Archives For insects

One of our favorite insects at the Chicago Botanic Garden is the praying mantis. So we were very excited to obtain an egg case earlier this spring. We decided to keep it indoors so we could watch it hatch, and then release the newly hatched insects into the Garden.

PHOTO: Preying mantid egg case on a twig.

About 100 praying mantises emerged from this ootheca and were released into the Grunsfeld Children’s Growing Garden.

A praying mantis egg case is called an ootheca (pronouned oh-uhTHEE-kuh). The plural is oothecae (oh-uh-THEE-see). The ootheca was produced by a female praying mantis last fall. She laid her eggs in this foam of protein that hardened around a stick and protected the eggs through the winter. The eggs usually hatch in mid-June to early July. The half-inch-long immature praying mantis nymphs resemble the adult, but they do not have wings. 

PHOTO: Hundreds of baby mantids pour out of an egg case.

Colorless praying mantis nymphs emerge from the ootheca all at one time. During their first hour, they darken in color to blend in with their surroundings.

After our praying mantises hatched inside an insect cage, I discovered that a bed of false sunflower plants (Heliopsis helianthoides) in the Grunsfeld Children’s Growing Garden was infested with red aphids. I released the praying mantises, and the hungry babies immediately began to feed.

PHOTO: Mantis nymphs on the head of a Rudbeckia flower covered with aphids.

At first, the praying mantis babies seemed a little bewildered by their new surroundings, but they quickly acclimated.

PHOTO: Mantis nymph on a flower stem eyes aphids—a tasty meal.

This mantis held very still as it eyed its prey.

PHOTO: A row of mantis nymphs on a leaf face a stem covered with red aphids.

These four little mantises lined up and stared at the aphids that would certainly become lunch soon.

It wasn’t exactly aphid carnage—much to the disappointment of our eighth grade Camp CBG helper, Joshua, who assisted me with the release—but the young predators did appear to enjoy their first meal.  

PHOTO: Preying mantis on liatris bloom in August.

By the end of August, some of our little friends will be as big as this praying mantis (and just as hungry)!

It may surprise you to know that although it looked like a bad infestation, aphids are not really a big problem for the plants. When they are very abundant, it does not take long for natural predators like praying mantises and ladybugs to find them and move in for a feast. Predatory insects will take care of the problem if you are patient and let nature take its course. If aphids show up in your garden and they bother you, we recommend hosing them off with water rather than using an insecticide, because chances are pretty good that there are beneficial insects on your plants, too. Hosing with a strong jet of water will knock off all the bugs and kill most of the aphids, but it won’t be as devastating to the mantises or other beneficial insects as poison.

We have placed praying mantis oothecae in the Regenstein Fruit & Vegetable Garden and Elizabeth Hubert Malott Japanese Garden, as well as in the Children’s Growing Garden, to ensure that there will be a population of our favorite insect for you to find. Many of them will survive on aphids and other insects they capture and devour on our flowers, and they will grow up over the summer. The next time you visit, stop by and see if you can find them helping our plants remain healthy and less bothered by pests.

©2014 Chicago Botanic Garden and my.chicagobotanic.org

Cicadas by the Numbers

Kathy J. —  September 23, 2013 — 2 Comments

Cicadas have been out and singing for a while now. If you live around trees, you may be enjoying their late summer serenade. You also may be finding them on the ground. After they emerge from underground burrows, they molt and enter their adult stage. Then they mate, lay eggs, and die. When you find one, you can examine it to learn more about these big bugs.

Did you know that cicadas have five eyes?

In school we learn that insects have compound eyes, and we use toy bug eye viewers to get a sense of what dragonflies and bees see. But the real picture is a little more complicated. In addition to the pair of compound eyes, many insects, including cicadas, have three simple eyes. They are easy to see on a cicada if you look carefully.

PHOTO: Front "face" view of a cicada, showing 5 eyes.

This cicada’s three simple eyes show up as three spots reflecting the flash from the camera.

The simple eyes are called ocelli, and they are usually arranged in a triangle between the compound eyes, like those in picture of the cicada’s face. Grasshoppers, bees, and praying mantids also have them.

PHOTO: Side view of a cicada.

The Latin name for this cicada is Tibicen canicularis. “Canus” is the Latin word for dog. Why do you think he’s called the Dogday cicada?)

Let’s do some cicada math!
If you find a cicada on a tree or the ground, see if you can count:

1  mouth part to drink sap from trees

2  antennae that grow under the eyes and look like whiskers

3  body parts: head, thorax, and abdomen

4  wings, arranged in two pairs

5  eyes, 3 simple + 2 compound

6  legs

Want more cicada by the numbers? Click here to download a Color-by-Number Cicada.


©2013 Chicago Botanic Garden and my.chicagobotanic.org

Chicago Botanic Garden camp instructor Aimee Frank discusses the fun and adventures kids experience during Spring Break Camp and Camp CBG. During Spring Break Camp (March 29-April 2) children ages 5-8 discover bulbs, look for birds and other wildlife, and learn about all aspects of nature at the Chicago Botanic Garden. Starting in mid-June, children can attend Camp CBG which provides exciting outdoor learning opportunities for kids ages 2-15.