Bees exposed to pesticides do poor job of pollinating.

[Catherine]

Killer bees are a hybrid and I believe they can't exist in colder climates.

When in doubt. look it up.
https://en.wikipedia.org/wiki/Africanized_bee


I think there were problems when the  "killer" bees first happened as an accidental cross. Now that they have established themselves we don't hear much about them.  If someone was attacked they must have made the hive feel threatened. The hybrid bees are more protective of their hives than the bees we are used to.

Considering how serious the bee decline is we should hope that the killer bees at least are strong enough to survive.
One day we may be dependent on them. We can't pollinate our crops ourselves.  Without bees we face some very serious food shortages.

http://www.theguardian.com/environment/2...ps-says-un

It is basically an emergency. If we do not act quickly we could lose many of the worlds pollinators.