When is Sevin not Sevin?


The name Sevin® has long been associated with flea control in pets, as well as with vegetable garden pest control.

Any gardener who’s been around the block a few times has probably used the insecticide Sevin®, known generically as carbaryl. First introduced to the public in 1956, carbaryl was the first commercially successful product in the carbamate insecticide class.  Since then, it has been a pest control workhorse for vegetable gardeners and fruit growers.  It’s relatively low cost, broad spectrum activity, and relatively short (usually 3-day) interval between application and harvest made carbaryl a popular choice for growers.  Its relatively low oral and skin toxicity to mammals also made carbaryl a favorite treatment choice for on-pet use against fleas.

In recent years, newer, more powerful pyrethroid insecticides have come to dominate store shelves, making carbaryl harder to find. A few years ago the Sevin® trade name was purchased by the pesticide distributor GardenTech.  This year, GardenTech is switching the active ingredient in Sevin® Insect Killer from carbaryl to zeta-cypermethrin, a newer pyrethroid insecticide.

According to one industry rep, GardenTech “upgraded” the active ingredient in most Sevin® products to zeta-cypermethrin this year. Sevin® Insect Killer Lawn Granules are changing their active ingredient to bifenthrin + zeta-cypermethrin.  The Sevin® Ready-to-Use 5% Dust is not changing immediately. It is still carbaryl, though this may also change.

Manufacturers commonly change ingredients in brand name products; however I can’t recall a similar name change in an insecticide active ingredient so closely tied to a trade name as carbaryl and Sevin®.  It will be hard for me to disassociate myself from thinking of Sevin® as anything other than carbaryl. It is something akin to changing the active ingredient in Tylenol® to something other than acetaminophen.

So if you expect to be getting carbaryl the next time you go to the store, look carefully at the label. If it’s a GardenTech product you may be getting a different active ingredient than what you expected.  That’s not to say the change will be bad. Zeta-cypermethrin and bifenthrin are both excellent active ingredients with longer staying power than the old carbaryl. In some, if not most, cases, it will likely perform better than carbaryl. But for some pests it may not.

To verify the active ingredient in Sevin® or any other insecticide, look in the list of active ingredients at the bottom of the front label.  You should see a generic active ingredient name followed by its percent content in the product by weight. This is one of the first things I look for when shopping for a pesticide.  It’s a wise gardener who knows what they’re spraying on their plants.  For more information, see our fact sheet on Understanding Common House and Garden Insecticides.


Bug bombs away

Raid spray ad

Mr. Raid, from an early 1950s TV commercial, has influenced our thoughts about pest control.

For many of us, the ultimate solution for cockroaches and bed bugs and other household pests is the “bug bomb.” Remember the old Raid commercials, where bugs flee from Mr. Raid, only to be followed home by the ominous cloud of death?  The implication is that the cloud from a bug bomb is like a heat seeking missile, able to follow pests into their deepest safe houses.

So how well do bug bombs really work?  It turns out, not nearly as well as the animated ads suggest. Give a bed bug even a slip of cotton fabric to hide under, and even highly pesticide-susceptible bed bugs are unaffected by a total release fogger (bug bomb) blowing its top only a few feet away. This, according to a study conducted at Ohio State a few years ago.

Pest control professionals have long known that bug bombs in kitchens and other areas rarely eliminate cockroaches. Rather they seem to drive pests deeper into walls and utility areas.  It turns out that aerosol insecticides do not penetrate cracks and crevices where pests spend most of their time.

Then there’s the growing concern about safety. A recent CDC report documented 3200 illnesses resulting from use of TRFs in just a few states between 2007 and 2015.  Of these cases, 92% occurred in homes.  Symptoms of exposure included cough, shortness of breath, chest irritation, vomiting, nausea, and cramping.  78% of cases were classified as low severity, and four out of the 3,222 cases were fatal.  Some cases occurred when users did not vacate the treated areas while treating. Other times people entered too soon, or before the home was adequately aired. Moderate and severe illnesses occurred in men over 60, people with preexisting asthma, or who did not leave the treated area as instructed on the label.

Insects that escape into cracks and crevices are tougher than TV ads would have you believe. Insecticide fogs are not designed to penetrate under or inside furniture or walls.

This is no “smoking gun” report, implying that TRFs cannot be used safely indoors. Rather it seems to indicate that many people are not following fogger label directions, and thus reaping unhealthy consequences.

And then there are those folks who guess as to how many bug bombs they need, rather than following the label. It seems to be a universal human belief that when it comes to insecticides, “if a little is good, more will be better.” But besides increasing the risk of pesticide overexposure, using too many TRFs can lead to explosions, especially when aerosol particles build up around an open flame, like a stove or water heater pilot. This fact helped elevate bug bombs into the follies section of Snopes.com (a myth busters website dedicated to exposing urban legends).  In this case, Snopes investigated the idea that bug bombs might cause explosions and found that indeed explosions can result from using too many bug bombs at a time. One recent explosion, not only destroyed an apartment, but killed the owner’s cat.

The lesson from all this is that foggers are not very effective for insects that spend most of the time hiding, such as immature fleas, cockroaches, bed bugs and ants.  They can help rid a room (temporarily) of flying insects, or insects otherwise in the open; but these problems are much less common. There are many other, better, ways of managing cockroaches and bed bugs that you can read about in the Citybugs website.

Personally, I don’t often recommend total release foggers.  But if you choose to use one, take the time to calculate the size of the room (length X width X height) before your purchase.  Then read the product label in the store to calculate how many TRFs you need. Do not buy or use more than recommended. It is a waste of money and potentially dangerous to you and your pets.

A day in the life of a mint

sweat bee

A type of sweat bee, Agapostemon splendans, on mountain mint in a Connecticut schoolyard. Photo by D. Cappaert.


Growing plants is so much more interesting when you get to know your garden’s wildlife. Few of us will ever take the time to spend an entire day watching all the insects, spiders, birds, and reptiles attracted to our backyard garden. But if we did, we would probably be amazed at all the critters calling our yards “home.”

Fortunately for us impatient folk, retired entomologist David Cappaert has done just that. Last summer, after noticing an unusual abundance of insect life attracted to just one kind of plant in his local school garden, he decided to spend 12 hours of a day photographing all the fun.  The result is a 12-minute video showing 52 different insect and spider species attracted to the mountain mint, Pycnanthemum sp., in a Connecticut schoolyard.

The kind of insect diversity illustrated by this video is not something one will only find in Connecticut, or in a nature preserve, or in a uniquely special Eden. David’s school garden resides in a [biologically] “degraded urban habitat,” as he describes it.  The point is that there is much beauty to see in the plainest of flower patches.

The most famous of U.S. entomologists, E. O. Wilson, has observed that one could easily spend an entire scientific career peering into the life and chemistry of a shovelful of soil, or a trunk of a tree. “When you thrust a shovel into the soil or tear off a piece of coral…You have crossed a hidden frontier known to very few. Immediately close at hand, around and beneath our feet, lies the least explored part of the planet’s surface.”

I hope you’ll check out David’s video and, when spring returns, spend a little time observing the visitors to your garden.


Give the love of insects this Christmas

Kids who can touch and manipulate real insects are most likely to connect with, and love nature.

Parents, here’s a Christmas idea for your kids. A hand lens, an insect net, a set of pins and an insect collection box could provide a doorway to the love of nature for your child. For some kids an insect collection can be the best way to learn about insects and connect with the outdoors. Photography is also good, but collecting engages all the senses in ways that a camera cannot.

Many entomologists got their start collecting insects. An insect collecting kit as a Christmas present got one of my entomologist friends started on his lifelong love of insects.  And though young entomologists more often than not drift into other interests, like biology or medicine or other sciences, one thing I know: Anyone who spends much of their childhood in the woods and fields hunting insects (or snakes or frogs, or whatever) will love nature more than someone who did not. And goodness knows, our planet needs these kids more than ever.

A 2016 publication by the Louisiana State Arthropod Museum, and the Clemson University Arthropod Collection, provides a great introduction for anyone wanting to start their own insect collection.  Click here to download your copy The two page brochure provides simple instructions starting with how to get specimens for your collection, where to get the basic supplies, and how to pin your catch.

To this I would add these simple recommendations:

At this point, you may be asking yourself if you want to encourage your child to kill things. Great question! No gentle soul likes to kill something, but an insect collection with real insects is the best way to know the true identity of an insect. And all knowledge of insects starts with an actual collection. You shouldn’t worry about endangering an insect population through collecting. The benefit to nature from a child getting to interact with, respect and even love his or her catches will far outweigh the sacrifice of a few insect lives (and insects have very short lives).

A butterfly-collecting acquaintance of mine maintains a large personal collection at his home. He will tell you that each of his specimens, along with the labels he painstakingly recorded collection data on, represents a memory and a connection with the place where it was collected. Hunting and fishing probably come closest to a similar bond, but insect collecting is, I think, more personal.

Lastly, if your child loves being outdoors and learning about all kinds of animals and plants, consider 4-H.  It provides a great opportunity for kids both in rural and urban settings. Two of my entomologist friends and colleagues got their start in 4-H by making a collection (1st place insect collections at the Minnesota and Indiana State Fairs!). If you’re in Texas and want to learn more, check out the entomology site for Texas 4-H.  Not all counties will have an organized entomology club, but some do. And you can always be the one to start one.

2nd Edition of Garden Insects of North America

Whitney Cranshaw with book
Whitney Cranshaw with book

Whitney Cranshaw shows off his new book at the Entomological Society of America annual conference in Denver.

The Master Gardeners I have trained over the years may remember the big stacks of books I bring with me to every insect class.  I love books and use them a lot in my job. One of the most useful references I use and recommend to Extension volunteers is the Princeton University Press Garden Insects of North America.  It’s been a great resource, and a bargain to boot, since it came out in 2004.

Now Garden Insects of North America has a second edition.  The original author, Whitney Cranshaw from Colorado State University, is joined in the new edition by David Shetlar, professor of urban landscape entomology at the Ohio State University. Together, these two guys make the most knowledgeable and experienced ornamental entomology writer teams I can imagine.

Both authors are experienced photographers and have taken many of the pictures in the book. In any case, the original edition has been enhanced by more and larger pictures (3,300 total!), and the text significantly updated.  If you’re serious about knowing what’s chewing-on, boring-in, or sucking-from your plants, you need this book.

Fair warning: this book is about the insects. It does not provide control recommendations. But knowing the insect on your plant, and its biology and behavior, is the first step in finding a solution.

Cost is $35 ($24.50 with discount) and it is expected to ship in early December.  To view information about the book or to pre-order, go to https://press.princeton.edu/titles/11145.html  and make sure you select the 2nd edition. When you go to the checkout, use the promotion number EX213 to get the discount. It could make a nice gift for any gardener on your Christmas list.  I’m ordering mine today.


Devastation of Monarch butterfly habitat in 2016

monarch butterfly on goldenrod
dead monarch butterflies in snow

Mostly dead butterflies in Sierra Chincua Sanctuary, Mar 11, 2016. Photo by Dr. Isabel Ramirez, Journey North website.

For all fans of monarch butterflies, a new article in American Entomologist may be of interest.  Lincoln Brower and colleagues describe the most devastating weather event for the monarchs since studies began 24 years ago.

For many years it was known that monarch butterflies migrated; but not until 1975 did scientists discover that most monarchs in the eastern half of the United States migrate to a remote mountainous site in south-central Mexico. The Monarch Butterfly Biosphere Reserve was designated a World Heritage Site in 2008, and is located in a pine-oak forest ecoregion on the border of Michoacán and State of Mexico, about 60 miles northwest of Mexico City.

The actual size of the preserve used by monarchs grows and shrinks each year depending on the numbers of returning monarchs and weather conditions at the site.  Since the early 1990’s when records began, the size of the overwintering site has fluctuated from a high of 44 acres in 1996-97 to a low of 1.6 acres in 2013-14.  Computer models have predicted that, due to concerns about effects of illegal logging in the preserve, weather extremes possibly due to climate change, and the large fluctuations in the modern population of overwintering monarchs, the chance that the eastern monarch migration will cease and the butterflies become functionally extinct over the next 20 years is between 11 and 57%.

Just when scientists hoped the monarch preserve was making a comeback a 2016 storm blew down trees in the reserve and reached lethal low temperatures, killing many butterflies.  Brower’s article and its accompanying pictures tells the story. The authors note with alarm that government permission given to private companies to log fallen trees in the preserve following the storm has caused serious thinning of the protective tree canopy.  They estimate that between 30 and 38% of all overwintering monarch butterflies were killed during the 2016 storm.  Of even more concern, however, is that the long-term health and viability of the Monarch Butterfly Biosphere Reserve may be compromised.

It’s monarch season right now in Texas, so don’t miss your best opportunity to get outdoors to catch our Texas state insect as it slips south to Mexico.  The story of the monarch plight reminds us not to take our noble black-and-orange butterfly for granted.  If we do, the fall monarch migration may be a sight that our next generation will no longer remember.


Class labeled a “bug success”

insect collecting
insect field trip

Bee expert Karen Wright (left) shares information about her catch with class members (from left) Carol Clark, Greg Tonian and Rebecca Schumacher.

By all accounts, this year’s Master Volunteer Entomology Specialist (MVES) training was a “bug success”. The 2017 class was held Sep 18-21 at the Texas A&M AgriLife Center at Dallas, and represented the 12th time we’ve offered the course since 2003. I hosted this year’s class with lots of help from colleagues.

Every year’s MVES class agenda is unique. In addition to core sessions (general entomology, insect orders, integrated pest management, and insects of trees and landscapes), we heard talks on insects that eat other insects, beekeeping, native pollinators, butterfly gardening, and environmental education. Our two field trips visited the Heard Nature Museum in McKinney and the Plano Environmental Education Center and Community Gardens.  All students receive a bug collecting kit, high quality magnifier and field guide. After field trips to collect insects, our instructors helped everyone start their own insect box.

The talk on native pollinators by our entomology museum curator Karen Wright was especially interesing. Karen is an expert on native bees, and provided a unique perspective on the importance of this often overlooked group. Karen also wowed the class with her 20-year-old Subaru, tricked out with roof-hugging bee sculpture and a variety of insect artwork.

Erin Hoffer, Environmental Educator with the City of Plano, provided a change of pace by demonstrating interactive games, craft projects and songs.  She showed how insects can be used to engage children (and adults) in learning about the natural world.

A honey tasting session with bee educator Janet Rowe, stimulated everyone’s taste receptors and provided a better appreciation for the subtle differences in bee honey.

We offer the MVES class every year to active Master Gardeners and Master Naturalists. If you complete the class, and volunteer 20 hours on entomology-related activities, you receive a pin identifying yourself as an Entomology Specialist.


Perhaps the best testimony about a class comes from the participants themselves. Here are a few comments we received about this year’s training:

  • Thank you for a very enjoyable class.  I was feeling stagnant as a master gardener and it  rejuvenated me and piqued my interest again.
  • I cannot begin to thank you enough for hosting and leading this year’s training. I am completely self-taught [in spiders] and it was so amazing to actually learn from experts in the field. The biggest thing I learned is: I might have missed my calling.
  • I thoroughly enjoyed the hands-on, engaged and educational training I attended this week. and know more about insects now than I ever did! The presenters and presentations were exceptional and valuable. I look forward to apply what I have learned.
  • The class, the speakers, tour guides, and fellow students were all great!  I have participated in quite a few very good specialty training  classes, but this was the best ever! Thank you!
  • I had initially been hesitant about the class after an experience with another poorly-organized specialty class, but Entomology Excels!  Thanks so much.
  • I have attended many certification courses over the years for both professional and personal projects.  This course was the smoothest ever and all of the professionals involved and the auditor volunteers were amazing.  Truly an exceptional experience and this is coming from one with the most discerning taste and high expectations.

Join Us

For any Texas Master Naturalist or Master Gardener interested in being a specialist for your county or chapter, the class will be offered again next year in College Station.  For more information, visit our MVES website at https://agrilife.org/insectspecialist/ Information about how to register for the upcoming class is usually posted each June.

And now it’s mosquitoes

Hurricane Harvey continues to leave its mark on Texas. Besides the giant cleanup, hoards of mosquitoes are now descending in many areas. The pictures are impressive. Just a couple of examples are enough to make the point. The young man in the picture here was fortunate to have chosen a sturdy shirt before venturing out last weekend.

Heavy mosquito invasions are covering portions of the Harvey-affected areas two weeks after landfall.

The mosquitoes in this picture are probably in the genus Psorophora, (sore ROFF oh ruh) one of our largest, most painful and aggressive biters.  Psorophora mosquitoes have some impressive chops when it comes to survival.  One of the so-called floodwater mosquito species, they lay their eggs on land rather than water like most mosquitoes.  But not just on any land–eggs are laid at the edges of receding floodwaters, where they will re-hydrate and hatch during the next large rain event.

Because Psorophora are opportunists, taking advantage of brief rainstorms, they must have a quick lifespan.  The larvae of floodwater species like Psorophora are the speediest growers of all mosquitoes.  They need as little as 3 to 3.5 days of standing water to pass through the four molts common to mosquitoes. The pupal stage has even adapted to survive and complete its development on the mud surface of drying puddles.

mosquitoes on a truck bumper

A Texas sized bumper covered with Texas-sized mosquitoes following the rains of Harvey.

What we see in these pictures is evidence that floodwater mosquitoes had already primed the pump when Harvey hit the upper Gulf coast two weeks ago.  When the rains came, previously laid eggs hatched across thousands of square miles of coastal prairie and marsh, and billions of Psorophora larvae raced through a quick childhood.

Add to this the scope of the disaster. Harvey’s unprecedented rainfall impacted over 400 miles of Gulf shoreline, dumping an estimated 27 trillion gallons of water. The city of Houston doubled it’s previous all time monthly rainfall record with 39.11 inches (and Houston gets lots of rain).  With some 400 miles of Gulf coast prairies producing mosquitoes, I suspect the number of mosquitoes flying around the state right now is also unprecedented.

So don’t be surprised to read and hear lots of mosquito stories over the next couple of weeks.  If you have to be out and about in this part of Texas, there is protection you can carry. For extreme conditions a mosquito head net will be necessary. Wear light colored, tight knit, long-sleeved fabrics. T-shirts or short-sleeved shirts will not be enough.  Permethrin-impregnated shirts and pants may be worth their weight in gold.  And don’t forget to bring DEET repellent. Lots of it.

Thanks a lot, Harvey!

Fire ants make water rescue… interesting

floating mat of fire ants in Houston floodwater
floating mat of fire ants in Houston floodwater

A floating fire ant mat in Houston this week is one of the lesser known hazards of water rescue. Photo by Omar Villafranca NBC DFW Channel 5.

What’s reddish-brown, rides the water like an air mattress, changes shape like an amoeba, and stings like the devil?  If you answered fire ants floating in floodwater, you’ve probably been in Texas high water before.

Floods bring all sorts of wildlife into close and sometimes uncomfortable contact with people, but none perhaps so uncomfortable as fire ants. When their mounds are flooded, fires ants survive by riding air bubbles to the surface, joining feet (tarsi) with nest mates, and floating.  The ingenious behavior that allows ants to float is the result of special waterproof waxes on the fire ant’s body, as well as via the colony’s ability to close ranks and form a waterproof pocket around the precious queen.

Floating colonies can look like ribbons, streamers or a just a massive blob of ants floating on the water. These fire ant rafts can contain all of the colonies’ members—worker ants, brood (eggs, larvae, pupae), winged reproductive males and females, and queen ants. Besides being a way to survive a flood, rafts are another way fire ants colonize new areas.

Research done a few years ago shows that this behavior does not necessarily involve self sacrifice on the part of the ants. Ants on the top of the raft slowly change positions with the ants on the bottom, supplying the whole colony with oxygen and allowing longer survival. In the laboratory floating fire ant rafts survived from 24 hours to 12 days.

But for Texans sloshing through flood waters, the most important fact about floating fire ants are the stings. Before flooding, fire ant colonies may contain up to 100,000 worker ants.  To my knowledge, no survey has been made of raft sizes in the wild, but they certainly can range from thousands to tens of thousands of ants.  That’s a lot of potential stings.

According to A&M AgriLife entomologist Dr. Paul Nester, author of “Flooding and Fire Ants:
Protecting Yourself and Your Family
,” the other thing to know is that you don’t want to bump into one of these colonies while wading or swimming. Once contact is made, he notes, they disperse explosively, quickly covering clothes or skin.  After that the only thing to do is brush them off as quickly as possible.  Sprinkling water or submerging is no solution as the fire ants will only hold on more tightly.

Soapy water may be the fire ant’s Achilles’ tendon, however.  Research has shown that soapy water spritzed on a floating fire ant raft will sink and kill it.  The soap acts to break the hydrophobic coating on the fire ants bodies, causing them to drown.  Plus, soap is mildly insecticidal against many insects.

So if you live in fire ant country, and you have to be out in floodwaters over the next few days, here’s what I recommend:

  • Give any floating ant rafts you see a very wide berth.  At the edges of these rafts worker ants splay their legs ready to grab any dry object.  If that happens to be a boat, oar or you, they will quickly swarm from the water and sting readily.
  • Be equally careful with handling and moving flood debris, as ants may be hiding within. Use gloves and a shovel or other implement when first moving any flood debris, especially if it has been sitting for a few days.
  • If you are on the water and seeing floating fire ant mats, it would be a good idea to carry liquid dish washing detergent (e.g., Dawn or Ivory) and a sprayer or squirt bottle.  1-2 Tablespoons per gallon of water is sufficient to sink and kill a floating mat.  Soap will also be handy for washing off any ants that get in the boat or on someone.
  • If soapy water is not available, immediately break off contact with the raft and peel off ant-covered clothing. Brush ants off your skin with your hands.  Don’t try to wash off with plain water.
  • If you know you are allergic to bee or fire ant stings, either carry an epi-kit, or else find a different way to serve flood victims. You don’t want to end up in the water as a victim yourself.

A chance to fight malaria

How would you like to save a life today? It’s not as hard as you might think.

In the years since Bill Gates retired his position as CEO of MicroSoft Corporation, he and his wife Melinda have devoted tremendous effort to battling malaria.  Malaria and the mosquitoes that transmit it is the single greatest killer of humans in the world, accounting for most of the 700,000+ mosquito-caused deaths annually.  But unlike many of the other major problems in the world, solutions to the malaria epidemic are available now.

The Gates Foundation is partnering with the NGO World Vision to give away 100,000 bed nets. These nets protect families from mosquitoes that carry deadly diseases, including malaria. Each one is treated with an insecticide solution that kills mosquitoes but is safe for humans to touch. Insecticide-treated bed nets have played an enormous role in the fight to end malaria.

If you are willing to take two minutes to learn more about the fight against malaria, and take a one question quiz, Mr. Gates has pledged to donate a bed net on your behalf to a family in Inhambane province–an area in the south African country of Mozambique where malaria is common.  You can do this at the Gates Notes Bed Net Giveaway website.

On a related note, my wife and I recently watched a film about the malaria problem in Mozambique called Mary and Martha, with Hillary Swank playing an American mom who loses a son to malaria.  It’s a sad but compelling and uplifting film, well worth watching.  And it shows how a simple thing like a treated bed net can make a world of difference for families in another part of the world.