Definitive answer on Giant Mealworms?

[JeepFreak81]

Hi everyone, so I'm looking to order a decent amount of mealworms perhaps in the next day or two. My original plan was to order 500 regular sized mealworms and 250-500 GIANT mealworms. We picked up 100 Giants at Petco recently and all 3 of our geckos like them, in fact a couple of them seem to prefer them over the regular sized ones.

I've read through a number of threads and sifted through some things on Google search about Giants. I've read everything from "they are fine to feed to geckos" to "THEY WILL KILL YOUR HERP!"

So does anyone have a definitive answer on this? Originally I was told that the hormone used keeps them from pupating which in turn makes them grow larger, and that the hormone does not transfer to Herps. Is that true? Just want to keep our little girls safe, but also I really like the giants and they do as well!

 

[ZombiGecko]

I have no idea but would love to hear some ansewers about this too

Sent from my M865 using Tapatalk

 

[TokayKeeper]

Giant mealworms are the same as regular mealies and are in fact created with a growth, or juvenile hormone (which is technically a insecticide by definition as it interferes with the life stage of the insect, resulting in death) to inhibit the maturation process from larvae to pupae to adult. The hormone was originally used for pest control in flies.

To my best searching knowledge there have been no studies done on whether the hormone has negative impacts upon animals that consume giant mealworms. Many keepers on insect and arachnid forums I glance at from time to time typically avoid the giants as they are unsure of what the hormone may or may not do to their animals. A quick Google search seems to confirm this within other animal keeping type forums where insects can be used as a food source. New York Worms (nyworms.com) goes as far as suggesting to only use them for bait purposes.

Additionally, I typically avoid the use of mealworms due to their high fat content and thicker chitin (exoskeleton). Studies of the affects of such diet have not been done on leos, but for me it's quite easy to see by how obese some leos appear on a diet of solely mealies. It is somewhat well documented in bearded dragons of how fat they can get on a diet of mealies, going as far as leading up to the possible death (warning: graphic necropsy photos) of them.

Interestingly enough though, there was a recent university study on growth rate variation with captive species. The animals used were leopard geckos, with 1 group being fed crickets, another group fed a mix of crickets and mealies, and the last group fed solely mealies. The group raised solely on mealies had larger morphological traits (larger head, limbs, tail etc) than the groups raised on crickets or a mix of crickets and mealies. The authors do go on to caution:

While further studies are required to establish the potential negative consequences of an exaggerated fast growth rate and evaluate the long-term dietary effects from juvenile stages to sexual maturity that different prey items have on growth and ultimately fitness, our study adds to the limited data concerning the effect of diet on the growth rates of captive animals.

 

[JeepFreak81]

^^Good Info. I'm going to be switching up from solely Mealies to Dubia Roaches, in fact I just ordered a small amount to try. But we have a couple of new Tremper Albino Giant girls that are still pretty shy and only come out to eat when we aren't around making meal worms the best choice for us right now. Have fed some giants and they really seem to enjoy those. Might discontinue this, although still reading mixed reviews about it. Can't wait to start feeding the roaches though! Will still feed mealies as well and hoping to add some phoenix worms to the mix soon too.