough to make it a surreal experience,” he says. “You have millions of locusts flying above you. All you hear is their wing flaps. Because it was a small swarm, it was not like a cloud and it certainly did not block the sun.”
But what about the big swarms? Song offers some back-of-the-napkin calculations to estimate whether locusts could genuinely block out the sun:
“A very large swarm can contain up to about 80 million locusts in a square kilometer, and the size of swarm can reach up to several hundred square kilometers. Let’s do some calculation. Each locust is about 6-8 centimeters (cm) in body length, with a wing span of 8-10 cm. For simplicity, let’s just assume that each locust in flight can occupy about 64 square cm (8 cm body x 8 cm wing).
“If there can be as many as 80 million locusts in a square kilometer, that means there can be 8,944 locusts in a linear kilometer (calculation: square root of 80,000,000 = 8944.27191). If we line up all locusts wing to wing, the total length would be 0.71552 kilometers (km) (8,944 x 8 cm = 71552 cm = 715.52 m = 0.71552 km). Likewise, if we line up all locusts from head and abdomen, the calculation will be the same, 0.71552 km.
“This means that the physical area occupied by 80 million locusts, if they are all next to each other horizontally and vertically, is just a little bit over 51 percent of a square kilometer (0.71552 km x 0.71552 km = 0.5119688704 square km).
“Of course, locusts do not fly side by side touching each other’s wings, and the swarm is three dimensional, meaning that some locusts fly above others. Eighty million locusts per square meter is a lot of locusts, but they are not dense enough to block the sun.
“I think that, even with a very large swarm, with the size reaching several hundred square kilometers, you should still be able to see the sun without any issue.”
So, there you have it. A swarm of locusts is no solar eclipse.
But locusts do eat, so the impact that 80 million of them (again, that’s just per one square kilometer) have on vegetation and crops can be hugely destructive. Song’s research seeks to understand the roots of their swarming behavior, in hopes of better informing potential control efforts.
“There are more than a dozen locust species around the world, but we really don’t know much about how and why they swarm, except for two well-studied species, the desert locust and the migratory locust. Swarming locusts have evolved multiple times and different locust species have different mechanisms for forming swarms. And what we have learned from these two species does not necessarily apply to other locust species,” Song says.
“Locusts are the only mass-migrating pests that can have a very quick devastating result to people. In this day and age, we still do not have a very good way to predict and manage these pests. This intrigues me quite a bit,” he added.
Dealing with invasive species in our industry has become more and more common. Some of the more notable ones, such red imported fire ants, Africanized honeybees, Asian lady beetles, brown marmorated stink bugs and Formosan subterranean termites, to name a few, have become common, if not even daily, occurrences for us in the industry. Take a moment to look up only the list of invasive insect species, not counting mammals and reptiles, and it will blow your mind how many of them you deal with all the time. As the world becomes smaller through travel and commerce, the risk of new, non-native species being introduced into the U.S. is always a possibility.
The Turkestan cockroach, Blatta lateralis (Walker), also known as the “red runner” or “rusty red” cockroach, is an invasive species found primarily in the southwestern United States. WAIT! Before you say, “Well, this doesn’t concern me; I don’t live in the Southwest,” read on. Turkestan cockroaches are a native species to areas of the Middle East through Central Asia. Their distribution includes countries like Afghanistan, Pakistan, Iraq, Iran, Saudi Arabia, southern Russia, and now, the United States. But, how much of the U.S. they have already moved to and how far can they go, we really don’t know. That’s the thing that can be fascinating and, to some degree, unpredictable when a non-native species is introduced into an environment. How will they adapt to environmental conditions to which they have not been previously exposed? Will the new conditions restrict them or allow them to flourish even more robustly than before? What effect does their emergence have on other established species?
The Turkestan cockroach was first reported in the U.S. in 1978 at Sharp Army Depot in Lathrop, Calif. Shortly thereafter, in 1979, they were reported at Fort Bliss in El Paso, Texas. Other reported sightings through the early 1980s in Arizona and Southern California were documented, as far east as Fort McPherson in Georgia in 2005. OK, so let’s put two and two together. Middle East. Military bases. Yep, you guessed it. Transport of military equipment and supplies from the Middle East is the most likely explanation for the initial introduction.
The next question is, “What will the potential distribution pattern across the U.S. look like?” Well, the distribution pattern could be literally as wide as the internet. Turkestan cockroaches have become popular with reptile breeders as a food source for their animals. You can go online and have 25 to 35 Turkestan cockroaches shipped right to your home for less than $10. (Except in Florida, apparently. They think they have quite enough cockroaches already!) The attraction of this species of cockroach is its hardy, easily maintained nature. It is also unable to climb smooth surfaces, and breeds rapidly in large numbers. This could be the first time in history that an invasive urban pest species is widely distributed through the internet by sales of live insects.
So what’s the big deal? It’s just another cockroach, right? Not quite. The Turkestan cockroach has become the primary peridomestic cockroach in the Southwest United State by displacing the Oriental cockroach. This has been achieved in a relatively short amount of time, probably due to the Turkestan’s relatively short time span to mature from an egg to adult. In addition, the female Turkestan will produce many more oothecae during her life span than the Oriental cockroach.
BIOLOGY. Adult females produce between 2 and 25 oothecae over their life span. The male and female nymphs go through five molts, maturing into adults in an average of 222 days. In lab settings, many of the adults live for at least 13 months after being paired together. These reproductive and life span rates under the right conditions may well outcompete other common peridomestic cockroach species, such as the smokybrown and American, as it has done to the Oriental cockroach in the Southwest U.S.
In Arkansas, there has been a dramatic increase in sightings, as well as the size of the populations found since 2013. We went from two known locations (both near a U.S. Air Force base), to 29 cities, with some reporting multiple locations within the city, in 2017. I’m sure there has been some distribution of the species during this time; we also may have improved our identification process, which may contribute to the sudden apparent explosion in sightings.
Most of the information published about Turkestan cockroaches lists outdoor locations as the most common places to find them, such as water meter boxes, center block walls, compost piles, leaf litter, potted plants and, occasionally, sewer systems. While this holds true in many cases, we are just as commonly finding them in relatively large numbers on the interior of structures, under and behind baseboards and door frames, wall voids, around hot water tanks and sinks, around floor drains and coolers of bar areas, and even in drop ceilings. Could finding large populations on the interior of structures be an adaptation to the regional environmental conditions?
TREATMENTS. Some of the published material on Turkestan cockroaches, as well as interviews with PMPs in the Southwest U.S., claim bait formulations are readily accepted. In our region (Arkansas) where Turkestan cockroach activity has been found, we have had inconsistent acceptance of baits. Several different gel, granular and dry flowable formulations have been tested. One observation was that only the males would show any interest in the bait, while other populations seem not to be attracted to bait products at all. With bait formulations not performing reliably across the board, we have shifted our treatment strategy to dust formulations, primarily in harborage voids. This approach has provided the most consistent treatment results for our clients. However, the main drawback to this method is the fact that you may flush out 40 to 50 cockroaches that are each 1 to 2 inches long.
CONCLUSION. In our industry, you never know what’s on the horizon. Maybe that’s what makes it so enjoyable for so many of us. It will be interesting to see how Turkestan cockroaches move across the United States over time and adapt. Could they possibly become a mainstay pest in our industry? Or, does Mother Nature’s checks and balances kick in and Turkestan cockroaches fade away into obscurity? Time will tell and lessons will be learned, of that there can be no doubt.
Reference: Life History and Biology of the Invasive Turkestan Cockroach, Tina Kim and Michael K. Rust, Journal of Economic Entomology, Volume 106, Issue 6, 1 December 2013, Pages 2428–2432.
Copesan is an alliance of pest management companies with locations throughout North America. To learn more, visit www.copesan.com.
Christian Wilcox, A.C.E., is the technical director for McCauley Services in Central Arkansas. He is chair of the Copesan Technical Committee, serves on the NPMA Technical Committee and is an ESA member.
Colorado Tri-Flo released the Tri-Flo 120 20 Amp bed bug heating solution that kills bed bugs in rooms around 120 square feet, the firm says. This solution comes with two ER1800, 110-volt, 20-amp heaters, a high-temperature fan and a laser infrared thermometer.
“The Tri-Flo 120 20 Amp provides bed bug solutions for smaller-size rooms. It also provides the ability to turn a small room into a bed bug heating chamber, killing bed bugs where they live and breed,” said Ron Elsis, vice president of operations. “Don’t let the size of the ER1800 heater fool you. Each heater has only one plug, weighs 16 pounds and puts out 6,150 BTUs. Two of these heaters easily raise the temperature in a small room to over 121°F, sufficient to kill bed bugs.”
Bird Barrier recently launched two bidding apps to its website: The Product Advisor and The Quick Quote.
Product Advisor helps PMPs to find the best product solution for any bird problem. This tool narrows your selection down based on three questions: What kind of bird is causing your bird problem? What are the birds doing? Where are they doing it? After completing these questions, Bird Barrier’s most effective product solutions will pop up, starting with the best. After choosing the right program based on the Product Advisor, Bird Barrier’s Quick Quote can help determine an estimate.
Quick Quote helps PMPs get a quick estimate so they can gauge the customer’s interest before making a final proposal. It is an easy way to get a feel for how much the project may cost, and whether the customer is able to make the investment, Bird Barrier says. The estimates can be saved for future use. The Quick Quote process includes:
- Name the project, and the area on the building
- Select the product to be used
- Enter the length and width of the ledge, or area to be protected
- Rate the complexity (from “Easy” to “Hard”)
- Enter an estimate in dollars for cleaning
- Enter an estimate in dollars for lift rental
- Enter your company’s hourly rate
- Press “Calculate” and PMPs instantly will have useful information
The Quick Quote will display a price range, not a final quotation that can be discussed with the customer. If the customer is willing to learn more, the company should conduct a thorough inspection, measure accurately, create a materials list, and assess the costs of labor, cleaning, lift rental and other variables, Bird Barrier says.
Each Quick Quote result can be saved, and is automatically emailed to the user so it can be shared within the company.
The UCT-15 is the newest innovation of Gardner Fly Lights. This light is an ideal fit for mounting under bars and counters to help with fly control, the manufacturer says. Additionally, this portable light can be mounted horizontally or vertically on any wall or placed on top of any flat surface. The UCT-15 comes with an easy-to-use mounting bracket. PMPs simply secure the bracket to any flat surface and slide the backside of the light onto the bracket, Gardner says. Mounting locations include: near trash compactors, on countertops, under bars, under counters, in entryways and in hallways. The UCT-15 is easy to service as well, with two 3- by 11-inch glueboards that slide in and out of the ends of the unit. Available in multiple colors, including green, black and silver, the UCT-15 will easily blend into customers’ decor, Gardner says.
The fly light attributes include:
- 24-hour, non-chemical trapping
- Energy-efficient UV Insect Lamp (15 watts)
- Easy-to-use mounting bracket
- Five-year warranty
Central Life Scienceswww.centrallifesciences.com
The Zoëcon Professional Products division of Central Life Sciences announced the launch of Lava-Lor Granular Bait. The company says this new addition can be used indoors and out, providing effective control of cockroaches (excluding American cockroaches), crickets, nuisance ants (excluding carpenter, fire, harvester and Pharaoh ants) and other listed crawling pests through multiple modes of action.
“Lava-Lor Granular Bait is ideal for tough cockroach and cricket infestations in sensitive sites,” said Tony Schultz, business manager for Zoëcon Professional Products. “This solution provides pest control professionals with quick knockdown in an easy-to-apply bait.”
Lava-Lor Granular Bait features two active ingredients: hydramethylnon and imidacloprid. This ready-to-use bait is approved for indoor void and crack-and-crevice treatments in sensitive areas, including food handling and processing facilities. Lava-Lor Granular Bait also can be used to control listed pests outdoors for turf and perimeter treatments with no “watering-in” necessary. Available in two sizes, a 10-ounce bottle and 25-pound pail, the new bait can be used in a bait station, or applied via shaker or spreader for flexible application options.