Insects in the City
The fear of picking up bed bugs in a hotel room shouldn’t keep you from that next great adventure you’ve been planning. Yes, frequent travelers do have a good chance of eventually encountering bed bugs; but a few simple steps can dramatically reduce your risk of bringing these pesky insects home.
To learn more, check out this new video, produced by my colleague Dr. Pat Porter, that explains what you can do to avoid the curse of the bed bug. And enjoy that next vacation to New York City!
For many years the go-to solution for DIY pest control was the bug bomb. Got fleas? Get yourself a bug bomb. Cockroaches in the kitchen? Bug bomb! Most recently, it’s bed bugs. See a bed bug? Reach for the bug bomb.
But do bug bombs (also known as total release aerosols) really work? Not very well according to a recent paper was published last month in the Open Access journal BMC Public Health. Researchers at North Carolina State University found that not only did bug bombs under-perform (not even killing cockroaches penned in open containers), they left residues on floors and counter-tops.
All homes in the study were infested with German cockroaches, the most common and difficult-to-control cockroach found in homes and restaurants in the U.S. Twenty homes were treated according to label instructions with one of four total release aerosol products. Ten homes were treated with over-the-counter gel baits designed for cockroaches. Cockroaches used for the test included insecticide-susceptible, lab-reared cockroaches and wild cockroaches collected from the tested apartments. Cockroaches were confined in open-topped containers and exposed to the fogs either on the apartment floor or in an open cupboard.
While the wimpy, lab-reared cockroaches exposed in open cages suffered 90-100% mortality, the tougher, “wild” cockroaches, similarly caged, suffered only 10-38% mortality. Keep in mind that unlike cockroaches in your kitchen, the caged cockroaches in this experiment could not escape exposure to insecticide fog. In actual kitchens, cockroaches typically hide in protective crevices when they sense an irritating insecticide.
Researchers also counted “free-range” cockroaches in apartments treated both with foggers and baits during the test. In fogger-treated apartments there was no significant drop in these wild cockroach numbers two to four weeks after the kitchens were bombed. In apartments treated with gel baits cockroach numbers dropped 70-95%. In other words, the “bombs” bombed, and gel baits worked pretty well.
Gels outperformed the bug bombs in terms of safety as well. No insecticide residues were found on untreated surfaces in bait-treated apartments; but all fogger-treated apartments had detectable insecticide residues on horizontal surfaces (floors, counter-tops, inside cupboards) up to a month after treatment. Admittedly, residues were low, and likely of little importance to human health; but foggers do have a record of causing health concerns in people when they are used improperly. Common health concerns among people exposed to fogger contents include coughing, difficulty breathing, itchy throat, headaches and even nausea and vomiting.
Dr. Susan Jones at Ohio State University saw similar results in her studies with bed bugs and insecticide foggers a few years ago. Wild bed bugs almost literally laughed at researchers setting off foggers only feet from their cages in that test.
The lesson? We need to stop thinking about bug bombs as effective tools against any insect that hides in protected places (like cockroaches, bed bugs and fleas), and especially those insects like bed bugs and cockroaches that have developed some degree of resistance to the insecticides used in foggers.
Given these data, it makes little sense to keep wasting money on these old-fashioned, risky and ineffective insecticide devices, especially when there are good alternatives available, like cockroach gel baits. Maybe, when it comes to cockroach and bed bug control, it’s time to kill the bug bomb?
Only with public support will our annual monarch migrations continue for many years.
News headlines often bear a second look. And this week’s “good news” about monarch butterflies is no exception. News sources this week are reporting that monarch butterfly colonies covered almost 15 acres of Mexican mountainside in 2019, a 144% increase from last winter.
Colony sizes are based on estimates of the total acreage of trees covered with monarchs in the Monarch Butterfly Biosphere Reserve in Mexico–the main overwintering site for eastern monarch butterflies. Acreage estimates provide an index as to how many butterflies survived the previous year’s migration, and how many butterflies will be ready to make the journey north in the spring.
While certainly good news, these gains do not mean monarch butterflies are out of the woods (no pun intended). Consider the historical data on monarch colony size fluctuations. According to the group Monarch Watch, between 1994 and 2004 the average overwintering colony size was about 22 acres (equivalent to the size of 7 football fields). Between 2004 and 2018 the average overwintering colony was about 8.5 acres (2.5 football fields). The lowest year on record occurred in 2014 with colony size shrinking to only 1.5 acres (1+ football field).
These areas may still sound relatively big, but these sites represent all monarchs in the eastern U.S. Loss of even part of this habitat due to development or logging could affect monarch butterflies over half the country. What a shame it would be for our next generations to not know the beauty of monarch butterflies.
A separate monarch population blesses the western states. West of the Rocky Mountains all monarchs migrate to protected sites among the hills and redwoods of the California coast. Western monarchs may be even more at-risk than their eastern cousins. One study predicted a 70% chance that these west coast monarchs will go extinct within the next 20 years. Average winter abundance during the 2000s is only 5% of what is was in the 1980s.
We can all pitch in to save these fascinating insects. Consider planting milkweeds and other nectar producing flowers in your gardens this year. Milkweeds provide a food source for monarch caterpillars. Other flowers provide nectar for the adults. Together such gardens can help make up for all the land being converted to concrete and houses. Learn more about what you can do at Monarch Joint Venture. And if you golf, or know someone who works in the golf course industry, tell them about the Monarchs in the Rough campaign to donate enough seeds to plant one acre patches of milkweed in golf courses around the country.
Just as little things, like butterflies, can make a big difference in our lives, your concern can make a big difference in the future of the monarch.
Monarchs resting in a hackberry tree on their way south to Mexico in fall.
Where have all the butterflies gone? If you think there are fewer butterflies, and just plain bugs, on your windshield compared to a few years back, you’re probably right. Recent studies point to alarming declines in both insect and butterfly populations.
Most scientists think that the primary causes for these declines are the many changes we humans are making to our environment. As we replace plant-diverse rural landscapes with simplified urban and suburban streets and lawns, we reduce habitat abundance and food supply for butterflies, among other insects. One of the hardest hit species is the Monarch, whose 2018 populations are at historical lows and down 14% from last year.
The National Wildlife Federation is cooperating with Native Plant Society of Texas to try and slow the decline. The idea behind their most recent project is to persuade more people to devote parts of their home landscapes as butterfly habitat. By providing nectar sources, food plants and safe habitat for migrating Monarchs and other butterflies we help them better adapt to a changing world.
This year these folks will be offering a series of Monarch butterfly-oriented workshops around the state. The first class is scheduled for Spring, Tx on January 25th. It’s an intensive, day-long course covering the basics of monarch biology, conservation and habitat creation. Participants will be trained to pass on their knowledge to others in a grassroots effort to drive change in the way Texans shape the environment.
If you’re interested and would like to learn more, check out the website and registration page.
Consider it payback for the pleasure Monarchs give every spring and fall, and an investment in your grand kids’ enjoyment of nature.
Two Good Sams. Sam Hunt (left) and Sam Kieschnick, Texas Parks and WildLife biologist, were responsible for discovering the first emerald ash borer in north-Central Texas.
Last summer Texas Parks and Wildlife biologist, Sam Kieschnick, was going through pictures on iNaturalist and saw a picture of an insect taken by someone he knew. It was a shot of a shiny green beetle that 10-year-old nature enthusiast, Sam Hunt, had snapped in his own driveway near Eagle Mountain Lake in west Tarrant County.
Something about the picture bothered biologist Sam, so he forwarded it to colleagues who were experts in a group of insects called buprestid beetles. The expert consensus seemed to be that 10-year-old Sam had taken the first picture of an emerald ash borer in the central Texas area.
Emerald ash borer is an exotic beetle that has steamrolled its way through the upper Midwest states since its discovery in 2002. As it spread through Michigan, Ohio, Indiana and other states, something became clear. This insect had the potential to be one of the greatest forest disasters ever to hit the U.S. Not only did it kill millions of young and old ash trees, it appears to be poised to completely eradicate wild ash trees from most of the area it has invaded.
And now, it appeared, this same ash borer had jumped from Louisiana and a few Texas border counties to the outskirts of Fort Worth, part of one of the largest urban forests in the state.
One blurry picture, however, is not enough when it comes to making costly decisions about whether to institute quarantines or alert the public to consider making costly insecticide applications to their trees. An actual sample would be needed.
Dying ash tree in a backyard near the first known sighting of emerald ash borer in Tarrant County.
Meanwhile, the photo stirred interest among professionals at the Texas A&M Forest Service. Consequently, last summer TFS forester Allen Smith organized two expeditions to the area where 10-year-old Sam had taken his picture. On the second trip he and colleagues were able to collect beetle larvae from under the bark of dead ash trees from the neighborhood. This month those larvae were confirmed, via DNA testing, to be emerald ash borer.
How the beetle made its way to Tarrant county is still being investigated, but it’s likely that the beetles found this fall have been in the area for several years. It typically takes around three years to kill mature ash trees, and the infested neighborhood appears to already harbor many dead or dying ash trees.
The Texas Department of Agriculture is currently considering steps to declare Tarrant County, and possibly nearby counties, part of an emergency quarantine zone to prevent transport of any suspect firewood or tree trimmings to un-infested areas. This will require the cooperation of wood carvers, firewood distributors, utility and tree care companies, as well as the public. Although there is probably no way to keep the ash borer from eventually spreading throughout the state, efforts to stop accidental human transport will slow the spread of the beetles to your home.
Current recommendations developed from experience with the beetle in the Midwest suggest that valuable ash trees within 15 miles of a known ash borer infestation be preemptively treated for the pest. This would mean that many residents of Fort Worth and the nearby city of Weatherford should consider treating any valuable ash trees within the next 2-3 years.
Fortunately for us, ash trees make up a relatively small percentage (about 6%) of urban shade trees in the Dallas/Fort Worth area. But if you have a beautiful ash tree in your yard, and it provides good shade, you may want to consider treating it every one to three years to protect it from the emerald ash borer.
For most of us, it’s not yet time to panic. But keep in mind that as the borer nears your home you will be face with the decision whether to treat or not. Just keep in mind that if you don’t treat, you can probably kiss your ash goodbye. 😥
[Note: There is much good information on ash tree treatment online. However, we will be following up with Texas treatment recommendations in coming months. Stay tuned.]
Monarch adults need a variety of flowers, including lantana, for energy as they fly south for the winter. A single monarch typically travels 50-100 miles a day.
In case you haven’t seen your first monarch butterfly of the fall migration, you should start looking now. Mid-October is peak monarch observation month in Texas.
So what is fall migration and why all the fuss about monarch butterflies? Monarchs are one of relatively few insects that have true migration. And one of the few migrant animals who instinctively travel thousands of miles to an overwintering site they have never seen before.
The monarch migration starts each spring with old butterfly adults that have overwintered on a dozen or so mountains in the Mexican states of Mexico and Michoacán, west of the capitol, Mexico City. These mountains provide an ideal overwintering site for resting monarchs. In February each year, these overwintering monarchs leave for the southern U.S. where they will find milkweed plants suitable for their eggs and caterpillars. Here these overwintering monarch adults die, but somehow mysteriously pass on knowledge of the migratory pathways to their offspring. This happens 2-3 more times, all the while they travel further north, until the advent of shorter days and dropping temperatures. These are cues which tell the 4th (or 5th) generation that it’s time to head back to Mexico.
This map shows the annual migratory pathways of the eastern population of Monarch butterflies. Green arrows show Generation 1, followed by second (blue) and third (dark blue). Red arrows indicate the two major fall migratory pathways by which monarchs return to their overwintering home in Mexico.
The citizen science project Journey North provides real time tracking of the monarch migration each year. To see the progress of this year’s migration, click here. And to see a map of historical Texas data on monarch migration, including when they are likely to be in your area, click here.
For more information about the amazing monarch journey, click here to see a great 12 minute video by National Geographic. But don’t just be content with a video. Now’s the time to take a walk and look for monarchs. Chances are that any butterfly you see has already come hundreds of (or even a thousand) miles on its long trip south.
Moths, like these fall armyworm moths, have emerged by the millions this week in north Texas.
If you live in the Dallas/Fort Worth area, or any other place that has had a recent outbreak of fall armyworm caterpillars, you may have noticed an increase in fast-flying, grey-brown moths. I started noticing these last week, and they appear to be growing in numbers today. If you drive early in the morning, or in the evening, you might even catch these moths in your car headlights.
It’s all part of a circle of life: moths lay eggs, which turn into caterpillars, which pupate (think of a cocoon, or chrysalis), then emerge again as moths . This kind of moth outbreak happens commonly enough that Texans, and others around the country, have even given such moths a name. You may hear older citizens and farmers referring to “millers”. Millers, as far as I can tell, is a generic name for any moth that becomes abundant in and around homes. In some areas, millers show up in large numbers in the spring, and in others during the fall. Most people consider them a nuisance, and commonly worry that they are a precursor to some great plague.
Scientifically, these insects are called Noctuoid moths, a collection of several families that include armyworms and cutworms. Night-fliers all, miller moths avoid sunlight and head for hiding places in bushes, tall grasses and flowers when daylight arrives. To see if you have been visited by millers, find some bushes or tall grass and do a little brush beating. If present, you will see big gray moths zig-zagging away. Many of the ones I’ve seen appear to be fall armyworms, which I wrote about a couple of weeks ago as being unusually abundant this year.
With enough warm weather, it is possible today’s miller moths will turn into another generation of caterpillars; but given the long-term forecast for cooler weather in the next two weeks, I’m guessing this won’t happen. With cooler weather, the armyworm life cycle slows considerably, as does its appetite for crops and grasses.
Nevertheless, it won’t hurt to keep a close eye on your vegetable gardens and lawns over the next few weeks. Look for small caterpillars and leaf damage. If you do catch early damage, armyworms and cutworms can be treated with B.t. sprays or with the biological insecticide, spinosad.
By the way, given the warmer temperature cycle we are in, one of the things we can count on will be more and longer pest seasons. Later frosts mean more time for moths like the millers to reproduce and start a new family. One more reason to wish for cooler weather.
Armyworms are common caterpillars that prefer lawn grasses over other plants in your yard. When present in large numbers they appear to march in army-like formations, migrating to areas of fresh grass. These caterpillars are about 3 cm (1 inch) long.
I’ve noticed something lately. People are consistently amazed when nature intrudes on their lives, as if it’s a great exception to some law that states “nothing unusual should ever happen to me.” Whether it’s hurricanes or a snake in the house, or something as mundane as a caterpillar outbreak, the usual reaction is astonishment. That seems to be the common thread among callers this week with regard to the latest fall armyworm outbreak.
I say “latest,” because fall armyworms are nothing new. According to Dr. Allen Knutson, extension agricultural entomologist in Dallas, fall armyworms are present every year; however, this year they are a widespread problem for hay producers and small grains producers across the state. “I’ve had calls as far west as Wichita Falls, south to Comanche and across east Texas,” he said. Locally, my turfgrass colleague, Dr. Lindsey Hoffman, and I have gotten many calls this week from concerned lawn owners, schools and reporters in the north Texas area.
The caterpillar stage of a drab brown moth, fall armyworm is known scientifically as Spodoptera frugiperda. It feeds primarily on grasses, though it has been reported feeding on dozens of non-grass plants and weeds. It earns the name “armyworm” from its habit, during times of major outbreaks, of marching, army-like, across fields and roads and yards, consuming everything in its path. This is one of those years.
Click here to see a video of fall armyworm that shows what to look for https://www.youtube.com/watch?v=ZEK_l7eMEvI
Fall armyworm caterpillars can vary in color, but generally have three yellow dorsal stripes; an inverted, white Y on the face; and three stripes on the plate just behind the head.
Not to worry
While some farmers may be hit in the pocketbook by the outbreak, homeowners don’t have much to worry about. Armyworm damage in home lawns can be breathtaking, but it does not usually hurt the lawn in the long-term. Because armyworms feed on the leaves, and not on the critical roots and stolons, a little irrigation or a rain should restore lawns to their original condition within a week or two. Fall armyworm will feed on most common lawn grasses like bermudagrass and St. Augustinegrass.
Lawn browning often appears to occur overnight, though armyworms need three to four weeks of feeding to do their damage. The last week or so of the larval stage is when most of the feeding, and damage, occurs.
If you want to treat for aesthetic reasons, standard residual insecticides like bifenthrin, cyfluthrin, permethrin, esfenvalerate, or carbaryl should quickly eliminate an armyworm invasion. These products are best applied as a spray; a hose-end sprayer is a convenient applicator.
Organic gardeners should either leave the infestation to run its course, or treat with the natural insecticide, spinosad. The organic gardener’s other favorite caterpillar spray, Bt, can kill armyworms but has a very short life on the grass and will be less effective than spinosad.
Fall armyworms differ from many other caterpillar pests in that they do not survive the winter in areas where it freezes. In Texas, they probably survive winter only in far south Texas. As a result, whether you treat or not will have no effect on whether you are likely to see this caterpillar next year.
So don’t be shocked this fall if you see caterpillars in your yard, or marching up sidewalks or exploring the sides of your house. Unusual things like fall armyworm invasions can happen, even in your yard; but this one is no disaster. For more information, see https://tinyurl.com/fallarmyworm
YouTube is both a tremendous waste of time and also one of the best things to happen to DIYers in, like,… forever. I find myself checking it constantly for instructions on how to do everything, from troubleshooting my computer to making repairs on my car. So why not a video on how to control crapemyrtle bark scale?
What is crapemyrtle bark scale (CMBS)? It’s a small sap-feeding insect that lives on the bark of certain plants, especially crapemyrtle. Thanks to its sugary excrement, it turns crapemyrtles with beautiful honey-colored trunks into black sticks with sticky leaves. It also reduces blooms and weakens some trees.
The good news is that we now have some good insecticidal control methods for CMBS and we are seeing more natural control with the help of beneficial insects. Several kinds of lady beetles are helping to keep scale numbers down in many locations.
To show you how to put our research findings to work for you, we’ve put together a 9-minute YouTube video. To get the whole lesson, grab the popcorn, sit back and click this link or the video above. (Remember that control may take several weeks to become evident, and dead scales will not fall off on their own.)
If you have a crapemyrtle tree in your care, and have not yet encountered CMBS, consider yourself lucky. But, for the rest of us, this insect is a pestilence. And if you think you’ll never have the problem, think again. It’s just a matter of time before CMBS will be found throughout the southeastern U.S.
If you are seeing CMBS for the first time, it may be new to your area. Consider reporting your backyard or local infestations to the EDDMaps website, which is tracking spread of this pest.
A gardener recently asked me what she could do about squash vine borer. She then proceeded to list all the recommended treatments she had tried already, ranging from shooting the vines up (literally, with a hypodermic syringe full of Bt), to putting out yellow bowls to catch adult moths, to watching a gazillion videos on YouTube, to praying to the bird gods to eat the little buggers.
To answer her question I spent time reviewing a new and old publications, including a new review of the literature on this pest. Entomologists around the country also took the time to provide input on the question. As a result, I thought I would share some of the thoughts and ideas I gleaned with you.
The squash vine borer adult is fast moving and wasp-like in appearance. Photo courtesy Kansas State Unversity.
What is squash vine borer?
First of all, if you don’t know about squash vine borer and you live in Texas, you’re either very lucky or you’ve never tried to grow summer squash in your garden. Squash vine borer (SVB) can be one of the most frustrating pests on zucchini and other squashes. With zucchini at least you can have some fun squashing squash bugs and their eggs. Not so with vine borer, which burrows down into the vine as a tiny caterpillar. Once inside the plant, the larval stage burrows in the plant stem or crown, disrupts water and nutrient flow, and causes wilting and eventual death of the plant. All the while it remains mostly invisible to the peering gardener.
Adult squash vine borers are moths. They are attractive insects with bright red-orange scales covering the body and wings with a metallic green to black sheen. The hind wings are mostly clear. In flight, and in movement on the plant, they look much like a wasp.
One of the first important things to know about a garden pest is when it is active, and its number of generations annually. Squash vine borer adults are out as early as April/May in Texas and remain active until as late as November/December. There are thought to be at least two (overlapping) generations in Texas, meaning they can be active throughout the summer and fall.
The SVB has not been well-studied in Texas, but there are several good resources for information about its biology, life cycles and control. Check out the following if you want to dig deeper:
Squash vine borer larvae live inside the stems of squash bushes and vines. Photo courtesy Kansas State university.
For the rest of us, here are some control suggestions. You will note that the title of this post is “Living with Squash Borer”. That’s because none of these techniques are magic, nor is there any perfect way to completely control this especially tenacious pest. But you can increase the life of your squash and improve your yield if you consider these suggestions. If you have a small garden, I suggest that you not rely on just chemical or on non-chemical methods alone, but integrate them together:
Non-chemical controls
Chemical controls
Surprisingly, for reasons not fully understood, small home gardens seem to have worse problems with SVB than large farms. Despite the challenges posed by this frustrating pest, you can still grow summer squash in Texas with a little persistence and patience. And maybe next year you’ll even have enough to share with the neighbors.
