Friday, December 21, 2012

Carpet beetles...not bed bugs

I've had numerous people in the past month calling with "bed bug" problems.   After encouraging samples to be submitted for identification,  I discovered that while some people had problems with bed bugs, others had carpet beetles.  I want to point out that just because a "bug" is found on a bed does not necessarily mean that it is a bed bug.

Carpet beetles and bed bugs are quite different.  First of all, they are in different orders.  Carpet beetles are in Coleoptera while bed bugs are in the order Heteroptera.  Carpet beetles have chewing mouthparts while bed bugs have piercing-sucking mouthparts.  Carpet beetles have complete metamorphosis- egg, larva, pupa, adult.  Bed bugs have incomplete metamorphosis- egg, several nymphal stages, adult.

Carpet beetle adult.
Carpet beetles can be solid black or mottled browns, greens and white.  Carpet beetle adults are oval in shape and relatively small in size (smaller than 1/4 an inch).  Adults have fully developed wings, with the front wing hardened (called an elytra).  The larvae are also fairly small, elongated and often have long tufts of hair coming off the body.  Larvae are usually considered the pest stage.  Larvae feed on and cause damage to high protein items such as pet hair, wool, silk, fur, feathers and some stored pantry items.  Hairs from larval stages can cause a biting sensation or irritation for some people.

Bed bug. Photo by Alan Brown.

Bed bugs are brown to reddish-brown, small insects without wings.  The body is oval and color varies depending upon whether the insect is engorged with blood.  The nymphs look very similar to the adults, but are smaller in size and lighter in color.  Both nymphs and adults feed on blood and can be found around sleeping areas of their host.

Here comes the tricky part- both carpet beetles and bed bugs can be found on a bed.  If you know their biology (see above) then it makes sense.  Bed bugs can be on the bed to be near their host that provides a blood meal.  Carpet beetles can be found on a bed because of food, but they are not feeding on blood.  Food for carpet beetles on a bed can range from feathers inside blankets and pillows to pet hair (if you're like me and you have a menagerie sleeping with you).
So now that I've made everything as clear as mud, let me remind you that if you need help identifying insects- whether you find them in bed with you, in the kitchen or in the garden- I can help with identification.  You can either take a photo and email it to me or collect a sample and bring it by the office.  If you go the photo route, put something in the picture for size reference....and be aware that I have no idea how large your hand is, I only know mine.  When collecting samples, try to get more than one specimen and try to keep them intact.  They can be placed in a ziptop baggie and placed in the freezer to kill (and preserve) them.  Please do NOT collect samples on tape; if you have an unknown biting you, then put out glueboards to capture the critters.  To transport glueboards, cover the sticky surface with plastic film.  Do NOT stack glueboards as they will stick together and I won't be able to look at anything.

Friday, December 7, 2012

Brown Marmorated Stink Bugs

Brown marmorated stink bugs (BMSB) were confirmed in Corpus Christi, TX in late 2011.  These insects are a new pest to Texas and a relatively new pest to the United States.  They are a true bug with piercing-sucking mouthparts and they have a large list of plants that they may feed upon including numerous ornamentals, vegetables and fruits.  These stink bugs are shield-shaped, about 5/8 inch and mottled brown in color.  The last two antennal segments have alternating light and dark bands.  The edges of the abdomen, which are exposed from above, also have alternating light and dark bands.

BMSB usually cause small necrotic areas by feeding on plant tissue, but they may also cause stippling, seed loss or transmit diseases.  Damage to fruit can be scarring, pitting, catfacing and sometimes changing the texture to be more mealy or grainy.  Not only do these bugs attack many high value crops, but they can also be a nuisance pest and move into homes when temperatures drop.

We have been doing work with the media lately to encourage people across Texas to report suspected infestation of BMSB.  If you suspect that you have seen brown marmorated stink bugs in the Austin area, please collect a sample and send it to Texas A&M AgriLife Extension for confirmation.  Recent media includes a story on AgriLife Today and a spot on KXAN.  For images of the stink bug, see this publication.

As for management strategies for BMSB, many pesticides that we currently have available don't work very well for managing populations of this particular insect.  In backyard situations, stink bugs can be hand-picked from plants (wear leather gloves) and dunked into a bucket of hot, soapy water.  It may also be possible to vacuum stink bug populations from plants or other surfaces. 

To keep stink bugs out of the home follow these ideas:

  • Install weather stripping around loose fitting doors and windows (if you can see daylight around a door during the day then the weather stripping should be replaced).
  • Block weep holes in homes with a brick or stone facade with steel wool or copper mesh (use copper on light colors since steel wool will rust if it gets wet).
  • Use caulk or expanding foam to fill in cracks and crevices on the outside of the home and around pipe and wire penetrations.
  • Keep window screens in good repair.
  • Use stainless steel mesh wire to block access points in the attic (vents, etc.).