Biological control graphic

I found this unused graphic while cleaning out a 'pictures' folder on my computer. 

Releasing ladybugs!

In the past few weeks I've been working on part three of my attack on the aphids byt releasing ladybugs and parasitic wasps in the greenhouses.  It has been fun!

The ladybugs come from A-1 Unique Insect Control.  They came in a loosely woven cotton bag and were kept in a fridge prior to release.  I sprinkled them over the greens concentrating on areas that I knew had lots of aphids.  Once they warmed up the ladybugs became very active and few all over the place (even up my pants!).

Ladybugs are aphid eating machines, supposedly. I've tried really hard, but have yet to see any I've released actually eating an aphid.  The aphid population has decreased, so they must be doing something.  Eventually they settled down and then seem to spend all their time in warm spots.  Like the edges of trays or the sunny side of the greenhouse.

Attack on the Aphids

There were so many aphids in the greenhouse it was almost embarrassing.  Remember the pictures of leaves covered in aphids?  It was about time I did something to stop them. 

Goodbye greens!  This cart full of plants contained the very worst of the aphids.  So they got thrown out in the blue dumpster.  (Usually I compost everything, but the road to the compost pile is too mushy to drive on right now.)

Luckily the aphid infestation is in the non-organic certified greenhouse.  So, we sprayed two types of pesticide (by 'we' I mean the farm manager did the spraying).  The cocktail contained one part Botanigaurd and one part Azatin.  

BotaniGaurd is a mycoinsecticide, meaning spores adhere to the host and produce enzymes that dissolve the hosts cuticle.  

Azatin is an insect growth regulator.  When an aphid (and many other insects, fish and aquatic invertibrates) comes in contact with the pesticide it interferes with with the organisms ability to molt, thus killing it.  This is a pretty typical kind of pesticide.

Next week I'll release two beneficial insects: ladybugs and parasitic wasps.  They will control the aphids on a long term basis.  (The picture above is neither of these.  It's just an ordinary wasp on goldenrod.  I don't take many insect pictures.)  I'll write about them in detail next week when they get released.

Attack of the aphids

Last week I announced that there are aphids in the greenhouse.  By now there are more, lots more and we have begun a three-pronged attack on them.  But first, it's important to know just who we are dealing with.

The foxglove aphid, Aulacorthum solani, has a huge range of host plants and can transmit 45 diseases, so it's pretty bad.  The adult aphids are 1.5-3 mm long and are dull green or brown.  Their antenna are longer than their body and have dark joints.  Their legs also have dark joints and their cornicles are dark at the ends.  The picture below (which I did not take) shows all these characteristics really well. 

Photo taken by Andrew Jensen (aka Aphidman)

They like to colonize deep in plants on tender, young leaves.  I definitely found this to be true.  See how gross the young spinach leaves look?  What really kept me up at night is the reproductive rate of these aphids.  In just THREE DAYS the population doubles in a 55 degree environment.  How could I sleep when I knew aphids were busy multiplying that fast?  Happily, we've started attacking the problem.  You can look forwards to the next installment of "Attack of the aphids."

Sources: AphidID, Jandricic et al., 2010, RIS

Aphids in the greenhouse

Aphids are a common problem, so it was just a matter of time before some wondered onto my greens.  At least that's what I'm telling myself now that I've found some lots.  Aphids are in the Homoptera order of the insect family.  Their distinguishing characteristic are two exhaust pipes, called cornicles, on their butts that secrete a warning scent when they are being attacked.  My camera is not powerful enough to take a picture of the cornicles, but you can see them here.