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#3 - Ohio's Beneficial Bugs!
#2 -
Plant Myths Debunked #4 - Organic Plant Care
#5 - Rufous Hummingbird
Predators, Parasitoids, and Pollinators
Ohio's Beneficial Bugs!
This scholarly research article is provided to you by the Ohio Nursery & Landscape Association.
When we think about insects in our Ohio landscapes we often think of pests, like the mosquitoes that attacked at a recent barbeque or the cucumber beetles that helped themselves to garden plants last summer. Insects can definitely be pests, but there are also many insects that provide us with important benefits. These beneficial bugs include predators and parasitoids that kill insect pests and pollinators that facilitate the production of many fruit and vegetable crops. Many of these good deeds go unnoticed in home landscapes, so in this article we are going to highlight some of these important beneficial arthropods.
About Natural Enemies

These are organisms that provide pest control. Natural enemies feed on insect pests such as aphids, thrips, caterpillars, and beetles that damage crops and landscape plants. There are three main groups of natural enemies: predators, parasitoids and pathogens.

Predators will kill and consume many insects within their lifetime. These arthropods can be found throughout a home landscape: on plants, on the soil surface and below-ground. Some arthropod predators specialize on one type of insect pest, while others are generalists and will consume many different types of prey. There are many types of arthropod predators including beetles, true bugs, lacewings, predatory flies and spiders. The second group of natural enemies is the parasitoids, which have a very unique life cycle. An adult female parasitoid spends her time looking for insect prey to provide food for her offspring. When a female finds a host, she will lay one egg, or more, either on or inside the body of the insect. These eggs hatch and the parasitoid larvae consume the host insect, eventually killing it.

The majority of parasitoids are either wasps or flies. Pathogens are the third group of natural enemies. Like humans, insects can be attacked by many pathogens. Insect pathogens include bacteria, viruses, and fungi. Below, we discuss several important arthropod natural enemies.

Meet the Lady Beetles
Ladybugs, or lady beetles, feed on aphids, scales, mites and small caterpillars. There are many species of lady beetles present in Ohio, including both native and introduced , exotic species. Lady beetles have four life stages: egg, larva, pupa, and adult. Eggs are laid in clusters on plants; they are oval and bright orange in color. The larvae are alligator-like and spiny. Lady beetle adults are round or oval in shape (3-8 mm) and often have brightly colored wing covers with dark spots; however, some species have black wing covers with light spots or no spots at all! Below are pictures of two species you are likely to find in home landscapes. To find out more about lady beetles and download an identification guide to Ohio’s lady beetles, visit our website:

True Bugs
These are a group of insect species that includes both plant feeders and predators, all true bugs have a straw-like mouth, and predatory species pierce their prey and then suck out he liquid contents. There are many important true bug predators which are commonly found in home landscapes. These range in size from the very tiny minute pirate bug (2-5 mm) to the wheel bug (20+ mm). These insects will consume a diversity of prey including insect eggs of many pests, aphids, caterpillars such as corn earworm, and many beetle larvae including Colorado potato beetle.
Minute Pirate bug
Wheel Bug
These insects get their name from the intricately veined wings of adults. Adults (12-20 mm) are slender bodied with four net-veined wings and long antennae. They lay their eggs on thin stalks; it is thought that this prevents the voracious larvae from consuming their un-hatched siblings. Lacewing larvae are grey to brown in color
Predatory Flies
Not all flies should be swatted. Actually, some species are very beneficial. Hover flies actually provide two services in home landscapes, the adults are pollinators and the larvae are natural enemies. Adults resemble bees and are typically black with yellow or orange stripes or patterns. These flies get their name because they are often found hovering over flowers. They can be separated from bees by having only two wings instead of four. In addition to visiting flowers, female hover flies also spend time looking for aphid patches to lay their eggs. When the eggs hatch, slug-like larvae provide pest control by feeding on aphids.
Hover Fly
What lurks in your basement may not be all bad. Spiders, a relative of the insects, are very voracious predators of pest insects. All spiders are predators, and the vast majority are generalists that will feed on whatever they can catch. Spiders attack their prey in different ways. Some spiders are active hunters which do not build webs. These spiders hunt on plants or on the ground. Some, like crab spiders, sit and wait for prey to come to them with legs outstretched ready to grab anything within reach! Other species like wolf spiders use visual and vibrational cues to know when prey are close by. These spiders are fast moving and can catch and kill many types of insect pests.

There are also many types of spiders that use webs to capture their prey. It is often times easier to identify them by their web than by the

Wolf Spider
Orb Weaving Spider
spider! The webs produced by spiders are extremely variable. Orb weaving spiders build the ‘characteristic’ spider web: large, round, with a circular grid pattern, funnel weaving spiders build a funnel-shaped web. The spider will hide in the funnel and wait for unsuspecting prey to land. Some spiders, like cobweb spiders, even build irregular, messy webs.
Wasp Parasitoids
These are a diverse group, including species that range in size from the head of a pin to more than 2 inches long! All wasp parasitoids share two diagnostic features that greatly contribute to their success. First, the female wasps have an ovipositor that allows them to deposit eggs on or in the both of the host insects. The ovipositor is a modified sting, so these wasps so not sting or harm humans in any way. Wasp parasitoids also have a narrow ‘waist’ which allows their abdomens to be very flexible.
Aphid Mummies
This facilitates quick attack of active insects. Some parasitoids attack aphids. These wasps will lay an egg inside the aphid, which will develop and eventually kill it. The dead aphid will serve as a place for the wasp to pupate. These dark brown to black aphids are called ‘aphid mummies.’ Look for them in your garden as a sign of wasp activity.
When the wasps re ready to emerge as adults, they chew a hole through the ‘mummy’ and search for a mate. Caterpillars are also attacked by parasitoids. Some parasitoids even can detect potential hosts within trees. These wasps insert a very long ovipositor inside the tree and lay their egg inside wood boring tree pests!
About Pollinators
Pollinators are those organisms which facilitate flowering plant reproduction by transferring pollen grains from a flower’s anther to a stigma. While doing so, pollinators provide an enormously important service for mankind: ensuring crop production. It is estimated that one out of every three bites of food humans consume results from the work of pollinators. Many types of organisms, including birds, bats, and numerous insects function as pollinators, but bees are by far the most important.

Bees are a diverse group of pollinating insects that spend the majority of their adult lives gathering pollen and nectar from floral resources. There are about 500 bee species in Ohio alone. Some crops, such as almonds, broccoli, and asparagus, are bee dependent, and require bees to pollinate, them. Many other fruits and vegetables experience an increase in set and

Honey Bee
Bumble Bee
yield with bee-mediated pollination. Bees come in a wide variety of colors, shapes, and sizes but their basic body plan remains the same. They all have four wings, chewing mandibles and a tongue, and are generally covered with hairs, at least some of which are branched. Female bees have a sting, which is a modified ovipositor, and specialized hairs adapted for pollen collection. While honey bees and bumble bees are social, living and working together in the same nest, most bees aresolitary and nest alone. Bees call many places home, including deserted rodent burrows, tree cavities, inside stems, and crevices in manmade structures. Some will even bore through exposed wood or dig underground to create their own nest! To learn more about bees and download an Ohio bee field guide, visit our website
Attracting Beneficial Insects

There are several ways in which you can help attract beneficial insects and enjoy the ecosystem services they provide. Mulching in your garden has several benefits. Besides reducing weeds and soil erosion, mulching also provides natural enemies with alternative prey, summer shelter, and overwintering habitat. Common mulches include straw, wood chips, newspaper and ‘living mulch,’ which is a cover crop planted between rows of vegetation. You can also increase habitat by adding insect retreats.

This can be as simple as placing a bale of hay or a log in your garden, or as elaborate as incorporating a rock garden in your design. Another habitat option is to create bee nesting boxes and natural enemy retreat boxes by simply drilling holes into blocks of wood. These boxes are also commercially available.Finally, try adding floral resources to home landscapes. Not only are they visually pleasing, but they will provide beneficial insect habitat, as well as food resources in the forms of pollen, nectar, and alternative prey.