Friday, August 13, 2010

Whiteflies in the Landscape

Lately, we have been receiving many calls at the office about tiny, whitish, flying insects on veggie garden plants and around trees. These insects are probably whiteflies, a sap sucker that can be a pest of ornamental or agricultural plants.

People who have them are noticing a wet feeling when they stand under trees where the bugs are present. This is probably their honeydew. These guys are sap suckers, and in order to get enough nutrients, they have to get rid of the extra water they suck up. What they "pee" out is honeydew. The honeydew can encourage ants to come to feed and can also cause sooty mold to grow. In most cases, sooty mold is just ugly, its not a problem for the plant.

Whiteflies seem to thrive in tomatoes and sweet potatoes in our area. If you have those plants, and they are infested with whiteflies, there are a few things you can try. Cultural control measures include:

  • Prevent over watering, which can encourage whiteflies

  • Avoid planting new plants when populations are high (they will just spread!)

  • Use covers to keep populations stuck on one plant and prevent spread

  • Avoid planting plants that attract whiteflies (tomatoes, sweet potatoes)

  • Control weeds (adults use these to rest)

If you feel the need to treat, make sure they are actually causing some damage. On ornamentals, trees and shrubs, they seem to just be a nuisance when you walk past the plant than they are actually doing damage. There are some products you can try: insecticidal soaps and oils which will give you a short-lived knock down. Only use soaps and oils when you see whiteflies present, otherwise you won't kill anything. Remember, there is no residual with those. Other products that contain the active ingredients acephate, bifenthrin or cyfluthrin can be effective as well. Be sure the product you use is labeled for the plant you will be spraying it on (for example, don't use a tree and shrub spray on your veggies).

I don't have a good reason why they seem to have exploded this month, but they certainly have. People who have never had whiteflies before are seeing them. As you start your new fall gardens, be sure you remove and destroy all old plants that may be providning harborage for your whiteflies. And remember, destroying doesn't just mean pulling it up and throwing it across the fence; remove them completely from the area!

Tuesday, August 3, 2010


Yes, it does seem like the crickets are out of control this summer! And, yes, you are right, there are more this summer than there have been in the past. Crickets are a normal occurrence each summer, but during wetter years their populations explode. They will remain through the fall, but their number will be dramatically reduced.

Right now, the crickets are dying off in most areas of town. The mass explosion of the populations have ended, but next comes the worst phase in my experience: the die off! Now that all these crickets have lived their lives, they will start to die and cook in the sun. They seem to be especially attracted to the lights of large buildings, congregating there at night staying there during the day. They can make their way indoors, sneaking in through tiny cracks and crevices.

But, since they emerge from the egg nearly all together, their short lives will end very close together. This leaves large masses of dead crickets to rot in the sun. Crickets are pretty large bodied insects, and when they die they do stink. For many businesses, this is worse than then jumping around outside and making their way indoors. What many people don't realize is that crickets around buildings, businesses, and other locations has nothing to do with sanitation. However, when they start to die off, this does pose a sanitation issue.

The only solution is just to sweep them up as often as they die and throw them away. I rarely advise anyone to treat for the crickets, because their life is so short, you really never know if they died naturally or from the pesticides - and there's no use applying pesticides to the environment if it won't do any good. The best thing to do is turn off outdoor lights at night and within a few days they will subside.

Give it a couple more week or less, and we won't see a cricket explosion like this until the next wet summer!