One of the advantages of gardening in the hot summer weather is the virtual disappearance of many of the pests that plagued our plants in the spring.

One of the advantages of gardening in the hot summer weather is the virtual disappearance of many of the pests that plagued our plants in the spring.

Gone are the aphids and spittlebugs that once covered our poor gardens, trying to weaken the members growing there by sucking out their juices. No longer are we mortally fearful of the nightly raids of slugs and snails from their daytime hiding places onto the foliage of ornamentals and edibles alike. Even the ferocious-appearing earwigs are down to just the occasional marauder at midnight.

This doesn't mean that our yards and gardens are maintenance-free zones now. Watering has replaced weeding as the No. 1 chore, and keeping the produce picked to ensure a continued supply of cukes and zucchini can become a monumental task if you planted a sizable area with these prolific producers. But the lawn needs less mowing and overall the threat to the survival of plant life has lessened.

Or has it? On my early morning hand-watering chores this morning I ran into two old foes that can cause plenty of trouble in any garden. The frustrating part of seeing them is that at one time, these insects were almost benign in most gardens. Yes, they were present here, but not in what would usually result in life-threatening numbers. Who are these culprits and what happened to give them prominence in our plantings?

I first met these culprits as a greenhouse grower more than 30 years ago. It was there that the conditions that favored their growth were so prevalent. In fact, I didn't even know that they lived outside the hothouse environment. It was a real revelation when I first saw them outdoors several years later.

They are spider mites and whiteflies. Both are small insects that attack the underside of leaves and extract the juices the plant is producing, thus weakening the host and making it susceptible to other pests and diseases. This week, we'll look at the whitefly and how to control it.

Many plants can be susceptible to this tiny, 1/16-inch pest that indeed looks like a small, white fly. When present in numbers, a white "cloud" will appear to rise from any leaves that you disturb. Unfortunately, whitefly has proven difficult to control by use of insecticides alone and this is where some of our current problems stem from.

Many predators of whiteflies have been eliminated during attempts to control this insect. Even worse has been the mutation of the survivors into new, more effective strains of insecticide-resistant species. The B-strain of silverleaf whitefly is one such insect that is spreading widely now. It has been found on more than 500 different host plants and is associated with viral infections spread from plant to plant. To top it all off, it has been shown to be a prolific breeder, rapidly building population during hot weather.

What can be done to control this tiny but mighty invader? To show any effectiveness, a multi-pronged approach should be taken at the first appearance of the pests. Put out yellow sticky traps to monitor the population. Sometimes, if the planets are aligned perfectly and you've been living right, this is all that's needed for control. Don't count on it, however. In the last several years I've noticed that populations are building up sooner and sooner every year. It used to be late September before I spotted any. Now, it's the beginning of August.

The next step may well be the establishment of predatory, parasitic mites in the garden. Big-eyed bugs and lacewings have shown an appetite for whiteflies as well. Spraying with insecticides should be avoided during this period as you would destroy the predators along with the pests. And it may prove harder to re-establish the good bugs. If any spraying should prove necessary, try insecticidal soaps and/or insecticidal oils like neem. These will provide some control of whiteflies and will be less harmful to the beneficials than other sprays.

Now is the time to keep an eye out for these tiny invaders. Early control measures are more effective than trying to eradicate large populations. Isn't that the way it always is with gardening?

Stan Mapolski, aka The Rogue Gardener, can be heard from 9-11 a.m. Sunday mornings on KMED 1440 AM and seen on KTVL-TV Ch. 10 every Wednesday during the 5 p.m. news. Reach him at stanmapolski@yahoo.com.