Monday, November 12, 2012

Tiny, Shiny, Reddish-Brown Beetles - Spider Beetles

spider beetle, shiny, hump-backed, reddish-brown
These tiny beetles are fairly uncommon but because they resemble mites or even bed bugs they get a lot of reaction from homeowners when they are found.
Spider beetles are small (1.5 - 4mm), shiny, hump-backed, reddish-brown beetles that are considered to be minor stored product pests (infest stored foods and natural fabrics). They are usually not a major problem in homes but can damage museum collections of animals and dried insects. These beetles are especially common in older buildings.

On first sight people sometimes mistakenly identify spider beetles as mites or bed bugs. They are of course completely unrelated to either of these critters.

The majority of questions I get about spider beetles come from New York City but these beetles occur in other regions of the country as well. There are at least three species that can be found in homes.

Since spider beetles are general scavengers they can infest a wide variety of organic debris so finding a few beetles is generally not a reason for concern. Cleaning and food source elimination is usually enough to manage the infestation. Insecticides are not needed nor are they very effective in this case.

Identification and control tips for a wide variety of other household pests can be found at our main site LivingWithBugs and DIY pest control supplies, including traps and baits, can be found here.


Wednesday, September 05, 2012

Types of Mites

follicle mite
Mites live on plants, in the soil, in our homes, and sometimes even on us!

Mites are among most abundant and diverse animal groups on earth.  Mites occur literally everywhere; in our homes, on our garden plants, in the soil at our feet, and some even live on us -- so it is indeed a good thing that most are so small that they are barely visible!

A "typical" mite is about the size of a grain of salt but some, such as ticks (yes, ticks are a type of mite), can be as large as your fingernail while others like the demodex follicle mite (left) are small enough to live inside a normal hair follicle, with room to spare.

brown recluse spider
Mites are related to spiders but they are much more abundant and diverse than their arachnid cousins. While all spiders are predators (i.e. they feed on live prey) mites exhibit a range of lifestyles from the small plant feeding spider mites to tiny ectoparasitic scabies mites and to the relatively large, free-living predatory mites that can be found in most soils.

Mites usually have eight legs like spiders but they don't have the distinct separation between the head/thorax (called the "cephalothorax") and abdomen (the part behind the legs) that is seen in spiders. Notice the narrow "waist" between the legs and abdomen in the drawing of the brown recluse spider (see drawing), but the lack of this same constriction in the follicle mite (see drawing above).

This blog is about the mites that bite people and pets as well as those that feed on plants (plant pests). I'll discuss the identification and new control methods for scabies/mange mites, demodex follicle mites, chigger mites, ticks, mold/dust mites (these mites don't bite but can cause allergy), bird/nest/rodent mites, and pymotes (pyemotes) mites, and many others.

chigger mite
Seeing Mites Close-up

Most mites are so small you'll need some sort of magnification to tell what you've got. Many are about the size of the period (.) on a printed page. A good hand lens is sometimes enough, especially if you know what you are looking for, but a microscope may be needed to clearly see others.

Mites typically have 8 legs (4 pair) like spiders but some newly hatched mites only have 6 legs (for example chigger mites) and some have only 2 pair (for example the plant-feeding eriophyid mites.  

Many mites are covered with hairs or "setae". These hairs can cause an allergic reaction in some people. Two notable examples of this are mold mites and dust mites, which in fact are closely related to each other.

Collecting Mites for Identification

A good way to collect mites is to use a damp Q-tip to carefully pick them up and transfer them to a vial of 70% rubbing alcohol. Don't stick samples to tape as this can make identification very difficult.

In the US samples can often be submitted to your state university for identification. Contact your local Cooperative Extension office ( for details.


Sunday, July 15, 2012

Underground-Nesting Yellowjacket Wasps

nest entrance at base of tree
Nest entrance (lower center) at base of tree.
wasps guard nest entrance
Yellowjacket wasps guard entrance to nest.

Between mid-summer and early fall yellowjacket wasps that nest underground can be a real threat in some areas. These yellowjacket wasps hide their nests underground, often in cavities made by decaying roots, stumps (see photo) or rodent burrows. Nests may contain hundreds to thousands of worker wasps that will aggressively defend the nest against all intruders.

When disturbed wasps can swarm from this ground nest. A single sting can provoke other wasps that are summoned to attack the "enemy" of the nest (for this reason always quickly leave the area if you are stung). Wasps are especially sensitive to ground vibrations or low frequency (bass) noise as this may signal an animal such as a bear or skunk trying to dig out the nest. This is why wasps will sometimes swarm in response to a careless hiker that steps on the nest entrance or the low growl of a passing lawnmower.

wasp nest underground
Notice surface of papery nest in center right.
The nest entrance leads to a papery nest (see photo) that houses the queen and large numbers of workers and larvae (only a few males are produced at the end of the season). Nests are usually begun in the spring and will die once the weather turns cold in late fall. During mid-summer to early fall the nests will reach their maximum size.

Ground-nest structure (drawing).
The nest itself is very similar to the more familiar wasp nests that are built above ground with a papery envelope enclosing layers of cells that house larvae (see drawing). Worker wasps feed the larvae and queen as well defend the nest with a potent sting.

Ground nests can be left alone as long as they are not in an area where they pose a threat from an unwary person. They can, however, be especially dangerous when they occur near playgrounds, picnic areas or along hiking trails.

Threatening nests can be destroyed by treating the nest entrance with a "Wasp & Hornet"- type insecticide. For details see "Treating Yellowjacket Nests".


Monday, March 05, 2012

How To Identify A Bug Online

hummingbird mite and human hair
Scenario: You've found a bug in your home that you don't recognise. You ask yourself "Is this bug dangerous, a threat to my family? Could it damage my house?" Where can you go to get answers and reassurance?

One option is to call a local pest control company (exterminator) but this may not be your best option. Keep in mind that while many pest control companies will give you honest, expert answers to your questions their bias, their business, is to sell treatments not information. In the worst case they may sell you treatments that are not entirely necessary.

Your best option (in the US) is to contact your local Cooperative Extension office (do a google search for "find local extension office"). Every US county has an Extension Office that serves to connect the local community to the subject matter specialists at the state agricultural university. The Extension office can get you in touch with experts at the university that can assist you with your bug questions, and these services are usually free. Many states maintain an "Insect Clinic" to which bug samples can be submitted for identification.

One caveat - Extension can be slow especially during the spring and summer when most of their staff time is consumed by commercial agriculture clients.

What if you want to do it yourself?

You'll need a good hand lens (magnifier) and some reference guide books to start. Nowadays most bug questions can be answered with resources available online if you know where to look.

tick under flashlight light
First, get a good photograph of your subject bug and/or of the damage/injury you suspect is bug-caused. Even moderately-priced digital cameras usually have some kind of "macro" function which allows you to get a close-up picture. The image of the mite above was taken with an inexpensive digital camera in "macro" mode then enlarged with simple photo editing software.

Unfortunately the cameras in cell phones may not be as useful because they typically don't focus close enough. If you need more light on your subject an ordinary flashlight works well (see photo of tick).

Online "bug identification" resources

BugGuide - a large database of images catalogued taxonomically. An excellent resource if you have a pretty good idea of what you are looking for and just need an image for comparison. Does not accept images for id but you can post an image which other users may comment on.

LivingWithBugs - this is my own site about home and garden bugs.

What'sThatBug - images can be submitted for id but not all submissions are accepted because of their limited staff. Excellent photos for comparison but like BugGuide you'll need to know what you are looking for.


Sunday, March 04, 2012

Mold Mites In Homes

mold/grain mite
The tiny white/tan "bugs" that people find swarming over surfaces often turn out to be mold mites (also spelled mould mites). Since the mites are also attracted to warm surfaces they may appear to be infesting electronics like computers and televisions.

When found in homes mold mites are usually associated with some type of moisture issue which has caused mold growth. The moisture source can be as simple as a leaky pipe or as difficult as a leaky roof or foundation. The mites feed on the mold and populations can grow rapidly. The mites are tiny, and usually white or tan in color, and have very long "hairs", or setae.

See Mold Mites In Homes for additional life history and control information.

Mold mites are sometimes called "grain mites" because they also commonly occur in grain storage warehouses on the surface of grain sacks.

The mites are harmless. They don't bite or cause structural damage. However, the long body hairs can contribute to indoor allergens when they become airborne. The mites are generally an indication of a mold/moisture problem which is usually more of a concern than the mites themselves. No treatment is needed other than reduction in moisture.

See the "Mold Mites In Homes" article cited above for more information.