The garden is in full swing, despite overflowing rain guages. My daily stroll includes more than seeing blooms and harvesting fruits and vegetables —
THE GOOD
Numbers are high this summer for both and pests. If you let take care of the pesky bad guys instead of reaching for a chemical solution, you’ll have , and you’ll get to enjoy watching them.
When plants are being attacked by pests, they actually release chemical signals that attract beneficial insects — in essence, ringing a dinner bell for the predator insects. It may take time for them to show up, so be patient.
Lady beetles, a.k.a. ladybugs, are out in droves this season. Over 80 species live in Colorado. Most are bright red-colored, but some species are dark brown, mostly black or even striped. The amount of spotting varies per species. Both the larvae and adult lady beetles dine on aphids, mites, mealybugs, scale insects and the eggs of several other pest insects. Adult lady beetles may also feed on pollen or “honeydew” — aphid excrement.
Lady beetle larvae look like small black-and-red or black-and-orange alligators. Store-purchased lady beetles are generally not effective as those born in your garden, because most will scatter to lay their eggs elsewhere when released in the home garden.
Syrphid flies, also known as hover flies or flower flies, look like small wasps with a black-and-yellow or white-striped abdomen. They hover like hummingbirds while sipping nectar from flowers, but they do not sting. They are pollinators as adults, while their larvae (small, tapered, brown or green maggots) consume aphids, young cabbage worms and other soft-bodied insects. You can attract them to your garden by having flowers in bloom all through the gardening season.
Dragonflies and the smaller damselflies (shown) are feasting on gnats, mosquitoes and midges this summer near ponds, lakes, ditches, reservoirs and backyards. There are more than 108 known species of the two in Colorado. Their wings are either clear, lightly colored or patterned. Both types of insects are sometimes called “mosquito hawks,” because they use their superb flying skills to scoop up insects by the hundreds. More: southwestdragonflies.net
Leafcutter bees do exactly what their name implies. They slice perfect half-rounds out of plant leaves, mostly on roses, green ash, Virginia creeper and lilac. These solitary bees use the leaves to make nests in the canes of roses or other hollow twigs. Leafcutter bees cause little harm to rose canes and are important native pollinators of many plants — so just roll with the minor leaf damage and know they’re good guys.
THE BAD
The feeds on all varieties of bean leaves and pods. It looks similar to a lady beetle, except is yellow to copper/brown in color, with no white markings between its head and body. It has 16 total spots on its wings. Mexican bean beetle larvae are light yellow covered with bristly spines.
Aphids are tiny, pear-shaped, soft-bodied insects that can be green, brown, yellow, red, gray or black and winged or not. , causing all sorts of plant problems — curled or distorted leaves and stems, discolored or stunted leaf growth. They can be found on many plants including trees and shrubs. They may also infect healthy plants with viral diseases they pick up from unhealthy plants. Aphids excrete a sticky, glossy fluid that’s a nuisance for cars parked under aphid-infected trees. A gray mold can grow on honeydew, and that mold attracts ants, yellow jackets, bees and flies. Grossed out yet? Here’s the good part: Most aphids can be dislodged with a heavy spray of water. Another gardener trick: Avoid overfeeding plants, because excessive nitrogen leads to lots of tender new growth, which attracts aphids.
Branch tips on affected shrubs and trees such as ash, plum and honeysuckle can appear wrinkled and distorted, but worse yet, the distorted foliage shields the insects from the water spray. If only a few branches are affected, prune them if they’re reachable — or do nothing and let natural enemies fight them. Severe infestations may need insecticide control: read more at www.ext.colostate.edu/pubs/insect/05511.html
Leaf-eating pests — as opposed to the leaf-cutter bee — are on the attack. By recognizing their typical type of leaf damage, you might be able to figure out the insect causing the damage. chew and make small irregular notches on edges of leaves including peony, lilac, rose, cotoneaster, euonymus, clematis, lilies, phlox, strawberries and raspberries. They look like small, ½-inch brown to black beetles with a head that shapes into a snout at the end. They chew leaves and plant roots at night, so you rarely see them. Most plants can tough out the leaf chewing, but if the weevils chew too many roots, the plant may suffer or die. To detect their presence, shake the plant over a white sheet at night. If your plant is affected, place burlap around it to trap the weevils during the heat of the day. Other controls are available: www.ext.colostate.edu/pubs/insect/05551.html
Grasshoppers chew round or ragged holes from the outer edges inward on the leaves of lettuce, beans, onions, carrots and sweet corn. They do not like tomato or squash leaves. Their natural predators include birds, spiders, rodents and certain fly species.
Slugs love moist conditions and But the slimy invaders don’t stop there; they’ll also eat mature annuals and perennials. Their favorites include tender vegetables like lettuce, ripening strawberries, tomatoes and peppers. They avoid fuzzy plants like lamb’s ears, lavender, salvia and most herbs. They dine at night, making irregularly shaped holes in leaves. Trap slugs in sunken containers of beer or rolled-up, wet newspapers, but also, reduce moisture around plants. You can handpick slugs to destroy them. More: www.ext.colostate.edu/ptlk/1436.html
Japanese beetles like to gather in groups. Given free rein, these pests will skeletonize or eat entire leaves, buds or flowers of roses, Virginia creeper, grape vines, green beans and American linden. Never squish these shiny green, copper-brown round beetles on a plant, because their squashed remains will only attract more beetles. Handpick them early in the morning and drop them into a jar of soapy water. Traps are not recommended because they may just increase the pest’s numbers. Neem-based products containing azadiractin (one trade name is BioNeem) can deter the beetles for a few days.
Betty Cahill: gardenpunchlist.blogspot.com or bettycahill@ymail.com
