Daylily leafminer damage. Photo by Sharon Galloway.

This small, shiny black fly is native to Japan and Taiwan.  It’s presence is identified by long, gently meandering leaf mines in daylily leaf blades, especially on the upper leaf surfaces.  The damage is caused by a small, yellowish maggot (up to 5 mm-long) burrowing through leaf tissue.

This pest is not reported to kill daylilies, though heavily attacked plants retain their damaged and much disfigured leaves, until removed or replaced by new growth.

To all you daylily growers and afficionados, my condolences.  Little is currently known about insecticidal control, though some control may be achieved by removing and destroying infested leaves as they appear.  More information is available at the American Horticulture Society. 

Although this leafminer has already been reported from Texas, this was the first time I was aware of it.  If you are noticing the characteristic signs of damage, Gayle Williams of the Maryland Department of Agriculture is tracking the spread of this pest.  You can send images and information to her at her email per the article on page 8 in  the NPDN newsletter.  If you think you’ve seen this pest in Texas, you can comment to this post also.  And thanks to Keith Hansen for this heads up.

Neonicotinoids are toxic to bees and other
pollinators, especially when sprayed directly.
Applications of neonicotinoids directly to
flowering plants during daylight hours should
be avoided, per label directions.

What could present a more peaceful, bucolic image than the scene of beekeepers tending their bee hives? Beekeepers are traditionally seen as the gentlest of agriculturalists, not killing for food but merely reaping the labor of an industrious insect in exchange for nurture and protection.  Yet there is little peaceful about the verbal and political battle swirling about beekeepers and honey bees at the moment.

You may have seen the headlines in recent years proclaiming the doom of the honey bee.  The domestic bee industry in the U.S. and in other countries around the world was hit hard in 2006 with puzzling bee and colony losses, since referred to as Colony Collapse Disorder (CCD).  In a typical year beekeepers expect to lose 10-15% of their colonies to disease and various stresses.  Since CCD arrived, colony losses have averaged 30% each winter, a significant increase.  Despite dire headlines warning of the doom of agriculture, according to one 2012 report, the costs of CCD to consumers so far seem to be minimal and honey bee colony losses have been compensated for effectively by beekeepers themselves.

Nevertheless, something seems wrong with the world if bees are dying. Initially all sorts of crazy ideas were promoted about the cause of CCD, including radio waves from cell phone towers.  Since then the theories have narrowed to other, more reasonable suspects.  In the past few months some researchers and advocates have claimed that pesticides are the principle cause.  And whenever pesticides are mentioned, the debate is sure to get lively.

The USDA, university researchers and EPA have been mostly united for several years in the position that CCD is the result of multiple causes including parasites, lack of nectar source diversity, diseases, and overworked bees.  However some recent research on neonicotinoid insecticides has raised alarm bells for critics, and has even led to a temporary ban on this group of insecticides in Europe. The research in question includes laboratory studies with bees and field studies with bumblebees, thought to be more sensitive to insecticides than honey bees because of their smaller colony size.

The smoking gun for environmentalists opposed to neonicotinoids came in the form of studies reported last year that show that one of the sub-lethal effects of low exposure neonicotinoids include loss of the bees’ sophisticated ability to find their way back home. This loss of homing ability would account for one of the more distinctive symptoms of CCD, namely colonies that slowly decline with no signs of dead bees around the hive. Other forms of colony decline typically include dead bees around the colony entrance.

While there is no doubt that neonicotinoids are toxic to bees at high enough doses, scientists are still divided on the question of whether bees that forage on neonicotinoid-treated crops are exposed to high enough levels of toxicant to suffer from flight disorientation, and whether there is even a correlation between CCD and neonicotinoid use. Indeed, in some parts of the world where neonicotinoids are extensively used, such as Australia, CCD is not reported to be a problem.

If you’re a gardener, chances are that you’ve heard the dire warnings about these insecticides and are wondering if you should avoid their use.  After all, no one wants to be a bee killer.

If the scientists who study bees are divided on the cause of bee risks from pesticides, it’s likely that the answer to this question will be not be simple. But here are some points that might be useful as you consider whether these insecticides have any place in your yard and garden:

• Both the USDA and EPA recently issued a report summarizing positions that CCD is a result of multiple factors, not just pesticides.
• All labels are approved on the basis that when used according to label directions the pesticide must  not pose unreasonable adverse to humans or the environment, including honey bees.  The EPA has recently reviewed registrations for some of these insecticides and stands by its risk/benefit assessment that these products can be used safely if the label is followed.
• While research is suggestive of a potential risk to bees from agricultural uses of neonicotinoids, the case is far from proven. And so far, to my knowledge, no credible sources have suggested that urban residential uses of neonicotinoids pose any unusual risk to bee colonies in urban areas.
• The greatest potential risk to bees from neonicotinoids appears to be in agricultural settings, where bee colonies are exposed to large acreages of treated plants.  The diversity of plants and the relatively low use of pesticides in urban settings argues for lower potential risks in residential and commercial landscapes.
• Although neonicotinoids, like most nervous system toxins, are relatively toxic to birds, there is no pattern of bird deaths associated with appropriate use of neonicotinoids, as claimed by some.
• Neonicotinoid insecticides are moderately low in toxicity to people and mammals due to some unique nerve junction differences between us and insects. Just because an insecticide is toxic to bees doesn’t mean that it has broad ecological toxicity.
• Use of neonicotinoid sprays should be avoided on flowering plants during daylight hours.  Bees are at high risk when sprayed directly, or if they contact wet spray deposits.  In residential and commercial landscapes, neonicotinoids can often be applied effectively through root injection, greatly minimizing risks to pollinators like bees.

As a pest control specialist, I know that neonicotinoids are effective and valuable insecticides for a variety of pest problems around the home. For some landscape pests, especially some of our tougher scale pests and whiteflies, there are no highly effective alternatives. It’s up to all of us to ensure that these products are used in such a way that beneficial insects are protected. You can start by reading your insecticide labels carefully.  The label will tell you how to protect honey bees and other pollinators.  But a label is only useful if we read and follow them.

*******************

What are Neonicotinoids? Neonicotinoid insecticides are a relatively new class of systemic insecticides that have grown to make up approximately 20% of the global pesticide market. The first neonicotinoid to be introduced to the home garden and pest control markets in the U.S. was imidacloprid, used for termite control, garden and lawn insect control, and even flea control (in the popular Advantage® spot-on product).  Imidacloprid, remains at the center of the CCD controversy because of its widespread use in agriculture and in the ornamental landscape market.  The neonicotinoids currently available to consumers for garden pest control include imidacloprid, dinotefuran and acetamiprid.  If you are not sure whether a product you may be using contains a neonicotinoid, check the active ingredients list on the front panel of the insecticide container.  Because neonicotinoids are systemic, and can be taken up into plant tissues, they can be applied to root zones, eliminating the need to spray.  For this same reason, neonicotinoids are not generally labeled for fruits and vegetables, unless the insecticides are barred from the edible portions by plant physiological barriers.

Bees, with their many body hairs, are excellent pollinators

Got the gardening blahs?  Need some fresh inspiration?  Consider a visit to the new pollinator garden at the Lake Lewisville Environmental Learning Area (LLELA).  This Saturday will be the grand opening, beginning at 9:30 am.  I will be one of the speakers, sharing what I know about insect pollinators.  But Ken Stiegman, LLELA director will also be there giving a butterfly walk and Rosemary Carrizales, volunteer coordinator for the garden will answer questions about planting your own pollinator garden.

The garden, of course, is open all the time, and provides a wonderful opportunity to view North Texas prairie grasses and wildflowers. Part of the purpose of a pollinator garden is to give a boost to our native pollinators by providing habitat. Populations of bees, butterflies and other pollinating insects are in steep decline across the United States due to loss of habitat and other environmental issues. Without these often unappreciated creatures, about 75 percent of our flowering plants and crops would not develop fruit or seeds.

I have not yet seen the garden myself, but Janet Laminack, county horticulture agent for Denton County gives it two thumbs up, saying it looks real good.  We hope to see some of you local gardeners there.

Admission to LLELA is $5/person; children 5 years and younger are free.  The preserve entrance is at 201 E. Jones St., Lewisville, TX 75057. Please visit www.ias.unt.edu/llela or call 972-219-3930 for more information.

Monarch butterflies have been slowed by cool weather in their northern migrations this year. Photo by M. Merchant

By all accounts, this is not turning out to be a great year for monarch butterflies.  The NY Times reports the smallest overwintering populations in Mexico in at least two decades, and the cold spring weather is not helping matters.

An interesting animated map is available through the group Journey North showing how this year’s migration compares to the last few years’ migrations.  This kind of data is made possible through ordinary people with cell phone apps that allow anyone to report a monarch butterfly sighting.

GPS based phone apps have incredible potential for invasive species reporting, range and abundance reporting for a variety of organisms.  BugWood.org is just one such source for a growing library of apps for these sorts of uses.  If you know of a good app for identifying or reporting insects, let me know.  I will post the best of the ideas as comments to this post.

A honey bee swarm on a park bench demonstrates that bees will make use of any available resting spot.

Despite a winter that just won’t seem to let go, spring is definitely here. I know this because the honey bees are swarming, and local callers are reaching out to Extension offices for help coping with the sudden bee invasion.

According to Shelly Spearman of the Rockwall County Extension office, her office is getting one to two calls a day about bees. “We’re getting a lot of calls about bees hanging out in trees,” she said.

So why are bee mobs suddenly invading our trees and landscapes?  And what do we need to do to protect ourselves and our loved ones?

The first thing to know is that this is prime bee swarming season.  Bee “mobs” (actually swarms) are the bees’ way of coping with rapid colony growth in the spring following the return of flowers and their abundant supply of pollen and nectar.   As the colony begins to grow and crowd the nest, worker bees begin producing a new queen and drones (male bees).  Just before the new queen emerges, the old queen takes a portion of the colony and leaves her hive in search of a new home.

In flight, a bee swarm resembles a tornado of bees.  The departure of the queen from the old colony is  the trigger for the swarm, and the worker bees generally follow the queen wherever she goes.  In the course of this bee exodus, the queen and her colony occasionally stop to rest.  Resting sites may include just about anything from a tree branch to a car, a park bench to backyard play equipment.

So what’s the risk should a bee swarm land in your yard or place of work?  In most cases, it’s very low.  Most bee swarms are not aggressive and will tolerate lots of human activity nearby.  But there are exceptions, so it’s best to keep children and anyone with a known allergies to bee venom a safe distance away.   Swarms generally don’t stay very long either. If the swarm has just emerged from a nearby hive, it usually takes off within a matter of hours. In most cases, a bee swarm will move on within a day or two and you’ll never see it again.  On the other hand, if one of the colony’s scout bees discovers a good nest site nearby, the swarm could become a long-term neighbor or take up more or less permanent residence in your home.  For this reason, many people choose to call a pest control company or beekeeper to kill or collect bee swarms that settle near their house.

While bee swarms are generally harmless, bee colonies that get into the home can become an expensive problem. Now is an excellent time to check your home for holes and gaps that need filling, BEFORE the bees move in.

Most of us would prefer to move rather than kill a bee swarm.  The majority of folks who call my office want to “give” the colony to a local beekeeper.  But many beekeepers are increasingly wary of the genetics and potential diseases or mites associated with feral bee colonies.  And it’s increasingly rare to find beekeepers, especially in urban areas, who will remove bees at no charge.

In Texas, registered beekeepers who do not use pesticides can legally remove honey bee swarms and charge you for the service.  However, if pesticides are used, the beekeeper must have a pest control license and work for a licensed and insured pest control business to charge you for bee control.  If you live in a different state, check with your state Apiary Inspection Service or your county Extension office to find out what your local rules say.

It may seem ironic to talk about killing a bee colony, given our society’s appreciation for bees, and all the recent press concern about the decline of honey bees.  But wild bees are in no way endangered and, despite the stories you might hear, it is legal to kill a bee colony or swarm that is in an undesirable location.

In general, it’s rarely necessary to kill a bee swarm that is outdoors, in the open.  Swarms, depending where they land, are relatively easy to collect alive.  But once they get into a structure or home, they become much more difficult (and expensive) to extract peacefully.

Of course the best solution to bees is prevention.  Now is the time to check your home for holes and gaps, especially under the edges of wood siding, and around windows, roof lines and soffits.  These are the kinds of places that bees love.  Expanding foam, silicone sealant or other methods should be used to seal all voids and holes.  If you discover bees already in your home, look for a pest control company or beekeeper business that performs bee removals.

We’ve waited this long for spring, we should be enjoying it and not worrying about bees.  For more information about bee control in homes, see our Honey Bees in Homes factsheet.  To look for a local beekeeper who might be willing to collect a bee swarm, search for your closest beekeeping chapter at the Texas Beekeepers Association website .

These tiny seeds of the Oxalis plant sometimes adhere to man-made surfaces, or other plants, and confused with “bugs”.

I thought at first that these tiny (1.3 mm length) objects might be spores from the artillery fungus, in the genus Sphaerobolus.  Artillery, or shotgun, fungus is a type of primitive plant that grows as saprophytes on wood mulch.  It has tiny black spores that it can shoot for several yards.  The spores are sticky and adhere to a variety of surfaces, like walls of homes, sometimes leaving a stain when removed.  But, according to the submitter there was no mulch nearby, and according to my plant pathologist friend, Dr. Kevin Ong, the specimen I was looking at under my microscope was not round as typical for Sphaerobolus, .  

My sample of 20 or so objects were teardrop-shaped and ridged.  Fortunately I network with many experienced entomologists several of whom kindly informed me that the sample was the seed of Oxalis, a common garden weed or plant.

One entomologist noted that he once got a series of calls from a commercial greenhouse grower who was doing his best to “kill” these “pests” “crawling” all over his greenhouse, but with little success.  This is another example of why it is so important to identify the pest before reaching for the garden sprayer.

Oxalis seeds, it turns out, are pretty cool.  They are borne by the plant in a cylindrical pod.  When mature, or when the rip seed pod is touched, it shoots out the small seeds three to five feet.  The rough coats on the seeds helps them stick to some surfaces (like a hardy-board exterior wall, in this case). For a good video showing how Oxalis seed dispersal works, check this out.  The plants themselves are attractive, if sometimes difficult to eradicate from your yard.  The plant leaves are sour-tasting because of the presence of oxalic acid; but in small quantities are good in salads.

So let’s not always blame insects for strange occurrences. There are enough real insects in the world to keep us entomologists busy full-time.

Thanks to Wizzie Brown for alerting me to the recent, very cool video on cockroaches by NPR’s Science Friday.  Like cats that lick their feet and fur, cockroaches continually groom their feet and  antennae.  I’ve watched cockroaches groom themselves, but never in magnified HD with a lucid narration by North Carolina State University entomologist Coby Schal.  Dr. Schal reports on recent research by his laboratory to answer the question about why cockroaches groom, and he’s well worth listening to.

One thing the video does not mention is that we take advantage of this grooming behavior in pest control when we use certain insecticides.  Boric acid is a relatively low risk pesticide that can be used around the home.  Boric acid, it turns out, is ONLY toxic to insects (and coincidentally, people) when it’s ingested.  When we apply boric acid as a dust, and a cockroach walks through the dust layer, a small amount of the insecticide is picked up on the roach’s feet, body and antennae. It’s because of the grooming behavior documented so elegantly in this video, that the cockroach is poisoned by such dusts.  This may also be the case with other insecticides and other insect species, according to the news release by North Carolina State.

One caveat about using boric acid in the kitchen–don’t use too much.  Cockroaches avoid heavy deposits of any dust, including boric acid.  They are not repelled, however, by light dust deposits of boric acid.   So if you use boric acid, take it easy. You should not be able to see more than the slightest dusting of white residue after an effective application of boric acid.

What’s the most dangerous insect or arthropod? The answer might surprise you.

Ask people what the most dangerous insect or spider and you’re likely to get a variety of answers.  Brown recluse spider…ANY spider, bees, scorpions, hornets, ticks, army ants… the list goes on.  But few entomologists or medical experts would likely dispute that the tiny mosquito is probably the most dangerous arthropod on the planet.

To underscore this with just one of many mosquito-borne diseases, the World Health Organization has declared April 25th World Malaria Day.  While no one can fully know the historical impact of malaria, the incomplete statistics are still stunning.  Despite significant progress in battling malaria, the disease still kills an estimated 660 000 people worldwide.  About 90% of cases occur in Africa, and most deaths are children under five years of age in the sub-Saharan region. Every year, more than 219 million known cases occur (compared to 34 million AIDS cases annually); most of these cases are never tested or registered.

Even we in Texas can’t completely escape health risks from mosquitoes. Though in comparison to malaria West Nile virus may be considered a “minor” mosquito-borne disease, for those afflicted by it the health impacts can be severe and long.  I have a couple of colleagues who have been infected, and for them the illness will not soon be forgotten.

As many of my entomology colleagues are quick to point out, there are many different species of mosquitoes, most of which pretty much leave us humans alone.  We have 172 different mosquitoes found in the U.S., 85 in Texas, and approximately 40 or so species of mosquitoes in the Dallas area where I live.  Mosquitoes play an important role in the food chain of those habitats where they are found, though I would not be sad to get rid of a few of the “bad characters” that cause misery and disease, especially in domestic settings.

Ironically, mosquitoes are one of those pests that we would just as soon ignore unless they are causing a health or nuisance crisis.  Hence many county and city health department budgets devote relatively little money to surveying or integrated control of mosquitoes.  That’s changed a little this year in the north Texas area, after last summers West Nile epidemic.  More health departments are starting mosquito surveillance programs, and mosquito control budgets are being doubled in some communities.  Nevertheless, should West Nile virus cases return to low levels this year, county and city governments will likely quickly forget the health importance of this tiniest of pests.

While I don’t want to scare anyone from getting out of the home and away from the television set this summer, don’t underestimate the power of the tiny mosquito.  If you plan to be outdoors this summer, especially in the evening hours, use a good, proven insect repellent.  In addition to the gold standard DEET, there are many good repellents available today.  Buy them, and keep them in a place (I keep mine by the door) where you will use them.  It’s possible to beat the most dangerous insect, but you need to recognize her first.

Spring rains and warmer weather usually spell mosquitoes.  To prove this to myself, I’ve been watching my backyard fountain slowly fill with recent rains, leaves and catkins from nearby oak trees. Last week I was rewarded(!?) with my first mosquito wigglers. “Wiggler” and “tumbler” are informal terms for the larval and pupal (immature) life stages of mosquitoes.  Mosquito wigglers live in water, and as soon as temperatures get warm enough to drive their development, they quickly mature and emerge from pools and containers wherever they may be found.

After last summer’s record West Nile virus season, any news about mosquitoes is bad news to us in Texas, and especially the Dallas area.  But the species emerging right now are not likely to be the disease-carriers of last summer.  According to Scott Sawlis of the Dallas County Health Department, these are more likely to be Culex restuans, or one of the other early mosquito species that do better in cool weather.  These cool weather species do not spread West Nile virus.  Nevertheless, these mosquitoes still bite and are still unwelcome in our neighborhoods.

My backyard observation site gave me the chance to photograph and put together a short video about what to look for if you see a suspicious puddle of water around your yard.  In my case, after following the wigglers for a few days, I drained my fountain.  Should you find a suspected breeding hole, if possible drain it, or fill it in with sand, gravel or soil.  This will immediately kill any mosquito larvae breeding there.  If the source is too deep or impossible to drain, mosquito dunks or granules, available through most hardware stores and garden centers, will also kill mosquito larvae for up to 30 days.

We’d all rather get rid of mosquitoes before they become a problem.  So get outdoors now and check your yard. This is a great time to mosquito proof your yard in preparation for the summer.  For more information about where mosquitoes breed, and what to do about them see http://mosquitosafari.tamu.edu.

Termite swarmers are dark, about 1/4 inch-long, and may or may not have wings.

If you own a home in Texas you’re concerned about termites–or at least you should be.  Termites are likely to be the most expensive insect pest you will ever get in your home.  I was reminded of this fact this weekend cleaning out my mosquito filled water fountain at my home in Plano. There I saw several termite “swarmers” floating on the surface–my first termite sighting of the year.  I’m not too worried about my home–it has been treated in the past.  And termites are naturally just about everywhere outdoors in our part of the country.  But the sighting told me that swarming season is in progress, and that the phones in termite control companies are starting to ring again.  Warm weather and rain, like we saw last weekend (and is predicted for the coming weekend), provides the perfect trigger for springtime termite swarms.

So what are the signs of a termite problem in the home?  The most common sign that your home might have a problem is the sudden appearance of anywhere from a few to hundreds of small, black winged insects. These are termite swarmers, the reproductive caste of the termite colony. Once a year, swarmers leave the underground nest to fly and find mates–preferably mates from a different colony.  When swarmers show up indoors it’s almost a sure thing that worker termites are active somewhere in the house.

In this building, termites are emerging from their mud swarm tubes. Photo taken this week by Cecil Fueston, McKinney ISD.

Termite swarmers don’t fly as much as they crawl about indoors, and they may lose their wings quickly; but once you’ve seen them they are pretty easy to recognize.  They are small (about a quarter of an inch-long), with a black-brown body with wings that extend beyond the tail.  They are sometimes confused with ants, but lack the ant-ish pinched “waist”.

The other sign to look for inside your home is dirt in odd locations, like in a window frame, doorjamb or on a sheet rock wall.  Prior to swarming in a home, termites often build a small mud swarm tube at the point in the wall from which they will emerge.  The tubes may be small (less than an inch across), or relatively large (up to a foot long), but they usually have a similar consistency and look of a mud dauber wasp nest.  Remember, you will not likely see the small white worker termites in your home, unless you break open a wall, or one of these swarmer tubes.  Worker termites don’t willingly expose themselves to light, or dry air, and usually stay well hidden inside walls or underground.

If you find termite swarmers or suspicious mud tubes on the walls of your home, call a termite professional.  A professional will confirm whether you have a termite infestation, and will quote you how much it will cost to solve it.

The good news about termites, if there is one, is that today’s treatment options are very effective.  Non-repellent termiticides (insecticides designed for termite control), and outdoor and indoor bait stations are both effective and pose low-risk to your household and the environment.  For more information about termites and termite control, see the Insects in the City termite page.  And don’t ignore the telltale signs of termites.