Summer Bugs

Insects readily make their presence known at two points during the year - the spring when the aquatic insects emerge to mate, and summer when the more terrestrial bugs set out to do the same. The most noticeable of these warm weather wonders are either visually interesting, like the fireflies, butterflies, and moths or produce a cacophonous chorus like the katydids, crickets, and cicadas.

Summer wouldn’t be summer without the regular emergence of fireflies. Easily the most recognized bioluminescent set of species, fireflies’ characteristic green strobe illuminates the night from July to September. The light is a chemical reaction that, unlike most of the ways we can produce artificial light, produces very little heat. Fireflies use special organs to transport oxygen into their abdomens where it powers this unique reaction.

Model for Nitrogen-Oxygen control of the firefly lantern flash

The other common nighttime fliers are moths. Moths are highly specialized creatures that can navigate in near darkness using a variety of methods from active echolocation to the acute senses of smell and, believe it or not, acute vision. Most moths have surprisingly good nighttime vision which allows them to locate their preferred flowers or other food sources. Moths can actually slow down how quickly they see things, allowing their eyes and brain to perceive a less-detailed but still perceptible world in nearly complete darkness.

Neural Summation in the Hawkmoth Visual System Extends the Limits of Vision in Dim Light

The daytime cousins of moths, butterflies, make for pleasant flower visitors throughout the summer. Butterflies, like most birds, see well into ultraviolet wavelengths of light which makes things like flowers and freshly laundered clothes fluoresce brightly in daylight. All but one of our butterflies stay here in the winter in some form. Monarchs migrate to Mexico, but the remaining 132 or so species of butterflies left in the state find some sort of alcove to tuck into for the long winter ahead.

Continental Nomads: Monarch Butterflies

Summer has a much different night soundtrack than the spring. Where the amphibians are the major contributors to the auditory experience of spring evenings, insects are the main source in the warmer months.

The commotion created by crickets and katydids comes from tiny structures on their wings. One wing has tiny ridges and the other a hardened scraper that moves along the ridges “playing” the wing like a washboard. The process, called stridulation, produces the distinctive chirping sound of crickets and the eponymous sounds of the katydid.

Stridulation Organ, Illustration by Charles Darwin