Beverly Hills goes "buggy" over program.

The Beverly Hills Recreation and Parks Department's Urban Forest Division has chosen to implement a carefully manipulated Beneficial insect Program in lieu of any type of spraying or injections to trees.

For the past three years, the Recreation and Parks Department of the City of Beverly Hills, California, has effectively executed its Beneficial Insect Program as part of its overall Integrated Pest Management Program. Through the program, beneficial insects that are released appropriately feed on the unwanted infestation of aphids that inhabit the city's Arizona ash, American elm, and tulip trees and create a detriment to these trees and to the community.

The Beneficial Insect Program has proven to be a viable means of controlling this problem, both environmentally and cost-effectively.

Left alone, pesky aphids cause damage to the urban forest. Nymph and adult aphids draw the nutrients from the trees, which disturbs the balance of growth hormones within. Consequently, tree growth is halted, leaves curl, and food production decreases. To get the protein that they need from within, the aphids must draw out a large amount of this sap, which contains an excessive amount of sugar. The aphids then excrete the sugar as honeydew, utilizing only the protein for nourishment. This sugar-based substance falls on anything below, leaving the area sticky. This can create a nuisance, as attested to by the numerous calls that flood the park and rec offices.

To combat the problem, Beverly Hills Recreation and Parks Department's Urban Forest Division has chosen to implement a carefully manipulated Beneficial Insect Program over any type of chemical spraying or injections (to the trees). These beneficial predators cost the city about one-third of what it would take to use chemical spraying or injecting. In addition to being cost-effective, these beneficial insects are not harmful to the trees, nor are they hazardous to people or wildlife. Rather, they are a natural addition to the eco-chain. In addition, aphids have the ability to develop a resistance to chemicals. The Beneficial Insect Program allows the ecochain to remain in balance without harming the urban forest.

It is necessary to begin the release of beneficial insects early in the Spring and to continue throughout the summer. Hot weather can increase the problem, and additional release is needed. Constant surveillance by staff is essential. And phone calls from the community must be monitored carefully to identify and address problem areas. The appropriate insects -- in this case, ladybugs, lacewings, and aphid midges -- are chosen because they prey on the aphids.

Rapid Population Increase

Over the course of the program, some beneficial insects are released by bucket trucks into the tree canopies. Others are released at the tree's base and in the air. Almost immediately, they begin to feed on the aphids and lay eggs. In fact, the female lacewings will lay up to 300 eggs over a three-week period, allowing the beneficial insect population to increase rapidly. The ladybugs are used to feed on aphids during the day, while the nocturnal lacewings feed during the night. Aphid midges feed on the eggs laid by the aphids. The overall result on these activities is positive.

Ultimately, it becomes a continual, uninterrupted process that works to decrease the problem to an acceptable level. Since the program's inception three years ago, the aphid problem has become more manageable and created much less of a problem in the community.

This removal/replacement plan has been incorporated into the city's Street Tree Master Plan, which involves a long-term effort to replace declining trees with a less susceptible, more acceptable species. In the meantime, Beverly Hills can enjoy its beautiful trees -- some 24,000 of them.