>They were piled up in front of the hive and also dead bees inside the hive.
I suspect pesticide poisoning (a large
alfalfa field is relatively close).

Sounds like a pesticide kill to me.
Two kinds of kills in my opinion.
1. bees make it back to the hive and die (your situation)
2. bees die in field and hive dwindles.

A third type of kill I have seen on rare occasions is from pesticide
contaminated pollen. hard to detect and usually caused by use of sevin on
sweet corn in our area.

Number one can also be caused by a person living nearby not wanting a
beehive in the neighborhood. *If* you just moved a hive into a new location
I would wonder!

 We moved a semi load into a new area in Texas one winter. A neighbor set
out pans of poisen honey and killed many hives. When we found the source he
admited what he had done but thought he would not get caught as he did not
think the bees would have made it back to the hive. They did and were dead
out front.

We wanted to stake the guy over a fire ant nest but resolved the issue
without violence.

Spraying  Alfalfa can be a problem but bees do not like to work alfalfa and
a bit early for boll weavil spraying for our area but could indeed be the
problem. Especially if the Alfalfa was in bloom.  Records have to be kept
for spraying. Find the owner of the field and ask.

 The last pesticde kill I had I went to the MFA sprayer in our area and told
him I only wanted to know so I could rule out other possible causes and
would not try to sue for damages. He then looked in his records and MFA had
dragged a spray boom over the top of my hives when turning around in the L
shaped field. The guy I was talking to had been the sprayer. He said he did
not see the hives. He would have to been blind not to see the yard in my
opinion but not wanting to go to jail for blacking both his eyes and having
said I would not sue I dropped the issue!

 >Could the drawn comb inside the
hive be used or should it be discarded?

Without testing you can never be sure. You will get many opinions but the
final decision will be yours. Choose wisely.

Sincerely,
Bob Harrison

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