This is why I have nothing against -20 to -40 weather and really want it/
A recent spate of warmer-than-average winters over the last few decades, however, has allowed the populations of some types of creepy crawlies to explode. When winter temperatures never reach a truly deep freeze, bugs make it through to spring unscathed and ready to multiply.
For instance, Lyme-disease-carrying deer ticks—which are not actually insects, but eight-legged arachnids, like spiders—are now seen in larger quantities and have spread farther to the north than they once roamed. When temperatures drop well below 0°F, though, many individual insects die. The colder the temperature becomes, the fewer survive. The problem is, the ground is warmer where they hunker down, allowing them to survive even some of the deepest freezes.
How Cold Does It Have To Get?
The actual temperature required to kill off pests varies across species. The emerald ash borer, for instance, can generally withstand temperatures as low as -20°F. Any colder than that and about half of their population dies off. At -30°F, even more of the invasive pests are wiped out.
Some individuals will inevitably survive, but the reduced numbers could be beneficial to other species. For instance, a substantial reduction in the number of emerald ash borers could slow the predicted extinction of American ash trees. Likewise, gardeners and homeowners aren’t likely to mourn if Japanese beetles or brown marmorated stinkbugs were less abundant next summer.
This year the frost is down a couple inches, around here, with one whole night of -20, that kills nothing.
Not that long ago we frost going down well over six feet, that kill the SOBs.
In bog land like Alaska and Northern Minn. undisturbed by man, there are feet of mulch on the ground, so more insects live.
Mosquitos and Black Flies are the least affected as one survivor breeds hundreds and hundreds breed....