But don't expect the cooler weather to slow the bugs down. The twig aphids are reproducing. This typically happens right before bud break, and they are doing the same again this year. The difference is that it appears that bud break and perhaps shoot growth might take longer than normal. That means that the trees will be at their most vulnerable to twig aphid attack for a longer period of time. Also, the warm spring has allowed for good aphid survival and reproduction. It all adds up to a potentially bad year for twig aphids.
That is why I've always warned people that if you are beating the foliage and finding even a few aphids, they will reproduce and end up being a problem. Each female aphid can produce 10 to 15 live young -- making what you saw last week 10 times more this week.
Rust mites are also quite active and will remain so until temperatures really warm up.
The good news is there has also been a lot of rain, which will help the trees grow out of any twig aphid damage. The following aren't very good photos, but they illustrate my point. The first picture is of a tree with twig aphid damage in May. The second is of the same tree in July. Most of the damage has straightened back out.
|Shoots actively growing show lots of needle curl...|
|... but the mature growth has little damage.|
With as much wind as we've been having this spring, I know how hard its been to get sprays out. Just remember, that poor conditions for spraying will give poor control results. There's little need to waste time, money, and put the environment to risk by forcing a spray job under windy conditions.
Let me know if you have any questions, and good luck!