The humid Missouri summer air often carries a distinct, rhythmic pulse that many residents recognize as the soundtrack to the season. This sound, produced by the insect world’s most prolific singers, belongs to the annual and periodical cicadas found throughout the state. Understanding cicadas in Missouri reveals a complex ecological story involving synchronized life cycles, diverse species, and a significant, if temporary, presence that impacts trees, wildlife, and human activities.
Annual vs. Periodical Cicadas in Missouri
Missouri hosts both annual and periodical cicadas, which differ fundamentally in their life cycle timing and population density. Annual cicadas, often called dog-day cicadas, emerge sporadically throughout the dog days of summer, typically appearing in July and August. Their life cycle lasts two to five years, resulting in a consistent, though fluctuating, presence most years. In contrast, periodical cicadas belong to synchronized broods with mass emergences occurring at precise intervals, either 13 or 17 years. While Missouri historically hosted the massive Brood XIX (13-year) and parts of Brood IV (17-year), the state currently experiences significant 13-year periodical activity from Brood XIX, with isolated reports and potential overlaps linked to other emerging broods in specific regions.
Identifying Common Missouri Species
Several cicada species are commonly observed across Missouri each year. The annual cicada group includes the robust Tibicen species, which are large and often display vibrant green, black, and brown coloration, producing a loud, pulsating call. Another frequent smaller species is the slender Neotibicen winnemanna, recognized by its distinctive green markings and clear, ringing song. For periodical cicadas emerging from Brood XIX, residents encounter the classic black-bodied insects with bright red eyes and orange wing veins. These include males actively singing to attract mates and the quieter females, who respond with subtle wing flicks rather than the loud songs of their male counterparts.
The Ecological Role and Impact
Cicadas play a vital role in Missouri's deciduous forest ecosystems. As nymphs, they live underground for years, feeding on root sap and contributing to soil aeration. Their emergence as adults provides a massive protein source for a wide array of wildlife, including birds, raccoons, opossums, snakes, and wasps. This abundant food source supports predator populations and helps sustain the broader food web. While the sheer number of periodical cicadas can cause cosmetic damage to young or newly planted trees when females lay eggs in twigs, established trees typically withstand the pressure without long-term harm, and the ecological benefits generally outweigh these temporary effects.
Impact on Trees and Landscaping
Homeowners and landscapers often express concern about cicadas laying eggs on tree branches. Female cicadas use their saw-like ovipositors to cut slits into small twigs to deposit eggs, which can cause the twips to wilt and break, a phenomenon known as "flagging." While this can look alarming, the damage is usually minimal on healthy, established trees. To protect vulnerable young trees, the most effective strategy is to cover them with fine-mesh netting during the peak emergence period. Pesticides are generally not recommended due to the sheer number of insects and the potential harm to non-target species like pollinators.
Human Interactions and Cultural Significance
The emergence of billions of periodical cicadas can be a profound event for communities across Missouri, capturing regional and even national attention. The dense concentrations of singing insects create an intense, immersive natural soundtrack that defines a specific season for those living through it. While the noise level can be overwhelming for some, most people come to appreciate the remarkable biological phenomenon. These events serve as powerful, real-time reminders of the intricate cycles of nature, connecting people to the long-term rhythms of the environment in a way few other occurrences can.
