Controlling Squash Bugs

Pest Patrol:   Controlling Squash Bugs

 

 

The squash bug is one of the most difficult pests to control and the one I get the most questions about.  Infestations will make even the most committed organic gardener want to reach for chemicals.  However both organic and non-organic people seem unable to win the battle against this insect.  I've heard a lot of people say they are just not planting squash this year.  Sad to say this will not do the trick.  They will come back the next time you do plant so you need a more consistent effective plan.  The key to conquering is consistency.

 

You must know your enemy if you want to defeat it.  So a lesson on the life cycle of the squash bug is essential.  The adults overwinter in garden debris, under dirt clods and other protected areas. They lay bronze colored eggs on the underside of squash and pumpkin leaves. In our area we can have two maybe 3 generations.  

The key to conquering is recognizing the squash bug in the nymph stage.  It may be greenish, grey, or black and is much smaller than the adult.  It will molt 5 times before becoming the dreaded creature you recognize.  They are easily controlled as nymphs and very difficult to control as adults.  Most insecticides are not very effective on the adults.  Squash bugs have very few natural predators because of the odor they put off when squashed which making controlling them even more difficult.

So what is the plan of attack? Consistently monitor for eggs and adults. Crush eggs or cut off that section of the leaf or the entire leaf. Squash adults  or throw them in a bucket and feed to your ducks (they love them)  or throw them in a bucket of soapy water. 

 It's been helpful to me to follow a preventative spray program.  Every 2 weeks in a 1 gallon sprayer put  Neem oil, kaolin clay (optional) and two foliar fertilizers kelp and fish emulsion.  I spray this on squash, pumpkins, cucumber, and melons, everything in this family.  If I see any nymphs or adults I add Pyrethrin.  Be sure to use an organic form of pyrethrin.   Some pyrethrin formulas add additives or use a non-organic form of pyrethrin. Be sure to check the label.

The above mixture can be sprayed early morning or evening (to avoid pollinators) every 3 days when the bugs are present. I grow a lot of this insects favorite crops and refuse to lose the battle.  

The key is consistency.  You have to consistently do three things because you may have up to 3 generations:

• Look for eggs and remove them 
• Remove any adult squash bugs and monitor for nymphs
• Follow the preventative spray suggestions

 Only neem and kaolin clay should be sprayed as a preventative spray.    Pyrethrin should only be sprayed if you have the nymphs or an overwhelming number of adults.present.  

I hear a lot of, "I sprayed" but after learning about this pest you can see that one spray is not enough.  The key to getting rid of a pest is knowing its life cycle and when it is most vulnerable and attacking then.  Insecticides do not kill all insects at every stage.  The key is applying them when the pest is most vulnerable and when the insecticide is designed to kill.

So what's does each of these sprays do in your arsenal do?  

Neem will kill the eggs and nymphs. It is also a fungicide.  If powdery mildew is an issue this prevents it from colonizing on your leaves.  Neem must be ingested to cause damage so it doesn't harm beneficial insects.  It does not immediately kill the nymphs but interferes with their ability to molt so they eventually die.   

Kaolin clay is a deterrent not only to squash bugs but grasshoppers and other pests.  They prefer a plant without a sticky clay to munch and crawl around on.  Kaolin clay is optional.

Pyrethrin is a nerve toxin and does kill immediately but must make contact in order to do its job.  There is no point in spraying it if you have no pest to kill.

Caveli, my favorite favorite of zucchini

Other helpful hints.  Plant squash late.  When the adults emerge to lay eggs there is nothing to lay on.  Also clean all debris out of the garden at the end of summer.  Leaving plants in the garden over winter is a perfect squash bug condo to help them survive the winter.

Preventive Spray:  

Every two weeks use on all members of the cucurbite family

Spray in evening when temperatures cool down and pollinators aren't around.

Mix in one gallon sprayer with water

2 Tbsp Neem Oil

1 1/2 cups of Kaolin Clay (optional)

Kelp (fertilizer optionalP

Fish Emulsion (fertilizer optional)

Spray when nymphs or adults present:

Mix in one gallon sprayer with water

2 to 3 Tbsp of Neem Oil

1 1/2 cups of Kaolin Clay (optional)

Organic pyrethrin

The two foliar fertilizers are optional

Purchase organic sprays and fertilizers:

Neem

pyrethrin

Kaolin Clay

Liquid kelp

Fish Emulsion

One gallon sprayer

You can respray in 3 days if you still see nymphs with just the Neem and Pyrethrin;  you must also be willing to look for eggs and adults and remove them.

Healthy plants grown in a soil with plenty of organic matter.

Watermelons are also a favorite of squash bugs.