Stink Bug

Young stink bugs massing on eggs that were laid on cannabis leaves

by Nebula Haze

Various species of stink bug have been known to attack cannabis plants. They lay distinctive patches of white eggs, which hatch into small beetle-like insects and eventually grow into stink bugs. I’ve never personally encountered this insect myself, but they attack many marijuana plants both indoors and outside so I’m gathering pictures in information to help growers identify them. Stink bugs can suck the life out of flowers and leaves and love to eat seeds, but the worst part may be their terrible smell!

Note: The following pictures are by Professor Whitney Cranshaw, Colorado State University, Bugwood.org. A huge thank you to this amazing man for taking and sharing dozens if not hundreds of pictures of common cannabis bugs and other pests.

Often the first symptom most growers see is a patch of stink bug eggs on leaves. This mass of eggs comes from the conchuela stink bug (Chlorochroa ligata). Many stink bug eggs look very similar to this.

Eggs on cannabis leaves caused by the conchuela stink bug (Chlorochroa ligata)

These young red-shouldered stink bugs in Colorado have just hatched and are colonizing this cannabis plant. Stink bugs take different forms throughout their life and look different after hatching vs when they’re nymphs or adults.

These white eggs on a cannabis leaf just hatched the young of red-shouldered stink bugsNymph of a red-shouldered beetle on a cannabis leaf

Red shouldered stink bug nymph on a cannabis leaf

The nymph of a brown stink bug (Euschistus sp.)

A stinkbug nymph on a cannabis leaf of the Euschistus speciesAdult brown stink bug (Euschistus sp.)

Adult brown stink bug (Euschistus) on cannabis plant
Adult brown stink bug in hemp, Whitney Cranshaw, Colorado State University, Bugwood.org

The two-spotted stink bug (Perillus bioculatus)

Perillus predating on hemp in the afternoon sun, Melissa Schreiner, Colorado State University, Bugwood.org

Stink bugs often attack both male and female flowers of cannabis plants. They especially love to munch on seeds that are forming, like in this picture.

Stink bugs eating cannabis seeds and flowers

The following pictures were generously provided by NitroGrower. They noticed one of their cannabis plants started getting droopy with red leaves.

Red leaves droopy cannabis plant caused by stink bugs

Here are the red leaves up close. From NitroGrower: “I noticed one of my plants had some drooping leaves that were turning pinkish red.”

“After further investigation, I found Brown Stink bugs feeding on the main stem that all of the affected growth was happening on. None of the other plants were showing signs or had bugs.”

Thanks for sharing the pictures and information NitroGrower!

Get Rid of Stink Bugs on Cannabis

 

1.) Clean the surrounding area of leaves and debris

Make sure to clean any leaves or debris under the plants, and otherwise keep the grow area clean so bugs have no place to hide and nothing to eat. Outdoors, clear the area around your plant of weeds if possible.

2.) Remove or Spray Off As Many Stink Bugs as Possible

First off, before you do anything else, you want to remove as many stink bugs and eggs from the plant as possible to overall lower their numbers. Avoid swatting or squishing stink bugs as they will release a horrible smell. They also smell bad when they die, and their dead carcasses can attract other unwanted bugs like carpenter beetles, so you don’t want dead ones around. Try to collect them and dispose of the bugs far from your plants.

Before you start this step, prepare a bucket of soapy water (or water with bug killer) or other container to collect bugs where they can’t escape.

Gently remove any leaves that have eggs on them and dispose of them into your container. Spray bugs off plants with plain water using a hose or sprayer. If startled, the stink bugs may fall off the plant, so it’s sometimes possible to shake the plant slightly so some of them fall off, allowing you to catch them in your bucket.

Indoors, a vacuum can help you get started, but these bugs will leave a scent on the vacuum. Make sure to dispose of the contents of the vacuum immediately so bugs don’t crawl back out or start smelling up the house. If you can take the plants outside, a sprayer or hose is a better option than a vacuum.

It’s good to remove and collect as many stink bugs as possible before trying to kill any remaining ones on the plant.

Remove, shake or spray off as many bugs as you can, and immediately get rid of any infected leaves. Dispose of all plant matter, eggs and bugs immediately (far from your plants or they will stink up the place). A sprayer works if you don’t have a hose.

A One-Hand Pressure Sprayer is perfect for misting plants

2.) Floating row covers

Great for outdoor growers dealing with bugs that crawl onto your plants. These may not be the best choice for all cannabis growers, but these are very cheap and effective against many types of hard-to-stop bugs because they physically prevent them from getting to your plants without blocking light or using any unsafe pesticides. You can also water plants through the netting. Row covers are sometimes used to make mini “green houses” on the plants, and some growers will just drape them over the plant as they’re so light and airy they don’t really bother the plant. In addition to stink bugs, these can be good for Caterpillars, cabbage loopers & inchwormsCricketsGrasshoppersLeafhoppersLeaf Miners, and Slugs/Snails. These are much easier to use and are more effective with smaller plants, as it becomes difficult to fully cover larger plants. However, for young plants, these are great.

Floating row covers look like thin netting or mesh and provide a physical barrier against pests

3.) Be vigilant for eggs

It can be difficult to kill adult stink bugs, and even their nymphs have a protective coating. One of the best things you can do to get rid of a stink bug infestation is to inspect your plants daily and remove eggs and young bugs before they get out of hand.

4.) Neem Oil

Neem Oil is safe, organic, and effective at many bugs but just as smelly as the stink bugs. It’s relatively effective against eggs and very young bugs but older stink bugs have a protective coating that makes them difficult to kill with any typical insecticide. That’s why so many of the solutions for stink bugs are focused on killing them and stopping them from getting on your plants in the first place.

Never allow neem oil to touch any on your buds as it will permanently affect the taste and smell in a very negative way, and is not healthy to ingest. If used as directed, neem oil won’t hurt humans, animals, or most “good” bugs like bees, ladybugs, predatory wasps, etc. You will need a mister (also called a “One-Hand Pressure Sprayer”) to spray all the leaves evenly since neem oil and water can separate easily.

Use neem oil right before the lights go out (or the sun goes down) so it doesn’t burn your leaves.

Get Neem Oil Extract on Amazon.com!  A One-Hand Pressure Sprayer is perfect for misting plants

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