I know carpenter bees are big and mostly black and dig holes in dry wood for their homes. Don't know what you have.

In general, bees do not sting apples and fruits. But other insects do. Some wasps are attacted to sweet fruits. notably plums. A common pest is the yellow jacket, a wasp. These have been known to enter an open sugared soda bottle, so be careful while picnicing outside.

The bumble bee likes large blossoms and visit such for nectar. They do not sting the wood. In fact, true bees do not use their stinger except for defence because a bee dies after stinging an animal. The stinger has barbs and it pulls out of the bee with a venon sac attached. The sac continues to pump venon until it is exhausted, but the bee will die after loosing its stinger.

There are other insects that have an ovidepositor that can deposit eggs under the bark of trees. These are not stingers.

To sort out your questions, you will need to identify the insects you are observing. If it unnerves you to get very close to bees and wasps, use a pair of binoculars to obseve from a distance.

Most bees are non-agressive and attack only when threatened. However, africanized bees are a different matter. They can be agressive and dangerous. Use caution if you live in an area where these bees have invaded.

Here is a site that describes and shows pictures of what you most likely have happening:

http://www.whatsthatbug.com/2009/07/22/bald-faced-hornets-and-magnolia-scale/

Here is a link that might be useful: Hornets and magnolia scale insects

Thanks kay thats what it is...every year for 3 years ba;ld faced hornets built a nest somewhere in our yard.one tyear i was watering fruit trees,there was a nest in a[pple tree they came after me i ran they got in my hair.theyre nasty,some of the bees on tree are bald favced but there are others.sorry ifor mistakes cant erase ,my son is gonna fiwx it this weekend thanks kay.

Kay is exactly right. Many different kinds of insects are attracted to scale insects. It would not be unusual to see wasps, hornets, even butterflies, and many others fighting over some of the sweet honeydew excreted by the scale.