Cicadas, recognized by their distinctive buzzing songs, are a common part of the Texas soundscape. These insects spend the majority of their lives underground as nymphs, emerging as adults for a brief period to mate and lay eggs. Texas is home to numerous cicada species.
When Cicadas Emerge in Texas
Cicadas in Texas typically emerge during warmer periods, most notably in summer. Common “dog-day” cicadas, which are annual, are frequently heard from July through October. Their loud calls, produced by males to attract mates, are a familiar sound in the Texas heat. This emergence is not a single, synchronized event but rather a continuous appearance of individuals throughout the summer.
The timing of their emergence is closely linked to environmental cues, particularly soil temperature. When the ground reaches a consistent temperature of around 64°F (18°C) at a depth of about 8 inches, it triggers nymphs to burrow to the surface. This temperature threshold typically occurs in late spring or early summer, initiating the adult phase of their lives. While their song is a hallmark of summer, emergence can begin earlier.
Annual vs. Periodical Cicadas in Texas
Texas is primarily known for its annual cicadas, often called “dog-day” cicadas, appearing in late summer. These cicadas, belonging to the genus Tibicen (now Neotibicen), have life cycles ranging from two to five years, but their individual emergences are not synchronized. This means some individuals from various broods emerge every year, leading to their consistent presence each summer.
While periodical cicadas, known for synchronized mass emergences every 13 or 17 years, are not a widespread phenomenon in Texas. Texas does have one periodical cicada brood, Brood IV, also known as the Kansas brood. This brood last emerged in 2015 and is expected to re-emerge in 2032, primarily in a small portion of North Texas, including counties like Kaufman, Cooke, Fannin, and Lamar. Large, simultaneous emergences seen elsewhere, like Broods XIII and XIX, do not significantly impact most of Texas.
The Cicada Life Cycle
The cicada life cycle consists of three main stages: egg, nymph, and adult. Female cicadas lay their eggs in small slits created in tree branches using a saw-like ovipositor. After about six to ten weeks, tiny nymphs hatch from these eggs and drop to the ground.
Once on the ground, nymphs burrow into the soil, feeding on sap from tree roots and undergoing several molts as they grow. This subterranean phase can last anywhere from two to five years for annual cicadas, and 13 or 17 years for periodical species. When fully developed, nymphs dig tunnels to the surface, typically at night, and climb onto nearby vegetation to undergo their final molt, transforming into winged adults.
Regional Variations Across Texas
While common across Texas, minor regional differences in emergence patterns exist. The general timeframe of summer emergence for annual cicadas holds true across the state, from East Texas to Central Texas. However, the exact peak of activity might vary slightly depending on local climate conditions and specific species present. In regions like East Central Texas, particularly in alluvial forests along rivers, cicadas can be especially abundant in June and July. Overall, local temperatures and soil conditions play a larger role in determining precise emergence timing, leading to subtle shifts in activity.