Monday, April 29, 2013

Bed bugs hit Springfield

Thanks to Sherry Glick at the U.S. EPA for a heads up on the latest pop culture nod to the lowly bed bug.  In case you missed it, like I did, the Simpson's episode last night featured bed bugs.  If you didn't respect the bed bug's capacity to wreak havoc before, you will after watching this clip.

And many thanks to FOX network for reminding us all that April 22-28 is Bed Bug Awareness Week.  Personally I was having a hard time thinking of ways to celebrate national bed bug awareness, but now I have something to look forward to.  I will be looking to watch the rest of the "Pest Week Ever" episode on the Internet.

Monday, April 22, 2013

An odd "pest"

Even when not an insect, if an object is small and mysterious, it will often be called a "bug" and end up on the desk of an entomologist.  Such was the case with some specimens I received last week.  They were described by a pest management professional as "tiny bugs" that appeared on the south side of a customer's house every year.  No mulch or trees or shrubs were reported nearby.

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 a saprophyte 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 smoothly round as typical for Sphaerobolus.  

These tiny, 1.3 mm, seeds from the Oxalis plant are sometimes
ejected from the plant and stick to man-made surfaces, like
exterior walls, where they may be confused with "bugs".
My sample of 20 or so objects were teardrop-shaped and ridged/segmented.  Under the microscope they looked vaguely insect-like but appeared to lack legs and mouthparts.  Fortunately I network with many experienced entomologists around the country, several of whom kindly informed me that the sample was actually the seed of Oxalis, a common garden weed or plant.

One entomologist who wrote back 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 insecticide sprayer.

As it turns out, Oxalis seeds 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 be quick to blame insects for those strange objects that customers are prone to find around the home.  If you don't know what something is, have it checked out by me (if you're in Texas) or one of the other fine entomologists most states (and many pest control companies) are blessed with.  There are enough real insects in the world to keep all of us entomologists busy full-time.

Wednesday, April 17, 2013

Good grooming

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.   

Wednesday, April 3, 2013

Mosquito season upon us

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.

Mosquito "wiggler" and "tumbler" are informal terms for the larval and pupal (immature) life stages of a mosquito.  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 and Human Services Department, in north Texas we are now more likely to see  Culex restuans, or one of the other early mosquito species that do better in cool weather.  These cool season mosquitoes are not considered important in the spread of West Nile virus or other encephalitis diseases.  Nevertheless, these mosquitoes still bite and are not welcome around your customer's home.

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.  Mosquito larvae are not all that easy to see unless you know what you are looking for.  Any water-holding container, regardless of whether you see mosquitoes or not, should be considered a potential breeding site. Early in the season is a good time to scout out these water traps and treat or eliminate them before the REALLY bad mosquitoes show up.

I advised in my last post to take advantage of your residential service calls to check your customer's backyards for mosquito breeding sites. If you do find a suspected breeding hole, advise your customer to 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, containing Bacillus thuringiensis or S-methoprene are available through pest control distributors. Ask your distributor, but typically these professional products can last from 30-90 days.

I betting that, at least for some of your customers, a little good will in the form of pointing out a potential mosquito problem is likely to earn some customer-retention brownie points.