From Pennlive, but the problem appears to be affecting us as well: What happened to our butterflies this summer?
Many butterfly watchers across Pennsylvania, even those with pollinator or butterfly gardens or fields packed with butterfly-attracting wildflowers, have reported a noticeable decline in the big showy butterflies like monarchs and swallowtails, this summer.
Some have seen a bit of a resurgence in their backyard butterfly numbers later than normally expected in the past couple weeks. But overall summer 2020 has seen fewer butterflies in many parts of Pennsylvania.
The drastic decline in monarchs was expected after the Center for Biological Diversity announced that the winter 2019-20 population of the species in the central Mexican mountains where all monarch butterflies east of the Rocky Mountains spend the winter was less than half of what it was the previous winter. They also noted that it was less than half the population that scientists believe is needed for the species to avoid extinction.
But species like the eastern tiger swallowtail, great spangled fritillary, red spotted purple and orange sulphur do not migrate. Any decline in their populations in Pennsylvania would be caused by conditions right here at home.
“The people I spoke with concur that there was definitely a drought of butterflies for most of the spring and summer,” agreed Hazleton’s Rick “The Butterfly Guy” Mikula, president of Butterfly Rescue International and consultant to both the Association For Butterflies and The International Butterfly Breeders Association, of which he was a co-founder and president.
“Then about three weeks ago we had an amazing explosion of all butterflies to the point that our garden looks like a Disney movie. "
He believes the “overly hot summer” may have played a part.
“Many species, including monarchs, will go into a shut down when temperatures get too warm. Monarch eggs do not hatch in very dry conditions and dry weather can also kill milkweed.It's been a slow year for butterflies here too, and it was slow long before the temperatures started ramping up. I've only identified 31 species of butterflies this year, and several of the species that I normally consider gimmes, like the Variegated Fritillary and the Red Banded Hairstreak seem to have gone missing and I was blaming a cool, wet spring as well. In the past week or so, I think I'm seeing a little more activity, which would also suggest that high temperatures were not the culprit, since the two weeks previous to that were brutal, with 95 achieved almost every afternoon.
“There are several studies that have shown that temperatures above approximately 95 degrees Fahrenheit can be lethal to all stages of development and adults are incapable of mating. So that could explain a slow start. Now the sudden explosion of butterflies makes you wonder about the validity of the studies.”
The Wombat has Rule 5 Sunday: Kim Klacik up on time and under budget at The Other McCain.