Linda Tomlinson

Linda Tomlinson

Gardening: How predator insects can help with houseplant pests

Insects choose to live on plants that are already weak or struggling. They could be stressed from the incorrect amount of light, poor watering, lack of accessible nutrients or incorrect temperature.

Large greenhouse operations utilize computerized systems to ensure that plants have an optimum environment ensuring that they grow quickly and are ready to sell as quickly as possible.

Stores, buildings and homes are hard pressed to provide the same environment. By the time a plant has been shipped, set up in a store and sold it has become more inviting to insects. The tiny insects are hard to spot and can catch a ride on people, air or machinery.

Isolating a plant as it comes into the house helps to prevent insects moving between plants.

Placing plants in the correct lighting and putting them on a feeding and watering schedule makes for healthier plants as it can help avoid under or over watering plants.

Checking for insects regularly makes it more likely that the insects will be found and dealt with before the insects spread to other plants.

Once detected, a plan should be made and followed to eradicate the creatures. Discard any plant that is sickly and covered with insects. It isn’t usually worth the effort to try to save it.

If all stages of an insect’s life cycle, eggs, larva and adults, stay on the foliage, removing and disposing of the foliage will remove most of the infestation. Healthy plants usually have the resources to regrow their top growth.

There are various sprays on the market that are licenced for the use of houseplants. Be sure to read the label carefully and follow the instructions. Expect to repeat the process a number of times due to the eggs hatching.

Predator insects are an alternative and have been used in greenhouses for decades. Packages of predators are available at larger garden centers or online. Not all insects are available year round and some that are used in greenhouses and on outside crops are not suitable for buildings and homes.

Ladybugs hippodamia convergens are the best known predator insect for a good reason. They are not fussy eaters and the adults and larvae will feast on most insects, eggs, larva or adults.

Unfortunately, ladybugs are usually only available during the spring and summer months.

There are a number of different types of predator mites that will survive and thrive in an indoor environment. They are often used to rid and or control two spotted spidermites. The type of predator bought depends on the heat and humidity of the house as well as the predator mites ability to penetrate the two spotted mite’s webs.

Nematodes are thin worms that feed on eggs and larva in the soil. Indoors they are mainly used to control fungus gnats and thrips.

Predators will die out when their food source becomes scarce.

When purchasing predator insects, identify the problem insect and find the best predator available. It is hard to ship adult predators which means that often they come as larva or eggs. How fast the creatures mature and are able to feed on the offending insect population is determined by how fast the infestation can be stopped.

The earlier the infestation is discovered and treated the fewer insects need to be removed, and easier it is to successfully treat the problem.

Linda Tomlinson has gardened in Central Alberta for over 30 years. She can be reached at

Be Among The First To Know

Sign up for a free account today, and receive top headlines in your inbox Monday to Saturday.

Sign Up with google Sign Up with facebook

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

Reset your password

This site is protected by reCAPTCHA and the Google Privacy Policy and Terms of Service apply.

A link has been emailed to you - check your inbox.

Don't have an account? Click here to sign up