Harlequin bugs

[morgan]

I'm seeing lots of harlequin bugs on various brassicas that regrew from last falls crops. 

and egg cases

Anyone else have experience with a harlequin bug invasion?  Any suggestions on how to deal with them? 
I've been using the plants for early greens, they are now all starting to bolt but I'd like to still get what harvest possible from them, however would it be best to get rid of them all immediately or leave a few as trap plants so the bugs do not as quickly move over to the new cabbages, etc. ?  Any known specific predators? 

[Jason Akers]

I'm thinking what you are doing is the best approach for now.

Remove the eggs at once.  Mechanically pick and destroy the adults.  

I do not know of a specific predator insect for harlequins.  I'm not even sure if birds will eat them (probably) because they are so closely related to stink bugs.

And yep I'd leave these as trap crops through the flowering and everything.  No telling what the flowers will bring in for you as well.

Jason

[morgan]

Thanks Jason, I'll be patroling with with a yogurt container filled with soapy water for adults and eggs and keeping an eye on flowers to see what else shows up!

[Jim]

Harleys can be nasty on brassicas/mustards and they go after tomatoes, corn, beans, and peas.  Agree with Jason, and I might go a bit further depending on your situation:  

  If you are not planting brassicas, mustards, tomatoes, corn, beans, and peas near the problem area then let them flower.  You created a super trap crop.  You are also looking for parasitic wasps and flies to come in and control the future generations this season.  I would also plant other small-flowered plants to ensure the beneficials come in strong (like Jason always says).

  If you are planting new brassicas/mustards, tomatoes, corn, beans, and peas anywhere near the existing ones:

• Hand-remove all adult/Nymph Harlequins (not much can predate them due to semi-hard/hard shells)
• Hand-remove all eggs you find, regardless of type (no time for fast beneficials)
• Remove all brassicas material, mulch, and weeds that are in the block or small bed (if it is manageable)
• Plant your new plants and cover with floating row covers (like agribon or reemay)
• Grow your brassicas under the cloth most/all of the season this year (Harleys tend to make 2 generations or more a year)
• Plant small-flowered plants on the borders or inter-planted and don't monocrop if you can avoid it
• Keep your brassica beds weed-free since Harleys live in and around them as well

  If the Harleys come back hard again, the following can be used, but they can kill beneficials as well, so only apply to known problem plants:

• Garlic spray with some added dish soap (homemade or bought) <-- I use this outdoors
• Insecticidal Soap (homemade or bought) <-- I use indoors
• Canola or Veg Oil-based Horticulural Oil (sometimes called Dormant, Summer or Superior Oil) <-- I use this when bees are not around
• Kaolin Clay Spray (sold as a powder then mixed with water)  <-- I have never used this but some friends like it

You can find the above sprays at many garden stores and can be OMRI-compliant if you go down that path.  If you are looking for a more dark-side approach,  look into Petroleum-based Dormant/Superior Oils, Pyrethins, Rotenone, Spinosad, Neem Oil, Beauveria Bassiana, and a complete last-resort Sabadilla powders (this stuff is downright terrible) but nuclear option.  Most of these can kill the good guys including bees.  

[Jason Akers]

Like Jim said they overwinter in the garden.  Would it not be awesome to be able to tractor chickens over your garden all winter and let them scratch the little buggers out of the ground?  That is my plan with my kitchen garden once we get moved.  You gotta feed your chickens anyway!

They are pretty bugs though.  But I aint dealin with em.  LOL

Jason

[morgan]

Thanks Jim, lots of options to consider...

What distance would be considered "near"?  I have cabbage, kale, and rapini about 15 feet away.

Perhaps this is the year to invest in row covers.  There is also a population of cabbage loopers, altho the damage from them in previous years has been fairly minimal and tolerable.
 
The last few years I've been keeping the entire garden pretty well constantly mulched. That and the exceptionally mild temperatures may have contributed to the Harleys overwintering so well. Had a few last year, but nothing like the hordes showing up now.  Today I cleaned the row of turnip greens where most of the Harleys were hanging out except for about 5 interspersed plants, raked the mulch away and worked the soil with a stirrup hoe, catching any bugs that could be seen.  Would it be advisible to keep the area where the Harleys are seen mulch (straw) free ?

Several arugula and mustard plants are currently flowering, will let those go to seed.  There are also quite a few flowering herbs on the edges and scattered about the garden, but none are blooming as yet.  Part of this years plan is to continue to increase the number & diversity of flowering plants / herbs. 

I was not aware they went after tomatoes, corn, beans and peas also.  That's motivation to do whats possible to control the population!
I've used insecticidal soap with some success previously.  The Kaolin clay spray sounds interesting, never heard of it before, but do have a large bag of kaolin on hand. 

It would indeed be awesome to have chickens to tractor over the garden! 

[Jim]

What distance would be considered "near"?  I have cabbage, kale, and rapini about 15 feet away.
Would it be advisible to keep the area where the Harleys are seen mulch (straw) free?

Both questions unfortunately can only be answered in generalities.  The most distance the better.  Providing less habitat for Harleys is better.   That said, it sounds like just doing what you're doing is going a long way to solving a lot of problems, as in you may lose the battle but win the war.  If you can, create a perimeter of flower plants into that area.

What I would do (if it is even possible) is plant an insurance crop patch way away from this area if you can, while you are guiding beneficials into the older patch.  If you do not have the space/time to do that, I would keep fighting the battle with mechanical controls (as you/Jason already said), and escalate to spraying infected plants area directly.  Row covers are a great thing too if you do get them. 

[Brian Ring]

Sorry I am kind of late to this post, but wanted to make sure to pass on one this, If they are eating your cabbage or anything brassica they become poisoness to all birds.  I don't know how much, but I know that because of this none of my chickens would eat them.  I put a whole tray full with them and they ran from them.