decorah envirothon - good bugs, bad bugs

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Good Bugs, Bad Bugs

Good Bugs, Bad Bugs

Todays presentation is about some of the bugs we like and some that we do not. Does anyone know what bug is in this photo? The honeybee!1

Honeybees are arguably the most beneficial bugs in the world.


We know they pollinate most of our beautiful wild and garden flowers.

Other insects play a huge role in pollinating both wildflowers and garden flowers. The good thing about honeybees is that they can be transported to huge fields of almonds in California where there are not enough natural pollinators to do the job.3

Honeybees are also the main pollinator for many crops we grow for food.

They say about 1/3 of humanitys crops rely on insect pollinators. In NE Iowa the most important crops would probably be apples and alfalfa. Most vegetable and sweet fruits need insect pollinators; grain or cereal crops do not. 4

This apple orchard blooming in April needs to be visited by bees before any fruit can form.

Red ripe apples in autumn, thanks to the work of busy honeybees.


Honeybees get a reward, in the form of nectar, for that work.

Honeybees turn that nectar into honey, which we can siphon off a sample from their hives, for a real sweet treat.

The cicada killer is another bee, albeit a big one, that could be considered beneficial.

Cicada killers key in on catching cicadas. Surprisingly, they dont eat cicadas but their larvae do. Adults drink flower nectar

A cicada, also known as the harvestfly. Cicadas are famous for making a deafening din around the neighborhood in summer.

Some cicada species spend 17 years underground, slowly growing into that creepy-looking critter, before crawling out.

Baby cicadas climb up a tree trunk before splitting their skin and popping out the noisy flying adult form

Lady beetles are often called ladybirds or ladybugs, but they are indeed beetles.

Native lady beetles are never a nuisance and hibernate under decayed tree bark out in the woods. They dont bite or stink.

Asian lady beetle adults can be big problems for people. They seek winter shelter in our houses en masse & smell awful.

Another good one is the Halloween ladybug, because that is the time of year that it tends to show up in peoples homes. Originally from Northeastern Asia, it was brought to the U.S. and used to control aphid populations in greenhouses throughout the 20th century. A wild population got established in the early 1990s and by 2000 it had become common in the Upper Midwest.


All ladybird beetle larvae are beneficial. They eat aphids and scale insects and other bugs that cause gardeners headaches.A

All ladybird beetle larvae are beneficial. They eat aphids and scale insects and other bugs that cause gardeners headaches.A

The Asian lady beetles actually make a huge difference for farmers by eating up thousands of soybean aphids.18

Adult lady beetles are also predators and feed on mealy bugs and spider mites. They can live for three years!

These characteristic make lady bugs a popular choice for greenhouses and other small-scale agricultural producers to purchase as beneficial insects to keep pests like spider mites under control.19


Green lacewings are another good bug to have around the house.

Green lacewings are named for their delicate lacy-looking wings. They live out in the fields and around our gardens and adults feed on flower nectar. Theyre most active in the evening.

Green lacewing larvae look like little alligators and aggressively attack 70 other bugs, mostly bad things like aphids & thrips.

Thrips are also called corn lice and suck the juices from commercial crops like corn & soybeans as well as garden crops.

This plain-looking bug looks pretty dull during the day but really shines at night, hence the common name firefly

Fireflies or lightning bugs are actually beetles. The strange light source is located under those wings on their abdomen.

There are a few ways to tell the difference between a bug and a beetle. Beetles will always have two plates called elytra that cover up their wings when they arent flying. True bugs have more membranous that stay exposed.

Beetles are often omnivorous, and they have mouthparts made for chewing. True bugs use straw-like mouthparts to feed on juices; usually they go for plant sap or nectar, but some will consume animals. 25

Fireflies use that cool green light to attract mates; each sex sending out communication signals to identify their species.

Firefly larvae are specialized predators that focus on snails & slugs in the swampy areas they like to live.

Firefly larvae suck the life juices right out of captured slugs. They glow in the dark too, all the time, & are called glowworms.

Heres a glowworm going right inside the shell to get to the snail hidden inside.

The best-known good bug is probably the praying mantis.

Praying mantis look like science-fiction monsters.They suck the life blood right out of luckless flies.

Harvestmen, or daddy longlegs, look like spiders but notice how their whole body is fused into a single oval form.

In addition, daddy longlegs dont spin webs and they dont have venom so they cant hurt you. Note the really long legs.

Harvestmen eat small slugs and bugs, like this tiny froghopper.

Harvestmen eat small slugs and bugs, like this tiny froghopper.

They are called froghoppers because of their excellent jumping abilitiesup to 2.5 feet vertically. They have relatives called leafhoppers and tree hoppers.34

Froghopper nymphs are known as spittlebugs, famous for making frothy white hideouts that look like spit.

A spittlebug basking in a tub of bubbles.

Garden spiders arent insects but might be considered good bugs.

Garden spiders set out nets to capture critters like grasshoppers that are quickly consumed.Garden spiders are harmless to people even though they look dangerous.As the saying goes, live and let live.

Garden spiders often surprise me when I am walking through weedy, neglected corners of my familys garden.38

This little crater in the sand is made by an insect called the ant lion. Careless ants crawl in and then cant crawl back out.

When a trapped ant reaches the pits bottom, that immature ant lion rears its head out and eats the ant.

Immature ant larvae are awfully ugly little bugs.

Adult ant lions look a lot different than those grotesque larvae.

Adult ant lions have long webby-looking wings and live around sand prairies here in Iowa.

Robber flies are always on the lookout for another victim.

Robber flies hunt down and attack other airborne insects, including pesky flies or scary bees.

Goldenrod soldier beetles search for aphids to eat, especially aphids that are infesting goldenrod plants.

Black ground beetles may look bad but they eat slugs.


American carrion beetles are natures garbage collectors, consuming dead stuff.

These American carrion beetles are tricked by a smelly stinkhorn mushroom.

The beetles will help transport the mushrooms spores to new territory. Many plants use the same trickstinky flowers encourage flies and beetles into performing pollination services. 49

Dung beetles clean up critter poop

Burying beetles serve as natures undertakers, digging underneath small dead animals like mice so they fall into a hole, and then covering up that critter so they can feed in safety and comfort.

These brightly-colored burying beetles are checking out a dead squirrel body.


And then weve got our bad bugs like aphids

Aphids are really tiny little bad bugs.

Aphids suck the nutritional juice straight out of plants. Their mouth is designed like a straw

Aphids are a real problem when they become abundant, cutting down on plant productivity if not killing them.

This beautiful little moth, the squash vine borer, might not be welcome in the garden

Squash vine borer moth larvae burrow right into the squash vine

Affected squash plants soon wilt and die.

There are a couple of ways to help avoid damage from the squash vine borer. In NE Iowa we can cover up the squash plants while they are small. That helps the plant get started and produce some fruit before the borer can kill the plants. Take of the row cover when the first flowers start to appear. Crop rotation, secondary plantings, simple traps, insecticides, and physical removal of the larva are other steps that gardeners can take to deal with this pest.59

The Colorado potato beetle is another common garden pest, also called the ten-striped spearman.

They became a pest in Colorado during the 1800s when the beetle decided to start eating potatoes rather than its normal host, the buffalo bur plant. Now they prefer potatoes, but they will also prey upon eggplant, peppers, tomatoes, and other solanums.60

Colorado potato beetles & their larvae eat potato plants.

Colorado potato beetles can be very prolific.

There are usually 2 generations per year in the northern Midwest.62

Colorado potato beetle eggs are laid beneath potato leaves and are yellow.


Colorado potato beetle larvae get fat fast feeding on potato leaves.

The larva are awfully gross, glistening things. They are one of the few bad bugs that I dont enjoy squishing. The older larva are responsible for most of the damage.64

Potato plants look like skeletons after Colorado potato beetles are done feeding.

Management is difficult. Insecti