Winter Storm of Texas - what impact did it have on insects?

 It is only natural after having a very unprecedent storm like Uri that just shut down Texas, to start thinking of what other impacts will we see. As an entomologist, the questions I am receiving are along the lines of "how did or will the storm impact the insects this year?"

Since I grew up in Florida and did my schooling there prior to moving to Texas, I really have no first hand data on what winter does to insects. Definitely two states that don't have real winter and my home town is always above 70 to 100 degrees year-round, most years.

So I decided to ask my colleagues for their insight and basically we all say about the same thing. 

The northern counties of Texas, which do have some winter, will have little to no impact on their insect populations despite the snow and freezing temps. Reason? The insects are still hibernating. They are in their egg or pupal stage and are winterized. If the storm had hit later into spring, there could have been some impact.

In the southern counties of Texas that could have active insect stages already, there could be impact but probably only minor. It takes extended periods of freezing temperatures to affect whole populations and while a few individual insects may have been impacted, not all would have been. 

Since my main areas is mosquitoes and flies, I will address them in particular. 

For mosquitoes, I would say little impact based on the species of concern but Culex may be worth watching this year as they overwinter as adults. The others overwinter as eggs and are designed for extremes.

For flies, emergence is usually not until March to May, depending on species, and they would not be impacted by the storm. We typically do not see fly populations return until spring and while the storm has stopped any early stable fly emergence, there will be others that did not emerge yet that will in the next couple weeks and get the population back on track. 

Comments from my colleagues in regards to other insects of concern.  

“I suspect red banded stink bugs took a hit, and to a lesser degree fall armyworm.  It may delay sugarcane aphid to some extent.” From Dr. Kerns, College Station 

“The thick layer of snow and ‘subterranean’ structures, I suspect, will lead to no drastic changes in pest complex in urban or greenhouse settings this growing season – but that’s a hypothesis. Our house water line which is about 1-foot underground didn’t freeze, and even after our first snow fall, I was able to find melted snow at the soil level. Snow is quite a good insulator – so temps at the soil level (or below) didn’t reach quite as cool as ambient.” From Dr. Vafaie, Overton 

“The cold will have no effect on corn rootworm because the eggs are below ground. They can’t even freeze them out in Minnesota or Canada.” From Dr. Porter, Lubbock

 “I did get my soil thermometer out during this mess a little bit, and at the coldest we got to about 15 degrees and our soil at 6” was still at 38 degrees. We had very little snow here, and there was ice on the ground. I am interested to see how this year shakes out after that mess, and I hope the red bandeds took a hit.” Kate Crumley, Wharton, Jackson, & Matagorda Co.

 “Looked at some wheat this afternoon and did not see much of a reduction in bird cherry oat aphid numbers. The beneficial population took a big hit out of this winter weather.” Tyler Mays, Hill & McLennan Co

 “Brown marmorated stink bug overwinters as an adult in anthropogenic structures and under tree bark. It tends to survive quite well despite “polar vortexes” that occur on the East Coast. However, as noted by others, the impact will be species-dependent and whether any warm periods preceding the cold weather broke diapause too early.” Dr. Ludwick, Corpus Christi

So short answer, probably won’t be a big impact since it was still winter for most insects. If this had come after spring hatch, then things would be different. Saw bees at my house yesterday! So it is what it is. Insects are very resilient. 😊 

 Photo credits: Confessions of an Entomologist, Mosquito Joe, and Purdue Extension