Hi,

I am an undergraduate student doing an honors thesis on the
disposition (pharmacokinetics) of a chemical in honeybees. I am just
beginning these studies, but have done some reading about the
anatomy and physiology of honeybees from the books of Snodgrass and
others.

I would greatly appreciate any help that you can provide related to
the following.

As a basis for my studies, I am using a paper from Suchail et al.
(Pest Management Science, 60(11), 2004). In these studies, they
orally exposed bees to a chemical dissolved in sucrose solution.
After the exposure, at certain time points (0, 2, 4, 6, ..., 72
hrs), they dissected certain of the bees and measured the
concentrations of the chemical in several body compartments/tissues:
head, thorax, abdomen, midgut, rectum, and hemolymph. So, they
essentially ended up with data for the amounts of the chemical in
these compartments over time.

The results showed that the amount of the chemical in the thorax and
abdomen started out relatively high and decayed over time. The
amount in the midgut started out low, increased and then decreased.
The amount in the rectum was much higher than that in the midgut,
but followed the same trend.
In general, at early times, the amount of chemical in the thorax and
abdomen were higher than those in the other compartments, and the
amount of chemical in the hemolymph (as taken from the dorsal aorta)
was relatively low throughout.

My understanding is that food flows from the mouth through the
esophagus, into the crop, through the proventriculus, into the
ventriculus, into the anterior intestine, and then into the rectum.
I am also assuming that nutrients pass out of the ventriculus (and
anterior intestine?) into the hemolymph to be circulated throughout
the body.

In this light, I found these experimental results confusing, since I
would have expected the amount of chemical in the midgut to start
out high and decay over time and the amount in the abdomen to start
out low, increase, and then decrease.

Do you have any ideas to explain the experimental results?

Do chemicals pass back and forth from the hemolymph to the
ventriculus? Do the Malpighian tubes play a role in this process?

I apologize for my ignorance on the subject and am grateful for any
help or insights that you can provide.

Also, if you know of good books or papers related to this topic,
please let me know.

Thank you very much.

Kind regards,
gyro

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