How to get rid of Brown marmorated stink bugs?

What are brown marmorated stink bugs?

Brown marmorated stink bugs are a type of pest that pierces the host plant to feed.

This can lead to big problems such as dimple formation on the fruit surface, seed loss, and transmission of plant pathogens.

During winter time, the stink bugs shield themselves from low temperatures by creeping into our houses.

They can hide between walls and even in attics.

Although the name includes “brown”, there are also green stink bugs as well. Both bugs have a shield-shaped body.

My first encounter with these bugs

A few days ago I noticed some orange spots on the leaves of one of my Meyer lemon trees. I noticed the odd spots straight away as the leaves are generally a green color.

The spots were mainly present on some of the higher branches so I couldn’t see them very clearly.

It wasn’t until I zoomed in on them using my iPhone camera, that I realised that these were baby brown marmorated stink bugs (aka nymphs).

I didn’t notice these bugs when we first moved in over a year ago. However, I do recall dismissing the trees as low maintenance, as we were just settling into the new area/environment.

Yes, this is probably an excuse…so this year, I have committed myself to do something about the infestation.

A primitive solution

Initially, with a fallen twig, I brushed them off the branches and onto the ground and (sorry!) smashed them with a large stone.

It sounds cruel, but I wanted to make sure they didn’t return and harm the lemon tree.This is certainly a primitive solution and very time-consuming.

After dealing with a couple of nymphs, the next step was to combat the adult bugs, which are brown in appearance. These were present in larger numbers than the nymphs!

This time, I didn’t want to spot and kill them one by one. Instead, I googled “how to get rid of stink bugs”.

Quite a few promising methods popped up, but I wanted to find the most humane and organic method to solve this problem.

In the end, I decided to go for a Neem oil spray.

Neem oil sprays work on garden pests

Neem oil is a natural pesticide produced from the seeds of Neem trees. This wonderful natural oil can also kill aphids, which generally infest and cause problems with roses.

Neem oil works through the bitter taste it produces, deterring pests.

It is not harmful to beneficial garden insects such as bees and ladybugs unless sprayed on directly, and thus is a humane solution.

So, how do you make Neem oil spray? Well, it’s super simple. All you need to do is grab yourself the following ingredients:

Neem oil spray recipe (1 litre of solution with a 0.5% dilution)

Left to right: Neem oil, incecticidal soap, 1 litre of warm water, measuring spoons, clear bottle, spray bottle

① 　A clean clear plastic spray bottle (can be a coloured bottled as long as it’s transparent.)

②　5ml (1 tsp) of Neem oil (pure cold pressed)

③　A clean clear plastic bottle (such as from a water bottle)

④　1 litre of lukewarm water ( around body temperature; to allow the solution to mix well)

⑤　1-2ml (1/3 tsp) insecticidal soap (optional, but can double the effect!)

Side note:

Insecticidal soap is based on potassium fatty acids and is used as a pesticide for many plant pests. It only works on direct contact with the pest and is most effective if it’s dissolved in soft water*. There is much more to say about this miracle soap, but maybe another time!

Tap water

It can be placed on a spectrum ranging from hard water to soft water and can vary depending on where the water comes from. Soft water is typically low in ions of calcium and magnesium, which is necessary for metabolism in our organisms.

The lack of these ions potentially leads to many health issues. As opposed to soft water, hard water is high in ions of calcium and magnesium, which can cause scale buildup in pipes and reduce the effectiveness of soap and detergent.

Now follow these simple steps;

①　Pour the Neem oil, insecticidal soap and water into the plastic water bottle and stir well

②　Pour the mixture into the spray bottle

③　Apply solution to infested leaves/area (make sure to spray both top and back surface of leaves)

④　Please be aware that you should use up all of the solution in one go as soon as it’s prepared as it will lose it’s effectiveness if left in the spray bottle. (Do not leave it more than 2 hours)

This neem oil solution won’t kill pests instantly, so you will need to be a little patient. It will take about a week or so to start seeing the effects of the spray. This is because it is not a chemically driven pesticide, but an organic oil (which I personally prefer).

I’ve sprayed this solution on our lemon trees just twice, and the presence of the stink bugs has reduced dramatically. Instead, more lemons have begun fruiting from the trees!

Check out my other article about “Identifying Pest and Disease Problems (Part 8 of 11)“, one of Horticulture articles.