Other strains of BT are effective against mosquitoes, fungus gnats, Colorado potato beetles and elm beetles. Another bacterium, Beauvaris bassiana, fights aphids and whiteflies. Granulosis virus is a natural enemy of the codling moth, a common pest of apples, pears and walnuts. If you have a pond, be aware that there is also a small fish called Gambusia that eats mosquito larvae.
You can also allow more good bugs to work their magic by hosting them in your garden. Start by growing plants that attract them. Nurseries have blends of insect-attracting plants that attract beneficial bugs and provide a habitat for them. Using insect-attracting plants allows for pest management throughout the season. When the pests come in later in the season, the beneficial bugs are there. So the beneficial populations eliminate the pests before the pest population exceeds acceptable levels. Usually, gardeners don't even realize that pests are threatening their garden.
If you want good bacteria to kill bad bacteria, protect them with integrated pest management (IPM). IPM includes tolerating minor plant damage, hand-picking some of the bad bacteria, and using botanical insecticides and insecticidal soaps. For severe infestations, IPM recommends using selective chemicals and not broad-spectrum insecticides. For more information on IPM, visit ipm.ucanr.edu/PMG/menu.homegarden.html.
Chemical insecticides are often more devastating to beneficial insects than to pests. Less toxic products include insecticidal soaps and highly refined summer oils. Summer oils kill pests by suffocating them rather than poisoning them. Other insecticides of natural origin include pyrethrins (from Asteraceae flowers) and neem oil (from neem seeds). These “natural” insecticides are synthetically manufactured and easy to use. You can find them in stores alongside chemical insecticides.
The bottom line is that by inviting in the “good” ones and keeping the “bad” ones in check, your garden will be in balance.
Gardeners will be available to answer questions live at the Visalia Farmers Market (Tulare County Courthouse North Parking Lot in Visalia) from 8 to 11 a.m. Saturday, Aug. 3. Call 559-684-3325 or visit the website at ucanr.edu/sites/UC_Master_Gardeners .
