Most insect species favor habitats located in humid and rainy tropical to subtropical regions, and very few insect species have become well adapted to thriving in arid environments. The fact that most insect species require substantial moisture in order to survive is well exemplified by the tendency of urban insect pests to establish indoor harborages in high moisture conditions. Many insect pests congregate around basement water heaters, in wall voids where plumbing leaks or pipe condensation is present, in tubs, beneath sinks, within drains, and beneath bathroom, kitchen and laundry room floorboards.
In central Texas where the climate can be categorized as humid and subtropical, a small number of common indoor insect pests seem to tolerate, or even favor relatively dry living conditions. Some of these pests include brown-banded cockroaches, firebrats, native fire ant species, chinch bugs, and multiple drywood termite species, most notably the western drywood termite. Unsurprisingly, insect pests will readily move into homes to seek much needed moisture during bouts of dry weather. This is understandable, but homeowners are often perplexed to find some of the most moisture-dependent insect pests invading their home in response to heavy rainfall.
Arthropod pests like cockroaches, non-biting gnats, and millipedes are particularly susceptible to the desiccating effect of dry air, so it seems reasonable to assume that these insects would appreciate heavy summer downpours. While millipedes are well known for invading homes during periods of drought, they quickly become overwhelmed by bouts of rainfall. This is because millipedes are too slow to escape from their soil habitat in time to save themselves from drowning in shallow rain puddles.
German and brown-banded cockroaches dwell within manmade structures at all times, but other thirsty cockroach pests in central Texas like American, Australian, Oriental and smokybrown cockroaches alternate between outdoor and indoor habitats. These roach pests remain in close proximity to bodies of water for most of their lives, but compared to other insects, roaches cannot survive long after becoming submerged in water. In fact, all of the above cockroach pests thrive in sewer habitats, but when heavy rainstorms cause sewer waters to rise, these roaches flood out of manholes and into homes, and many travel into homes and buildings through sewer pipes.
Perhaps worst of all are the mosquitoes that suddenly become overabundant as floodwaters recede in central Texas following heavy storms. Many nuisance and disease-carrying mosquitoes readily reproduce within the ubiquitous water sources available in the environment following heavy storms. In the past, West Nile virus cases in Texas have spiked following hurricanes and heavy bouts of rainfall, and experts believe receding flood waters were to blame.
Have you ever noticed an influx in insect pest activity following heavy storms?
