Author: Anna Aquino, Co-chair Bee City USA Richmond
Capital Trees is doing better by bugs! Together with community members and partners (Department of Parks, Recreation, and Community Facilities, and the four Richmond clubs of the Garden Club of Virginia), we are co-sponsoring Bee City USA Richmond, an initiative of the Xerces Society for Invertebrate Conservation.(1) Bee Cities commit to implement the following principles and practices
- create and enhance pollinator habitats on public and private land,
- increase the number of native plants,
- provide nest sites,
- incorporate pollinator-conscious practices into city policies and plans; and
- use fewer pesticides.
When we protect and conserve bees and pollinators, we are protecting all “the little things that run the world.”(2) Only 1% of insects are considered problematic for people, 99% are doing their job contributing to robust ecosystems, and many of those are considered especially beneficial to humans in invaluable ways — like pollinating 15 billion dollars worth of food yearly in the US!(3)
Pesticide resistance and pollinator loss
The use of pesticides soared after World War II with the discovery of chemicals that were inexpensive and effective. DDT and 2,4-D made food cheaper with few identified adverse effects. However, it wasn’t too many years before houseflies showed resistance to DDT.(4) In 1962 Rachel Carson wrote Silent Spring. She is credited with heralding environmentalism.(5)
Integrated Pest Management (IPM)
Pesticide resistance and insect loss were so alarming in the 1960s that two entomology professors conceived and advanced Integrated Pest Management, IPM, a hierarchical plan to help determine what measures may or may not be needed in regard to controlling or leaving insects alone.(6) The EPA describes Integrated Pest Management (IPM) as “an environmentally sensitive approach to pest management that relies on a combination of common-sense practices. IPM programs use current, comprehensive information on the life cycles of pests and their interaction with the environment including, but not limited to, the judicious use of pesticides.”(7) Pesticides should be the last resort.
Sharon Selvaggio, Pesticide Program Specialist with the Xerces Society, implores us to be more tolerant, to be more holistic in our thinking about insect damage, more open to live and let live, and open to watching for natural processes to take over, and they usually do.(8)
Integrated pest management parses the different options – cultural, mechanical, biological, and chemical measures. For intervention it is essential to correctly identify the offenders: What is the weed, the insect, the fungus, and how does it behave?
Emily May, a Pollinator Conservation Specialist with Xerces, writes “thinking about my own yard, I came up with three main goals:
- to conserve and support the diversity of insects, birds, and other wildlife living around me with native flowering plants;
- to create a beautiful space that I enjoy watching in the morning and in the evenings; and
- to manage land with as little effort as possible. (yes, that’s right, one of my goals is lazy gardening—why not!)”(9)
IPM Biological Control (Ladybug)
Jessica Walliser, author of Attracting Beneficial Bugs To Your Garden, A Natural Approach to Pest Control, tells us about sticky sap dripping from her tulip poplar onto her patio furniture. Ms. Walliser thought to call a tree or landscape company, but slow down, there’s little doubt they will recommend a foliar spray or a soil injection of a synthetic insecticide to stem the outbreak of aphids. Who wants that? And heaven forbid they try to sell her a “periodic spraying” package. The insecticide will likely impact adjacent plants, and a cascade of loss will occur. She considered that for some people this would warrant tree removal, horrified at this thought. (Sadly, this is a not uncommon outcome of an aggravating pest infestation.) Shaking off having impetuously contemplated quick fixes (“that’s not me!”), and thinking to let nature take its time, its course, several weeks later, there was less honeydew on the chaise lounge. Ladybugs and their remarkably alligator-like larvae populated the leaf undersides, another week or so, clean. So it was handled.
About a decade ago, the author of this blog cried “uncle!,” influenced by the likes of Doug Tallamy, completely stopped the weeding, edging, mulching, and exotic plantings, dispensed with any chemicals whether synthetic or organic (11 & 12–for a comparison of the two, see footnotes), and hired a company to do “certified” organic lawn care, mostly amounting to aeration and some years adding iron to the soil. And what a world of difference it has made to her life and to the garden. It’s incredibly busy with wildlife, and is no longer incongruous with its surroundings next to a marsh next to the Chesapeake Bay. And no guilt. No worrying that the birds foraging in the grass or the dogs walking through the grass are being contaminated. What a relief.
Pollinator loss and pesticide use in intensely managed landscapes
What is the cost of a perfect plant? It’s an American boxwood, native to Southern Europe and Northern Africa. Some might contend that it is taking up good native plant real estate, but there’s no doubt that boxwood is the architectural backbone of many a fabulous garden. And yes they make oxygen and sequester carbon and other plantie positives. The environmental cost of this plant in an intensively managed landscape is that it’s likely teaming with a neonicotinoid systemic pesticide. In a highly controlled landscape that is orderly and sanitized, where pesticides and fertilizers are routinely used, there is likely an out-of-kilter predator prey cycle. It is important that ecosystems be resilient, not rigid, which a heavily manipulated landscape is (always remember Doug Tallamy—“A messy garden is a healthy garden.”) American boxwood are very prone to leafminer; the mosquito-like female lays her eggs in the new growth, the eggs hatch and the larvae tunnel throughout the leaf tissue mining for food, leaving noticeable blisters and squiggles.(13) The most commonly used insecticide, is toxic to any chewer or sipper of our boxwood. Usually applied as a soil drench, sometimes as a foliar spray, the plant is thoroughly covered with this systemic neonicotinoid, and research reveals that it can stay in the plant tissue for years, traveling quickly to the shoots and flowers.(14) (15) If a neonic product is used, keep it as far from flowering plants as possible. Because systemic neonicotinoids are so toxic to bees and implicated in colony collapse, they are banned in Europe, and they are being banned in cities in the US. Jessica Walliser’s video shows alternatives, including pruning the tips where the bugs are (so obvious). Let the predator prey cycle takeover, nature will out, balance, and solve. Ladybugs and parasitic wasps predate leafminer as do others. Another pest on people’s minds is the crape myrtle bark scale. Predacious ladybugs and mealybug destroyers would love to have at these crepes.(16) It turns out the bark scale is attracted to fresh cuts—another reason not to “crape murder.”
So is it the pest or the pesticide? When a synthetic chemical is applied, pests’ natural enemies are killed. Most of the pests will be killed, but some will survive. Because bugs move through generations quickly, populations adapt with speed, resulting in new resistant local generations. There are only a handful of pesticides that target specific species, the vast majority are broad-spectrum, killing everything. There is a lag time between evidence of the pest—the aphid, mealy bug, mite—and the arrival of the predator. But believe this, the plant sends out chemical signals (semiochemicals) that request specific predators for specific pests, marshaling the predators to do their work. Organic pesticides like horticultural oil can be as lethal as synthetic pesticides to most insects they encounter (oil and insects don’t mix); a benefit is that organics usually do not persist in the environment. A label may say do not apply when you see bees, but the many beneficials that are keeping the predator prey system in balance are often under leaves, in crevices, working at night, small, and it is impossible to tell if prey are parasitized by wasps and dying. The chances of another outbreak after spraying is much greater.(17) IPM suggests monitoring, researching, shifting cultural practices, trying hand removal, and an avenue that is less used but highly successful — the introduction of beneficial predators.(18) Ladybugs, nematodes, parasitic (non stinging) wasps, green lacewings, and others can be purchased.
It is important to have plants available that are preferred by most predaceous insects, generally, these don’t have tubular flowers, but have umbels, like dill or other flat-topped flowers.
A ladybug eating aphids, a non-stinging parasitic wasp laying eggs in caterpillars, and the all important mealybug destroyer.
Ladybugs, belied by their adorableness, are the ultimate predators. It is stunning to learn that native ladybugs are in trouble, those ladybugs you find in your house are Asian. In fact most of the insects wreaking havoc in the US and not being controlled by native predators are exotic. Watch this video to see the fascinating ladybug life cycle, and the video about how to keep ladybugs happy and where you put them.
Cornell University started the Lost Ladybug Project,(19) a citizen science project so we can all assist in helping to understand what’s happened to native ladybugs and how we can restore them. There is no doubt excessive use of pesticides, including mosquito spraying companies, are the reason for the extraordinary decline in ladybugs, of insects, and for upsetting the natural predator prey balance.
So let’s all head over to Central Virginia Waste Management to get rid of hazardous pesticides (20), then head to our favorite predator purveyor.
- E.O. Wilson’s lifelong passion for ants helped him teach humans about how to live sustainably with nature
- Wild Bee Conservation
- The Evolution of Chemical Pesticides
- How Rachel Carson’s ‘Silent Spring’ Awakened the World to Environmental Peril
- Salute to the Father of Integrated Pest Management
- Integrated Pest Management (IPM) Principles
- Phone conversation, Spr 2023, S Selvaggio & A Aquino
- How To Identify And Respond To Pests At Home
- NATURAL-ORGANIC GARDENING & LANDSCAPING INFORMATION
- Restoring Nature to the World’s Soils
- Boxwood: Boxwood Pests
- How Neonicotinoids Can Kill Bees
- Neonicotinoid contamination in wildflowers.
- CRAPEMYRTLE BARK SCALE
- Oregon IPM Center
- Lost Ladybug Project
- Household Hazardous Waste