by Leslie Cox; Friday; June 9, 2017
I wrote about this pest in my latest Duchess of Dirt column in the June 8th edition of the Comox Valley Record newspaper.
This blog article is a follow-up with more information and more photos.
(View my column article at: http://www.comoxvalleyrecord.com/community/garden-pests-are-back-with-a-vengeance/)
In my newspaper column, I bemoaned the damage being done to two of our azalea shrubs at the edge of the driveway. The shrubs were being hit especially hard by the larvae of the tiny azalea sawfly…a black, fly-like insect which is only 0.3 inches (8 mm) in size.
There are two species of azalea sawflies, Amauronematus azalae and Nematus lipovskyi. At the larval stage, it is virtually impossible to tell the difference between the two species…and even hard to properly identify at the adult stage apparently. (FYI: The entomology department at Oregon State University has positively identified the azalea sawfly in their state as Nematus lipovskyi.)
Proper identification aside…the newest leaf growth on our two shrubs are being horribly decimated by small green sawfly larvae. And eradication is difficult.
Most resources recommend hand-picking. But that is difficult…even if you are not squeamish. The green colouring of these blighters blends in perfectly with the leaves, as you can see in the photo to the right. You really have to focus on each leaf to determine if a caterpillar-like creature is attached.
Okay. I know you are probably thinking ‘look for a chewed leaf and you’ll find the culprit’. Yes, you might. But then again you might not. Not all chewed leaves have a sawfly larva on them and those that do…well, it is easy to miss the pest.
Reading this sounds loony, doesn’t it? But it does explain how very difficult it is to see the pest larvae. Trust me. My husband and eldest daughter, Jacqui, scoured the two shrubs looking for azalea sawfly larvae. (Dad was giving Jacqui a photography lesson on how to use her new camera.) Surprise! They couldn’t find any larvae to photograph.
So Mom stepped in. Well…there’s one, and another, and another, and another one…two over here, and another one over here.
(Can you spot the sawfly larva in the upper right corner of the photo above?)
Point is: once you know what to look for, your eyes become accustomed at spotting the larvae so you can pick them off and destroy them…either by squishing them, stomping on them, or dropping them in a container of soapy water.
Click on the photos in this blog to have a closer look at this pest. You do want to get rid of the larvae to cut down on the numbers of adult azalea sawflies next year. Thankfully, there is only one generation per year but the larvae will be dropping into the soil to pupate…if they have not done so already. I plan to try yellow sticky traps next year to catch the adult sawflies before the females have a chance to lay their eggs on the underside of the leaves.
Note to Self: Set out sticky traps at the end of April to catch the sawflies emerging in May.