Cicadas are large insects that emerge seasonally, with annual species appearing every year and periodical species emerging in massive numbers every 13 or 17 years. While the loud, buzzing adults may be startling, they do not bite humans, nor do they cause lasting damage to mature, healthy trees. Their primary threat is to young trees and saplings, where females lay eggs in small branches, causing a characteristic injury known as “flagging.” This article focuses exclusively on safe, non-chemical, do-it-yourself methods to manage cicadas and protect vulnerable plants during their emergence.
Physical Barriers: Protecting Vulnerable Plants
The most reliable defense against cicada damage is physically excluding egg-laying females from susceptible plants. Females use a sharp ovipositor to create small slits in tender twigs and branches where they deposit eggs. This process can severely weaken or kill young plants, especially newly planted saplings and fruit trees, causing branch tips to brown and die.
Protecting these plants requires fine-mesh netting to physically block the insects from reaching the branches. The netting mesh must have openings no larger than 1/4 inch; any wider aperture will allow the cicadas to pass through. This netting should be draped completely over the tree or shrub and secured tightly around the trunk at the base before the emergence begins in late spring. Cicadas often begin to emerge when the soil temperature reaches approximately 64 degrees Fahrenheit.
Proper installation involves ensuring the netting is fastened securely to the ground around the base of the trunk, preventing the insects from climbing up underneath the barrier. Once the emergence is complete, typically within six weeks, the netting can be removed and stored for future use, as it allows for normal air and light transmission while in place. Mature trees usually do not require this protection because their large branches can tolerate the egg-laying damage without significant long-term harm.
Manual Management and Cleanup Strategies
Directly managing the cicada population on your property relies on hands-on methods that avoid sprays or chemical treatments. One effective strategy is manual collection, where adults can be shaken from tree branches onto a sheet or tarp placed on the ground below. These collected insects can then be scooped up for disposal or repurposed.
For broad cleanup of large numbers, an outdoor-rated shop vacuum can be used to gather cicadas from surfaces like patios and sidewalks. When disposing of collected cicadas, the safest and most recommended method is to bag the bodies securely and place them in the regular garbage. Alternatively, the collected insects are rich in nitrogen and can be added in small quantities to a personal compost pile or simply buried in garden beds, where they will decompose and enrich the soil.
The shed exoskeletons, or molts, which accumulate on surfaces, should be swept or raked off driveways and walkways, as they can attract other insects and rodents if left in large piles. While the noise of the emergence can be overwhelming, using physical barriers like closed windows and doors, or introducing white noise indoors, can help dampen the acoustic nuisance.
Debunking Common Non-Working Remedies
Common household mixtures are ineffective at controlling a mass cicada emergence. Sprays containing ingredients like dish soap, garlic, vinegar, or essential oils such as peppermint and eucalyptus fail to provide meaningful control. Cicadas have a tough exterior, and a simple water or soap solution is not potent enough to eliminate them in the necessary numbers.
Applying strong-smelling substances like essential oils or garlic spray is not a sustainable deterrent against the sheer volume of emerging adults. The insects’ mobility allows them to easily fly around a localized spray, and the scent quickly dissipates, requiring impractical constant reapplication. Similarly, attempting to use a garden hose or sprinkler to knock cicadas off plants is only a temporary measure. While water may dislodge some insects, they quickly return to the trees to continue their reproductive cycle, wasting water without achieving population control.