Urban IPM

Friday, May 15, 2015

Occasional invaders during heavy rain- millipedes and pillbugs

I'm loving the rain we've been getting in Central Texas, but it has been leading to some pest problems that people haven't really had to deal with for awhile.  I thought that I would touch on some of them.

The first and foremost for me are millipedes.  Yesterday afternoon when it was raining, I took the opportunity to head outside to look for millipedes for photos.  I could not find a single one.  While disappointed, I knew that I had seen some at home so I figured I could get my photo there.  When I got home I was starving so I started making dinner.  In the middle of cooking bacon (it was a breakfast for dinner night),  I was looking around the kitchen and spotted a millipede walking across the ceiling.  Instead of climbing on the counter to take a picture, I went outside and found plenty to photograph.  After that, I proceeded to pick up about 30 millipedes in various areas of the house.

Millipedes have long, worm-like bodies with a single pair of antenna.  Their body is cylindrical and usually brown in color.  Millipedes have two pairs of legs per body segment and often curl into a spiral for protection or when they die.  They feed on decaying organic matter, though some are carnivorous.

Pillbugs are the other big one that can venture inside when we have heavy rains. Sowbugs and pillbugs are crustaceans (related to crabs, crayfish and lobsters).  They require moist environments and usually die quickly when they move indoors due to lack of moisture. Sowbugs and pillbugs have oval shaped bodies, 7 pairs of legs and 2 pair of antennae (only one pair is easily visible).  Sowbugs have two tail-like appendages that come off the tip of the abdomen.  Pillbugs do not have a tail-like appendage and pillbugs can also roll up into a ball when disturbed (hence the name roly-poly).

Another nuisance pest I should mention are amphipods, also known as scuds.  Calls that I get on these critters are when they have already died inside the home.  Living amphipods are yellowish-brown in color and live in moist areas like under mulch or groundcover.  When we get heavy rain, they can move indoors where they die from lack of moisture.  When the amphipods die, their body turns a reddish-pink color (these are also a crustacean and closely related to shrimp).  You can find more on amphipods here.

If you are having problems with these nuisance pests moving indoors, then you should focus on the outside of the structure to exclude them.  Once things dry out then it should go back to normal.

  • turn mulch often; adjust watering schedules
  • remove any debris laying near structures or areas you do not want pests 
  • allow air to flow through crawl spaces by using the proper amount of ventilation
  • fix any leaking faucets, AC lines, water pipes, etc.
  • make sure gutters and drains carry water away from the structure
  • make sure doors and windows have a proper seal; replace weather stripping, thresh holds, etc.
  • apply sealant to any cracks & crevices and to where pipes or wires penetrate the building
If you are having a mass invasion of pillbugs outside and they are eating your plants (it doesn't happen too often, but conditions are ripe for this right now), then you can try making traps.  I still need to test out what specifically works, but I'm sure you can search for ideas.  If you feel you need to treat for the pillbugs, make sure that you check the product label so you choose a product with pillbugs and sowbugs on the label.  There are snail & slug baits that also can work on pillbugs and sowbugs, but not ALL snail & slug baits control them.  You could also treat with a contact pesticide.  Unfortunately, while those products could work, they should not be applied when it is raining or there is a chance of rain, so pesticides are currently out as an option.

I'll need to cover mosquitoes soon....stay tuned!

Friday, May 1, 2015

Four-lined plant bug

Have you seen me?  Not me, as in me, Wizzie, but me as in me, this bug.  We have them in the demonstration garden and I've been getting reports of them from all over town.  Some people have seen damage, which is often mistaken for fungal damage. I suggest that you head out to the yard and start looking.

Four-lined plant bug with damage.
Four-lined plant bugs are brightly colored.  Nymphs (immatures) are red while older nymphs start to have wing pads with yellow and black stripes.  Adults have fully developed wings that are yellow and black striped.  Adults look similar to- and may be mistaken for- striped cucumber beetles.

These insects have piercing-sucking mouthparts they use to suck out plant juices.  The plant bugs suck out chlorophyll and leave a "window" between the upper and lower epidermis of the leaf. Damage appears as white, dark or translucent spots of foliage.  Feeding may also cause curling and browning.  Fortunately, damage is mostly cosmetic, but if you are trying to eat the foliage of the damaged plant it may become a problem.

The insects feed on a wide variety of hosts, including fruits and vegetables, annuals and perennials and  woody plants.  When disturbed, the insects are fairly good at hiding.  They either crawl to the underside of the leaves or drop to the ground to hide among foliage.

If you feel the need to manage these guys and gals, try insecticidal soap.  If that doesn't work, you can try azadirachtin (neem- concentrate, not oil; it's getting too hot to use oil formulations) or pyrethrins.  If that doesn't work then try a residual contact product.

Friday, April 17, 2015

Caterpillars- buck moth caterpillar, cankerworms and tent caterpillars

The insects seemingly have arrived in our demogarden the past week.  I was out there with Master gardeners this morning and there was a lot to see....it makes me EXCITED (the Master Gardeners, not so much, as many of the insects are eating the plants they are tending so carefully).

So two items have already been covered recently in blog posts written by Dr. Mike Merchant in Dallas, so I'm going to direct to those pages and you can get all your information there.

Tent caterpillar
First are the tent caterpillars.  I had my neighbor find one last weekend and she sent me a picture for identification.  Mike's post on tent caterpillars.

Secondly, would be the cankerworms.  If you have oak trees in your area (and this is Texas, so who doesn't have oak trees, right?) then you probably have seen these or at least evidence of their activity.  Have you seen the silken threads hanging down from trees?  If so, then you have seen webbing from cankerworms.  Again, Mike has a great post on cankerworms here.

The last thing I want to cover is a caterpillar you DO NOT want to pick up.  This caterpillar has branching spines that can deliver a sting if touched.

Buck moth caterpillar
Buck moth caterpillars typically have a background color that is dark, but they can have varying coloration so some can be very light.  The body has white spots and the spines are double branched and form multiple rows along the body.  They can be almost 2 1/2 inches when fully grown.

Buck moth larvae are gregarious and will group together for the first three instars (smaller caterpillar stages).  After the third instar, they will wander off from the other caterpillars to feed on other plants until it is time to pupate.  And remember above how I was talking about oaks in Texas?  Well, that is the preferred food of buck moth caterpillars.

The adult buck moths are quite pretty and have a wingspan of 2-3 inches.  Wings are blackish in color with a white stripe running through the center with dark eyespots. Females have a solid black body while males have a black body with the tip of the abdomen being reddish-orange.

As mentioned previously, you DO NOT want to pick up the buck moth caterpillars.  The branching, urticating spines can deliver a sting when touched.  Reaction from the sting can vary but may include immediate pain, itching, swelling and redness.