Saturday, August 16, 2014

Good Plant, Bad Bug

I hadn't intended to tackle this job today, not at all, it really could have waited, except that I found out that it couldn't. This part of the main path through the vegetable garden is still wood chips and plenty of things like to grow in wood chips. For the most part I keep the weeds pulled but I like to allow the bloomers that attract beneficial insects to volunteer here. Earlier in the year it was home to chamomile, then the Olive Leaf arugula which volunteers all around this end of the garden started to take over, and then my perennial favorite Sweet Alyssum filled in the gaps. It was getting to be a bit crowded, but I could still get through and the good bugs were feasting on the flowers.


This afternoon I was poking around in the alyssum to see what the sow bug population was like because they like to hang out in there during the day and when there's lots of them I toss in a little Sluggo Plus. The sow bugs weren't too bad but I spotted a bug that sent me inside ASAP to do a little research, I had a feeling... Oh crum, I guess it was just a matter of time before it showed up, the new bug turned out to be a nasty invader from Africa called a Bagrada Bug (Bagrada Hilaris). I had seen the pest alert issued by UC and I had also been contacted by caper grower in southern California who had a terrible infestation that ruined her caper crop. This bug's main host is anything in the mustard family. It feeds on many cole crops and other cruciferous plants and it's a huge agricultural pest where it has become established. It has already been found in Monterey county where I live but I hadn't seen it in my garden until today.

Bagarada Bugs doing IT (you know, IT)

It turns out that one of the plants that they are very much attracted to is Sweet Alyssum (I had no idea that it is in the brassica family). Indeed, one of the management techniques recommended by UC is to use traps baited with Sweet Alyssum. When I took a look at the Alyssum plants in the path I found scads of these bugs of all ages, adults were mating, little red nymphs were running for cover, they were EVERYWHERE. 


So I promptly mixed up a sprayer full of Pyganic/Insectcidal Soap mix. Pyganic is a pyrethrum based organic pesticide and the UC Bagarada Bug Management Guideline suggests that pyrethrum based treatments may suppress the adults. As I pulled the Bagarada Bug infested alyssum from the path and stuffed them into the big plastic bag that you see in the first photo I also took aim at all the BB's I saw and gave them a good spray. I also put the arugula into the bag because that's another plant that the BB's like to feed on. However, I did leave two clumps of alyssum as trap plants in the main path and the outside path where I had found more of the bugs. I've looked around the garden and so far I'm not seeing any of the bugs on the cruciferous plants in the garden. If they love the alyssum so much I'll leave a couple of plants to grow and I'll be checking them every day and eliminating any bugs that I see. I also checked my caper bushes and didn't see any in there either. It seems that the BB's prefer warm spots and they were loving the alyssum that was growing up against the walls of the beds that get full southern exposures. 

It saddens me that I'm going to have to limit the growth of Sweet Alyssum in my garden. It is a pretty plant and has been a reliable grower year round and is also very attractive to beneficial insects. Too bad it is also extremely attractive to one really bad bug.

8 comments:

  1. Hmmm. That is a severe blow for you, but it's good that you found out before the bugs got round to eating your vegetables. Globalisation of our food supply must surely have introduced numerous pests that we hadn't previously had to contend with. By way of compensation though, at least we have the internet so that we can research what they are and how to deal with them!

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  2. Oh no! Thank you for showing the picture of the bad bug, never seen one before and hope not to see one in the future. Good thing you catch it before they do massive damage to your crops.

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  3. Oh ick that is too bad. I love sweet alyssum. It lines my brick path in the garden. It just grows so happily without me even planting it or doing anything. And I never knew it was a crucifer either. I guess it makes sense with its flowers. I always knew wallflowers were but not alyssum. It amazes me that I miss things like that sometimes. When I found I couldn't even touch the solanum family, I found out petunias were in that family. I had known nicotiana were, but petunias to me don't have flowers that look much like the rest of their family to me.

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  4. What a shame - It's so disheartening when you have to pull a loved plant because of a bad bug. I'm glad that these bugs are so attracted to the alyssum that you can at least keep a few as a trap crop - hopefully they will continue to do a good job in keeping them away from your veg.

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  5. In Southern CA, we've had infestations for a while now, so I've landed on one strategy that works for me: I cannot grow ANY brassicas in warm weather. Kale, collards, etc all are devasted in days when a flush of bagradas happen. Bagradas don't attack in the winter, and we have temperate winters, so it's the perfect time to grow sweet-tasting brassicas. Most of my fellow gardeners who try to grow perennial brassicas through the summer and who have used organic pesticides have found no success with them. I hope you have better success than they've had. Good luck. This bug is a bully.

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    1. Thanks for the tip. It's going to be interesting to see what happens as we move into fall since that's the warmest time of year here. I'll be keeping a sharp eye on my brassicas, especially the new ones that I will be setting out soon. So far I've only found the bullies in the alyssum and only in the warmest parts of the garden up against sun warmed walls - I hope it stays that way.

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  6. This is one I haven't seen, thank goodness. Hopefully it won't take hold here because of our cold winters. We had an invasion of Southern pests like green stink bugs and tortoise beetles, but two nasty winters in a row and I have not seen any this year.

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  7. We had those last year (in Las Vegas). I grow my brassicas in winter and the bugs showed yup when the plants were done, thank goodness. As soon as i got rid of the plants the bugs were gone.

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