What’s the most dangerous insect?

wolf spider close up
wolf spider

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.

 

Mosquitoes to make first showing of 2013

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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 season begins now

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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.

termite emergence by Cecil Fueston MISD_sm

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.

Bill signals new interest in mosquitoes

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Neglected pools can become breeding sites for thousands of mosquitoes. Photo by M. Merchant

Neglected pools can become breeding sites for thousands of mosquitoes. Photo by M. Merchant

After last summer’s West Nile virus epidemic in north Texas there is a heightened awareness of mosquitoes and mosquito issues around the state.  Last week the Texas Senate gave thumbs up (28-3 vote) on a measure (SB 186) introduced by Sen. John Carona (R-Dallas) that would give municipal health officials authority to enter empty or abandoned properties to treat mosquito breeding sites that pose a public health nuisance.

The idea behind this bill is that abandoned homes, most notably those with untended,  “green” swimming pools, can be a source of mosquito breeding that can affect homes within at least a mile radius.  Such mosquitoes can be both a nuisance and a health hazard. It can be difficult for health authorities to gain access to such properties without a search warrant.  This bill would allow a “public official, agent or employee charged with the enforcement of… laws” to enter the premises at a reasonable time to inspect or treat the nuisance stagnant water.

Any attention given to the problem of mosquitoes and mosquito-borne diseases is a positive thing, but the responsibility of identifying and eliminating mosquito breeding sites extends beyond state or local government to all of us.  As the temperatures rise this spring, mosquitoes will become active again very soon.  It’s time to be sure that your back yard is not one of those nuisance sources.

Some of the more commonly overlooked mosquito breeding sites:

  • Water- and leaf-filled bird baths
  • Gutters that fail to drain properly
  • Buckets, plant pots and wheelbarrows without drain holes
  • Landscape and gutter drain lines that catch and hold water (should have a pop-up drain emitter)
  • Water catch basins/septic tanks
  • Uncapped steel fence posts
  • Plastic or canvas covers on boats or trailers that catch water
  • Any container that catches and holds water more than a week
  • Unscreened rain cisterns and rain barrels

A few years ago, Dallas County did an evaluation on the properties of citizens who complained about mosquitoes in their backyards.  They found that 25% of these citizens had mosquito breeding sites in their own yards.  This is a good time for all of us to check your own backyards to make sure we’re not contributing to the problem of biting mosquitoes.

Turfgrass knowledge online

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Granular insectide spreader on lawn

Maintaining a healthy lawn does not have to be difficult, but does require know-how.  There are a number of excellent online resources at Texas A&M AgriLife to help you get the lawn you want.

Integrated pest management starts from the ground up…literally.  Nowhere is this more evident than your lawn.  The foundation for good turf pest management is good lawn care.  And if you want advice on the best varieties, proper soil preparation, correct fertility, and watering, you should head out right now for the AggieTurf website. The sections on selecting the right grass and how to care for your lawn are especially useful.

Proper fertility can help or hinder pest control.  Over fertilizing is known to attract chinch bugs and can make your grass susceptible to disease.  Under-fertility makes your grass weak and more susceptible to a variety of pests.  Knowing what fertilizer to apply, therefore, is a critical first step to a healthy lawn.  To get your soil tested, follow the directions and send a a sample either to the Texas A&M AgriLife Extension Service Soil, Water and Forage Testing Laboratory, or (for a private test lab) the Texas Plant and Soil Testing Lab.

Not all turfgrass pests are insects.  In fact, disease-causing pathogens and nematodes are probably as important, or more important, than insects in causing problems for your lawn.  To learn more about turfgrass diseases, or to find out how to send in a turf sample for diagnosis, check out the Texas Plant Disease Diagnostic Lab website.  Getting a sample evaluated costs at least $35.

To read about some of the insect pests that affect turf in Texas, be sure to check out the turfgrass pests section of this website.  The two most common pests of home lawns are white grubs and chinch bugs; but several other pests show up occasionally, including stunt mites, armyworms, and mole crickets.

Fire ants may not feed on turfgrass, but they do disfigure lawns with their mounds, and make the lawn less usable due to their presence and painful stings.  For everything (and more) that you want to know about fire ants and their control, check out the eXtension fire ant web pages.

 

A better way to enhance natural pest control

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The lady beetles that come naturally to your garden are likely to have more impact on pests than ones you buy and release. Photo by M. Merchant.

Today I received a call from a Master Gardener who wanted to advise a local organic garden on the best beneficial insects to release to control pests. My answer surprised her a little.  I generally recommend against gardeners releasing beneficial insects.

It’s not that I am opposed to biological control, or don’t believe in the value of predatory and parasitic insects.  I know that releasing insects to control other insects is a time-honored, and historically successful, approach to pest control.  The annals are full of stories of highly successful programs to introduce exotic beneficial insects into locations where new pests have become established(read about the vedalia (lady) beetle that saved the U.S. citrus and the miraculous control of Klamathweed by a tiny beetle) .

Nevertheless, stories like these have had the unfortunate result of convincing many people that controlling pests is as simple as opening a box to release a beneficial insect.  It’s not so simple. Consider some of the insects commonly recommended for backyard sowing…

The lady beetle is photogenic, but it flies away too quickly to do much good.  Trichogramma wasps, tiny egg parasites of caterpillars, have had the fight bred out of them in rearing laboratories, and have not proved effective when released in trees to control caterpillars.  And the intimidating praying mantid can’t reproduce quickly enough, and is too general in its food preferences, to control garden pests.

Before being branded a party pooper, I do think there are practical things that gardeners (organic and low-impact gardeners especially) can do to encourage good bugs.  The answer is not buying and releasing expensive beneficial insects (although they do have their place), but rather making your garden more attractive to good insects.

There is much to still learn about this approach to gardening, but the principles are relatively straightforward.  If you plant a physically heterogenous garden (e.g., tall plants/short plants, evergreen/deciduous, grassy/broadleafed), with lots of year-round nectar and food sources, the good bugs will come.  If this idea intrigues you, some excellent resources are available with a few clicks of the keyboard.

Mother Earth News has a nice list, gleaned from work of entomologists, of plants well-suited to attracting beneficials to your garden.  As ME reminds us, besides attracting predators and parasites, these plants are attractive to many pollinators which can further enhance the yield of your vegetable garden.

Several great resources are also available through the work of Michigan State University’s Cooperative Extension.  To learn more about their website and Extension publication on this subject, go to the eXtension website.

The challenge is how to design a garden that provides space for vegetables and plants that attract good bugs.  And, if you don’t live in the community where studies have already been conducted, discovering what companion plants are best for your backyard may be in your future.

Let’s not give up on enlisting beneficial insects in our pest battles.  But let’s focus on where we can do the most good, namely helping the millions of good guys find your garden and thrive there.

Kids love bugs

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I usually start my Master Gardener entomology training classes with the same question: “How many of you have dreaded insect training because you hate bugs?”  Inevitably, a few honest people will raise their hands.  It seems that there is little love to lose between many adults and insects.

Insect Expo 2013 Las Cruces NM photo by Shari Hill LC Sun News

Kids explored all aspects of the arthropod world at this year’s Southwestern Branch meeting of the Entomological Society of America in Las Cruces, NM. Photo by Shari Hill of the Las Cruces Sun News.

On the other hand, unless kids have been pre-programmed by adults, they’re just as likely to be fascinated, as they are to be repelled, by bugs.

That’s what I thought about as I read the report from the Entomological Society of America’s most recent regional meeting in Las Cruces, NM.  Over 1,200 kids attended this week’s event hosted by entomologists from across the southwest.  Besides engaging in insect art projects, betting on insect races, and handling large millipedes, scorpions and cockroaches, participants were also invited to nibble on tasty cooked insects (When a similar event came to Dallas many years ago, I was astounded that my fussy-eater daughter, a sixth-grader at the time, joined other friends in tasting fried mealworms.  The power of peer pressure is impressive!).

The point of all this is that, when presented in the right way, kids are usually fascinated by insects. And that’s a good thing.  As our children get more and more isolated from wild places, and encounters with wildlife in natural settings, arthropods are one type of wild life that is eminently accessible.  One need travel no further than the backyard to find roly polys and caterpillars, beetles and flies, buttereflies and bumblebees.  When presented the right way by a wise adult, these encounters can lead to greater interest in natural things.  And if our world needs anything right now, it’s a new generation with interest in and sympathy for the green world.

Check out the story if you have time.  And next time a child brings you an insect from the garden, don’t go YUCK.  Instead, take a minute to retrieve a magnifying class and look at the minute legs and antennae, and marvel at the colors and weird designs that would delight an animator designing the latest adventure flick. You’ll both be the richer for it.

Waiting for the bees

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bumble bee from Texas Bumblebees

One of the simplified illustrations from Texas Bumble Bees, which make bumble bee identification a snap.

As the season tilts toward spring in Texas I begin to look forward to the increase in insect activity. Not the pest activity, like mosquitoes and fire ants, but the vast majority of insects that are either harmless or who actively benefit us in one or more ways.

Bumble bees are among those creatures which are mostly beneficial to people, though many of us have little appreciation for the gifts they give. In fact, according to Texas Parks and Wildlife biologist Michael Warriner, it’s been 100 years since anyone has devoted a significant amount of research to  Texas bumble bees and their importance to the ecology.

Unlike honey bees, which are relative newcomers to our North American landscape, bumble bees and the many other species of native bees, have evolved alongside our native plants.  As a result they are excellent pollinators, ideally adapted to the Texas landscape.

Warriner’s website, Texas Bumblebees, lays out the case for why bumble bees are important and why we find them threatened in many areas today.  It’s also a great site for learning more about these important insects, and how to identify the eight species of bumble bees common in the state. Also check out the podcast on Warriner through Cecelia Nasti’s blog Field & Feast.

Check it out, and keep your eyes peeled for the first bumble bee of the year–a sure sign of spring.

Dallas gardeners perceive mixed impacts of mosquito spraying

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Mosquito spray planes line up for takeoff from Dallas Executive Airport last August. 2012 was the first time since 1966 that aerial mosquito spraying was conducted over Dallas county. Photo by WFAA, Monika Diaz.

For us who lived through the summer of 2012 in north Texas, this year might well be remembered as the “Year of the Mosquito”.  A perfect storm of weather and ecological conditions conspired this year to make it the worst year ever for West Nile virus transmission in Texas, and the second-worst year nationwide.  There were more WNV cases this summer in Dallas County (388) than any previous year (the previous worst year was 104 cases in 2006).

On the other hand, for many residents of Dallas and surrounding counties, 2012 may also be remembered as the “Year of Aerial Insecticide Sprays”.  For the first time since 1966, airplanes were used to apply insecticide over the city in an effort to slow the alarming number of human cases of mosquito-borne disease.

Needless to say, there was much public and official concern this summer about the impacts of aerial spraying on both human health and the environment. So when Dallas County Master Naturalists, Sue John and Marilyn Waisanen, approached me in early August looking for ideas for an entomology project, we immediately agreed that a study of the impact of aerial spraying on backyard beneficial insects and fish would be appropriate.

Because of the short time we had to organize the study, we decided to assess the perceptions of gardeners concerning the impact of the sprays on their backyard bees, butterflies, spiders and fish.  We developed an online survey and Sue and Marilyn mined their social networks for willing participants from the gardening and beekeeping communities.  Ultimately we got 75 people to tell us what they thought went on in their gardens while the spray planes buzzed overhead.

The results were interesting and reflected the diverse array of opinions and feelings about mosquito spraying.  Instead of a strong consensus, the gardeners we surveyed were strongly split between seeing little to no adverse effects on backyard wildlife, to seeing strong impacts on their birds and bees.  For each one who said, “I observed no change in insect activity” there was another who reported, “I have noticed [fewer] mosquitoes… butterflies, dragonflies, [and] flies. Have not been able to find any… praying mantis…”

Without actual insect counts, it’s hard to say who was more accurate in reporting the real impact of sprays on the butterflies, bees and spiders.  However respondents who observed fish and bees reported no major problems following spraying.  Of those with fish in ponds, 14 of 17 covered their ponds. Of these, 88% reported no or slight impacts of the sprays on their fish. None of the three gardeners who chose not to cover their ponds reported any fish loss. Of those with bee hives or colonies in their backyards, four (80%) reported no observable impact, and one reported slight impact.  If the study shows anything, it supports the contention of public health officials that there would be no ecological disasters after the spraying.

For those who would like to see the actual results and read more, a copy of the study can be found by clicking here.  Thanks to Sue and Marilyn for their hard work contacting participants, reviewing and validating surveys, and helping write the final report.

 

 

Another fall pest for Texas homes?

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An aggregation of brown marmorated stink bugs outside a window. These kinds of invasions are not uncommon in states where this bug has become established. Photo by Leske, 2010.  (not from Texas)

The brown marmorated stink bug is the latest in a string of unwelcome foreign pests that want to share our homes during the winter months.  A couple of weeks ago I posted a description of the hackberry nipplegall maker, which is a native insect pest that enters homes in the fall.  The brown marmorated stink bug (let’s call it BMSB) is from Asia and has been settling into its new home in the eastern U.S. since it was first noticed in Pennsylvania in 1998.  It was spotted in south Texas one year ago, and hasn’t reappeared since.

According to a recent A&M AgriLife news release, homeowners, ag producers and professionals alike are encouraged to keep alert for these bugs.  Besides being a nuisance in homes, where they seek shelter in the fall, the BMSB is a likely pest on pecans, tomatoes, peppers, beans, fruit trees and other crops.  They readily hitchhike in vehicles from infested states.  In fact, the one Texas sighting came when a Corpus Christi resident noticed bunches of the bugs hiding out in his travel trailer after a trip to Pennsylvania.

How to modify your vacuum cleaner to safely suck up lady beetles and other pests you which to release outdoors. Insert a nylon stocking into the nozzle tip or flexible hose of a vacuum and secure it with a rubber band. When finished vacuuming simply pull out the stocking and release the insects outdoors (away from your home). Another option is to insert a stocking, with both ends open, into the long tube to soften the impact of beetles on the intake tube walls and keep the suction tube clean. The stocking used to catch the beetles is then secured inside the flexible hose to catch the beetles before they enter the vacuum engine.

The BMSB joins several other foreign insects like the multicolored Asian lady beetle and the kudzu bug (not yet in Texas) that like to invade homes in the cooler months.  Over the past few weeks I’ve had several calls about what appears to be a better than usual year for lady beetle invasions.

The best solution for unwanted fall invader insects is your vacuum cleaner.  Sprays that kill large aggregations of insects indoors or in attics may result in odors from masses of the decaying pests.  A vacuum allows you to remove (and even preserve, if desired) the unwanted pests and dispose of them outside the home. Remember to dispose of the vacuum cleaner bag after use, or use a capture method like the one illustrated here.