In case your memory of 2007 and 2011 has faded, you will be able to repeat both years in 2024. This coming year we will see the synchronized emergence of two of the most damaging periodical cicada broods, for the first time since 1803.

The colored USFS map shown here identifies the approximate ranges of the 15 major periodical cicada broods, including the massive broods 13 and 19 which affect virtually all of Illinois plus large areas to the north, west, and south. Both broods, as well as their life cycles, are prime numbers and they do not overlap in timing for several human lifetimes. 2024 is the year!

The older black and white enlarged map indicates the traditional ranges of every brood affecting Illinois, even though it is somewhat out of date and does not show recent expansion of the ranges. For example, brood 13 has expanded to the south and we have been within its range for at least two cycles. Brood 19, expanding from the south and west, was seen for the first time at Starhill Forest in 2011 and is also well entrenched now.

For us, and for those who live near us, this means we expect to endure the worst cicada outbreak in human history in 2024. But even if you live south of brood 13 or north of brood 19, you are likely to see and hear at least one of the two larg-est cicada broods in North America. What does this mean for you?

1. Adult cicadas have no mouth parts and will not eat your plants. Their sole purpose is to breed and lay eggs.

2. While the songs of male cicadas can be louder that a chain saw at full throttle (personal experience here), it’s the females that do the damage via oviposition of eggs in a zipper-like sequence that kills the twig used. Those twigs usually break loose and fall to the ground, giving the hatching larvae an easy opportunity to escape predation and burrow underground for either 17 or 13 years, depending upon the species. Brood 19 comprises 4 synchronized 13-year species in 16 states, while brood 13 includes three 17-year species in 5 states.

3. Herbaceous plants are not attractive for oviposition, and neither are most conifers, due probably to their resin content. Shrubs can be used, but they normally do not grow central leaders so this amounts to little more that a pruning for them. Deciduous trees, on the other hand, are at risk.

4. Old trees in our area normally have discontinued their elongation of the terminal leaders, so “egging” them is not much worse than what happens to shrubs. Young trees reaching for the sky can be seriously affected, required pruning and training to restore a central leader and losing two or three years of growth. And new young trees, still undergoing transplant shock, can be killed.

So what should you do? We aren’t sure. But among your options are to enclose the entire young tree with insect-proof netting, tying the netting tightly around the trunk to prevent cicada entry. Failing that, at least you might protect the central leader, knowing that low lateral branched are temporary anyway. Your problem is that nets with 3/4 inch or larger spaces will not stop cicadas, and finer mesh or “mist” netting required a special permit for bird banding to purchase and use.

One option you might consider is to avoid transplanting any trees next spring until the cidada swarm has faded away, sometime in June. But you can’t dig trees that late, so they will need to be dug in March and stored in a cool warehouse to wait it out. Surely there are other steps you can take – please tell us and we’ll both know!