Because insects are cold-blooded, Raupp said, temperatures drive their development. "As climate warms, animals that rely on temperature will emerge earlier and they will develop quicker."
The recent spider and bedbug infestations in the news are not related to climate, experts said. Rather, both are consequences of increased global travel and trade, which is also driving insect dynamics worldwide.
Infestations on ships are frequent occurrences that only occasionally get reported, experts said.
"I don't think it's unusual to have a lot of spiders on a ship as long as there is plenty of prey" Raupp said. "Spider populations are driven by the availability of prey."
Kimsey agreed, noting that she was once involved in the turning back of a ship at the Long Beach port that was "literally covered" with Asian gypsy moths, a species with the potential to decimate the U.S. landscape if it becomes established here.
Bedbugs, meanwhile, were once commonplace in the United States, but DDT all but wiped them out. DDT was a long-lasting pesticide that lingered on surfaces for the bedbugs to encounter when they snuck out of their hiding places.