In a presentation entitled “The Bugs That Bug You,” Blake Dinius, the entomologist educator for the Plymouth County Extension, hosted a webinar on Monday aimed at educating county residents on Tick and Mosquito Biology, Ecology and Bite Prevention.
The theme of the webinar was “blood-feeding” and included a historical sketch mixed with educated guesses as to how the northeastern seaboard became such a center for Lyme Disease and mosquito infestation.
To wit, ticks are 400 million years old, even predating dinosaurs, while mosquitos are more recently developed, estimated to have existed for 200 million years. ”Why do they suck so badly?” asked Dinius without the slightest hint of sarcasm. He then proceeded to rattle off one interest fact after another, setting the table for some advice that was based on important truths and common sense.
Fun facts featured the following: Only female mosquitoes look to drink our blood, and they do it directly from blood vessels for necessary egg production. Ticks are long-term feeders and create feeding lesions, and they spend from 4-7 days feeding on a wound they create. As the tick feeds, it injects things that keep a person from feeling an inflammatory response. Mosquitoes are technically pollinators and feed on nectar. Ticks only feed on blood their entire life.
Things have changed for the worse in recent years where it concerns pathogens and diseases resulting from tick and mosquito bites.
From 1900-1920 there was only one disease associated with tick bites. In the past 20 years, it’s not only the number of diseases that have increased but the number of cases. Lyme Disease cases are mostly along the northeast coast and to a lesser extent in the upper midwest.
Eastern Equine Encephalitis (EEE) is the most concerning mosquito-borne disease; 2019 was “a banner year.”
This amount of and kind of information can be troubling to many who live here, but Dinius says not to get caught up in gloom and doom.
“If you just focus on what’s going on the news, I can see you becoming an incredibly anxious individual. And so, while I’m glad we have freedom of the press, we want to (dissect) what’s going on here,” he said.
Speculation abounds as to why Lyme Disease was only recently discovered, and Dinius thinks that it’s long flown under the radar, like since the last ice age 60,000 years ago.
Factors in how these creatures have become more of a nuisance are multifaceted, including environmental as our hunter-gatherer ancestral society encountered fewer pathogens, and our 40,000-year-old agrarian/agricultural society is likely to blame. An 1888 study suggested the destruction of wild hosts and wild habitat, replaced by community living and, starting 14,000 years ago, domesticated animals.
More ticks (thanks to the changing habitat) may have been diverted (by us) away from feeding on rabbits, for instance. The result of the compounding factors likely led to more disease. Lyme and EEE, among other diseases, says Dinius, cycle between ticks and mosquitoes and certain respective non-flying and flying animals.
Often thought of as a germ, Lyme is bacteria, a living organism with its own life-cycle. Mice get the bacteria and pass it on to ticks; humans cannot pass it back.
New England’s domination of Lyme may be due to close contact with an expanding number of hosts (i.e. deer). Deer disinfect ticks from Lyme and don’t get sick doing so. The infection rate of Lyme comes from small animals.
With its white-cedar swamps, the northeast is a perfect breeding ground for Lyme and for EEE. Mosquitoes also breed in trash, including large discarded items like tires. Degrading habitats contributes to increasing mosquito population.
Dinius discussed the topic of climate change with the caveat that he considers himself unqualified to decide that climate change does or does not exist. But he gave examples of how warm temperatures accelerate the reproductive cycles of mosquitoes.
Strategies for our survival are based on a triangular relationship between the pathogen (Lyme), the vector (tick), and the host (human).
The pathogen-vector relationship can be affected somewhat by aerial spraying and the control of animal populations such as the removal of deer or mice; the pathogen-host relationship can be affected by a vaccine, but the most important relationship that Dinius focuses on is the vector-host relationship because that’s the over which humans have a realistic amount of control.
We can buy and apply repellents or spraying in our yards, or even benefit from aerial spraying.
“I never let a tick or a mosquito scare me from doing something I enjoy doing,” said Dinius, who enjoys fly fishing and camping.
Ticks dwell in the soil, and only 6.3 percent are active at a time. They require 82 percent humidity for survival so a tick inside a house is almost doomed.
Mosquitoes are aquatic organisms and need access to water to survive.
While there are many theories on what makes a yard more susceptible to an invasion of larval ticks, a 2019 study isolated a few contributing factors. On the negative side, being near a forest, having a rock wall, or having trash on the ground all attract the tick population, while a solid fence discourages the same. Logs, animals, plants and gardens, and even a warning track between the yard and the woods won’t make a difference.
A neat yard discourages ticks, and raking leaves will reduce the population by 75 percent.
Yard sprays are more effective against ticks than they are against mosquitoes. For ticks, use a pyrethroid-based (synthetic) spray, first spraying in early May, and then in early June; repeat annually. Dinius says the all-natural sprays do not work, but because he is confident in other strategies he does not spray his own yard. Dinius considers several sprays to be beyond unnecessary, calling it ineffective and reckless – and if commercially done then it’s unethical – while overexposing the resident to compounds.
Dinius says a professional sprayer should cost around $300 per year. Spraying should be confined to the perimeter and not the entire lawn; 82 percent of ticks in yards are within 8 feet of the edge.
If you do it yourself, buy a spray that is EPA registered and made for lawns and gardens, one that says it controls deer ticks or ticks, and is listed as “ready to use” or “ready to spray.” That way you can avoid mixing and just hook it up to your garden hose. Do not spray flowers in bloom. Follow listed instructions on the container to the last detail.
When it comes to mosquitoes, homeowners often look toward a stagnant pond down the street as the culprit, but they often overlook the breeding grounds on their own property. Mosquitoes can breed in the amount of water it would take to fill a bottle cap. Dinius recommends keeping water moving or replacing it frequently.
Yard sprays can control ticks for a whole year; for mosquitoes, they don’t last more than a day or a week depending on product, technique, wind, time of day, and species. Dinius says spraying for mosquitoes only makes sense as a short-term strategy for the sake of an event like a backyard wedding.
The best technique for personal prevention is to cover up. In the case of mosquitoes, that can mean wearing a head net; in the case of ticks, it always means tucking one’s pants into his or her socks.
Time of day matters for mosquito bites. While 34 of 428 pools of mosquitoes tested during the day were carrying EEE and one in 87 were carrying West Nile Virus, those ratios exploded at twilight and night to 394 of 428 for EEE and 86 of 87 for West Nile.
The lasting impression from Dinius’ wealth of experience and knowledge is that what we know most reliably we’ve actually known for a long time.
Tick testing costs $15 for Plymouth County residents and $50 for those living outside Plymouth County.
By Mick Colageo