Cicadas are a hot topic this year as two different kinds of these insects are emerging with millions of cicadas invading. If you have these two things in your backyard, you're going to be seeing more cicadas than most, and we'll explain why.

There are two types of cicadas that we are talking about this year, Brood XIX which only emerges from underground once every 13 years. Brood XIII emerges once every 17 years. This year both broods have emerged at once.

The last time these two broods of cicadas emerged at the same time was back in 1803! 1803 was a year in which President of the United States Thomas Jefferson was negotiating the Louisiana Purchase.

Cicadas Return To Midwest
(Photo by Scott Olson/Getty Images)

Why have they all come out at this time?

It's for reproduction. It's time to make more cicadas and the two broods' life-span years have just happened at the same time.

Once they have found a partner, and the deal is consummated, the female cicadas will lay their eggs in tree branches or branches of bushes and shrubs.

Eventually, the eggs hatch, fall to the ground and burrow in there to live. It's a rich environment down there where there is water and roots for food.

Leon Neal Getty Images

Why Are There So Many Cicadas?

It's Nature's way of giving cicadas an advantage over predators. It's about being available in greater numbers.

Professor of Biology John Lill explains to,

By their sheer numbers, they can gain a reproductive advantage over their potential predators. The long time between emergencies is important because if they emerge say, every three years, then their predators could potentially anticipate them.

Is My Yard More Attractive to Cicadas If I Have These Two Types of Items?

Well, according to officials at the Morton Arboretum, cicadas do tend to pick the following trees more often in which to lay their eggs:

  • Apple
  • Birch
  • Dogwood
  • Elm
  • Ginkgo
  • Hickory
  • Linden
  • Maple 
  • Pear
  • Willow

When it comes to shrubs and bushes they tend to pick the following ones more often in which to lay their eggs:

  • Rose
  • Lilac
  • Forsythia

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Gallery Credit: Angela Underwood