Month: October 2020

Just in time for Halloween, insect zombies! Mind-altered crickets, ants, beetles, flies, and cicadas

 

Next spring Massospora fungi will zombiefy periodical cicadas, taking control of their minds and behaviors while turning their abdomens into buff-colored fungus gardens.

Next spring Massospora fungi will zombiefy periodical cicadas, taking control of their minds and behaviors while turning their abdomens into buff-colored fungus gardens.

 

For a variety of reasons, Halloween is one of Bug of the Week’s favorite holidays. In years past we have visited many bugs dressed in orange and black including monarch and Gulf fritillary butterflies, milkweed bugs, assassin bugs, and milkweed tiger moths not to mention several scary spiders like black widows, recluse spiders, and tarantulas.  But what could be more fun and in sync in the year of the pandemic than a visit with some zombie insects? These are not the kind of Haitian voodoo zombies where a corpse is reanimated by a bokor to conduct some dastardly deeds. Nor are these the ilk of George Romero’s zombies intent on consuming flesh of other insects, as in the Night of the Living Dead Insect. Nah, insect zombies are more akin to zombie apocalypse creatures, hapless victims of a mind-altering pathogen directing deadly actions to further the spread of its own kind. In a delightfully ghoulish paper, D. Donald Steinkraus and colleagues define zombie insects as “… insects infected with an entomopathogen or parasite that alters their behaviors and morphology in ways that benefit the pathogen or parasite.” Boom, insect zombie apocalypse!

Crickets committing suicide

Crickets become “suicidal” after being infected by horsehair nematode worms. Click here to see images of horsehair worms.

Crickets become “suicidal” after being infected by horsehair nematode worms. Click here to see images of horsehair worms.

One amazing case of an insect zombie involves a European cricket called Nemobius and a horsehair worm called Paragordius. To breed, the horsehair worm must encounter its mate in water. However, the nematode’s eggs are laid near riverbanks where they are often ingested by hosts in which they will develop, arthropods including Nemobius. Inside the cricket, the parasitic nematode grows to its full extent which may be more than 5 inches. To complete its life cycle, the parasite must return to water and here is where the zombification part of the story happens. By a mechanism not yet fully understood, the nematode takes control of the cricket’s mind and alters its behavior, forcing the cricket to wander from its usual dank habitat into open, brighter areas until It encounters a body of water. The water body could be natural such as a stream or pond or human-made such as a swimming pool. The latter is where scientists documented a second bizarre behavior. Upon encountering the swimming pool, infected crickets took a “suicidal” leap into the water. By making the cricket take a plunge, the nematode can escape from its cricket host and seek a water-bound mate to complete its life cycle.

Ants take a drive from treetops and lock-jaws on leaves

Ready to release their spores, parasol-like fruiting bodies of Ophiocordyceps rise from the corpse of their zombie ant host. Photo courtesy of David P. Hughes

Ready to release their spores, parasol-like fruiting bodies of Ophiocordyceps rise from the corpse of their zombie ant host. Photo courtesy of David P. Hughes

Several species of fungi also play mind games with their insect hosts. Zombie ants often make splashes in the news. These unfortunate creatures were first described by famed naturalist Alfred Wallace more than a century and a half ago. Zombie ants are found in tropical forests on many continents and in temperate forests in South Carolina and Florida. Zombie ants are members of the genus Camponotus, commonly known as carpenter ants. The carpenter ant destined to be a zombie is arboreal, spending most of its time high in the canopy of a tree. Occasionally, to get from one tree to the next, it must descend to the earth where spores of the fungus Ophiocordyceps lie in wait. Upon contacting the surface of the ant, these spores awaken and bore into their host. As the ant ascends back into the treetop the fungus, which has now reached the brain, causes the ant to spasm and tumble to the ground. Like the slow moving, foot dragging ghouls in Romero’s films, the fungus causes the zombie ant to seek a microhabitat with just the right conditions of temperature and humidity for the fungus to survive. Once the location is found, zombie ants ascend a plant and use their powerful jaws to lock onto the midvein of a leaf in a “death grip.” Some 4 – 10 days later a fungal fruiting body erupts from the body of the dead ant and releases infective spores into the environment to await the next victim. Widespread infections by Ophiocordyceps sometimes produce massive graveyards of zombie ants.  

A soldier beetle’s last salute

Other species of fungi gain mind control over other insects including flies, beetles, and cicadas. Soldier beetles, a.k.a. leatherwings, are cousins of fireflies. Like other members of this clan, soldier beetles are natural born killers in both adult and juvenile stages and are highly beneficial insects to have around the garden. But it is not all fun and games for soldier beetles in the garden during cool moist seasons. A fungal pathogen called Eryniopsis lampyridarum lurks in the landscape waiting to infect soldier beetles. Once the beetle unwittingly picks up a spore from the landscape, the spore germinates and penetrates the exoskeleton of the hapless beetle. Inside the beetle it multiples and takes control of the beetle’s nervous and muscular system, turning it into a zombie. The fungus causes the soldier beetle to march to the upper leaves of a plant in a behavior called summiting. There the beetle clamps onto a leaf with its jaws and dies. Spore producing structures within the cadaver cause the beetle’s abdomen to swell and in a grisly final act, the wings of the beetles open to expose the swollen abdomen, a final postmortem salute.  This allows fruiting bodies to erupt from the upper surface of the beetle and spew their spores into the environment, where they disperse and infect other victims.

When normally active soldier beetles become infected with Eryniopsis, they do a zombie walk to the tips of leaves, grab onto leaves with their jaws, and die. After death, the fungus within causes their wings to spread, facilitating the release of spores into the environment.

Dead flies deceiving hapless suitors

Seedcorn flies infected with Entomophthora climb high on plants. Their grotesquely swollen abdomens are attractive to male flies that will attempt to mate with them, thereby becoming infected and furthering the spread of Entomophthora.

Seedcorn flies infected with Entomophthora climb high on plants. Their grotesquely swollen abdomens are attractive to male flies that will attempt to mate with them, thereby becoming infected and furthering the spread of Entomophthora.

Cool, wet springs also spawn legions of seedcorn maggots, a pest of many horticultural and food crops including soybeans, corn, peas, onions, potatoes and beans. As temperatures warm, peril awaits adult seedcorn maggot flies. Hiding on the springtime vegetation are infective spores of a fungus called Entomophthora muscae. When the fly alights on vegetation, unseen spores attach to the surface of its exoskeleton. When the right combination of temperature and humidity conspire, spores hatch and fungal hyphae penetrate the skin of the fly, establishing a lethal infection. Once inside its host, the fungus invades the fly’s tiny mind and body transforming it into a fly zombie.  By taking control of the fly’s nervous system, Entomophthora causes the doomed, but inherently fidgety fly to move ever more slowly upward and outward on a plant until it creeps to its final resting spot at the tip of a leaf or branch. From this elevated perch, the fungus erupts from the skin of the fly and spews spores into the air, all the better to distribute its spawn on vegetation where other flies will inadvertently become infected.  In a related species of fly, the common house fly, Musca domestica, another strange twist happens in this zombie insect tale. The fungus infection causes the abdomen of a fly to swell dramatically. This large abdomen is highly attractive to male houseflies seeking a mate. Large abdomens may be an indicator of higher fecundity in a potential mate and, yes, just like Sir Mix A Lot, male houseflies like big butts. Causing the abdomen to swell may increase the chances of attracting a randy suitor that will become infected, further helping the fungus to multiply and disperse.     

Male cicadas get in touch with their feminine side  

One of the strangest twists in the zombie insect genre is set to take place in millions of backyards next spring with the return of the Big Brood, Brood X periodical cicadas. Beneath trees where cicadas spend their youth sipping sap, spores of the fungal pathogen Massospora cicadina have been waiting for 17 years. During April and May as cicada nymphs escape from the earth, resting spores of Massospora adhere to their exoskeletons. Compounds on the surface of the cicada send a signal to the spores that dinner is served and it is time to germinate. The fungus penetrates the skin of the cicada and multiplies, turning the cicada into a fungus garden. Spores of Massospora are then released into the environment where a second, more sinister wave of infection takes place. At this stage of their cycle, thousands of newly molted adult cicadas populate the landscape to begin their courtship rituals. Ubiquitous spores of the fungus spewed from the nymphs adhere to the skin of adult cicadas, germinate, and begin to infect the airborne legions. The infection sterilizes both male and female cicadas, but does nothing to quell the libido of sex-crazed male cicadas. Infected males continue to seek and attempt to mate with females despite their contagious infection. In a game of tit for tat, female cicadas infected with Massospora remain attractive to healthy males that soon become infected and then mate with other cicadas.  If this was not weird enough, Massospora twists the minds of infected male cicadas. Male cicadas adopt female courtship behaviors including a coy wing flick, the female’s signal that she is ready to accept a mate. This results in hyper-sexed uninfected males attempting to mate with infected drag queen males, further enhancing the spread of Massospora. Massospora becomes a cicada STD as it moves from one cicada to another by the behavior modifying process called Active Host Transmission or AHT. As the fungus develops within its host the abdomen of the cicada disintegrates, leaving behind a buff-colored mass of fungus. Infected cicadas are flight capable and their peregrinations carry the fungus to new habitats as they fly about. A second wave of infections produce resting spores that inoculate the soil with Massospora that will await the return of the cicadas in 17 years. While the loss of an abdomen spells instant death for a human, this is not the case for a cicada. Throughout cicada land male and female Massospora zombies walk and fly about missing their abdomens, macabre reminders of a very clever fungus.

As cicada nymphs emerge from their galleries next spring, Massospora spores lurking in the soil for 17 years will germinate on their exoskeleton, bore their way in, and multiply within the cicadas. Soon the cicada’s abdomen will disintegrate, enabling fungal fruiting bodies to disperse spores. Sterile but still randy males spread Massospora to other cicadas in futile mating attempts. In a mind control coup, infected male cicadas mimic female courtship behaviors that entice uninfected males to mate with them, further accelerating the active transmission of Massospora in the cicada population.

Jack o' Lantern.jpg

Bug of the Week hopes you have a happy and safe Halloween without any worms or fungi trying to make you a zombie unless, of course, you wish to be one.        

Acknowledgements

Bug of the Week thanks Bronwyn Mitchell-Strong for providing the inspiration for this episode and for affording the opportunity to share insect zombie stories with the Natural History Society of Maryland. Many thanks to Dr. David P. Hughes for sharing his gruesome image of an ant infected with Ophiocordyceps. The following fascinating studies were consulted in preparation for this episode: “Do hairworms (Nematomorpha) manipulate the water seeking behaviour of their terrestrial hosts?” by F. Thomas, A. Schmidt-Rhaesa, G. Martin, C. Manu, P. Durand & F. Renaud; “Water-seeking behavior in worm-infected crickets and reversibility of parasitic manipulation” by Fleur Ponton, Fernando Otálora-Luna, Thierry Lefèvre, Patrick M. Guerin, Camille Lebarbenchon, David Duneau, David G. Biron, and Frédéric Thomas; “Zombie soldier beetles: Epizootics in the goldenrod soldier beetle, Chauliognathus pensylvanicus (Coleoptera: Cantharidae) caused by Eryniopsis lampyridarum (Entomophthoromycotina: Entomophthoraceae)” by Donald C. Steinkraus,  Ann E. Hajek, and Jim K. Liebherr; “A fungus infecting domestic flies manipulates sexual behaviour of its host” by Anders Pape Møller; “Behavioral betrayal: How select fungal parasites enlist living insects to do their bidding” by Brian Lovett, Angie Macias, Jason E. Stajich, John Cooley, Jørgen Eilenberg, Henrik H. de Fine Licht, and Matt T. Kasson; and “A specialized fungal parasite (Massospora cicadina) hijacks the sexual signals of periodical cicadas (Hemiptera: Cicadidae: Magicicada)” by John R. Cooley, David C. Marshall  Kathy B. R. Hill.

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Waxy ladies dance like someone’s watching: Woolly beech aphid, a.k.a. boogie-woogie aphid, Grylloprociphilus imbricator

 

That’s not snow you see on the branches of an American beech tree. You’re looking at white wax produced by thousands of tiny sap-sucking woolly aphids.

That’s not snow you see on the branches of an American beech tree. You’re looking at white wax produced by thousands of tiny sap-sucking woolly aphids.

 

American beech, Fagus grandifolia, an iconic stalwart of North American deciduous forests, is prized for its massive size at maturity, dark glossy green foliage, and smooth grey bark. While wandering in a forest here in the DMV, I was startled to find an American beech with dingy black leaves and strange growths on its branches, several of which were flocked with a pulsating blanket of brilliant white wax. What mischief befell this paragon of the woods? The answer lies within the coat of white wax on the branches. A strange aphid called the woolly beech aphid, a.k.a. beech blight aphid and boogie-woogie aphid, makes American beech its home. This aphid is capable of producing incredible amounts of fluffy white wax from specialized wax glands lining its abdomen.

Life for a beech blight aphid begins with an egg that has survived winter’s chill on the bark of a beech tree. From this egg hatches a nymph that eventually develops into a wingless adult capable of producing legions of offspring. These youngsters develop into winged adults, some of which remain on the host while others depart to find a swamp cypress tree. Here they enter the soil, settle on the tree’s roots and develop by removing sap from the vascular bundles of the roots. How strange is that? Those that remain on beech trees will be parthenogenetic; a legion of Amazonian females reproducing in the absence of males. You go girls!

Honeydew excreted by legions of aphids rain down on leaves and branches below. This sugar-rich solution is the substrate for a specialist sooty mold fungus, Scorias spongiosa . This fungus cloaks leaves and branches and sometimes forms dense sponge-like mats several inches thick.

Honeydew excreted by legions of aphids rain down on leaves and branches below. This sugar-rich solution is the substrate for a specialist sooty mold fungus, Scorias spongiosa. This fungus cloaks leaves and branches and sometimes forms dense sponge-like mats several inches thick.

The colony will grow from just a few in spring to thousands by late autumn. Like other members of their clan, these aphids suck nutrient rich phloem sap from the vascular tissues of the beech. Excess fluid is excreted as a sugar rich product called honeydew. Vast amounts of honeydew rain down on leaves and branches below the colony. This sticky coating serves as a substrate for the growth of a unique sooty mold fungus, Scorias spongiosa, which, at first, is a thin black coating on leaves and bark. Later, as honeydew accumulates from thousands of aphids, the fungus forms a large dark sponge-like mass that may be crowned with yellow fruiting bodies of the fungus. Although sooty mold is not believed to be directly pathogenic, it may cloak leaves and reduce photosynthesis. Luxuriant honeydew and attendant sooty mold beneath infested beech trees may reduce survival of beech seedlings struggling to grow below.   

While taking a photograph of the colony I disturbed a branch, which instantly sent the aphids into paroxysms, with myriad aphids waving their wax covered rear ends up in the air. The rhythmic swaying of aphid posteriors gives rise to the moniker boogie-woogie aphid. This remarkable behavior is thought to confuse predators considering an attack on members of the colony. It certainly confused me. So, when someone is watching, aphids may dance.

Brilliant white wax produced by thousands of beech woolly aphids turn small beech branches snowy white. When disturbed, aphids break into a massive swaying dance routine with abdomens and wax held high. This group reaction is thought to confuse or distract predators. Or could it be that ladies just like to dance?

Ah, but the aphid has one more defensive trick up its sleeve or, should we say, at the end of its nose. The piercing mouthparts inserted into the vascular tissue of the tree to remove sap are comprised of tiny needle-like stylets. Researchers discovered that when caterpillars were introduced to the colony, squads of hostile female soldiers attacked and stabbed the caterpillars causing them to fall from the branch. A colleague tempted the ferocity of the aphid defense when he unwittingly grasped a branch infested with aphids. He described the encounter as “…something like a cross between a burning and stinging sensation.” In the waning days of autumn, take a walk in the woods and see if you can discover a colony of boogie-woogie aphids. Maybe bust a move with them. Dance like no one’s watching.       

Acknowledgements

Bug of the Week thanks Joe Boggs for providing inspiration for this episode after enduring an attack by beech woolly aphids. His Bug Bytes Blog “Attack of the Boogie-Woogie Aphids” and two fascinating studies, “Colony defense by wingpadded nymphs in Grylloprociphilus  imbricator (HEMIPTERA: APHIDIDAE)” by Shigeyuki Aoki, Utako Kurosu, and Carol D. von Dohlen, and “Cascading effects of a highly specialized beech-aphid–fungus interaction on forest regeneration” by Susan C. Cook-Patton, Lauren Maynard, Nathan P. Lemoine , Jessica Shue, and John D. Parker were consulted to prepare this episode.

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Eastern Equine Encephalitis-Infected Mosquitoes Found in Massachusetts

Massachusetts Department of Health Warns Public of Second EEE Case of 2020

Health officials have reported finding mosquitoes infected with Eastern equine encephalitis (EEE) in areas of Massachusetts, including Bridgewater.

The mosquitoes collected on August 7, 2020, are part of an ongoing testing initiative across the state. Each of these mosquitoes tested positive for the virus. The infected mosquitoes were collected in the Northeastern part of Bridgewater.

Additionally, a positive sample was collected on August 4, 2020, in Hanson, Mass. Other positive samples were collected in Middleboro, Carver, Plympton, Kingston, and Wareham during the month of July this year.

On August 3, 2020, a boy under the age of 18 became the first Massachusetts resident to test positive with Eastern equine encephalitis in 2020.

The state confirmed its second case on August 15, when a 60-year-old woman was exposed to the virus in Hampden County.

Massachusetts residents and visitors are urged to take precautions.

Dusk until dawn are considered peak hours for mosquito bites, outdoor activities should be rescheduled for earlier in the day.

And even though the temperatures are rising, long-sleeve shirts and pants can help protect your skin from potential bites.

What is Eastern Equine Encephalitis? 

Eastern equine encephalitis virus was discovered in 1933 during a large-scale equine epizootic in the mid-Atlantic area of the United States.

It was only five years later, in 1938 when the first confirmed human case was discovered in Massachusetts.

The mosquito-transmitted virus, Eastern equine encephalitis, is also referred to as Triple E, EEE, or sleeping sickness. It is classified as an arbovirus, which is a disease spread by a mosquito or other arthropod.

When we think of mosquito-transmitted viruses, West Nile virus typically comes to mind first, as it is much more prevalent. But EEE tends to be more debilitating, even deadly.

What are the Risks of EEE to Humans?

EEE is transmitted through an infected mosquito bite and can lead to a brain inflammation known as encephalitis.

The virus can also cause ongoing neurological problems, even death.

People at the highest risk of developing a disease or complication due to EE are individuals under the age of 15 or over the age of 50.

Those who live in wooded or swamp areas, like some areas of Massachusetts, have a greater chance of potential exposure.

What are the Symptoms of EEE?

If a person has been bitten by an infected mosquito, they can anticipate developing symptoms of EEE in approximately four to 10 days.

The symptoms of EEE include the sudden onset of fever, chills, headaches, and vomiting. Symptoms can then progress to disorientation, seizures, and then a coma.

At this time, there is no treatment for EEE. Options like anti-viral drugs and antibiotics have proven to be ineffective against the virus. But there is an EEE vaccine for horses.

Supportive therapy including hospitalization, respiratory support, and IV fluids can be used to help make the person a little more comfortable.

How to Prevent Mosquito Bites & EEE Transmission

As we enjoy our time outside, it can feel nearly impossible to prevent mosquito bites.

But there are ways to discourage groups of mosquitoes (known as scourges) from lingering on your property.

Homeowners and business owners are encouraged to take precautions in an effort to eliminate a mosquito infestation on their property.

Standing water is a favorite spot for the pest as it is an ideal place to lay their eggs. Standing water areas can include wetlands, pools, plastic toys, tarps, even plant saucers, or water bowls.

Eliminating the standing water, removing debris and/or clutter from the property can help encourage mosquitoes to look elsewhere.

To further reduce the possibility of an infestation, Catseye Pest Control offers a one-of-a-kind organic program that helps eliminate mosquitoes and ticks.

Our Organic Tick and Mosquito Program includes an in-depth inspection of the property, establishing a customized treatment plan, and monthly visits to create an organic protective barrier around the property.

The products used by our technicians are environmentally friendly, safe for your family, guests, and pets while providing a protective barrier around the property.

To learn more about how Catseye can protect you from unwanted pests like mosquitoes, contact our pest and wildlife professionals today.

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An unusual but not unpleasant home invasion by a beneficial beetle: Big-headed ground beetle, Scarites subterraneus

 

The big-headed ground beetle, Scarites subterraneus, sometimes makes a surprise visit to homes in autumn. Photo credit: Frank Roylance

The big-headed ground beetle, Scarites subterraneus, sometimes makes a surprise visit to homes in autumn. Photo credit: Frank Roylance

 

The waning weeks of summer and first few weeks of autumn are times when many six and eight-legged critters begin to invade homes here in the DMV. Previous episodes of home invasions featured nefarious brown marmorated stink bugs and multicolored Asian lady beetles lurking on walls and windows, a wolf spider wandering in a sink, camel crickets and house centipedes milling around bathtubs, and a velvety soldier beetle larva that somehow find its way indoors. Many of these creatures, like spiders and larval soldier beetles, are predators on the prowl for a tasty arthropod to eat. Others, like stink bugs and lady beetles, are simply trying to find a safe place to chill out and spend the winter until food returns in spring.  

Several days ago, I received a fine image of a striking predator known as the big-headed ground beetle, Scarites subterraneus. This beauty had been found trespassing in a friend’s kitchen. The big-headed ground beetle is part of a very large family of beetles called ground beetles, a clan more than 40,000 species strong. Scarites is a fierce predator both as larva and adult. I often find them under mulch or beneath rocks lining my flower beds. On several occasions I have seen Scarites larvae dashing across patios and walkways as they move from one planting bed to the next. Both life stages attack and kill a wide variety of pests that frequent our gardens and landscapes, including ground dwelling caterpillars such as cutworms and armyworms, as well as wireworms, fly larvae, ants, aphids, snails and slugs.

Ground beetles are super important predators in gardens and landscapes as both adults and larvae. They hunt and kill a wide variety of pests including snails, slugs, grubs, and soil dwelling caterpillars like cutworms and armyworms. Both adults and larvae are fast movers and are often seen beneath stones, mulch, logs, and sometimes running across sidewalks, roadways, and patios. It is not unusual to have them as guests entering your home in autumn. Simply collect them in a jar or water glass and release them back into your landscape where they enhance sustainability by reducing populations of pests.

Calosoma wilcoxi (right) is about one third the size of its cousin, the fiery searcher Calosoma scrutator (left). Both climb trees to devour caterpillars.

Calosoma wilcoxi (right) is about one third the size of its cousin, the fiery searcher Calosoma scrutator (left). Both climb trees to devour caterpillars.

As their common name implies, most species of ground beetles forage and live at the interface of soil and air. However, a few species such as the fiery hunter, Calosoma scrutator, and its smaller cousin, Calosoma wilcoxi, trend arboreal. They devour gypsy moth caterpillars and cankerworms in the treetops and feast on unlucky inchworms that fall to the ground.  Ecosystem services provided by ground beetles don’t stop at demolishing insect pests. Many ground beetles are omnivores and when not consuming meat, they feed as granivores on the seeds of weeds. Harpalus pensylvanicus and Anisodactylus sanctaecrucis are two common granivorous ground beetles that occur throughout much of North America. Scientists have found Anisodactylus and Harpalus adept at removing seeds of important agricultural, lawn, and garden weeds including lambsquarter, pigweed, foxtail, crabgrass, and velvetleaf.  After snapping a shot of Scarites, my friend scooped up his unusual house guest and released it back into the landscape. In its natural surroundings it will continue to provide excellent service by removing pests from the garden, just as Mother Nature intended.

References

Special thanks to Dr. Shrewsbury for providing insights and references for this episode. We also thank Frank Roylance for providing the great image of Scarites that inspired this episode. The fascinating study “Ground beetles as weed control agents: effects of farm management on granivory” by Jonathan G. Lundgren was consulted in preparation of this episode.

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EPA Approves Zika-Fighting Genetically Modified Mosquitoes

Florida Residents can Expect Species of Genetically Modified Mosquito to be Released into Environment in 2021

Just when we thought we’d heard and experienced it all for 2020, we’ve now learned the Environment Protection Agency (EPA) has approved the release of genetically modified mosquitoes.

Despite objections from some Florida residents, over 750 million genetically modified mosquitoes are expected to be released in the Florida Keys in 2021 and 2022 to help battle diseases like Zika Virus.

Purpose of Genetically Engineered Mosquitoes

After years of investigating the impact of disease-spreading mosquitoes and the possible outcome of releasing some of the genetically altered insects, Oxitec was given approval to proceed with its project to do so.

It was no easy feat. In fact, it took nearly a decade to obtain project approval in the state of Florida.

The genetically modified mosquitoes in question, named OX5034, have been altered to produce female offspring that don’t live past the larval stage. This means they will not hatch or grow large enough to bite or spread disease.

Male mosquitoes typically only feed on plant nectar, so they are less likely to carry disease.

Approved by the EPA in May 2020, the project is designed to test if a genetically modified mosquito is a practical way to control the Aedes aegypti — instead of insecticides.

Aedes aegypti is a species of mosquito that carries several deadly diseases, such as Zika, dengue, chikungunya, and yellow fever — making it a risk for many Florida residents.

Federal approval was also given for the mosquitoes to be released in Harris County, Texas, beginning in 2021. State and local approval has not been granted as of August 2020.

The British-based company is hoping to protect area residents against vector-borne viruses and harmful insecticides.

Vector-Borne Illnesses in Florida

Although mosquitoes found throughout the country are culprits of spreading numerous diseases, like Eastern Equine encephalitis, dengue fever and yellow fever are most commonly found in warm or tropical areas.

During 2009 and 2010 outbreaks of dengue fever occurred in parts of Florida, particularly Key West, leaving many searching for a new option. And, despite the best efforts of some in the area, the Aedes aegypti mosquito prevailed and proved insecticides were ineffective.

These outbreaks led the Florida Keys Mosquito Control District to seek an alternative solution from Oxitec.

So, how does genetically altering a mosquito help the current mosquito situation?

Oxitec has developed a male mosquito, OX513A, that is designed to die before reaching adulthood, unless it is grown in water containing the tetracycline antibiotic.

Batches of these male mosquitoes would then be allowed to live with and mate with female mosquitoes. But the offspring would inherit the altered DNA and die, thus limiting the population.

The male OX513A mosquito has been tested in areas like Brazil, Panama, and the Cayman Islands. Oxitec reported great success rates, including a 95% reduction of the Aedes aegypti mosquito in an area of Brazil.

The new male mosquito, OX5034, is programmed to kill female mosquitoes, leaving males to survive for multiple generations. During this time, the modified genes will be passed along to subsequent offspring.

Oxitec is required by the EPA to notify state officials 72 hours before releasing the mosquitoes. The British-owned company is also required to conduct ongoing tests for a minimum of 10 weeks to ensure the females do not reach adulthood.

Organic Mosquito Control Concerns

Despite this news, Florida residents and environmental groups worry about the spread of a genetically modified mosquito.

Their concern is for the safety and health of birds, insects, and mammals that feed on mosquitoes. With many endangered species of birds found throughout the state, the cause for concern is valid.

Protecting residents while also reducing the risk of spreading diseases like Zika, dengue, and yellow fever is important, but protecting the environment is also important.

Harmful chemicals, insecticides, and genetically altered mosquitoes are not the only option when it comes to mosquito control.

Catseye Pest Control offers a one-of-a-kind Organic Tick and Mosquito Program designed to help protect your property from the nuisance pests.

It’s not easy to keep your business, home, family, and pets safe through the high-alert tick and mosquito seasons. But it’s possible for our technicians.

Taking an all-natural approach to pest control that utilizes the latest and most effective preventative services to help control ticks and mosquitoes leaves you with peace of mind throughout the season.

Our program includes:

  • An in-depth inspection of the property.
  • Tailor-made treatment plan for the property.
  • Consultation with a Catseye technician to learn ways to eliminate breeding sites and other conditions conducive to mosquitoes and ticks.

Catseye is committed to using organic, environmentally friendly solutions that provide much needed protection for the property without putting endangered species at risk.

Contact us today to learn more about the organic solutions we have to offer and how we can help keep your property safe from mosquitoes and other pests.

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Garden spiders rockin’ in the DMV: Black and yellow garden spider, Argiope aurantia

 

Gardens around the DMV seem to be having a bumper crop of black and yellow garden spiders this year. Image credit: Jill Moore

Gardens around the DMV seem to be having a bumper crop of black and yellow garden spiders this year. Image credit: Jill Moore

 

Black and yellow garden spiders can be quite entertaining when they spin their webs in windows. Notice the beautiful stabilimentum. Image credit: Steve Hand

Black and yellow garden spiders can be quite entertaining when they spin their webs in windows. Notice the beautiful stabilimentum. Image credit: Steve Hand

In a previous episode we lamented the unusual paucity of large swallowtail butterflies in our gardens this year. But 2020 has not been a rotten season for all of our six and eight legged friends. Over the past few weeks, I have received several images and a few videos of black and yellow garden spiders who have made their homes in flower beds and gardens here in the DMV. Some of us have shared the experience of wandering along a path through a meadow and bumbling into an enormous spider web ruled by a fearsome yellow and black spider.

Argiope aurantia, the so-called black and yellow garden spider, is extraordinarily common this year in some locations. Webs of the black and yellow garden spider can be gargantuan, often spanning several feet. Fortunately for Bug of the Week and for the first time in several years, one of these gorgeous arachnids, a female by the name of Sylvia, has taken up residence amongst my zinnias where she helps to keep blow flies, stink bugs, and other less desirable arthropods at bay.

One of our past resident black and yellow garden spiders, Charlotte, demonstrates her skill at immobilizing and capturing prey. A brown marmorated stink bug stands no chance once it encounters the sticky strands of the web. Charlotte’s attack is eerily reminiscent of Frodo’s unfortunate encounter with Shelob in route to Mount Doom. After immobilizing the stink bug, she returns to feast on the remains of a former, now unrecognizable, victim. Spiders, along with many other home-grown predators, are part of the reason stink bugs are not the problem they once were here in the DMV.

A stabilimentum of heavy silk adorns the center of this web.

A stabilimentum of heavy silk adorns the center of this web.

One of the signature features of Sylvia’s web and those of other orb weavers is the construction of a zigzagging band of dense silk called a stabilimentum near the center of her web. The function of the stabilimentum is a topic of debate among arachnologists. Some suggest that the band helps disguise the spider from its predators by providing a form of camouflage as the spider rests in the center of its web. Others believe that the silk may act as a tiny parasol shielding the spider from intense rays of the sun. One fascinating study revealed that the conspicuous bands of silk acted as a visual warning to low flying birds, reducing the likelihood of devastating web-destroying crashes much the same way an image of an owl on a large plate glass window dissuades misguided birds from crashing and breaking their necks. Of course, the spider cares not for the welfare of the bird, but repairing bird-damaged webs takes time away from important projects like capturing and eating insects.

How many spiderlings will emerge from an egg case the size of a very large marble?

How many spiderlings will emerge from an egg case the size of a very large marble?

One recent misty morning, more of a rule than an exception this year, provided a grand opportunity to witness another curious behavior of Sylvia the orb weaver, her skill at web-flexing. While stationed near her stabilimentum and grasping strands of silk, Sylvia flexed and extended her front legs repeatedly. Her rhythmic gyrations set the entire web rocking back and forth. Swaying the web in rhythmic motion is called web-flexing, a behavior often observed in orb weavers. Web-flexing has been reported as a way to dislodge potential predators, or to cause prey to become entangled in sticky capture-threads in the web. Flexing may serve other defensive purposes as well. Enemies of the orb weaver include predatory lizards, toads, and other spiders that rely on keen eyesight to locate and capture prey. In an interesting treatise on orb weavers, Wayne Tolbert suggested that web-flexing might be a clever way for the spider to conceal its exact location, thereby confounding hungry predators. On this rainy morning I wondered if Sylvia’s vigorous web-flexing might be a way to shed raindrops from the silken capture-threads of her orb. When you see orb weavers and other spiders in your gardens and landscapes, please avoid any urge to destroy them. We have found spiders to be one of the most important group of predators putting a beat-down on common pests of ornamental plants in residential landscapes.

On a rainy morning, Sylvia, a black and yellow garden spider, uses her forelegs to rock her web back and forth. This behavior known as web-flexing may help her snare prey, dodge predators, or, perhaps, shed raindrops that accumulate on capture-threads of her web. Another black and yellow garden spider has had a very successful season producing two marble-sized egg cases from her harvest of prey. Video credits: Michael Raupp and Ann Payne

Acknowledgements

Bug of the Week thanks Anne Payne, Jill Moore, Steve Hand and Gene Ferrick for sending images and videos and for donating black and yellow garden spiders, inspiriting this episode. Three great articles, “Predator avoidance behaviors and web defense structures in the orb weavers Argiope aurantia and Argiope trifasciata” by W. Tolbert, “Do stabilimenta in orb webs attract prey or defend spiders?” by T.A. Blackledge and J.W. Wenzel, and “Do top-down or bottom-up forces determine Stephanitis pyrioides abundance in urban landscapes?” by Paula Shrewsbury and M.J. Raupp, were consulted for this episode.

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