I'm wondering if anyone knows, or has heard or read, recommendations about removing the crop (and its contents) of feeder roaches before offering them to mantids? It seems I've read something about it before (recommending it be removed), but cannot remember where, why, or by whom it was suggested.
I would very much appreciate any comments, referrals to reliable sources of information, or personal opinions about the subject... whether it is beneficial and/or recommended or not; and explanations or opinions of reasons why. Answering the poll questions would be helpful and interesting also. Thanks!
This is a seriously interesting question, Katt in that I can't imagine why anyone would go to the considerable trouble of dissecting out all their cockroaches' crops and feeding their mantids a dead roach by hand.
First, for those of us like Brian, who have forgotten our basic insect anatomy, the crop is that area of the insect foregut between the esophagus and proventriculus. Food passes from the mouth, through the esophagus to the crop where carbohydrates are broken down by digestive juices. It then passes through the proventriculus where, in the cockroach, the food is ground by sclerotized plates before passing through the stomodeal valve into the midgut, which we don't have to discuss right now. (Damn! Love that hypertophic matrix!
)
In order to remove the crop, you would have to make an anterio posterior incision through the ventral surface of the thorax and abdomen, remove the fat body, dissect out the crop, making incisions at the distal end of the esophagus and the proventriculus. If you want to avoid the contents of the gut leaking into th body cavity -- rather defeats the purpose of the exercise -- you should tie off the crop for and aft before making the incision.
Mantids have been getting along very nicely for a very long time eating their roaches fat body, crop and all. They do the same with the roaches' cousins, the crickets and grasshoppers. Why not dissect them out too?
Incidentally, you could get the same result by not feeding the roaches for a day or so until the crop has emptied its contents into the midgut. If you remember where you saw this, Katt, I for one would be very interested to know who suggested it.
There are lots of pix of insect guts on Google, but for a very pretty cross section of the cockroach crop and dissected proventriculus to show its "hexaradial symmetry"
see: R.F. Chapman,
The Insects: Structure and Function 1998, Cambridge University Press p.39
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O.K. Here's a URL for a dissected cricket showing the crop.
http://educatus.com/main/samples/default.asp?lid=801505&scid=8015050020
Sure you want to do this?!
I see that it's 0224. Shouldn't we all be asleep?