Large decline in insects in SW Michigan....

Not sure what causes population fluctuations. Read many articles and even a book on the topic. I do not believe that global warming has been caused by man. I believe that the earth warms and cools by its own design.

I have read that a single volcano can produce more CO2 in one week than all of mankind will produce in the next ten century's. Of course a little flatulence by a couple of you might prove to be disastrous to the Earth.

Could someone upstream have been mining gold and discharged mercury into the water source? That or some similar serious pollution event may explain why trees are seriously affected in the vicinity of the waterway. It is also possible that fish and amphibians were poisoned too.

luehdorf made a pertinent comment about pesticide use, some types of which would certainly kill off pretty much all insects downwind of the area sprayed.

Adam.

I should think it would not be radiation because radioactive particles are heavy elements and should sink to the bottom of the ocean. It is unlikely they could travel so far from Japan to Michigan. Pesticides are unlikely as well unless there has been something new come onto the market recently that all of the farmers in the area are using. Windblown pesticides would affect the periphery of forests, but not so much the interiors.

I think microwaves are the more likely culprit. The US is literally bathed in cell phone radiation. There are cell phone towers every few miles. The antennae of insects must be very sensitive to detect pheromones in tiny ppm concentrations in the air. If the microwaves are interfering with insects finding mates, it will be a problem. The huge decline in honey bees since the advent of cell phones is well known. The bee keeper around the corner from me told me that his bees were hard hit.

inhabitat.com/its-official-cell-phones-are-killing-bees/

You know, I think it would be rather easy for silk moth breeders to test this theory. Placing a freshly hatched female outside in a cage with an active cellphone might do it. One could wait for the males to appear in the vicinity, then activate the phone transmitter to see if it confused the males and kept them from finding her. Or you could keep the transmitter on from the beginning (that means using a power supply on the phone instead of a battery) and see if any males show up at all.

There have been huge insect declines in Europe. Germany and Britain are just two examples,and these are the implications for all landscapes dominated by agriculture, the researchers said. Vast continued use of crop Pesticides have built up over time, these are the likely the reasons for declines in insects that a fall out from a volcano and mobile towers, its all man made, just like global warming this time around certainly is. Since insect are an important part of the lower food chain, and other life will struggle to live without them, things are certainly on the turn for the worst. The sad fact is planet earth is over populated and vastly over polluted, these are the real reasons for all animal/habitat decline. Humans being at the top of the food chain, and endeavouring very successfully to trash their own planet.

See article "Statewide butterfly monitoring by volunteer recorders in Ohio reveals a persistent decline in abundance, so what can we do?" Tyson Wepprich, News of the Lepidotperists' Society, Volume 61, Number 3 Fall 2019.

The author has the same question, albeit restricted to Ohio, where long-term counts have been implemented. In summary, he blames "habitat loss, climate change, and pesticides".

Of the 81 butterfly species studied, 9 (11%) were increasing, 40 (49%) were steady, and 32 (40%) were decreasing.

Wepprich cites climate change for the increasing species (as well as decreasing) as opposed to habitat loss, since Ohio hasn't changed much.

Of interest, the graph of counts demonstrates a rather steady loss (as opposed to a crash) of about 2% per year from 1995 through today. That there has been no general population crash (though some species have disappeared from Ohio) is indicative of a long-term trend perhaps only recently noticed. Notably, he cites an almost identical long-term 2% loss rate in UK.

Now, on to my observations:

The article extrapolates data from actual data into "predicted" data, due to differences in observation period and frequency, quantity of observers, etc. Fair enough (I suppose) but it isn't then real data, it's manipulated; albeit with the best of intentions, but manipulated data by its very nature is false data.

That said: as I've cited in other posts, I've noticed a decline in many species at my lights in the back yard. Callosamia promethea, in the past common enough to be a nuisance, was unseen in 2019. Polyphemus is way down, as are sphingids. While I could quickly blame climate change, as a problem solver I have to question other factors, such as the forest maturing and the loss of my two most productive UV lights.

Is climate change in my head? Those of my generation scare the younger generation with stories of massive snowstorms with accumulated snow over our head. Of course, we forget that we were 1.2meters tall, and that perhaps those events, spread over a decade of development, stick in our minds as if it were a non-stop occurrence.

That said, P chresphontes in recent (< 10) years has been established in my area. This warmer weather species may or may not (in my mind it certainly does) indicate a general warming.

Of greater concern is the spread of Lyme disease and ticks, virtually unknown until the past decade. As a kid constantly in the field I never saw a tick. Not one. Now, ticks and Lyme disease are so prevalent that I have virtually terminated any local field work.

So, climate change aside, what can cause the decline in Leps in my area of Upstate NY? The big culprit in my mind is agriculture, particularly pesticides. Note (like Ohio) that agriculture has not expanded, thus habitat loss (due to agriculture...now, new housing development may be a different story) is not an issue per se. What has changed is the crop composition: apple and grape farming has exploded. In some regions, these two crops are a multi-million dollar industry- so much so that the Sheriffs of strongly right-leaning counties will not chase down illegal aliens because the apple farms are dependent upon their work.

Whether a result of the change in crop composition or not, the estuaries into which the farming chemicals drain have in recent years exhibited deadly algae blooms. That the algae explosion and agriculture are linked has been well established. But, to my mind, fertilizers are unlikely to damage general insect populations.

That said, hand in hand with fertilizers are pesticides. I must suspect that pesticides, as with other technologies, have become more effective over the past couple decades. I further suspect (and I know I'm going out on this one) that the change to taller plants (apple trees, suspended grape vines) require a different, "higher", application and perhaps the pesticides are now more airborne, more likely to reach outside of the farm?

In any event, I am quite certain that nobody is going to tell me pesticides are less effective than they were twenty years ago, so I think we have our culprit. Not that anything is going to change, not when there is money behind it.

Chuck

The UFO moth in you SW Michigan post in not a Geometridae, close, but no cigar. It is a Drepanoidae, the family just before Geometridae.

It is Oreta rosea #6255. If you decide to check it out on MPG, click on the species page and you will find a duplicate of the one in your photograph.

I apologize for taking so long. It must be my age, I knew the moth, I just could not remember it's Family or name. Could be my age......