Oaks top the list. Across multiple studies of periodical cicadas in eastern North American forests, trees in the genus Quercus consistently attract more emerging nymphs, more singing males, and more egg-laying females than any other group. But the relationship between cicadas and their host trees is more layered than a simple ranking of favorites, shaped by branch geometry, light exposure, resin chemistry, and even whether a tree grows alone or among neighbors of different species.
Oaks Are the Clear Favorite
Research in Appalachian forests found that more cicada emergence holes appeared beneath oaks than beneath any other tree species. Oaks also hosted the densest chorusing centers, where males gather to sing, and bore the most oviposition scars, the slits females carve into twigs to deposit eggs. When researchers tested whether nymphs showed a preference underground, more nymphs turned up on oak roots than on maple roots.
This held true across all three species of Magicicada studied, though the degree of preference varied by species and by tree size. The pattern was consistent enough to call oaks the default host for periodical cicadas in forests where oaks are present.
1Journal of Forestry Research. Use of tree species by three species of Magicicada (Hemiptera: Cicadidae) in an Appalachian forestOther Trees Cicadas Attack Heavily, and a Few They Avoid
Oaks may lead the pack, but cicadas are far from exclusive. In a fragmented landscape study in the Midwest, egg-laying females showed strong preferences among available trees. Rough-leaved dogwood, slippery elm, box elder, and honey locust were all heavily attacked. Of these, dogwood received the most oviposition damage on average, making it a prime target in early-successional habitats where oaks might not yet dominate the canopy.
On the flip side, two species stood out for being almost entirely spared: smooth sumac and eastern red cedar. Females overwhelmingly left these trees alone, and damage to them was rare even when they were abundant in the landscape.
2PubMed. Spatial variability in oviposition damage by periodical cicadas in a fragmented landscapeThe avoidance of eastern red cedar fits into a broader pattern. Red cedar is a juniper, a conifer. Periodical cicadas as a rule stay away from conifers, and the reason is mechanical rather than nutritional.
Why Conifers Are a Dead End
Periodical cicadas almost never establish populations in coniferous forests, and the primary reason comes down to what happens after a female lays her eggs. Conifers produce resin, and when a female slits open a pine or cedar twig to deposit her eggs, the tree’s resin secretion seals the egg nest shut. The eggs cannot hatch. Research comparing hatching success in deciduous versus coniferous hosts found dramatically better survival in deciduous wood, with the reduction in pines directly attributed to resin entombing the developing eggs.
3Environmental Entomology. Why Don’t Periodical Cicadas Normally Live in Coniferous Forests?This means the avoidance is not really about adult preference in any active, choosy sense. A female cicada might occasionally lay eggs in a conifer. The problem is that her offspring never emerge from it. Over evolutionary time, any lineage that routinely chose conifers would fail to reproduce, so the behavior was effectively filtered out. The result is a near-total absence of periodical cicadas from pine, spruce, and cedar-dominated landscapes.
Branch Architecture Matters More Than You Might Expect
When researchers looked closely at what drives egg-laying choices within a given tree, an interesting pattern emerged: the physical shape of the branches was a stronger predictor of where females laid eggs than the identity of the tree species itself. Across both native and non-native hosts, cicadas consistently selected broader and longer branches for oviposition. Thinner, shorter twigs were less likely to be used, regardless of the species.
4Oikos. Plant architecture affects periodical cicada oviposition behavior on native and non‐native hostsThis makes intuitive sense. A female cicada needs a twig sturdy enough to carve a slit into without snapping it entirely, and long enough to accommodate multiple egg nests. Trees with a lot of pencil-diameter branches in the right range are going to receive more attention simply because they offer more usable real estate. It also helps explain why species rankings can shift between studies conducted in different forests: the particular growth form a tree takes, influenced by its age, pruning history, and light environment, matters alongside its species identity.
Light Guides Egg-Laying, Nutrients Do Not
You might assume that cicada females gravitate toward the healthiest, best-fed trees, since their nymphs will spend years feeding on tree roots underground. But experimental evidence suggests otherwise. When researchers enriched the soil around host trees with extra nutrients, it had no effect on how many eggs females deposited. The nutrient treatment did not change oviposition density at all.
5PubMed Central. Periodical cicadas use light for oviposition site selectionWhat did matter was light. Oviposition densities were significantly affected by how much light a host tree received. Females preferentially laid eggs on trees, or parts of trees, in well-lit positions. The researchers proposed that light might serve as a more reliable long-term signal than soil nutrients, which fluctuate over the years. A tree growing in a sunny gap is more likely to be vigorous and well-established over the 13 or 17 years that the nymphs will spend underground feeding, whereas a temporary nutrient spike today says little about conditions a decade from now.
Light also influences the behavior of singing males. Chorus activity, the synchronized buzzing that blankets a forest during an emergence, fluctuates with ambient light levels. Researchers recording Brood X cicadas found that both the frequency and amplitude of chorus cycling correlated significantly with shifts in light, suggesting that brighter conditions encourage more active singing and aggregation.
6PubMed Central. Self‐organizing cicada choruses respond to the local sound and light environmentThe upshot is that a tall, sunlit oak with broad branches is close to the platonic ideal of a cicada host. It checks every box: preferred species, good architecture, and ample light exposure.
Native Trees vs. Exotic Ones
Given that periodical cicadas have co-evolved with North American hardwoods for millions of years, you might expect them to ignore non-native plantings entirely. The reality is more nuanced. In a study comparing native plants, non-native species with close relatives in the local flora, and truly alien species with no nearby evolutionary relatives, cicadas were equally likely to oviposit on natives and non-natives. Both groups attracted significantly more egg-laying than alien species did.
7Ecological Entomology. Does the periodical cicada, Magicicada septendecim, prefer to oviposit on native or exotic plant species?Non-native trees actually had more oviposition holes per meter of branch length than natives, though natives showed more overall flagging, the dead, drooping twig tips that result from egg-laying damage. Alien species were the least attacked and the least likely to flag. The authors speculated that evolutionary history between cicadas and potential hosts plays an important role: a non-native maple from East Asia, closely related to local maples, is recognizable as a suitable host, while a truly unrelated import is not.
For homeowners, this means that planting an exotic ornamental tree does not guarantee it will be spared during an emergence. If it belongs to a genus with North American relatives, cicadas are likely to treat it just like the local version. Truly unrelated species from distant plant families are more likely to be left alone, but even that is not absolute.
Monocultures Attract Far More Egg-Laying Than Mixed Forests
One of the more striking findings in recent research involves not which tree species is present, but how many species are growing together. In experimental plots, cicadas were roughly three times more likely to oviposit on trees growing in single-species stands compared to those in mixed-species plots.
8University of Maryland Digital Repository. A GOOD NEIGHBORHOOD TO RAISE A BROOD: TREE SPECIES DIVERSITY DECREASES PERIODICAL CICADA OVIPOSITION AND TREE RESPONSEThe effect went beyond just receiving fewer eggs. Trees in diverse neighborhoods were also less likely to produce flagging, the visible branch dieback, even when they had similar densities of oviposition scars. In other words, a tree surrounded by other species tolerated the same level of damage better than an identical tree growing in a monoculture. The mechanism behind this improved tolerance is not fully clear, but surrounding diversity appears to buffer individual trees against the consequences of cicada attack, possibly through differences in root competition, microclimate, or resource sharing.
From a practical standpoint, this suggests that planting a mix of tree species rather than rows of the same one may reduce both the intensity of cicada damage and the visible consequences during emergence years. Orchardists and landscapers in periodical cicada territory have long understood that young fruit trees take a beating, but the monoculture effect suggests the problem is amplified by uniformity.
What Happens Underground
Cicada nymphs spend the vast majority of their lives beneath the soil, attached to tree roots. Histological work on the feeding sites of both 17-year and 13-year periodical cicadas confirmed that nymphs are xylem feeders throughout their entire underground development. Their piercing mouthparts create salivary sheaths that terminate in the xylem vessels of tree roots, the water-conducting tissue, rather than the sugar-rich phloem that many other sap-feeding insects prefer.
1Journal of Forestry Research. Use of tree species by three species of Magicicada (Hemiptera: Cicadidae) in an Appalachian forestXylem fluid is nutritionally dilute, essentially mineral-laden water with low concentrations of amino acids and sugars. This helps explain why nymphs need so many years underground to reach maturity: they are subsisting on one of the least nutritious food sources available to an insect. It also explains why they need a large, well-established tree. A small sapling’s root system simply cannot support a dense population of nymphs drawing on its xylem for over a decade.
Remarkably, nymphs appear to track time by counting the annual cycles of their host tree rather than by measuring the passage of real time. Researchers who experimentally altered the seasonal rhythms of trees, compressing multiple apparent growing seasons into fewer calendar years, induced premature metamorphosis in the nymphs feeding on those roots. The nymphs treated two artificial seasons as two real years, emerging early. This means the tree itself serves as the cicada’s clock, and the nymphs are physiologically tuned to the annual rhythm of sap flow in whatever root they are attached to.
9Ecology Letters. How 17‐year cicadas keep track of timeHow Cicadas Affect the Trees They Choose
The relationship is not one-sided. Trees pay a cost for hosting cicadas, though the toll is more subtle than the dramatic flagging of twigs might suggest. A dendrochronology study of 89 individual trees across five species in Indiana, including sugar maple, white ash, pin oak, black oak, and sassafras, found that three of those species showed a measurable reduction in growth during or immediately after an emergence year. The damage from egg-laying, which kills the tips of egg-bearing branches, appears to be the main driver: it reduces the tree’s photosynthetic canopy right when the growing season is underway.
10BioOne (The American Midland Naturalist). The Effect of Periodical Cicadas on Growth of Five Tree Species in Midwestern Deciduous ForestsInterestingly, the same study found no detectable growth suppression from the years of root parasitism leading up to the emergence. Despite potentially millions of nymphs feeding on roots in a given patch of forest, the drain on the tree’s xylem was too diffuse or too minor to register in growth ring data. The visible damage from egg-laying, by contrast, was sharp enough to leave a clear signature in the wood.
There is a possible silver lining for the trees. Three of the species showed an increase in growth about five years after an emergence event. One explanation is the natural pruning effect: the dead branch tips shed after oviposition allow more light to penetrate the canopy, stimulate new growth, and reduce the load of old wood. In a sense, the cicadas may be providing an involuntary pruning service, though the short-term cost is real.
Do Dead Cicadas Fertilize Trees?
After a mass emergence, billions of cicada carcasses blanket the forest floor. Each body is a packet of nitrogen and other nutrients, and the scale of the die-off is large enough to qualify as a genuine nutrient pulse. Some earlier research suggested this might boost tree growth, creating a fertilization feedback loop. However, a carefully controlled experiment adding cicada bodies to the soil around sycamore trees found that the extra nutrients did not translate into improved tree performance over a four-year monitoring period.
11PubMed Central. Acute resource pulses from periodical cicadas propagate to belowground food webs but do not affect tree performanceThe cicada bodies did increase plant-available nutrient levels in the soil and shifted the community of soil nematodes, boosting populations of bacterial- and fungal-feeding species. But those belowground effects did not propagate upward to measurably change tree growth. The researchers concluded that even massive short-lived nutrient pulses from arthropod die-offs can be attenuated quickly, absorbed by the soil microbial community before trees can capitalize on them. The romantic image of cicadas giving back to the trees that raised them does not quite hold up, at least not in any directly measurable way.
How Chorus Centers Form on Specific Trees
Before females choose where to lay eggs, males have to attract them, and the trees males prefer for singing are not random either. Chorus centers, the patches of forest where cicada song is loudest, tend to form around taller, more widely spaced trees. An analysis of ash trees found that tree height and the spacing between trees were significant predictors of whether a given tree would become a chorus center, in addition to the density of cicada emergences nearby.
12PubMed. Predicting emergence, chorusing, and oviposition of periodical cicadasThis makes sense acoustically. Taller trees give singing males more elevation, which allows their calls to propagate farther. Wider spacing between trees creates openings that let sound carry rather than being absorbed by dense foliage. Females approaching a chorus center will encounter these same trees first, so oviposition tends to be concentrated on and around chorus center trees. The result is a feedback loop: trees with good structure in well-lit, open positions attract singers, which attract mates, which attract egg-laying, which concentrates nymph populations on the roots of those same trees for the next cycle.
Protecting Young Trees During Emergence Years
Mature trees generally survive cicada damage without lasting harm, but young trees, especially fruit trees and recently planted ornamentals, can be severely set back or killed when a heavy emergence strips most of their small branches. The most effective protection tested is a fine mesh netting. In trials on nonbearing apple trees, a green tubular netting with roughly one-centimeter mesh physically excluded cicadas and prevented oviposition injury. Netting with larger openings was useless; cicadas simply crawled through and caused damage comparable to unprotected controls.
13Journal of Economic Entomology. Effects and Control of Periodical Cicada (Homoptera: Cicadidae) Oviposition Injury on Nonbearing Apple TreesChemical treatments in the same study had mixed results. Several insecticides produced excellent knockdown of adult cicadas on contact but did not significantly reduce oviposition damage, because new cicadas simply arrived and laid eggs between spray applications. Only one compound in the trial actually reduced egg-laying scars meaningfully. Given that periodical cicada emergences last only four to six weeks, netting is the practical recommendation: drape it over vulnerable trees before the emergence begins and remove it once adults have died off. There is no need to treat trees that have trunks thicker than about 10 centimeters in diameter, because established trees tolerate the flagging damage and recover fully within a season or two.