Insect Updates - Page 11 of 32 - Insects in the City

Bracing for ZIKA

Posted on December 29, 2015 by p-porter

Will Zika be the next mosquito-borne disease to capture headlines in 2016? Or will it be the little disease that few (at least in the U.S.) have heard of? That’s the question being debated by public health officials this year.

For many years it seemed like new things happened relatively slowly in public health in Texas. In the mid 1980s entomologists reported the Asian tiger mosquito in Texas for the first time–a daytime-flying mosquito from Japan that is not shy about biting humans. Then in 2002 the first cases of west Nile virus hit our state. Carried by the southern house mosquito, WNV affected a couple of hundred people or less each year. This was the case until the blazing hot summer of 2012 when over 1800 cases were reported, including 83 deaths. Health departments throughout the state are still reeling, in some ways, from the impact.

A woman in Brazil holds her daughter, who was born with microcephaly. An increase in the disease — a form of brain damage — has been blamed on the Zika virus. Credit Felipe Dana/Associated Press

Now health officials are bracing for another mosquito-borne disease caused by Zika virus (abbreviated ZIKV by epidemiologists). A cousin of west Nile virus and dengue fever, ZIKV has been thought of as a less severe form of these flavivirus. Most people who get ZIKV show no, or very mild symptoms. Others exhibit a rash, conjunctivitis (inflammation of the eye), and flu-like symptoms. Most people do not get as sick with ZIKV as with dengue fever or chikungunya, and recover relatively quickly.

For this reason, since its discovery in 1947 until 2007, it was not on the radar of many public health experts. But in 2007 ZIKV cases started to spread throughout Micronesia French Polynesia, and eventually Easter Island. There it was thought to possibly be the cause of a twenty-fold increase in cases of Guillain-Barre syndrome–an autoimmune disease of the central nervous system that can be highly disabling, at least temporarily.

In 2015 the disease made its appearance in Brazil and has since spread to at least nine other member states of the Pan-American Health Organization (PAHO/WHO), and prompting that organization this month to issue an alert to all of member public health agencies.

So here’s where things get a little scary. Since the arrival of ZIKV to Brazil, the virus has been detected in babies born with a condition known as microcephaly. Microcephaly is a relatively rare condition where the brain fails to develop normally. It may result in miscarriage or in babies being born with under-sized brains. There is no cure for the condition. The PAHO/WHO alert noted that the number of diagnosed cases of microcephaly has increased to 2700, a 10-fold increase, in Brazil this year. Health officials there are worried that there might be a connection between this unprecedented increase in microcephaly and the arrival of ZIKV. And last month, unusual nervous system birth defects were also reported in Polynesian mothers who tested positive for flavivirus antibodies.

Public health officials guess that these cases may result when a pregnant woman who is bitten by an infected mosquito contracts the virus. The virus then infects the developing fetus, resulting in this serious condition.

So far there is no hard proof of a connection between ZIKV and microcephaly or Guillain-Barre syndrome, but medical researchers are rushing to learn more about the virus and its possible effects on human health. According to one expert, quoted in the New York Times, it could be that the risk of microcephaly is increased among people who have previously contracted dengue fever or chikungunya, neither of which diseases are common to Texas or the U.S. If this hypothesis proves correct, the risks to the unborn in this country would likely be negligible.

Currently, ZIKV is thought to be transmitted by the yellow fever mosquito, Aedes aegypti. This mosquito, along with its close relative, Aedes albopictus, the Asian tiger mosquito, are both very common throughout Texas and the southern U.S. Unlike west Nile virus, which is primarily a disease of birds, ZIKV is solely a disease of primates. To be spread among people, it must be picked up from another infected human.

Dengue and chikungunya are similar, human-only, viruses that have not been quick to spread in Texas or other U.S. locations. This may be the result of lower rates of mosquito biting in the U.S., perhaps due to our more indoor lifestyles, or more common use of repellents. Some experts argue that for similar reasons ZIKV is likely to be slow to establish in the U.S. Nevertheless, Brazil shows that given the right conditions, this virus is capable of establishing itself very rapidly, with 85,000 known infections in its first year of spread.

A few U.S. cases of ZIKV have been reported this year, but all from travelers who contracted the virus elsewhere. Mexico has also seen a few cases this year. However there are still no known cases of ZIKV that have been contracted within the U.S.

So be prepared to hear more about the zika virus this year. It may turn out to be a big event, or it may not. Regardless, we don’t need more reasons to dislike biting mosquitoes. But now we have one more reminder of the importance of putting on the insect repellent when we venture outdoors.

Kissing bug identification requires closer look

Posted on December 1, 2015 by p-porter

Adult Triatoma, kissing bug next to a penny.

Because most of us take little time to look closely at insects, it should not be surprising that recent television stories about “kissing bugs” and Chagas disease have created a frenzy of sorts among people thinking they have captured or seen kissing bugs around the home. While a few of these have turned out to be actual kissing bugs (genus Triatoma), most are not; and laboratories set up to identify and test kissing bugs have been overwhelmed this month with samples.

But not all insects vaguely resembling the pictures you might see on television or in the newspaper are kissing bugs. In fact, there are over 38,000 different kinds of insects in the “true bugs” suborder to which kissing bugs belong. So to make things easier, let’s review what to look for when a suspicious “bug” shows up in your home or landscape.

Triatoma head. Notice the straight tapering mouthparts under the head. Photo courtesy Alex Wild (www.alexanderwild.com)

All insects in the suborder Heteroptera, to which kissing bugs belong, have piercing sucking type mouthparts, as opposed to the chewing mouthparts found on most larger insects. Such mouthparts are visible from the underside of the body, and are relatively easy to see on the kissing bug–at least with a good handlens or magnifying glass. Unlike some other large bugs, which have very thin mouthparts pressed against the body (plant feeding bugs), or heavy curved mouthparts (most predatory bugs), the mouthparts on kissing bugs are stout and straight.

Adult, fully grown kissing bugs range in size from 1/2 inch to over 1 1/4 inches long (usually about 1 inch-long). They are pear-shaped and dark brown to black in body color, often with distinct, reddish- to cream-colored stripes visible along the edges of the abdomen (tail). There are no markings on the wings, although some kissing bugs may show some orange at the base of the wings, next to the shield behind the head.

Three of the different kinds of kissing bug found in Texas vary slightly in size and coloration, but share all the key characters of this genus. Photo courtesy Gabe Hamer, Texas A&M University.

The head is stick-like but tapering, with eyes bulging from the sides and bottom of the head. Besides “kissing bug”, these insects are often called “conenose bugs”.

The six legs are relatively thin and tapering, not swollen or bulging. There are no distinctive spines or spikes on kissing bug legs, sides or top.

While some insects may have some of these characters, only insects with all of these characteristics are likely to be kissing bugs. Add to this that kissing bugs come out mostly at night, and it shouldn’t be too difficult to distinguish kissing bugs from all other insects.

Common Imposters

Of course there are other insects that have some of the characteristics of kissing bugs. So lets look at a few.

	Bed bug. Small indoor bugs, only 3/16 inch-long when fully grown. Oval shaped, reddish brown and flattened. When present indoors, may be found in clusters of a few to dozens, usually on or close to a bed or couch. Has a painless bite and is not known to transmit disease.
	Wheel bug. Outdoor insects. Note the stout, curved mouthparts and spined “wheel” arising from the middle of the shield behind the head. A type of assassin bug that is a common predator throughout Texas and is found well into cool weather. Has a painful bite if handled.
	Box elder bug. smaller than most kissing bugs, red eyes and markings on the wing. Lacks bands around margin of the abdomen. Feeds on the seeds of maples and box elder trees. Common in the fall, often entering homes for warmth. Does not bite.
	Squash bug. Approximately the same size as kissing bug, but note the short, triangular head–it lacks the cylindrical shape and long “neck” of kissing bugs. Mouthparts thin and held close to body. This insect is a plant feeder and common pest of zucchini and other squashes. It does not bite and rarely comes indoors.
	Bark stink bug. Smaller and less elongated than adult kissing bugs. Mouthparts slender and held next to the body. Spines along front margin of the shield behind the head. It does not bite and is rarely seen indoors.
	Leaf-footed bug. As large, or larger, than kissing bugs. Hind legs swollen or flattened, sometimes into leaf-like shapes. These insects feed on plant seeds. They do not bite and rarely come indoors.

For more pictures and information about kissing bug identification services offered by Texas A&M University, click here. For more information about kissing bugs, why they are a health concern, and how they can be managed, see our factsheet on conenose bugs.

Oak leaf itch mite confirmed in Oklahoma

Posted on November 6, 2015 by p-porter

In the latest issue of Pest Alerts from the Entomology Department at Oklahoma State University, entomologist Justin Talley reports finding evidence of a biting pest that has not been seen in Oklahoma or Texas for over ten years.

Vein pocket gall, Macrodiplosis quercusoruca, on red oak leaves, caused by a tiny fly that lives next to the veins on oak leaves. The fly larvae inside the galls are thought to be one of the insects fed on by oak leaf itch mites.

The oak leaf itch mite, Pyemotes herfsi, is cousin to the straw itch mite–a predatory mite often associated with stored grain and stored grain insects, and known to bite people who come in contact with infested grain. It was first reported in the U.S. from Kansas in 2004, a year when the mite was unusually abundant and resulted in thousands of biting complaints from people working and playing outdoors. That same year the mite was found in Nebraska, Missouri and here in Texas.

The mite’s normal home is inside of leaf galls, and it is best known from marginal leaf curl galls caused by a midge (Macrodiplosis erubescens) on oaks; but it may be equally at home in other types of galls on different trees. The problem with this mite seems to occur mostly in late summer and fall, when mites are prone to dropping from trees. Although the mites are principally predators on insects, if they come in contact with skin they will bite, leaving a painful, itchy welt. For more information on the mites click here for a Nebraska fact sheet.

Gravid female oak leaf itch mites. The balloon-like structure is the mite’s abdomen full of eggs. This mite is feeding on a brownish fly larva responsible for making the gall. Photo by Rick Grantham, OK State University.

This little mite has a history in Texas too. In October, 2004 the Dallas area had what was believed to be a mini-outbreak of these mites, when Dallas County Health and Human Services received a number of complaints from schools concerning “bug bites” among students and staff–apparently from playgrounds. At that time DCHHS staff and I sampled leaves from a number of school campus trees and isolated a single oak leaf itch mite, confirming at least the presence of these mites in north Texas. The rash of bite cases was assumed due to this mite by DCHHS in its December 2004 monthly report of epidemiology activity. No remarkable incidents of these bite complaints have recurred since 2004, although a few suspect calls have been received this year.

These mites are very small (0.2 mm-long) and difficult to find. Bites, when they occur, tend to be around necks and shoulders, implying that the mites bite when they land, and do not crawl much on the skin before biting, like ticks or chiggers.

I don’t mean to be an autumnal spoil sport, but if you’ve experienced these bites around your home, leaping into leaf piles might not be advisable this year. If you have suspicious bites after being outdoors under trees, consider avoiding the area until first frost. The repellent DEET may provide some protection. When raking and bagging leaves, wear long sleeved shirts and wear repellent.

Recognizing emerald ash borer damage

Posted on October 23, 2015 by p-porter

Canopy thinning and epicormic shoots on ash tree under attack by emerald ash borer

Biologist Emily Cornell hangs a purple sticky trap in a Plano TX ash tree. Sticky traps are just one way to detect the first invasion of emerald ash borer.

This summer my assistant spent the better part of her summer hanging and checking over 100 purple sticky traps to determine whether Texas has been invaded yet by the dreaded emerald ash borer (EAB), Agrilus planipennis. The beetle has already been detected in neighboring states of Arkansas and Louisiana; but much to our relief, after thousands of miles of winding county roads and many hundreds of traps, neither she nor our colleagues in the Texas Forest Service or Sam Houston State University found a single EAB. However, this beetle is elusive. And there is a good chance it may already be infiltrating Texas forests and backyards. If so, the doomsday countdown will have already begun for millions of beautiful ash trees across our state.

Ash trees have compound leaves with 5-9 leaflets. Photo by M. Merchant, Texas A&M AgriLife.

In July I had an opportunity to visit Indiana for a workshop on how to identify beetles like the EAB. As I drove down the Hoosier highways it was both impressive and sobering to see all the dead ash trees scattered throughout the landscape. Forests invaded by this beetle are destined to be changed forever.

Trap lines put out by university and Forest Service researchers are only one way to detect this pest. We also depend on the eyes and knowledge of thousands of gardeners, invasive pest spotters, master volunteers and pest management specialists throughout the state. These observations are important, and if I were a betting man I would wager that it will be a report from one of these folks who will spot the first infested tree.

Bark flaking on ash (tree on the right) caused by woodpeckers is one of the earliest and easiest to detect clues to EAB attack. Photo by M. Merchant, Texas A&M AgriLife.

So how do you know if a tree is under attack by emerald ash borer? Here are a few quick tips that can save you a lot of worry, and us entomologists a lot of time chasing down unlikely leads.

Know your ash! First, be sure the tree is an ash tree. Emerald ash borer is known to attack only ash and a related tree called white fringe tree, Chionanthus virginicus. Ash trees are identified by their (1) opposite branching pattern, (2) compound leaves with 5-9 leaflets, and (3) diamond shaped bark ridges on mature trees. There are many other borers that attack trees other than ash. For information about general borer control in trees, see our fact sheet on wood boring insects.

Look for woodpecker damage. Ash borers usually attack a tree first in the upper parts of the canopy, so damage is usually far advanced by the time emergence holes or damage are seen on the lower trunk of the tree. The first sign of EAB attack is vertical cracks in the bark, usually accompanied by woodpecker damage. Woodpeckers are the most important source of EAB mortality, though unfortunately they cannot prevent beetle attack. When foraging for EAB larvae they typically leave bark flaking or “blonding” which is often visible from the ground, even in the tops of trees (see accompanying image). In addition to flaked bark, woodpeckers leave behind irregular peck-holes where they have probed for the beetle larvae under the bark. For more images of woodpecker signs, see this publication from Michigan State University.

Canopy thinning and epicormic shoots on ash tree under attack by emerald ash borer. Photo by Leah Bauer, USDA Forest Service Northern Research Station, Bugwood.org

Canopy thinning and epicormic shoots at the base of an ash tree under attack by emerald ash borer. Photo by Leah Bauer, USDA Forest Service Northern Research Station, Bugwood.org

Canopy thinning. As the attack progresses, bark cracking continues and the upper ash canopy shows signs of thinning. As the canopy dies back, epicormic shoots may appear at the base of the tree or on the trunk. Epicormic shoots, or water sprouts, are shoots that grow from trees after stress or injury to compensate for the loss of productive leaf surface. These shoots appear as vigorous new growth below the damaged parts of the tree.

The proof: tunnels and emergence holes.

The S-shaped galleries of emerald ash borer serve to distinguish it from all other borers attacking ash. Photo by M. Merchant, Texas A&M AgriLife.

The next clue to an emerald ash borer infestation is the presence of S-shaped tunnels under the now-loose bark of the tree. If you see looping, S-shaped, frass-filled galleries under the bark of your ash tree, you have the first convincing evidence of EAB attack. Though not easy to see, you may also notice 1/8 inch long, D-shaped holes in the bark of the tree. These are emergence holes, used by the adult form of the insect to leave the tree in search of a mate, and the next ash tree to attack. The sizes and shape of the holes are important. Holes longer than 1/8 inch, or holes that are round rather than flattened on one side, are not EAB.

Emergence holes of emerald ash borer are small, only 1/8-inch across. Note the flat bottom, giving the hole a D-shape. Photo by M. Merchant, Texas A&M AgriLife.

So let’s all keep our eyes open for unusual signs of ash dieback, but be sure to check carefully before raising the alarm. If you believe you have strong evidence of EAB in a tree, you can report it through the Texas Invasives Website reporting form for this pest, or contact your local AgriLife Extension or Forestry Service office.

Sharing the Million Pollinator Challenge

Posted on October 19, 2015 by p-porter

Bumblebees on aster - NC Arboretum Asheville2

Bumble bees are one of the fastest disappearing types of pollinators due to their complex habitat needs, climate change and, possibly, their special sensitivity to environmental pollutants, like pesticides.

This week I had the opportunity to attend the First National Conference on Protecting Pollinators in Ornamental Landscapes. The meeting took place outside of scenic Asheville, NC and drew entomologists, industry personnel and extension educators from all over the country. I thought I would use this post to help me digest some of the things I learned, and pose my readers a challenge.

First of all, it was nice to get the chance to interact with folks on both sides of the bee wars–that culture/science clash between the green community and pesticide manufacturers over the cause of recent bee declines. Most meetings I attend seem to include like-minded people that generally agree with each other. Applied entomologists like myself like to talk about how to manage pests more effectively (IPM), and usually end up commiserating about the loss of key insecticides for control of important pests. Conservationists often gather to decry the loss of rare species, while plotting how to battle forces of evil in the guise of industry and “progress”. This week’s meeting was one of those rare times when generally pro- and anti-pesticide groups sat down to find common ground and share ideas for solutions.

How refreshing it was to see these normally hostile groups coming together in support of an often overlooked part of the urban ecosystem, namely bees.

As speakers at this conference reminded us, bees are a diverse group of organisms. There are 4000 species of bees in the U.S., and 25,000 known kinds of bees worldwide. While one species, honey bees get most attention from the public, the other 3,999 species of pollinator bees provide most of the pollination services to native and agricultural plants. Tomatoes and eggplants, for example, rely largely on bumble bees, a type of bee that is rapidly disappearing from our urban and natural landscapes. Many of these other bees, like leaf cutting bees, mason bees and sweat bees, go largely unknown and unappreciated by most people, including many gardeners. Much of the meeting focused on these “other” bees, and what is being done to protect them.

Even though I’ve always liked bees, I learned that bees (and not just honey bees–pollinators in general) are definitely becoming cool for gardeners, and the public in general. Even the White House this spring launched a new initiative to protect pollinator health. The three goals of the initiative include

Reducing honey bee colony losses to economically sustainable levels;
Increasing monarch butterfly numbers to protect the annual migration; and
Restoring or enhance millions of acres of land for pollinators through combined public and private action.

And political support from the Executive Branch is nothing to sneeze at. It is likely to lead to increased funding for research and more public monies going to pollinator gardens and conservation programs. In addition, many states and cities are launching pollinator awareness programs and declaring themselves “Bee City USA Communities” (Asheville was the first of what is now approximately 15 Bee City USA Communities).

The Challenge

The Pollinator Partnership (P2) is an organization devoted to the protection, promotion and research on pollinators and their ecosystems. P2 is working with the Million Pollinator Garden Challenge to establish a million gardens across the country that are designed to provide food, water and habitat to critical pollinator species. If you are interested in doing something to preserve the pollination services and survival of bees, would you consider establishing a pollinator garden in your backyard, garden or local green space? Or maybe you already have a garden that would qualify as pollinator heaven. Would you commit to learning more about how to improve and expand the number of pollinator species that you attract?

If so, consider joining me this year as I upgrade and register my garden through P2. The SHARE (Simply Have Areas Reserved for the Environment) project is committed to teaching gardeners how to grow a pollinator friendly garden, getting these gardens registered, and documenting the change. You may already be further along in this effort than me. If so, register! But before I register I’m going to make a few pollinator upgrades to my drought-strickened garden this winter and spring. Plus I plan to add a few pollinator friendly features like an upgraded bee hotel. The most important thing to remember when planning a pollinator garden is season-long flowers, preferably perennials. P2 provides the following tips for wannabe pollinator protectors:

My small “bee box” at home has attracted only one bee colonizer since it was installed two summers ago. This year I plan to expand the box, add wood boles with pre-drilled holes and provide the house with better shading. It may take several years to get a strong bee colony started in pollinator-poor sites.

Don’t be afraid to have a garden full of bees! Honey bees are quite docile when foraging for nectar, and native bees rarely sting. The only time bees or wasps really pose a threat is when their nest is disturbed. These are not the kinds of nests we want IN our pollinator garden anyway–unless you’re a beekeeper.
Avoid use of broad spectrum pesticides in your bee plantings. This means no mosquito misting systems, or general sprays for mosquitoes in the landscape. If you need an insecticide to protect a plant, either consider not growing that plant any more, or apply the pesticide at night, when bees are not active (follow the label).
Provide water, and mud or bare areas of sandy soil. Mud is an important nesting material for some bee species. Other bees may use light soil to seal off their nests. Others actually dig in areas of bare soil. Heavy clay soils in our area may not be very helpful in this regard. I plan to investigate digging some pits with amended soil and sand around my bee hotel to see if it helps attract more types of bees.
Plant native plants from your area. The Xerces Society publishes helpful lists of pollinator friendly plants for all regions of the country. They have also published a new book that might be helpful, called Attracting Native Pollinators.
When choosing plants try to provide a variety of nectar sources that will bloom over a wide period of the growing season. And don’t forget spring blooming trees like plums and cherry and redbud and holly (crape myrtles are not very attractive to pollinators). Spring blooming trees are especially important to early emergers like bumble bees.
Consider building a bee house or hotel. Holes can be drilled in the ends of cedar post scraps or firewood. The holes should range in size from 3/32 inch to 3/8 in diameter, and 4 to 5 inches deep, according to P2.

By the way, I have tried mostly unsuccessfully to attract pollinators to a bee box the past two summers using bamboo pieces crammed into a shelter box. My lack of success may be due to the lack of a shade roof, lots of ants, or just relatively few pollinators in my neighborhood. But I’m not giving up. I will keep trying until I find the right recipe for my home. I hope you will too.

One last piece of advice for perfectionists. Don’t let the feeling that you have to have the perfect garden or the perfect bee hotel keep you from working on a pollinator garden. Several speakers at our conference stressed that gardeners shouldn’t over-think the process. ANY pollinator plants you plant are better than none. Start with what you’ve got and build on it. No garden will be perfect the first year, but as it matures and you add to it, it will just get better. And for pollinators it doesn’t have to be native (though there are other reasons for liking native plants). The most important thing to have in a pollinator garden is your shadow (you!).

Bagworms in the fall

Posted on September 17, 2015 by p-porter

The brown, spindle shaped bags in this image are the cases of bagworms, a caterpillar that can be a pest in dozens of different trees.

You’ve been watching your arborvitae all summer and noticing brown, spindle-shaped sacs hanging from the branches. Someone points out to you that these are bagworms, a case-making caterpillar that feeds on leaves and can be highly damaging, especially to evergreen trees and shrubs like arborvitae and cedar.

Now it’s late September, what do you do?

Before I answer that question, it’s worth pointing out that bagworms are interesting insects with a decidedly non-traditional life cycle. Bagworms are not really worms, but caterpillars, the immature stages of a nondescript moth. They are called bagworms because, shortly after they are born, they begin spinning a silken case or sac around themselves, using silk from glands associated with their mouth. The case is added to continually as the caterpillar grows. The caterpillar feeds on the host plant by sticking its head and legs out of the top of the bag and chewing on nearby leaves. Its legs grasp the branch of the host plant, and propel the caterpillar like a kid cruising the monkeybars.

A now-empty case of a male bagworm is marked by the pupal “skin” left dangling from the bottom of the sac. The presence of these empty cases signals the end of a generation of bagworm feeding.

Bagworms have one generation each year in Texas (some species possibly two). Once the larvae are fully grown they stop feeding. Males pupate and emerge as adults, usually a little before the female. Adult male moths exit the bag through the bottom, and fly off in search of a mate. Females also pupate, but the adult female that emerges is eyeless, wingless and legless. She remains in her bag, emitting a pheromone to alert males to her presence. Male moths locate the female bags and mate. Once mated the female gestates her eggs and dies, leaving a bag full of eggs that will hatch the following spring.

Once both male and female bagworms enter this last phase of life, feeding is over and so is any chance for effective control with insecticides. Bagworm bags are made of tightly woven silk and bits of leaves from their food plant. For this reason, the caterpillars, pupae and eggs inside are well protected from insecticides. Only when actively feeding are bagworms vulnerable to insecticide sprays.

So it’s late summer. Is it too late to spray for bagworms? That’s a good question, and will require some close observation on your part. If you have a bagworm-infested tree, pull off as many bags as you can for a quick inspection. Do you see red-brown pupal skins sticking out from the bottoms of many of the cases? If so, this is an indication that pupation and mating by at least some of the bagworms has begun. Are the cases easy to pull off the tree, or are they tightly bound with thick silk? Cases with thick bands of silk attaching them to the branch are an indication that the caterpillar has started the process of pupation, mating or egg laying. Open up some cases with a pointed knife or scissors. Do you find caterpillars still in the cases? If so, a spray may be worthwhile. If most cases are empty, or have only pupal skins or eggs inside, you’ve missed your chance this year to treat.

Bagworms are slow to spread. Notice that the infestation damaging the middle tree has not yet spread to adjacent trees.

If you’ve missed your chance to spray this summer, that’s OK. Your bagworms will do no further damage this year. You have two options: wait until next spring to treat, or consider handpicking bags from trees during the winter or early spring.

Because female bagworms do not have wings, and there is only one generation a year, bagworm infestations are usually slow to spread. This means that on smaller trees, or trees that are deciduous (making the bags easy to spot), handpicking can sometimes eliminate or greatly reduce an infestation. Trees picked clean of bags are unlikely to become re-infested the following year.

Your other treatment option is to wait until spring when bagworms hatch (usually May to early June) to treat the tree. A relatively easy way to know the best time to treat emerging bagworms is to remove a number of bags from a tree and place outdoors in a screened jar in a shady spot. When the eggs hatch and young caterpillars are seen inside the jar, chances are that eggs are also hatching on your trees. Sprays such as Bacillus thuringiensis, spinosad and any of the pyrethroid insecticides are effective on bagworms, especially early in the season. Late season infestations, when bagworm caterpillars are larger and more difficult to kill, are best treated with pyrethroid sprays.

For more information on bagworms, including photos of many of the life stages, see the excellent publication by the University of Florida.

Hackberry defoliator in north Dallas area

Posted on August 28, 2015 by p-porter

caterpillar of Sciota celtidella on sugarberry

Webbing and defoliation on sugarberry hackberry by the moth Sciota celtidella. Photo by Courtney Blevins.

Over the past few weeks I’ve had several emails concerning a small caterpillar infesting hackberry in the Flowermound and Grapevine, TX area especially. After some initial head scratching over fuzzy pictures sent via email, my lab employees went caterpillar hunting yesterday and brought back a good haul of larvae feeding on sugarberry trees, Celtis laevigata.

After sending pictures to colleagues, James McDermott of College Station identified the critters as Sciota celtidella, an obscure moth that has been recorded feeding on hackberry, Celtis occidentalis (Alma Solis, Bull. Biolog. Soc. of WA May 2008: 88-106).

The half-inch long caterpillar of Sciota celtidella on sugarberry is easily missed

So why should a little moth that’s rarely seen or collected suddenly become such a pest? It is not uncommon for insects to go from extreme obscurity to being incredibly abundant over sometimes a very small area. This was pointed out to me by Austin entomologist Val Bugh, who maintains an interesting website and whose avocation is looking for obscure insects. Chances are that this year will prove an anomaly, and hackberries will happily grow undisturbed next year. But no one knows. These little surprises are part of what keeps entomology interesting.

If your yard or local hackberry fence line is turning brown right now from these caterpillars, you may choose to treat or let nature take its course. Untreated trees will not likely re-leaf this far into the season. But if the trees are otherwise healthy, they will most likely be fine next spring. If you want to preserve the remaining foliage on your hackberry tree, treating with spinosad or a pyrethroid insecticide should stop the infestation quickly.

Note that like many insects, these caterpillars are very host specific. Infestations will remain only on sugarberry or hackberry trees, and will not move on to other landscape plants or trees.

Hackberries, like most trees in north Texas, are under some stress from a long, hot summer, as well as previous years’ drought. So if your tree has been affected by caterpillar feeding, consider the following tree care suggestions from tree experts:

If your soil is very dry, supplemental deep watering around the base of trees can help a tree through late summer stress.
Most shade trees do not need special fertilization, however you can apply compost and mulch around the base of the tree. Ask an arborist whether your tree might benefit from root feeding–this often requires a soil test.
For trees in lawns with compacted soil, aeration of the lawn can help the tree better absorb water and nutrients.

If you see this insect defoliating trees outside the Lake Grapevine area, I would be interested to know. You can find my email address here.

New-bee volunteers

Posted on August 26, 2015 by p-porter

The inaugural class of Texas Master Beekeeper Apprentices, March 27, 2015.

A new resource was birthed this spring with the first graduating class of apprentice Master Beekeepers. In March the Texas Master Beekeeper program graduated its first class of 68 volunteers specializing in bee culture and protection.

Like its cousins, the Master Gardener and Master Naturalist programs, the Master Beekeeper program is intended to nurture trained volunteers to assist with public service and educational programs. But the Master Beekeepers will work on projects primarily related to honey bees.

With this first class Texas joins Florida, Georgia, Oregon and other Master Beekeeping programs. It is a minimum five-year training and certification program for people who already have experience as beekeepers. Entry into the program comes from meeting the apprentice requirements and passing the apprentice examinations on exam day. Additional levels beyond Apprentice are Advanced, Master, and Master Craftsman.

With 68 new apprentices and over 200 names on a waiting list for training and certification,Texas Apiary Inspection Service Chief Apiary Inspector Mark Dykes, feels like the program is off to a great start. To learn more about the program, visit the website at http://masterbeekeeper.tamu.edu.

Tougher head lice in schools this year

Posted on August 20, 2015 by p-porter

The head louse is a very small insect (2-4 mm-long) and well-adapted to spending its life among the hairs on human scalps.

Sending your children off to the first day of school comes with plenty of concerns. Will they enjoy their new teachers? Will they make good friends? But one concern often overlooked in the rush of the new school year is head lice.

Now the last thing anyone should stress over when it comes to schools is head lice. But with a new school year, reports of head lice always go up. And according to a new paper delivered at the American Chemical Society and reported this week in Smithsonian.com, this year’s head lice are running with a tougher crowd.

In the paper Texas is among 25 states shown to have head louse populations that are resistant to the most commonly used head louse shampoo treatments, including pyrethrins and the pyrethroid insecticide permethrin. In fact, most states (104 out of 109 samples) tested so far have lice that are resistant to these over-the-counter (OTC) louse treatment options.

Researcher Kyong Sup Yoon, at Southern Illinois University-Edwardsville, is lead author of the study. He points out that “Just one louse that manages to survive a pyrethroid treatment can live for up to a month and lay five eggs a day. Multiply that by an elementary school, a community, and soon you’ve got plenty of resistant lice.”

Not to panic.

There are almost as many home remedies for head lice as there are worried moms; but even resistant lice can be successfully treated with OTC products with careful attention to head inspection and combing after treatment. Using two methods (insecticide plus mechanical control in this instance) is almost always better than one method when it comes to controlling pests.

In addition, new treatment options are now available through your doctor. These products include ivermectin (Sklice®), spinosad (Natroba™), and benzyl alcohol (Ulesfia®). These products will likely be more expensive, you you might want to try the OTC route + combing first. But it’s always good to have options.

I remember the battle I had with my daughter and head lice several years back. It took three treatments and repeated sessions with the comb to exterminate the cunning creatures. At least we didn’t have to resort to the barber shears.

So send those little people off to school with a smile. Chances are they will have a great year. But in case they come home some night with unwanted friends, be prepared. For more information about head lice, see our free publication on human lice. If you are a doctor or nurse looking for treatment options for head lice, check out this recent paper from the American Academy of Pediatrics on head lice guidance for the clinician.

Mosquito threat highest Now

Posted on August 13, 2015 by p-porter

In 2012 Dallas was the national epicenter of a West Nile epidemic. A mild winter and very hot summer combined to make conditions that resulted in approximately 400 reported cases and 19 deaths in Dallas county alone. While 2015 has not approached the mosquito numbers or disease transmission potential of 2012, this year’s data suggests that risk for getting a WNV infection from a mosquito is peaking higher than any time since then.

Average mosquito trap catches (bars) and the Vector Index (VI) of disease risk (lines) for West Nile Virus in Dallas County in 2012 and 2015. The VI for Aug 2015 is the highest seen since

Traditionally the potential for WNV transmission peaks in August and this year looks like no exception. Data published this week by the Dallas County Health and Human Services shows a key measure of disease risk (the Vector Index) to be higher this month than at any time since 2012. The vector index peaked on Aug 1 at 0.31. In comparison in 2013 and 2014 the VI reached only 0.19 and 0.14, respectively. A VI of 0.5 is considered high enough to justify intensified vector control methods like aerial spraying.

Though numbers of WNV are still considered low for our area (only 3 reported cases this summer), there have already been 3 cases of Chikungunya (out of 9 cases reported in the state), a disease that wasn’t even on our health officials’ radar in 2012. So far these appear to have been cases picked up from out of country travel, but anyone infected with this disease can spread it back to mosquitoes locally. This has resulted in a number of locally acquired cases in Florida and could easily happen here.

All this to say that all of us should be taking special care to protect ourselves from mosquito bites this time of year. Don’t assume that because it’s not been raining, you don’t have to look for sources of standing water. As irrigation and septic systems continue to flow, and creeks begin to dry up, there are plenty of mosquito breeding sites around. And don’t assume that because you can go out during the day and not see mosquitoes, you don’t need repellent when out at night. The Culex mosquitoes that are our primary disease carrying mosquito come out primarily after dark.

On the other hand, anyone travelling to the Caribbean or Central America should also be diligent to wear repellent day and night to protect against Chikungunya, which is carried by day-active Aedes mosquitoes.

As the lazy days of summer pass slowly, consider this reminder. Don’t get lazy about protecting you and your family from mosquito-borne disease risk.

Insects in the City

The best in science-based, pest management solutions from Texas A&M AgriLife Extension Service