When to spray will depend on where you are and if the insect is present. You may have to consult your local university for answers. I say that because it will vary state to state. Where I am in southern WI we normally have 2 generations of coddling moths (roughly mid June and another generation sometime later in the season) and one generation of apple maggot (peak time tends to be the first 2 weeks in August).

What kind of worms? Apple maggot (railroad worm) tends to leave thin brown trails thru the fruit as the worms are tiny and come late in the season. Coddling moth larvae are large and tend to tunnel into the apple and get to the core to eat the seeds. Normally they enter thru the calyx but can drill into the apple anywhere.

Some people follow a spray chart and spray thru out the growing season on a calendar basis as a preventative measure. Others can set out traps and monitor for the pest. Red sticky ball traps can be used to monitor for apple maggot. When you trap more than 3 in a week, then spray within 5 days.

Best spray to use? Depends on what you prefer. I have tried Ortho Flower, Fruit and Vegetable insect killer with the active ingredient .5% acetamiprid and found it to work very well for apple insect control for the home grower. Available online.

I cannot help you with scale as I never had to battle it. I presume like all scale it is best to hit it in the crawler stage when they migrate out of their old shells. In my area that happens sometime mid-late May.

Thank you.

Dormant Oil twice sprayed in the late winter (for scale) when temps get above freezing in the night time. Then Captan once at green tip. Then Imidan and Captan at petal fall and every 7 to 10 days after (or a big rain washes your trees).

Let's clarify here :-)) Identification of the exact pest or problem is essential!!

'Scale' is an insect infestation. Depending on species, dormant oil may or may not be any sort of effective control - typically scale is treated while in its nymph stage and that would not be when dormant oils are are used. And Captan is fungicide, so of NO value when treating for scale!!

'Scab' is fungal problem and can be addressed with both a dormant oil spray as well as a registered fungicide applied during the early season when the conditions that promote scab are present (but never when the tree is in flower).

To know when and how to treat and with what, you need to accurately identify what the problem is. If you are unsure, post clear, in focus photos that illustrate the issues. Otherwise we are all just guessing :-)

Thank you all for at least trying to answer me. Of course, it is much too early to get pictures of the apples. The scale I speak of is my way of trying to convey what I have seen. This 'scale' looks like someone pressed a very lacy dry leaf on the apple and then dried it and glued or shellacked it to the apple. The worms, I have never seen the actual worms, but there are holes going into the apples and when you cut them open, there is a rusty looking track where the worm has been. I hope this helps some.

What you describe as "scale" sounds a lot like apple scab :-) It will affect the foliage first, showing up as olive green or brown spots that merge together to form large dark splotches. Often affected leaves will turn yellow and drop off early. Scab shows up on the fruit as tan/brown, netted looking areas, sometimes sunken, and with a corky texture. Sometimes the fruit will split along these lesions. There are lots of images online to confirm if you Google 'apple scab'. And details on how to treat as well, which will involve both sanitation and fungicidal sprays: Apple Scab.

The worms do sound like apple maggots. There are very few insecticides registered for control of these pests that are available to homeowners and most home orchardists use bagging or trapping to control the problem. Kaolin clay is also effective. Apple Maggot Control

Sandee:

Here are a few shots of damage to apples . Maybe these might look like what your apples get each year: