Rain, bug zappers and mosquitoes
Does this seem like a “normal” summer in terms of weather?
Well, when the data is crunched and people look at it years from now, the summer of 2020 will most likely be recorded as pretty “normal.”
This is due to the statistical methods used to analyze the data. Generally, during the month of August, we receive about 3 inches of rain overall. Last week’s tropical storm on Aug. 4, dumped from 3 to 6 inches of rain on our region, so any additional rain we get, will make for an “above average” rain month, even if it does not rain at all for the next 3 weeks as has been the case for the past 3 weeks.
One of the consequences of climate change is an increase in extreme weather events.
More hurricanes, more tropical storms, more extreme temperature swings, both warm and cold are to be expected. Oddly, though, when the numbers are “averaged,” it appears that not much has changed from year to year.
Tell that to the trees and shrubs that have been seriously stressed from lack of water since June. Major deluges, such as this past one, bring little relief to trees and shrubs since most of the rain simply runs off into the ditches and does not help trees at all. The way we manage water today in most of America is to try to get rid of it as quickly as possible.
We dig roadside ditches to allow run off to quickly move downhill, eventually ending up in streams and rivers, where it eventually ends up in the ocean. This rapid movement prevents rainfall from percolating into groundwater supplies where it remains available to replenish wells or supply trees.
It is like being allowed to eat as much food as you want for 8 hours, but then being denied any food at all for the next 30 days. That is hardly a healthy situation, but that is precisely what is happening to our native tree landscape.
Lawns, annuals and perennials can recover from short term droughts, but the damage to mature trees is often irreversible. Drought-stressed trees are much more susceptible to insects such as the Hemlock Wooly Adelgid, as well as several diseases.
Since there is nothing we can do about the weather, in the short term, I want to talk about something that we can do to address another environmental issue.
Each year, millions of suburban and rural homesteads put up electronic “bug zappers” in the mistaken notion that these devices will reduce the number of mosquitos around the property.
A study in Maryland revealed that of all the thousands of bugs that get electrocuted, less than 0.22% were mosquitoes. The bugs that did get zapped far more often, were insects that feed on mosquitoes. The net result of using them may actually be an increase in mosquitoes!
In addition to killing the bugs that feed on mosquitoes, the zappers also selectively kill moths and tiny wasps that are important pollinators.
I have heard from several gardeners this summer complaining of poor fruit set on crops like zucchini, other summer and winter squash, cucumbers and even tomatoes. Feral honey bees have pretty much disappeared in the past decade and we now must rely on native pollinators to provide this ecological service. Many of the “zapped” bugs are night time pollinators and this may be a factor on a small scale.
Even more importantly, remember that small insects, such as these devices kill, comprise the main diet of songbirds.
Most people do not care a great deal about insects, nobody want to cozy up to a spider or an aphid, but birds are another story!
It is estimated that bug zappers kill somewhere around 71 billion insects each year in the US. That is a lot of bird food that cannot be eaten by our feathered friends! Many of our favorite local birds, including Bluebirds, towhees, wrens, warblers, wood thrushes, whitethroated sparrows, swallows, cuckoos, buntings, and kingbirds are among the species that are in serious decline.
The reduction in insects overall is a worldwide phenomenon that has not been adequately explained, but it has serious consequences for our entire ecosystem.
If you want to reduce the number of mosquitoes around your property, make sure you empty any containers that trap water, even for as little as 3 or 4 days. Mosquitoes don’t need a lot of time to reproduce. Old tires, assorted junk, unused kitty pools, gutters that don’t drain, rain barrels and almost anything else that holds water need to be emptied every time it rains.
Consider putting up bat houses as well. These nocturnal predators will selectively eat thousands of mosquito-sized insects every night. There is no guarantee that bat houses will be occupied, but if you are fortunate, a colony will take up residence for the summer and your mosquito population will be greatly reduced.