Invaders of the Home & Garden
I’ve found them in the garden sucking the juice out of my once perfect peppers and sauntering on my kitchen counter. There’s no escape from the brown marmorated stink bug. These shield-shaped insects are a mottled grey and brown with white markings on the rim of their abdomen. Their antennae bear white bands, which distinguish them from other types of stink bugs.
Originally from Asia, the brown marmorated stink bug (Halyomorpha halys) first came to Canada in 2015. They arrived in the US in in the late 1990's and have become a serious agricultural and ornamental plant pest. They feed on more than 100 different plant species and are a threat to orchards and vineyards. No wonder they are also referred to as ‘the devil’s thumbtack’. Their more common and smelly moniker 'stink bug', refers to the unpleasant odor they produce when threatened and when crushed.
Life Cycle
There are many plants in British Columbia that act as hosts to this serious sucking insect pest. From fruit trees, ornamental plants, vegetables, grapes; its diet is vast and varied. B.C. has lost millions of dollars in revenue from damaged grape and apple crops.
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Stink bugs overwinter in buildings and are often seen inside homes when they emerge in early spring. Adults lay up to 400 eggs during the summer, which hatch in 4 or 5 days. Look for clusters of their white or pale green tiny eggs on the underside of foliage and along plant stems. Upon hatching, they grow through 5 nymph stages becoming bigger with each instar. The dull reddish - orange and yellow markings of the nymphs are lost when they become adults.
Because of our wet, cool climate, there’s only one generation a year, however in some locations of the USA, there are two a year. In Asia, where they originate, there could be up to 6 generations. Stink bugs like it hot and dry so if our summers continue to be drought ridden, the stink bug problem is going to get worse rather than better.
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Symptoms
It’s not just the adults that suck the sap out of plants, the nymphs do too. Look for small pale blemishes, depressions, callouses or dead areas on fruit and veggies. The foliage becomes pale with yellow and white blotches followed by wavy, curled and distorted leaves. Some will have dead patches before they drop to the ground.
Controls
Luckily, we have a few beneficial insects that prey on stink bug eggs such ladybugs, spiders, lacewings and red velvet mites. When infestations are severe, spraying stinks bugs them with soap and water is warranted, however, keep in mind that it will kill the good guys too. Surprisingly, bats, cats, and insect eating birds such as black-cap chickadee, cardinals, bluebirds and wrens feed on this foul smelling insects.
If you are not squeamish, wear neoprene or rubber globes to pick them up and dispose them in some soapy water or just squish them (ick!). They don’t bite, nor sting but you don’t want their smell on your hands and their remnants may cause irritation with some people.
Another option is to suck them up with a vacuum cleaner – inside and outside the house. Empty the vacuum immediately as their odor will linger and their residue may stink up your home.
If you are not squeamish, wear neoprene or rubber globes to pick them up and dispose them in some soapy water or just squish them (ick!). They don’t bite, nor sting but you don’t want their smell on your hands and their remnants may cause irritation with some people.
Another option is to suck them up with a vacuum cleaner – inside and outside the house. Empty the vacuum immediately as their odor will linger and their residue may stink up your home.
Biological Control
Luckily, when the stink bug left Asia, so did its predator, the samurai wasp. This tiny parasitic wasp lays its eggs inside the eggs of the stink bugs, killing them in the process. Populations of the samurai wasp are still relatively low in British Columbia, however the U.S and Italy are breeding and releasing them. The University of British Columbia have not released any but they are researching, studying and encourage feedback from the general public to report stink bugs and any parasitized eggs, if found. To learn more click on UBC.
Strangely enough, I have seen lots of our local wasps buzzing around stink-bug-infested plants. I don’t know if they are doing any harm to the bugs, I sure hope so.
Strangely enough, I have seen lots of our local wasps buzzing around stink-bug-infested plants. I don’t know if they are doing any harm to the bugs, I sure hope so.
Prevention
Since they overwinter in buildings, prevent them from entering your house when the weather turns cold. Seal any cracks in the house foundation, siding, windows and doors with a high-quality silicone or silicone-latex caulk.
Look for gaps around utility pipes, outlets, and behind chimneys. Replace damaged door and window screens. Ensure the weatherstripping around the front and back doors are intact. |
Replace outdoor lighting with yellow bulbs or keep them off at night as stink bugs are attracted to the light. Store food in airtight containers and keep firewood 20 feet from the house.
If all of that is too much, consider hiring a licensed pest professional in late summer or autumn to prevent stink bugs from overwintering in your house. |