What you are seeing are the so-called "secondary wood-boring insects": these are just opportunistic beetles taking the occasion to lay their eggs in dying and dead trees. They are not the cause of your troubles.
If these are mature trees that suddenly entered decline and died, you should research the condition known as "wet feeet". It's a combination of causes that usually affects mature trees growing in shallow and poorly drained topsoils.
The thing goes somewhat like this: trees are stressed and weakened by prolonged drought, making them susceptible to attack by root rot pathogens like Leptographium sp. A healthy tree usually has no problem resisting the infection but high rainfall in the Spring, coupled with poor drainage will "choke off" the roots and progressively damage them. As the damage accumulates year after year the tree will "suddenly" enter decline and die when the roots have been damaged bad enough.
There's no cure for this condition. Individual ornamental trees may be helped by improving drainage and providing water during droughts, but it's absolutely not economically to do this for large stands of trees. The only solution is not plant Red pine anymore in areas where "wet feet" is known to happen.
Sorry to be a bearer of bad news.
