GM Mosquito Progeny Not Dying in Brazil: Study

The biotech Oxitec had released the genetically engineered insects with the hope that they would breed with wild populations and produce offspring that die young. But that’s not always happening.

Sep 17, 2019


Update (September 18): Scientific Reports has issued an editor’s note, stating that “the conclusions of this paper are subject to criticisms that are being considered by editors.” In a statement sent to The Scientist, Oxitec says it takes issues with a number of conclusions the authors made in their report. Among them, “The authors infer that Oxitec’s self-limiting genes persist in the environment. Yet as confirmed by their own data, multiple other scientific studies and regulatory filings, this is not the case. Oxitec’s self-limiting genes do not establish or spread in the environment.” The journal’s note states that it will issue another response once the issues are resolved.


Afield experiment in Brazil that deployed genetically modified mosquitoes to control wild populations of the pest may be having unintended consequences. According to a genetic analysis of mosquitoes in the area, it appears the engineered stock has bred with wild mosquitoes and created viable, hybrid insects, scientists reported in Scientific Reports last week (September 10).

“The claim was that genes from the release strain would not get into the general population because offspring would die,” coauthor Jeffrey Powell, a professor of ecology and evolutionary biology at Yale University, says in a press release. “That obviously was not what happened.”

The biotech company Oxitec began releasing hundreds of thousands of genetically engineered mosquitoes in the city of Jacobina between 2013 and 2015. The idea is that genetically modified (GM) males would mate with wildtype females and pass on a gene that kills their offspring before they themselves can breed, ultimately knocking down Jacobina’s mosquito populations.

The study’s authors, who are not affiliated with Oxitec, began sampling mosquitoes in Jacobina before, during, and after the deployment of the GM insects. They created a genetic panel that distinguished the wildtype mosquitoes from the introduced ones and found that insects analyzed more than two years after the releases stopped were progeny of both wildtype and mutant, or OX513A, lineages. “The degree of introgression is not trivial,” the authors write in their report. “Depending on sample and criterion used to define unambiguous introgression, from about 10% to 60% of all individuals have some OX513A genome.”

Oxitec takes issue with Powell’s study. The company tells Gizmodo it is “currently in the process of working with the Nature Research publishers to remove or substantially correct this article, which was found to contain numerous false, speculative and unsubstantiated claims and statements about Oxitec’s mosquito technology.”

The company has reported positive results as far as reducing mosquito populations—and potentially mosquito-borne diseases—in its field sites.

Texas and Florida have considered using Oxitec’s GM mosquitoes to control populations in their states. On September 11, the Environmental Protection Agency posted a request for public comment on Oxitec’s application to release engineered insects in the Florida Keys. If approved, it would be the first deployment of the animals in the US.

Kerry Grens is a senior editor and the news director of The Scientist. Email her at

Tick ID, Testing and Reporting

Resources are Available for Tick ID, Testing and Reporting


TickSpotters help keep track of tick activity across North America (UMass Amherst)

You, and your pets can help monitor tick population trends and tickborne disease risk. TickEncounter is keeping track of tick encounters, and we need all of the TickSpotters we can get! Thousands of citizen scientists like yourself are submitting REAL data that’s helping drive tick awareness tools like TickEncounter’s Current Tick Activity app.

Tick Encounter Resource Center, The University of Rhode Island

Our Mission:  To provide a professional tick testing service to public individuals and agencies seeking more information about the risk of dangerous pathogens.

We’ve developed a battery of tests through years of research on disease-causing microbes in ticks. Since 2006, we’ve offered this expertise as service to the general public and health agency partners. Since that time, we’ve endeavored to keep costs of this testing to a minimum to allow us to serve the greatest number of subscribers. As the popularity of the service grew, the amount of data collected also grew and we now share that data as part of Tick-Borne Disease Network passive surveillance that we hope will continue to grow and provide unprecedented insights to who is being bitten by ticks, when they get bitten, and what pathogens those ticks are carrying. We welcome feedback on our web page ( and encourage everyone to SAVE THE TICKS!

Ticks and Tick-borne Diseases

Our July edition of Tree-Talk focuses on ticks and tick-borne diseases.   Our special guests this month are ANR Educators Tim McDermott, DVM (Franklin County) and Marcus McCartney (Washington County).  Check out these videos to learn how you can protect your family, pets and livestock from the increasing threat of ticks and the diseases that they carry.

Full episode (29 minutes) including Marcus McCartney’s personal experience with Lyme disease:

Protecting yourself from ticks (3:30 minutes):

Tick removal (3:41 minutes):


Useful websites:  (click on the tick tab on the top left of the page)

As Ticks Spread, New Disease Risks Threaten People, Pets and Livestock

One tick that a new study shows is endangering cattle in Virginia is able to clone itself, making colonizing new locations that much easier.

A lone star tick. To find a host, some ticks grope about with their forelegs from a leaf or grass blade, a behavior known as "questing." Credit: Smith Collection/Gado/Getty Images

Lone star ticks have been ranging farther north and west in recent years. When they bite, the aggressive ticks can spread diseases and even make humans develop a severe allergy to red meat. Credit: Smith Collection/Gado/Getty Images

It didn’t take long for one of America’s newest tick species to find Thomas Mather.

Mather, an entomologist who specializes in the tiny disease-carriers, had taken a team of scientists to Staten Island, New York, in hopes of collecting at least one Asian longhorned tick.

They were all of 50 feet from their car and had just unfurled a banner of white fabric, known as a tick drag, when the first longhorned tick landed in the fabric. Dragging a nearby patch of grass with the fabric, more longhorned ticks appeared. On a grass blade, Mather spotted an unusual clump and discovered dozens of tiny, seed-like tick larvae waiting for a victim to brush past.

If the Asian longhorned tick was unheard of in America just a few years earlier, it wasn’t a stranger here anymore.

Since 2013, the Asian longhorned tick has popped up in at least 11 U.S. states, mostly in the Northeast. Previously limited to Asia, Australia, New Zealand and some Pacific Islands, it likely found several ports of entry to North America, hitching a ride on animals or humans. Its ability to clone itself without a mate made colonizing new locations that much easier.

While the longhorned tick is still feeling out its range in North America, other established tick species are expanding theirs as the climate changes and the planet warms—with consequences for humans, pets and the livestock industry.

Several tick species have spread to new areas of the country, some carrying diseases that can pose serious health risks to humans, including Lyme disease, which can affect the joints, heart and nervous system, and Rocky Mountain spotted fever, a treatable but potentially fatal disease that causes fever and muscle pain.

An aggressive tick called the lone star, which has been creeping north and west from its original habitat, can transmit an illness similar to Lyme disease, as well as pass along a sugar molecule that can make humans develop severe allergies to red meat.

Infographic: Lonestar Tick: Its Range, Diseases and Biting Behavior

While the total number of tick-related illnesses is difficult to gauge since so many go unreported, the trend is clear. The number of cases of reported tick-borne diseases has been on the rise in the U.S., doubling from 2004 to 2016, and reached a record high in 2017, the latest annual data reported by the U.S. Centers for Disease Control and Prevention (CDC).

Higher temperature associated with climate change is one key factor affecting where, and how fast, ticks colonize new places, the National Climate and Health Assessment says.

Livestock Industry Faces a New Threat

Ticks can jeopardize animals’ health, too, and the longhorned species could become a formidable threat to the cattle industry, scientists said.

The longhorned tick is already suspected of killing cattle on farms in three separate Virginia counties by infecting them with Theileria orientalis, a parasite that causes fever, anemia, jaundice, and other symptoms in animals.

In a study published last week about the infections, researchers warned that the tick could put the Virginia cattle industry at risk. Once an animal becomes infected, there is no treatment or cure.

Infographic: Asian Longhorned Tick

Scientists warn that the longhorned tick could proliferate quickly, and since females can reproduce without a mate, ordinary ways of controlling pest population, like sterilizing males, won’t work. A single tick can populate a new location.

“As of right now, we don’t have a great way to stop that spread,” said Kevin Lahmers, a veterinary pathologist at the Virginia-Maryland College of Veterinary Medicine, who co-authored the new study, published by the CDC.

Several research teams are collaborating with the U.S. Department of Agriculture on research and surveillance of the tick, and researchers are studying the tick’s range in other countries to try to determine its potential distribution here.

Ticks in More Places

In general, ticks are expanding their ranges, Lahmers said. In Virginia, 15 to 20 years ago, Lahmers said he only saw dog ticks. Now, deer ticks—which can carry Lyme disease—are the predominant tick species there.

Infographic: Blacklegged Tick

Fluctuating climate and weather patterns can significantly affect diseases carried by ticks, as well as those carried by mosquitoes, said Ben Beard, deputy director of CDC’s Division of Vector-Borne Diseases.

With an increasing number of days without frost, for example, the risk of disease transmission starts earlier and extends later into the year. “If you look at climate change models and see how those models are advising those areas of risk, clearly there’s an impact that it’s having,” Beard said.

Infographic: American Dog Tick

In Germany, a tropical tick called hyalomma seems to have survived its first winter there, according to Ute Mackenstedt, a professor of parasitology at the University of Hohenheim, Stuttgart. Her team discovered the tick this year too early in the season to have been brought over by migrating birds.

“We expect new ticks species in Germany due to changing weather conditions,” Mackenstedt said. She said the hyalomma tick could become the second recently introduced species typically found in warmer conditions to establish a population in Germany, though it’s too early to be sure.

Hyalomma can transmit the Ebola-like Crimean-Congo hemorrhagic fever virus, though that virus hasn’t yet been found in Germany.

Preventing Tick Bites — at Home and in the Woods

The longhorned tick is able to spread a virus known as SFTS, or severe fever with thrombocytopenia syndrome. It can be fatal, particularly for people over 50, but it hasn’t yet turned up in the U.S.

The CDC urges precaution against all tick species, not just the longhorned.

“There’s a huge potential here for this tick to further complicate the problems we’re already having,” said Beard of the CDC. “It’s one of those things we can’t afford to ignore, but at the same time, we have to work on the problems that are already here.”

Crowd-Sourcing Tick Research

Several research efforts are gathering data about the spread of ticks from people who photograph or mail in ticks they’ve found. Mather runs one of those efforts, a website through the University of Rhode Island called TickSpotters, where his team of researchers fields questions from people who submit photos and samples to be analyzed.

He said there’s been a clear increase in submissions over the past few years: From the site’s inception in 2014 until 2017, he saw fewer than 8,000 entries. Last year alone, he saw nearly 15,000.

Infographic: Rocky Mountain Wood Tick: Its Range, Diseases and Behavior

One reason may be that ticks are spreading to new places. Mather said contributors frequently ask, “What’s going on? I’ve lived in this place for 15 years and never seen a tick before.”

Building a database of these findings can help researchers understand tick distribution patterns.

“It’s people that are encountering ticks a lot more than scientists,” Mather said. “TickSpotters has a chance for using the power of the crowd to help understand what’s going on.”

Ohio Vector-borne Disease Update 07/12/2019

As of 07/11/19, 5,389 of 5,642 pooled mosquito samples (170,866 Culex spp. total) have been tested and 7 samples were positive for West Nile virus (WNV) from Franklin (5), Ross (1) and Summit (1) counties. Below is a graph of the minimum infection rate (MIR) in Culex spp. mosquitoes collected in Ohio. As you can see, the MIR is below where it was at this time last year. No human cases have been reported so far.

While WNV activity in Ohio is currently low, in the past week, several suspected cases of La Crosse virus disease have been reported. Although these cases are pending confirmatory testing, this suggests La Crosse virus activity is ongoing in Ohio. Please ensure you continue with your community and public education efforts focusing on personal protection to avoid mosquito bites and source reduction to prevent mosquito breeding.

For more information, see the current Ohio vector-borne surveillance update at

NOTE: Since Internet Explorer is no longer being supported, ODH’s new webpage is best viewed in other browsers (e.g. Microsoft Edge, Google Chrome, Firefox, etc.).

Please do not hesitate to contact the Zoonotic Disease Program (614-752-1029, option 1) if you have any questions.

Ohio Vectorborne Disease Surveillance Update

The Ohio Department of Health (ODH) Zoonotic Disease Program, in partnership with ODH Laboratory, local public health partners and sanitary district partners, collects and tests mosquitoes and ticks from many communities in Ohio as part of statewide vectorborne disease surveillance.  This surveillance also includes monitoring for human and veterinary cases as well.

Collections of mosquitoes are identified and tested at ODH Laboratory, while ticks are identified by ODH entomologists.  Results from mosquito and tick identification and testing are shared with our partners who use the information to guide public health interventions.

We will monitor for mosquito infections and tick findings throughout the summer and fall and will report positive results and summary statistics on this website, updated each Friday at noon.  Please download the attached document for a more detailed summary of mosquito and tick surveillance in Ohio.

2019 Numbers At-A-Glance

As of July 3, 2019

West Nile virus

Infographic: West Nile virus surveillance statistics

La Crosse/Unspecified California encephalitis virus

Infographic: La Crosse/unspecified California encephalitis virus surveillance statistics

Travel-associated mosquito-borne diseases

Infographic: Travel-associated mosquito-borne disease surveillance statistics

* Ohioans traveling to areas where local transmission is occurring should be aware of the ongoing situation and make every effort to avoid mosquito bites.  Additional information can be found from the Centers for Disease Control and Prevention (CDC)’s Travelers’ Health and Pan-American Health Organization websites.

New Ohio State App Helps Users Identify, Prevent and Control Bed Bugs

New Ohio State App Helps Users Identify, Prevent and Control Bed Bugs

A close-up look at adult bed bugs, their eggs and fecal spotting. Photo: CFAESA close-up look at adult bed bugs, their eggs and fecal spotting. Photo: CFAES

COLUMBUS, Ohio – Not sure if the dark speck that crawled across your desk at work was a bed bug?

Wondering if the tiny insect you saw on the seat next to you at the movie theater or on the bus was a bed bug?

How about that fleck you thought you saw on the corner of the mattress the last time you stayed in a hotel?

A researcher at The Ohio State University has created a free new app to help you figure it out.

Created by Susan Jones, a professor of entomology with Ohio State’s College of Food, Agricultural, and Environmental Sciences (CFAES), the Bed Bug Field Guide app comes complete with photos, descriptions and enough information for consumers to know, definitively, what bed bugs look like, where to find them, how to get rid of them and, most importantly, how to ward off an infestation in the first place.

Jones is an authority on bed bugs having studied these pests for more than a decade. She is a founding member of the Central Ohio Bed Bug Task Force.

“Bed bugs can be found in homes, in the workplace, in schools, hotels, theaters, vehicles, in the soles of your shoes, nearly anywhere,” Jones said. “And, because they’re expensive to get rid of and many people are using ineffective chemicals trying to kill them, bed bugs aren’t going anywhere.”

Ohio has four major metropolitan areas ranked on this year’s list of top 50 cities with bed bug infestations, according to Orkin, a nationwide pest control company. Columbus ranks No. 5. Cincinnati comes in at No. 8. Cleveland-Akron-Canton holds the 13th spot, and Dayton ranks No. 32, according to the list.

That’s because bed bugs, which are strictly indoor pests, can reproduce quickly, travel easily and survive starvation for many months, occasionally even a year, Jones said. Additionally, Ohio’s many large cities are in close proximity and are linked by major interstate highways, so bed bugs are easily spread far and wide, she said.

“The bed bug problem is not going away, so we wanted to create an app to get factual, relevant information into the hands of as many people as possible in an easy-to-use format,” Jones said. “There’s so much misinformation out there, so we wanted to provide the most factual information that we can about bed bugs.”

With that in mind, Jones worked over the past year creating and writing the bed bug app. The app was funded through a grant from the U.S. Environmental Protection Agency via US EPA Region V pass-through funding to the Ohio Department of Agriculture, Division of Plant Health, and developed by EduTechnologic LLC.

In addition to photos, the app contains multiple chapters on all things bed bugs:

If you think you have bed bugs but aren’t sure, Chapter One: How to Identify Bed Bugs, can help you decide.

Chapter Four: Preventing Bed Bugs explains how to avoid getting bed bugs in the first place. (Hint: Make sure that a bed bug inspection of second-hand items is part of your normal routine.) Chapter Three: Inspecting for Bed Bugs tells you how to do so.

Want to get rid of bed bugs? Chapter Seven: Treating for Bed Bugs explains how. (Hint: It’s not easy or cheap, but hiring a professional is preferable to do-it-yourself approaches, which tend to fail.)

“Bed bugs are a complicated insect — there’s not an easy way to get rid of them, and they can be found anywhere in your home, from the floor to ceiling,” Jones said. “Bed bugs are a difficult do-it-yourself project and aren’t going to be controlled with a single insecticide treatment.”

Chapter Nine: Advice for Residential Visits explains how you can safely visit people who have bed bugs in their homes and not bring the bugs home with you.

“This information is relevant for social workers and first responders who go into infested homes or people with relatives who have bed bugs,” Jones said.

Chapter 11: What Not to Do for Bed Bugs dispels many myths about bed bugs.

“There is a difference between finding a single bed bug and an actual infestation,” Jones said. “People freak out if they see an insect they think may be a bed bug, and there’s often a general panic when there is a bed bug sighting at work or other public place.

“But that’s not a rational response. Chapter 10: Bed Bugs in Workplaces, Schools, Vehicles can help you with that.”

In Chapter 8: Tips for Travelers, Jones offers these tips to reduce the likelihood of returning home with hitchhiking bed bugs:

  • Check for bed bugs at hotels and refuse to stay in a room showing signs of bed bugs.
  • Store luggage on a luggage rack after you’ve made sure it has no telltale signs of bed bugs. You can also store it in the bathtub to prevent hitchhikers.
  • If you purchase secondhand clothing, keep it tightly bagged until you can wash and dry it.

And if you have an infestation, she offers these tips to help alleviate the problem:

  • Treat as soon as you discover bed bugs, before their population increases or spreads to other homes.
  • Don’t throw away your furniture unless absolutely necessary; it can almost always be treated.
  • If you have no choice but to discard furniture, make sure to wrap it securely in plastic sheeting before moving it outdoors. Prior to wrapping it, be sure to damage or destroy the item, and also label it “Bed Bugs” so that others don’t reuse it.
  • Don’t give away or share items with others until you have treated your infestation.
  • Decontaminate your clothing and other washable items by washing them and then drying them for 30 minutes on medium to high heat.
  • Items that can’t be washed but can survive the clothes dryer, such as shoes or stuffed animals, can be decontaminated in the dryer for 30 minutes on medium to high heat.
  • Check your shoes before leaving your house so you don’t track bed bugs around.
  • Don’t store your backpack, briefcase or similar items near your bed, and leave them in a sealed plastic bag or plastic tote when you go to work or school.
  • At school, make sure children don’t intermingle their coats, backpacks, etc. These items should stay in individual cubbies, bins or other spaces.

The app, which is available for Android and iOS devices, can be downloaded free by searching for “BED BUG FIELD GUIDE” in the App Store and Google Play Store. The app will frequently be updated with new information.

Tracy Turner

Susan Jones

The Tick App

April 22nd, Earth day, The Tick App – 2019 will be available in GooglePlay and iTunes!

Who are we? 

This study is conducted by researchers from Columbia University and the University of Wisconsin – Madison, members of the CDC Regional Centers for Excellence in Vector-Borne diseases. Funding for this study is provided by the Centers for Disease Control.

What is the study about?

In two words, Lyme disease. Lyme disease can be transmitted to humans after a tick bite. This study is designed to help us understand more about how  people’s practices and activities impact their exposure to ticks. This research is being done because Lyme disease is the most common vector-borne disease (infections transmitted by the bite of infected arthropod species, such as mosquitoes, ticks, sandflies, etc) in the United States. The information provided will help us design integrated control strategies to prevent diseases transmitted by ticks.

Why is my participation important and how is the app useful to me?

If you live in a high-risk area, sharing your experience and perspective with us will help us learn about the risk factors for tick borne disease and design better methods that prevent tick bites and tick-borne disease. We really appreciate your input!

We are also including information that will help you identify the different tick species, ways to prevent tick exposure and other information that will help you understand more about ticks and the diseases they transmit.

How can you help us?

Once you download the app and register for an account, you will be asked to take one enrollment survey that will help us capture your baseline risk of exposure to ticks.

You will then receive a weekly to monthly message to start your tick diary during the high risk months (May to September). The tick diary, or activity report, should take less than a minute to complete. It asks if you or a household member encountered a tick and what you did that day. When you start the tick diary, you will receive a daily reminder until you complete 15 reports.

Also, you can help us by reporting any tick through a quick form built in the app.

If I don’t want to use the app, how can I participate?

You can sign-up in our website and the surveys will be sent to your email. The informational material can also be found in this website


West Nile Virus Update

West Nile Virus (WNV)


As of today, 9/17/2018, ODH is reporting 23 human West Nile virus (WNV) cases, including 2 fatalities, and 6 asymptomatic WNV viremic blood donors in Ohio.  Additionally, 17 equine cases have been reported from 11 counties.  WNV activity in mosquitoes remains high at this time and virus activity has been reported from 64 Ohio counties so far this year.  The graph below shows where we are this year with infection rates in mosquitoes compared to 2012, a high WNV activity year (red dashed line), and 2016, a relatively normal WNV activity year (green dotted line):

La Crosse Virus (LAC)


ODH is also reporting 17 La Crosse (LAC) virus cases and 2 unspecified California virus cases.  Cases include 12 females and 7 males, ages 3-17, from 13 Ohio counties.  The rainfall we’ve had this summer has continuously filled tree holes and containers with water, creating ideal conditions for tree hole mosquitoes (vectors of LAC virus) to breed.  For more information about LAC and other arbovirus cases and surveillance data in Ohio, see the current Ohio arbovirus surveillance update at

Surveillance season is beginning to wind down, but with continued warm temperatures and active infected mosquitoes, the risk of new infections will continue until we have a hard freeze.  In fact, we have several suspect cases under investigation and we continue to receive new reports each week.  With this in mind, please continue your community and public education efforts focusing on personal protection and source reduction.  For more information, please check out our website at or you can call the Zoonotic Disease Program (ZDP) at (614) 752-1029.