do we have proof of that just yet?
I'm not posting the following as an argument on the subject, but I do resectfuly disagree with Phil on the subject of gutloading. it's not only for the benifit of the herp that might feed on the cricket, but it is benifitial to the insect as well. that cricket will be healthier when gutloaded on greens and fruits. thus the feeder is healtheier as a food to be fed off, as also said by Phil.
all I am saying is that there are two sides of the coin here. it may not truly be manditory to gutload, but it can't hurt and until I see further proof otherwise, may even be quite helpful.
Harry
Kova
Ah, Harry, "a man convinced against his will remains an unbeliever still." The claim in your last para seems modest enough, and your question in the first also seems reasonable, though it betrays a bad methodology. However, I make no personal claims of being more "right' than anyone else and almost always cite the appropriate literature in support of what I say. The following won't convince you, Harry, but this is a public forum and I hope that it will help some folks to see how a scientific or quasi scientific investigation should be conducted.
There is no reference in the literature, to my knowledge, that states that mantids benefit from eating gut loaded prey, and therefore, the burden of proof lies on you to show how it does. You offer no evidence for your claim that i have seen.
I believe, though, that you are in possession of a refereed, scholarly paper that states flatly that fruit flies fed to young spiderlings, which like mantids, are slow developers and show evidence of tritrophic nutrition (substances that their prey feeds on benefits them, nutritionally), were equally nutritious, whether or not their guts were full. "Proof" is often a subjective term, but this is certainly hard evidence, not contradicted by any other observed data.
I think that most folks feed their crix on cabbage or lettuce together with other vegetables. Lettuce contains up to 90% water and 40%+ of the dry weight is cellulose. Insects usually cannot digest cellulose with their own digestive enzymes, c.f. Marc Klowden's
Physiological Systems in Insects, p.175 (boring, but you did ask!):
Although cellulose is common in the diet of phytophagous insects, the innate ability to digest it is rare. [He then lists the three classes of enzymes and their actions]. These enzymes are produced by endosymbiotic organisms that live in the gut and not the insects themselves.
But mantids are obligate insectivores and do not have the intestinal flora to digest the cellulose, which is simply excreted, which means that only about 5% of the gut load contains what my be nutritious to the mantid. What the mantid does need, of course, is the protein provided by the cricket's flesh.
It may be argued that under normal conditions, phytophagous insects are always full of food, and therefor always "gut loaded", but the gut contents do not contribute to (or detract from) the insect's health until the food is digested, emptying the gut. An important aspect of this practice for herpers, as you know, Harry, is the introduction of essential vitamins and minerals and "color enhancers" missing in the captive animals' diets. This is not the case with mantids. They thrive and breed perfectly well without such additions, and scientific mantis labs do not gut load the prey, though mantids do seem to benefit from pollen carried on the outside of many prey insects.
So there you have it, Harry. If you believe that gut loading "may even be quite helpful' and wish to convince us of this, some hard evidence would go a long way towards attaining your goal.
