LEANNA MCMILLAN – Staff Naturalist
Have you ever wondered what that constant buzzing noise is that you hear outside? Especia- lly this month, its most likely Katydids or Cicadas Katydids sing at dusk into the night during their mating season in the late summer months. Katydids have one of the loudest songs of any insect in North America. The male Katydids are the noisemakers singing from perches high in deciduous or coniferous trees. They often form huge choruses, their combined songs drowning out nearly all other sounds. When there are many males in a location, each joins one or the other of two singing groups. Males within each group synchronize their songs while the two groups alternate their songs, thus creating a resounding pulsation of sound that can overwhelm the listener. Katydids look remarkably similar to a leaf on a tree with their bright green colored wings with veins that resemble veins on a leaf. It is extremely difficult to spot these katydids because they are generally high up in trees, especially oaks, and they blend well with their surroundings. During the breeding season, however, they may sometimes be found walking across roads, moving in the direc- tion of dense choruses. Cicadas sing during the heat of the day during the long hot days of summer and get increa- singly loud near the end of the summer months trying to attract a mate. Male cicadas have loud buzzing songs that are produced by special organs called “tymbals,” located on the first segment of the abdomen. Nearly all eastern cicadas are of the annual type, meaning that adults emerge every year, although some years may yield greater numbers than others. The life cycles of individuals within a population are staggered so that nymphs are emerging as adults every year. There are also periodical cicadas that have populations in which all individuals are synchronized in their life cycles usually every 13 or 17 years. When the cicada eggs hatch, the newly hatched nymphs drop to the ground and burrow. Cicadas live underground as nymphs for most of their lives at depths down to about 8 ft. In the final nymphal stage, they construct an exit tunnel to the surface and emerge. They then molt (shed their skin) on a nearby plant for the last time and emerge as adults. The exuviae or abandoned exoskele- tons remain, still clinging to the bark of the tree. Though a group of these insects is called a cloud or plague, cicadas usually don’t cause the harm that locusts cause to crops and local vegetation.