Friday, August 28, 2009

When life hands you maggots...

Soldier fly, Hermetia illucens, adult. Photo by Mike MerchantOne of the odder occasional invader pests PMPs can encounter is the soldier fly, Hermetia illucens. The adult soldier fly is relatively obscure and unlikely to attract much attention. The mature larva, however, is a creature from a bad sci-fi movie. Unlike most fly larvae, the soldier fly is leathery and grey or brownish in color--well adapted to crawling longer distances away from its moist larval habitat. It's just odd enough that a customer who sees one is sure to save it in a jar for you, the pest control guy, to identify.

Soldier flies in homes are most likely to be associated with decomposing animals, especially those in later stages of decomposition. But soldier fly larvae are also associated with compost bins or any wet accumulations of vegetable debris.
Soldier fly larvae from ProtoCulture LLC at http://thebiopod.com/pages/pages/bsf.html
A new phenomenon worth being aware of, especially among your green customers (you know, the ones who drive Priuses, install solar panels on the roof and want your "organic" program) is vermicomposting. Vermicomposting is a faster and safer way of disposing of kitchen scraps. Vermicomposting bins may consist of wooden or plastic bins (plastic sweater boxes are commonly used) layered with newspaper and kitchen scraps. It uses certain types of worms, especially red wrigglers, to help compost the food quickly with minimal odors. Occasionally soldier flies find their ways into these bins and can partly take over composting from the worms.

A new, entreprenurial twist on vermicomposting is "soldier fly composting". One enterprising young company is trying to sell America on the concept. The BioPod™ is a specially designed plastic container that makes soldier fly larvae (or, to use the company lingo, BioGrubs)easy to rear. If this vermi- biogrub- movement catches on, PMPs may see a lot more of these critters escaping from their compost bins and crawling through homes and apartments.

See a quick video about "Biogrubs"


My entomology colleague and fellow blogger, Kim Schofield, entertains and instructs hundreds of school children each year with, of all things, maggot art! She simply takes a few soldier fly larvae, some non-toxic paint, and a piece of paper. Dip the maggots in the paint, have the kids drop them on the paper, let them crawl for awhile, and viola! Art! Don't believe me? Well of course there's a website for everything, so check out http://www.maggotart.com

All this new interest in soldier flies is great proof of the human ability to make the best of an otherwise yucky deal. One could say if your customer hands you maggots, make maggot art! Or at least know what they're handing you.

Wednesday, August 26, 2009

Newest news on Colony Collapse Disorder

You may soon be hearing about the conclusions of the latest research on origins of colony collapse disorder in the news. Briefly, researchers with the University of Illinois are pointing the finger at viruses again, but this time with a twist. The suspected culprits are called "picorna-like" viruses. This viruses specifically attack ribosomal RNA, part of the cell's genetic machinery that produces proteins the bees need for protection against stress, disease and other assaults.

What's interesting about these new studies is that they rely on cutting-edge techniques and information that have never been available before. Writing in the Proceedings of the National Academy of Science, the team say they used "whole genome microarrays" to compare cells from bees' guts. According to lead scientist May Berenbaum from the University of Illinois, the research was possible only because of the prior publication of the bee genome (basically a complete roadmap to all the genes in honey bee DNA) in 2006.

The team's genetic analysis of the bees' guts failed to reveal elevated expression of pesticide response genes; however the new techniques did reveal an unusually high amount of ribosome fragments in the guts of CCD-affected bees. The data are consistent with damage caused by picorna-like viruses that, in effect, “hijack the ribosome” of bees to take over these protein factories. The deeds of these viruses are apparently difficult to trace with traditional techniques. Affected bees from CCD hives had “more than their fair share” of infection with these viruses, according to May Berenbaum, of the University of Illinois, who led the study.
The results, if confirmed, would seem to make sense of many previous studies' findings or lack of findings. Weakened bees could be more susceptible to stress, disease and other assaults.

I have to admit that this is technology that I didn't learn about in graduate school. Hence I must wait in the wings to see how the drama plays out among those researchers who thrill to talk of pico-viruses. In any case, it seems that these result continue to support the idea that pest control is unlikely to be the source of the honey bees' woes.

A look back in time

My monthly National Geographic magazine arrived in the mail yesterday. The cover carried an intriguing computer rendition of how Manhattan Island likely looked in 1609, next to its appearance today. This stuff is fascinating to me, as I have always wished I could travel back in time and see our country as it might of appeared to the pioneers or native Americans. I love to squint my eyes and try to imagine landscapes without power lines and pavement and people, two hundred or more years ago.

The Mannahatta Project people, who supplied National Geographic with the computer renderings, have done this. According to their website these folks have been working for over a decade, looking at historical maps and records to recreate the 17th century landscape. In one sense it is a wonder to see what "man hath wrought" in a couple of hundred years, sculpting the land to make it habitable and creating marvels of engineering. On the other hand it is sad to virtually see the beauty that once was, and is no more. Lakes that provided water for Indians, first polluted, then filled in and eventually paved over. Rich fisheries that have declined, and scenery transformed to blight.

Interestingly, PCTonline.tv just posted a video by Bobby Corrigan showing rodent activity and behavior in lower Manhattan. Norway rats are not native to North America and, as Bobby points out, lower Manhattan island was likely one of the first places in the continent where rats made landfall.

For better and worse, we humans have made our mark on this fair land. One of our biggest ecological sins, in my opinion, is the way we have redistributed a variety of plant, insect and vertebrate animals to places they did not evolve and do not live peacefully with native ecologies. The landscape of Manhattan island is now honeycombed with the warrens and runs of Rattus norvegicus. Prairies of Texas are now populated with Solenopsis invicta, the red imported fire ant, to the harm of native quail and snakes and myriad insects.

It's important that the public and, more importantly, our children know these things. There are still pests to keep out, and there are still plenty of places that resemble 1609 Manhattan, and there is a need to have both our New York cities and our wild places. Kudos to the Mannahatta project and all those people working to instill an appreciation among kids for our native landscapes. Now if we could just keep crazy ants and fire ants at bay.

Monday, August 24, 2009

Climate change and changing times add up to new challenge for PMPs

One of my favorite anecdotes is about the famous British architect Christopher Wren. According to Wikipedia, "Wren designed 55 of 87 London churches after the Great fire of London in 1666, including St Paul's Cathedral in 1710, as well as many secular buildings of note." The story goes that Wren approached a man who was working on one of the buildings he had designed. When asked what he was doing, the man replied, "I'm laying brick." Wren approached a second construction worker engaged in the same work and repeated his question. The second man looked up and smiled and said, "I'm building a cathedral."

Every so often I think it's important that we stop focusing so closely at what we do, and look at the larger meaning and impact of our life's work. What kind of business are you in? Is it a business to make money? Is it a job to kill bugs? Or is your business helping people to lead healthier, safer and more pleasant lives? You may be running a residential route, or servicing commercial clients, or making sure your employees remain productive, but if you are in the pest control business, your job is more than just controlling pests.

I was reminded of the importance of our profession thanks to a note this weekend from Steve Baker, of International Exterminators in Fort Worth. Steve send an article from the Wall Street Journal on the increasing frequency of new diseases being seen, especially along the southern border with Mexico. Much of this has to do with changes in immigration patterns, but some of the concerns focus on spread of new pests into the U.S. Although data is still scarce, some people believe that climate change may be encouraging the spread of insect vectors of disease further north. In a response to a letter about a recent article on the impact of climate change on insects, University of California entomologist John Trumble notes that the ranges of more efficient vectors of this disease may be spreading north, even as the parasites follow immigrants across the border.

In Texas a major concern of health officials is the spreading incidence of the mosquito-borne disease, dengue fever. Warmer temperatures and increases in dense, low-income housing favor the spread of this disease. Caribbean (Rasberry) crazy ants, fire ants, argentine ants, and numerous plant-feeding insects are all likely to be favored by current trends in climate change.

Of course all this adds up to the growing need for pest control. How about if today, when you wonder if it's all worth it, you think about the bigger picture? You and your employees are not just killing bugs, you keeping your friends, neighbors and customers safe and healthy. Having people take a pest-free home or pest-free business for granted is a sign that you are doing your job well.
Christopher Wren would be proud.

Thursday, August 20, 2009

Plague, prairie dogs and pesticide policy

Prairie dog town in Wichita Mountains, OklahomaUrban pest control encompasses an incredibly wide range of organisms including insects, arachnids, birds, bats and a smorgasbord of urban wildlife. I was reminded of this yesterday with a call from a PMP seeking help with flea control in prairie dog towns. It seems there is a plague epidemic among the prairie dogs living in and around Santa Fe, New Mexico.

Since plague is not a common phenomenon in the United States, a little background might be helpful. Plague is a disease caused by a bacterium called Yersinia pestis. The bacterium can be transmitted through the bite of an infected flea, through handling or skinning an infected animal or through the air from an infected human (or more frequently, cat) similar to flu. The term "plague" stirs most people because of its association with the black death of Europe, when dozens of millions died over a 300 year period starting in the 14th century.

There are two ecological forms of plague: urban plague, spread largely by commensal rats; and sylvatic plague, which is spread largely by wild rodents in rural areas. Both forms of plague remain a threat in this country, though the last outbreak of urban plague occurred in Los Angeles in the 1920s. Most recent U.S. cases of plague, 10-15 a year, are sylvatically transmitted and occur over scattered sites in the western states, including a few in Texas.

Rodent control by PMPs has, without a doubt, helped keep urban forms of plague rare over the past century. But effective pest control for public health is still needed to control of sylvatic plague in some areas. In the current Santa Fe epidemic, for example, one of the affected prairie dog colonies is adjacent to a school playground in an urban neighborhood.

Unfortunately, some citizens and politicians appear not to appreciate the seriousness of arthropod-borne disease. Perhaps this is because of our success in keeping arthropod-borne disease rare. Maybe it's a need for better public health education or a lack of understanding of science and medicine. Whatever the reason, in recent years I see more instances where vague health and environmental concerns seem to be trumping well-documented and real concerns about insect-vectored disease.

In Santa Fe, citizen pressure in recent years has led to schools and the city replacing effective conventional pesticides with generally untested, organic alternatives. One specific consequence of this approach is that city workers are being encouraged to use diatomaceous earth for control of Xenopsylla cheopsis, oriental rat flea, in prairie dog burrows. In a cursory review of the literature I could find no information to justify use of diatomaceous earth for flea control in prairie dog burrows. I was, however, able to quickly find peer-reviewed research on the effectiveness of field applications to prairie dog burrows of several other insecticides including carbaryl, DDVP, permethrin, deltamethrin, and pyriproxifen.

While it can be argued that none of these products provide an ideal, long-lasting or inexpensive solution to plague-bearing fleas, they do provide significant, quick control of fleas. They can also rapidly prevent or eliminate plague outbreaks in prairie dog towns. And at least some of these tested products should be acceptable to the staunchest pesticide critics. Pyriproxifen, in particular, is a low toxicity insect growth regulator that has shown excellent flea control in prairie dog burrows with minimal ecological disruption. Highly specific oral vaccines for prairie dogs are also being tested with promise for providing a longer-term solution to plague outbreaks.

On the other hand, my own work several years ago with cat fleas showed that although diatomaceous earth can control fleas under dry laboratory conditions, the addition of moisture to treated soil quickly renders treatments ineffective for control of adult and larval fleas. This casts serious doubt on the effectiveness of field applications of diatomaceous earth dust into damp underground burrows. At the very least it points out the need for field testing before recommending such treatments.

So why would a respectable community persist in requiring an untested, most-likely ineffective pesticide to control plague-bearing fleas? In this case it seems to be because anti-pesticide advocates, armed with little more than an easily-transmitted fear of technology, are able to persuade policy makers that "natural" is always better and safer. The same strategy is being used in my community to spread fear about the responsible, professional use of mosquito spray campaigns in areas of high West Nile virus risk. The big problem here is that untested recommendations are being taken seriously by government and public health.

It is one thing to choose to use untested home recipes in a backyard garden, where the worst that can happen is for the gardener to lose a few of his or her own plants. It's another thing to pressure communities to stop using proven pest control technology against pests that threaten community health. It make sense that before a community switches from a proven technology, advocates should provide (1) proof that the current technology poses an environmental or health cost that exceeds the value of the benefits provided, and (2) evidence that alternatives are both safer and equally effective as the current technology.

Decision-makers at the school, local and state level need to understand both the science and the stakes involved before restricting the kinds of pesticides that can be used by pest management professionals. This is what I believe is wrong with the growing crop of local ordinances banning municipal governments from using certain classes of pesticides in parks and schools and other public places.

You will get little argument from me that pesticides pose their own share of unique environmental and health challenges, but the problem is often less than the public is led to believe. And in many cases, the negative impacts of pesticides can be blunted by keeping them in the hands of professionals and using them in the context of a well thought-out IPM program. Our ability to control pests quickly at reasonable cost, often with a high degree of selectivity and environmental compatibility, means that pesticides will continue to be a valuable part of pest control in the foreseeable future.

I do not live in Santa Fe, and cannot speak to all the issues and circumstances of their plague management program there. But if I were a parent with a child in school next to a prairie dog town with a known plague outbreak, I know I would want a control option that had been tested and shown effective.

Thursday, August 13, 2009

Crazy ant findings spell bad news for San Antonio

I guess the crazy ant video posting from last week was timely in an unfortunate way. This week we have an official confirmation of the Rasberry crazy ant from west San Antonio, as well as the first confirmed site in Galveston county. Molly Keck, IPM program specialist from Bexar County, is concerned about the find, which was made by a PMP during a service visit to a commercial customer. According to Dr. Roger Gold, the identity of the ants has been confirmed by the Center for Urban and Structural Entomology at Texas A&M University.

One of the things I learned from the workshop last week was that humans are the main agents responsible for dispersal of this species of ant. By themselves these ants seem to spread relatively slowly, much slower than fire ants when they were invading Texas. According to researcher Danny McDonald, highlighted in last week's video blog, winged females have yet to be observed in this ant, so spread may be limited to the ground... unless humans help out.

We believe crazy ants are being spread in Texas through soil, hay bales and possibly vehicles or equipment that are stored on the ground. Moving potted plants or woody plants with root balls is likely a principal means of transport. Because this ant is not yet considered a quarantined pest, there is currently no inspection process or certification of nurseries or soil transporting operations. Advising a client with Rasberry crazy ant infestation to avoid spreading the problem by moving such articles will provide a service to the community.

As new counties are added to the list of confirmed counties with infestations, the BASF expanded label for Termidor (allowing expanded treatment zones around structures) will be amended by the TDA. If you have what you suspect might be a Rasberry crazy ant problem, send specimens to the Center for Urban and Structural Entomology using the Identification Request form on their website.

Monday, August 10, 2009

One more try...

Please excuse my inexperience with posting videos. The crazy ant workshop video is now public and should be visible to anyone. You can click on the video from yesterday's post, or go directly to the crazy ant report at http://www.youtube.com/watch?v=80UbzvlQB0U

Sunday, August 9, 2009

Rasberry Crazy Ant Workshop

Last week I had the opportunity to participate in a day-long workshop on the so-called Rasberry crazy ant. Sponsored by the AgriLife Extension Service and held in the small town of West Columbia, TX, it attracted about 50 extension specialists, regulatory officials, Fish and Wildlife Department officials and community representatives. Rather than report in writing I thought I would try my hand at a video report, since still pictures and descriptions seem inadequate to convey a feel for what this ant does and is.

For more information about this ant and what we can recommend about its control, check out the site sponsored by the Center for Urban and Structural Entomology's site at http://urbanentomology.tamu.edu/ants/exotic_tx.cfm