Girding our loins for emerald ash borer

Emerald Ash borer
EAB training class screen shot

Screenshot from the new emerald ash borer online learning module.

The emerald ash borer (EAB) that has devastated ash trees throughout the Ohio River valley and Great Lakes region has finally made its way to the Lone Star State.  So far the beetle has been found in only one location in Harrison County, next to Caddo Lake; but over the next few years it will continue to spread.  As it does, it will slowly change the face of our native forests as well as our urban tree landscape.

To prepare for the inevitable changes, Holly Jarvis with Texas A&M AgriLife Extension, has recently led an effort to develop an online training tool to learn about this powerful pest.

LearnOnline is a new Extension web resource for online courses.  The classes are free, and though not yet approved for pesticide applicator CEUs, they may qualify for advanced training hours for some Master volunteer programs.  Check with your local county Extension agent or Master Naturalist chapter officers for details.

Beyond getting official credit, the LearnOnline Emerald Ash Borer module is a great way to learn about, and prepare for, this new pest. To view the course, please go to learnonline.agrilife.org. You may be asked to set up and confirm your account via a link sent to your email address. Or, for the EAB course you can simply login as a Guest.

quarantine counties Aug 2016

Counties currently under quarantine (in yellow) for the Emerald ash borer in Arkansas, Louisiana and Texas.

To find the EAB course, click the category heading “Agriculture and Natural Resources”. A list of all courses in that category will come up. From there, click “Emerald Ash Borer”.  The course is approximately 25 minutes and includes a final quiz (optional if you want a certificate of completion).

Topics covered include “why should we care about EAB?”, “how to recognize the ash trees hosts of the beetles”, “recognizing EAB damage”, “EAB biology”, “who’s at risk?”, “reasons for hope and control options” for EAB.

Let’s get out there and “gird our loins” to fight the spread of this destructive pest.  If you have a favorite tree that’s an ash tree, you will benefit from knowing the battle plan.

New Zika publications

pregnant woman silhouette

Zika Precautions for Women is the latest of several new fact sheets designed to inform Texans about this new mosquito-borne disease.

I was asked a few weeks ago if the collective “we” (meaning the whole state of Texas) were going to be ready for Zika.  My answer was a cautious, “I think so”.  If we’re not, it at least it won’t be for lack of trying.

Zika is a much different disease than West Nile virus. It has different vectors, mosquitoes that prefer to feed on humans over any other animal (unlike WNV mosquitoes, which mostly feed on birds).  It is also very difficult to detect in wild mosquito populations.  The mosquitoes are more difficult to control with spray trucks, so responding to local cases is going to depend more on public cooperation.  Unlike WNV, it’s virtually undetectable in the blood supply, as there is no approved way to screen newly donated blood to see whether it has the Zika virus in it.

If Zika does make it into the country, it will also potentially affects more people.  Any family with members of childbearing age will need to be on high alert.

The CDC recently released its response plan for Zika.  It’s assumptions are sobering:

  • Travel-associated and sexually-transmitted cases will continue to occur and are likely to increase. (we just don’t know how much!)
  • Local transmission (spread) of Zika virus in US territories and affiliated Pacific Island countries is ongoing.
  • Neither vaccines nor proven clinical treatments are expected to be available to treat or prevent Zika virus infections before local transmission begins nationwide.
  • The ability for mosquito control efforts to reduce infection risks may be limited, as has been the case with similar viruses, such as dengue and chikungunya.

The entomology department, and especially my colleague Extension entomologist Dr. Sonja Swiger, has been busy in recent weeks trying to figure out how to best arm you with the best information on how to prepare for the “Summer of Zika”.  As part of the effort, some new fact sheets are now available to answer some of the more common Zika questions.

Quick fix for mosquitoes

This year my wife and I worked all spring to turn our backyard into a flowery paradise.  We installed drip irrigation, planted new plants (including a bunch of perennials for attracting bees and butterflies) and mulched everything against the coming drought of summer.

Now that summer’s here, however, the mosquitoes have decided that since everything’s so nice, they want to be in charge.  In fact I believe every mosquito on the block knows about our backyard, making it difficult to go outside for even a few minutes without repellent.

You see, clearing your own yard of mosquito breeding sites (as I have done) doesn’t guarantee a mosquito free yard.  So how do you take back your yard?  One quick fix that a lot of people are unaware of is the thermal fogger, available through most hardware and garden centers.

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A thermal fogger in use.  Apply fogs in the early morning or evening, when wind is low and bees are less active.  Focus on thick foliage, shrubbery and tall grass where mosquitoes are most likely to hide.

Thermal foggers use heat from a propane burner or electricity, to heat a coil that turns certain oil-based insecticide formulations into a dense smoke of very small particles (10-25 microns–1/10 the width of a human hair).  The small size of these particles allows them to hang in the air long enough to kill flying mosquitoes.  The small size is also effective for penetrating foliage to kill mosquitoes resting in hidden locations.

Thermal fogging is easy to do, and relatively fast.  In my experience, I get several hours to a day or more’s relief from mosquito bites when I fog my backyard–plenty of time for that barbecue, birthday party or wedding reception.

The signature smoke from thermal foggers has its good and its bad points.  On the good side, you can see exactly where the insecticide goes and direct it where needed.  On the other hand, depending on the wind, the smoke may drift beyond your yard.  It’s a good idea to alert the neighbors before fogging your yard, or you might be seeing the fire truck pull up in your front yard.  Also, not all neighbors will be pleased by unexpected mosquito insecticide drifting into their backyard.

So what are the risks of fogging? Risks to humans and pets are very low with the common over-the-counter insecticides sold for fogger use.  But I find few good studies on the impacts of consumer fogging machines on beneficial insects.  I think it’s safe to say that there likely are some temporary impacts on the smaller beneficials like parasitoid wasps, and possibly the smaller bees.  But these insects are also typically highly mobile and should be replaced by other beneficial predators and pollinators quickly.  I believe it unlikely that larger butterflies and bees will be harmed by the low exposure rates used in mosquito fogging.  Although I am still assessing, I’ve not seen any noticeable impacts of occasional fogging on the larger insects I love to see in my garden.

Mark the term “occasional”.  Fogging for mosquitoes is not something I do regularly in my yard (though my vengeful side may want to do it more often).  I reserve my fogging ventures to once or twice a summer, and only when I’m expecting guests or planning a special outdoor event.  This way I can enjoy my pollinator and butterfly gardens and get my quick mosquito fix when I need it.

The rest of the time insect repellent works well.  And I am enjoying our newly planted gardens, despite the mosquitoes.

Reminder: Mosquito season and the risk of mosquito borne diseases kicks into high gear this month.  So don’t neglect the repellent and checking your backyard to make sure you’re not the neighborhood source of mosquitoes.

Turning the tide against ash borer?

Green ash
Tetrastichus planipennisi adult

Tetrastichus planipennisi is an obscure little wasp that specializes in finding and parasitizing the larvae of emerald ash borers.

On one hand, we’ve learned a lot about how to fight emerald ash borer with pesticides in the past 14 years since it was first discovered devouring ash forests in Michigan.  But we’re still learning how nature keeps EAB in its place in its native Asian home.  Insect parasites and predators are almost certainly the reason EAB is not a major pest on the other side of the globe.

If only we could put some of those same beneficial insects to work for us!  Then maybe we could slow the spread of EAB, and save our ashes at the same time.

That’s the idea behind research being reported this month by USDA Agricultural Research Service scientist Jian Duan and other researchers with the US Forest Service and the University of Massachusetts.  They looked at a tiny wasp, Tetrastichus planipennsi, that specializes in laying its eggs in the bodies of EAB larvae feeding under the bark of ash trees.

Over the course of the 7-year study the researchers saw a 90% decline in EAB larvae in infested trees caused by both native parasitoid wasps and by T. planipennsi.  They believe that once these fighting wasps are released in an area they will reduce the population growth of EAB and perhaps prevent outbreaks in newly infested areas–like Texas.

This will certainly be among the tools that the Texas Forest Service and others will be bringing into play as EAB makes its first tentative steps into our state.  In the meantime, don’t transport cut firewood when you’re out camping this summer, especially in the Caddo Lake region of east Texas.  And stay tuned for more news concerning the spread of this devastating insect.

Closer than you’ve ever been

mantispid

mantispid by Levon BissPhotographer Levon Biss started out with portrait and sports photography, but got hooked on insects.  Now his extreme photographic skills have landed him a gig at the Oxford University’s Museum of Natural History.

Biss shoots his images through a microscope to create scenes that no human eye has seen before. That’s because, even for an entomologist with a very good microscope, it’s impossible to see a full insect, like the mantis fly image shown here, in complete focus all at once.

Biss achieves this by piecing together around 30 mosaic images, each of which might itself be a montage of 2-300 images shot at a slightly different focus point. Each picture in his exhibit at Oxford is comprised of between 8,000 and 10,000 images.

All this work allows Bing to create pieces of art that cover a canvas the size of a wall.  So if you can’t make it to Oxford University this summer, at least check out this video on Facebook to learn more about the process. Its worth the 5 minute watch time.

Emerald ash borer enters Texas

emerald ash borer damage
emerald ash borer damage

Dying roadside ash trees in another state. Ash trees are recognized by their opposite branching pattern and compound leaves. Photo by Leah Bauer. Bugwood.org

If you’re a Texan and haven’t heard about an insect called the emerald ash borer, that’s about to change.  The emerald ash borer (EAB) is an invasive beetle that feeds almost exclusively on ash (Fraxinus spp.) and has been slowly spreading through the eastern and midwest states from Michigan where it was first discovered in 2002.

On May 23 the Texas Forest Service, along with the U.S. Forest Service, announced that four EAB beetles had been discovered on a trap in Harrison County, TX along the Louisiana border.  Although no infested trees have yet been discovered in Texas, these beetles signal a perhaps inevitable change in fortune all for Texas ash trees.

Last summer I visited Indiana where EAB has been active for several years.  The destruction was sobering.  Dead trees along highways, in parks, and in yards.  In fact you would be hard pressed in Indianapolis or Lafayette, where I visited, to find a single healthy ash unless it had been treated with a protective insecticide.

Emerald ash borer affected trees typically die two or three years after becoming infested. Native to Asia, nothing seems to be stopping the EAB, short of continual insecticide protection. The beetles have killed tens of millions of ash trees throughout the U.S., and currently 26 states are under quarantine restrictions for shipping of ash wood.

In the United States, 16 ash species are susceptible, and Texas is home to seven. According to TFS, ash trees make up less than 5 percent of rural Texas forests but are a larger portion of urban street and park trees. Texas A&M Forest Service is currently working with APHIS, the Texas Department of Agriculture, Texas A&M AgriLife Extension and the U.S. Forest Service, among other state and federal agencies, to implement a state response plan.

In a web conference this morning, state and federal officials sought to reassure the Texas timber industry that, at least initially, any impacts to forest products industry should be low. The TFS has established a new website where Texans can follow the progression of any invasion, and learn what steps that can be taken to protect your personal ash trees.

If you have an ash in your backyard there is little immediate threat unless you live in Harrison county, or an immediately adjacent county.  Experience with EAB in other parts of the country suggests that there is no need to treat your ash tree unless your home is within 10-15 miles of a known infestation, and that still has not occurred anywhere in Texas.

For more information about how to spot EAB damage see my earlier post at http://citybugs.tamu.edu/2015/10/23/recognizing-emerald-ash-borer-damage/

And, by the way, if you’re looking for a nice shade tree to accommodate you in your retirement years, and you live in Texas, I wouldn’t choose any kind of ash.

2016 Entomology Specialist Training Announced

AgriLife Logo

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One of the great opportunities offered to Master Naturalists and Master Gardener volunteers in Texas is a wide array of specialized training opportunities.  Entomology has its own version of this with Master Volunteer Entomology Specialist training.

MVES pin awarded to volunteers who successfully complete the class and volunteer hours.

MVES pin awarded to volunteers who successfully complete the class and volunteer hours.

Offered every year, MVES training is a multiday event designed to expand on normal entomology training every Master Volunteer receives during the internship program.  The curriculum is designed to appeal to both Master Gardener and Master Naturalist volunteers with an interest in insects.  Everyone who completes the course and volunteer hours on an entomology project receives a pin and status as an entomology specialist.

Class organizer for 2016 is Molly Keck, urban IPM program specialist for Bexar County, San Antonio. Molly does a great job and is an enthusiastic teacher.  She will be joined by an excellent slate of guest speakers talking about all things insect.  Presentations will cover Entomology 101, how to make an insect collection, blacklighting for insects, intro to beekeeping, Integrated Pest Management, beneficial insects, urban pests, veggie pests, landscape & ornamental insects, invasives, pollinators and much more!

Dates for 2016 are Monday September 26 (noon) – Thursday, September 29, 2016 (noon).  It will be hosted this year by the Bexar County Master Gardeners, and classes will be held at the Bexar County office and at Hardberger Park in San Antonio, TX.

To find out more about the program, and how you can register, go to http://agrilife.org/insectspecialist/2016/04/18/2016-master-volunteer-entomology-specialist-training-scheduled/   To see pictures from 2015 training, click here.

 

New fact sheet on indoor flies

dark-eyed fruit fly
fruit fly

Dark-eyed fruit flies are just one of several flies covered by the new publication.

Got flies? A new House and Landscape Series fact sheet will help you figure out what you have, and how to search out the source of the problem.

Indoor flies are opportunists.  Give them a place to breed, and they’ll be all over the place just like, well, flies.  Knowing where these breeding sites are is much easier when you know what kind of fly is driving you crazy.  Indoor Flies and Their Control (ENTO-050) reviews and provides pictures and descriptions of the most common small and larger indoor flies.

The publication covers both the smaller flies, like fruit flies, phorid flies, drain flies and fungus gnats, and the larger indoor flies like blow flies, house flies and soldier flies.  Each of these different kinds of flies have a preferred place to raise a family.  And by far the best way to rid your home or business of flies is to find and eliminate these breeding “hot-spots”.

When it comes to flies, we’ve all been trained to reach for the spray can.  But insecticide fogs and sprays provide, at best, only temporary control of indoor flies.  If you really want to be fly-free indoors, check out the new fact sheet.

First mosquito of the season

yellow fever mosquito

Before it’s old news, I wanted to make it official.  It’s Aedes (AID ees) season again in north Texas.  Last weekend I spotted my first Aedes albopictus (Asian tiger mosquitoes) of the season.  So from now until November, get used to having these pesky mosquitoes around.

Alex Wild, curator of the insect museum at the University of Texas in Austin (the OTHER Texas University) tweeted his first Aedes aegypti (yellow fever mosquito) of the season a month ago.  Since then I’ve been tempting my local backyard mosquito population with my succulent, winter-white legs while doing yard work, to see when my first mosquito of the year would appear. Until last Saturday, there were no takers.

Generally the Aedes season in the Dallas area starts in mid- to late-April.  So this week’s mosquitoes were right on schedule.  Numbers generally peak in June, but remain high through October.

Ae albopictus by Susan Ellis bugwood.org

Aedes albopictus, the Asian tiger mosquito, along with its cousin the yellow fever mosquito, may be a Zika virus carrier this summer. Though markings on the thorax are different, both species have a dark body with white bands on the legs.

Despite my nerdy entomologist status, I’m not happy to see the return of these mosquitoes.  For one thing, they are especially annoying biters.  Their bites are itchy and their behavior is sneaky! One colleague recently referred to them as “ninja mosquitoes”.  They slip in, take a quick meal, and slip out before you notice anything amiss.  Three minutes later you’re itching like crazy. There’s little chance for revenge by slapping, because they’re so skittish and so fast–they’re usually gone before you know it. And no time or place is safe from these blood suckers.  Both are daytime and evening biters, and both will readily come indoors.

Perhaps the worst thing about Aedes is their potential as disease carriers.  Until now, neither mosquito was considered important health-wise in the U.S. Despite its ominous name, the yellow fever mosquito hasn’t had any yellow fever virus to transmit in the U.S. for many years (due to aggressive mosquito control measures and a vaccine). Neither was thought to be a significant vector of West Nile virus or the other encephalitid diseases that occasionally pop up in our country.

The arrival to the New World of chikungunya virus in 2013 and Zika in 2015 changes all that. The yellow fever mosquito, previously an important carrier of dengue fever, is almost certainly now also the principal vector (carrier) of both of these diseases in Latin America.  While dengue fever occasionally flares up in south Texas and Florida, it’s never really gotten established this side of the Rio Grande.  Even the easily-spread chikungunya virus has not found a home here.

Zika may be different. It’s highly contagious, and its health implications are more significant than chikungunya.  Scientists also think that the Asian tiger mosquito may be competent to spread Zika in the U.S. This is especially alarming because of the tiger mosquito’s more northerly range and greater numerical abundance here.  What’s not in question is that both mosquitoes are here in abundance, and stand ready to assume the role of disease carrier should the disease and right conditions come along.

These Aedes mosquitoes are not difficult to recognize.  Both are small and fast for mosquitoes.  Their entire body is covered with dark or black scales, but they have distinct white markings on the mouth parts, thorax and legs.  If you see a small black mosquito with distinct white rings around the joints on the legs, you are probably looking at one of these two mosquitoes.

It’s difficult to completely eliminate the breeding sites of these mosquitoes because they take advantage of many small water reservoirs.  The adult females are what are called “skip ovipositors”, meaning that they lay only a few eggs in any given breeding container, then move on to another site.  This type of behavior makes these mosquitoes more difficult to control through breeding site elimination because when one site is eliminated, they move on in search of another.

I can testify as to the difficulty of eliminating breeding sites.  I keep a close eye on any standing water in my backyard, but we still have high numbers of tiger mosquitoes in our yard every summer.  Although these mosquitoes do not travel far from their breeding sites, they could easily be coming from a neighbor’s yard not as well patrolled as mine.  Also, despite my diligence, I still continually find new spots with standing water after a rain. As in the memorable line from Jurassic Park, “Life (nature) will not be contained… [it] always finds a way.”

So if you’ve ignored the many warnings to wear mosquito repellent in recent years, and think you’re immune to diseases like Zika or West Nile virus, you might want to reconsider.  We don’t know whether, or how bad, Zika will be in the U.S. this summer; but it has the potential to pop up anywhere, without warning.  So far the only cases in Texas have been with travelers, or via sexual transmission, but the mosquito season is just getting started and Texas is a high risk state.

So keep those white legs covered, or else well protected with repellent, as you venture out in the garden this summer.  Let’s not let this be the summer of Zika.

Zika Virus: What you need to know

zika risk map

What is chikungunya and should I care?

Last December I wrote about bracing for a new mosquito-borne disease called Zika.  Since then, evidence of a connection between Zika virus and two scary health conditions called Guillian-Barré syndrome and microcephaly has grown.

Although there are still no known cases of Zika being acquired from mosquitoes locally, from within the U.S., there is a real possibility that Zika virus could reach Texas this summer.  If so, these issues will become as important to the average stay-at-home Texan, as it is to those folks who are willing to brave the traveler warnings and visit Zika-infested areas of Latin America this year.

Public health officials feel that the most likely scenario, if Zika does enter Texas, is that there will be small “pockets” of locally acquired human cases that start from infectious travelers returning from the summer Olympics in Brazil, or from other travel to the Caribbean (think cruises!) or any of the infected Central and South American countries.  If this happens it will lead to intense concern, especially among families of women of child bearing age.  Risk will be highest during the warmest months of the year, May to October.

The National Center for Atmospheric Research recently developed a map of areas with the highest potential risk of locally acquiring the virus. The map is based on international traffic and how common the primary mosquito carrier of Zika is in the various cities.  In Texas the highest risk cities include Houston and Dallas, Brownsville and San Antonio.

Many U.S. cities face potential risk in summer of low, moderate, or high populations of the mosquito species that transmits Zika virus (colored circles). The mosquito has been observed in parts of the United States (shaded portion of map) and can establish populations in additional cities because of favorable summertime meteorological conditions. In addition, Zika risk may be elevated in cities with more air travelers arriving from Latin America and the Caribbean (larger circles). For a high-resolution map, click here or on the image. (Image based on data mapped by Olga Wilhelmi, NCAR GIS program. This image is freely available for media & nonprofit use.)

NCAR estimate of risk for locally acquired Zika virus in the U.S. Colors represent the likelihood of Aedes aegypti being present, the mosquito species that transmits Zika virus. The mosquito has been observed in parts of the United States (shaded portion of map) and can establish populations in additional cities because of favorable summertime meteorological conditions. Circle size relates to the number of air travelers arriving from Latin America and the Caribbean. Based on data mapped by Olga Wilhelmi, NCAR GIS program (Image freely available for media & nonprofit use).

Texas AgriLife Extension recently published a new fact sheet titled “What Texans Need to Know About Zika Virus”. There are many good links to additional information through this fact sheet, so if you have any interest in the subject, this is a must read.

In addition, there are two new AgriLife website on Zika including the Preventing Zika site,  and the ZIKA 360 site  put out by the Texas A&M Health Science Center. These are excellent resources, and include text, videos and infographics.

Lastly, don’t forget the interactive Mosquito Safari website. It’s a great resource for people who to learn about the different kinds of mosquitoes, what kinds of places mosquitoes breed around the home, and how to control mosquitoes.