Biological control is the release of natural predators to manage plant-harming insects. Biologicals help greenhouses and gardeners avoid the need to use pesticide sprays and dusts! Many beneficial insects are already in your garden, patrolling for (and munching on) unwanted pests like aphids and borers.
You can also purchase sachets and egg cases of different beneficials from local greenhouse carriers. A combination of predators released at regular intervals works best in greenhouses and gardens that have a variety of plants. Listed below are the biologicals we use here in our greenhouse at Gulleys as well as a few we sell (*) for you to use in your own garden.
Aphidoletes aphidimyza is an important biological control for aphids in the greenhouse. These non-stinging flyers are tiny, a mere 1/8 of an inch, but voracious in their taste for aphids. They feed on over 70 different aphid species!
Beneficial Nematodes (*)
Beneficial nematodes are microscopic worms that occur naturally in soils all around the world. They are a natural and effective alternative to chemical pesticides, and are not harmful to non-target species like ladybugs, earth worms and other "good" garden insects. Some nematode species use an "ambush" strategy as they wait for prey to move by, and therefore work well against pests that are moving around the soil surface. Other nematode species do well fighting soil pests that are not as mobile because these nematodes are "cruisers", they actively hunt for hosts deeper in the soil.
Favorite meals include: fungus gnats, flea beetles, plant parasitic nematodes, root aphids, fruit flies, leaf miners, cucumber beetles, ticks, iris borers, and earwigs.
Predatory mites are another way to biologically control greenhouse pest populations. Hypoaspis miles is a highly effective generalist soil predatory mite, capable of controlling fungus gnat larvae, thrips pupae, pathogenic nematodes, and spring tails to name a few. Spider mites, a widespread greenhouse pest, have multiple enemies with predatory mites perhaps being the most important.
Praying Mantis (*)
An iconic hunter, the praying mantis eats almost any insect in reach. When you find a mantis egg case, there are around 200 baby mantises inside, just waiting for the chance to rid your garden of unwanted mosquitoes, mites, leaf hoppers, beetles, grasshoppers, aphids and more. Use three egg cases per 5,000 square feet. Attracted to twigs, leaves, fences, and other vegetation praying mantis egg cases may also be placed in the joins of a bush or tree. Do not place on the ground, as they become easy prey for ants. Praying mantises can start to be released after the last frost and continue through the summer months.
Did you know ladybugs can eat around 60 aphids a day? They eat many different kinds of pests like scales, mealy bugs, leaf hoppers, mites, and various types of soft-bodied insects... it's estimated that one ladybug can consume as many as 5,000 aphids in its lifetime! Due to their ravenous appetite and industrious reproductive capacity (each female can lay 10-50 eggs daily), ladybugs can wipe out problem aphid infestations. Living up to 3 years, ladybugs hibernate during the fall and winter, usually in protected logs or woody vegetation. In spring, they wake up and congregate in fields and yards to mate and look for food sources. Aside from aphids, ladybugs also require a source of pollen for food and are most attracted to fennel, dill, cilantro, caraway, angelica, tansy, wild carrot, yarrow, cosmos, coreopsis, and dandelions.
Neonicotinoids are a relatively new class of insecticides that are believed to play a role in recent pollinator declines.
Gulley Greenhouse, Inc. is concerned about the safety of these products and how they may affect pollinators. We want our customers to know that we have not used any chemical from this class on our finished perennials, finished flats of annuals, and of course nothing but oil, soap or biologicals are used on our herbs and vegetables.
We are introducing beneficial insects into our greenhouse environment to reduce the use of chemical pesticides. These insects include beneficial nematodes, predatory mites, and predatory wasps. They are safe for our consumers and our world!
We thank those customers who have reached out to us and questioned our use of any of these chemicals on our plants. If you have any questions or concerns, please do not hesitate to contact us.
The Gulley Family and Team