Hornworms??????

[Tygerr]

The Davison book mentions that they are an excellent feeder and somewhat fatty … so sparingly I guess.

Why would a hornworm be any more fatty than a silkworm? They seem to have a similar physiology and similar diet (unless tomato leaves are much more fatty than mulberry leaves ).

 

[roo_71]

I have no clue ... the book doesnt go into detail - somewhere on the net I saw a nutritional break down of feeders, I will look for it. When I have them I feed them out fast so my veiled gets a couple every other day. He really likes them and I really dont worry about him being over weight. He is a big dude - roughly 18"-19" total length but doesnt strike me as a "fatty".

-roo

 

[Heika]

The nutritional breakdown is on Cham News, but doesn't include hornworms. Here is the link: http://www.chameleonnews.com/year2002/sept2002/nutrition/nutrition_sept_02.html

lele's article says this about hornworms:


Q. How nutritious are they? A. They are very high in protein (approximately 58%) but also high in fat, therefore, you would not want to feed a steady diet of these to your chameleon. You should always offer a variety of food.

 

[Tygerr]

Yeah, I read that Heika.

According to CricketsOnline.com:
"Hornworms have the highest calcium content of any feeder on the market. (46.4mg/100g calcium, 3.07% fat). Great for brumating reptiles."
It's hard to compare that to the other figures on the Chameleons! Online site, because they list the calories from fat, and not the percentage from fat.
I do have a hard time believing 3.07% fat from CricketsOnline, when the study done by Warwick Insect Technologies (Silkworm Nutritional information) places silkworms at 10.6% fat.

That was done on artificial chow though. I expect the fat content to be lower if they're fed fresh leaves. Lele also only feeds off hornworms fed on chow. Maybe it's the chow that is fatty?

Either way, logic still tells me that a hornworm is bound to be similar to other leaf-eating caterpillars like the silkworm.
Until I see it in cold, hard scientific numbers, I simply can't believe the anecdotal view that they are a 'fatty' feeder.

 

[lele]

Why would a hornworm be any more fatty than a silkworm? They seem to have a similar physiology and similar diet (unless tomato leaves are much more fatty than mulberry leaves ).

Tygerr- just like any other organism/animal/plant there are varying amounts of vitamins, minerals, fat, protein, etc. Insects are no different. We are about the only culture that do not eat insects. Cultures who do consume them base their consumption on taste (treat, delicacy) as well as nutrition. For instance, the larval stage of any butterfly or moth (Lepidoptera) will likely be highest in nutrients b/c they are actively feeding in that stage inpreparation for their diapause and eclosion (emergence). So the fat content varies as well.

As for my statement of the fat content of 58% in my chameleonnews.com article was based on a scientific, peer-reviewed paper (if you want it I will have to go back and dig around as that file is zipped and stored), and of course even then there will be variable due to other physiological factors (size, instar, proximity to molting, etc.)

Now here is a good question (and if I find the time will research for my own curiosity) would a hornworm, which feeds in the northern regions and are in diapause (pupal stage) in the soil for up to 10-11 months overwintering before eclosing in the adult stage, contain more fat than those who have several broods/year in, say, So CA or MX?

I have been rearing Lepidoptera for 8 years (not as feeders) and they are my "specialty" in many ways - just not on my dinner plate

 

[Tygerr]

We are about the only culture that do not eat insects.

What culture are you referring to?

As for my statement of the fat content of 58% in my chameleonnews.com article was based on a scientific, peer-reviewed paper

I do not doubt your scientific sources, nor do I need you to send me the paper.
But the information does still surprise me. In most animals fat is used as a store of energy. For a worm that is being supplied a steady source of food every day, and is spending all its time actively grazing, what need is there to store energy?

However, your over-wintering and pupal stage theories make a lot of sense. Presumably when the worm is preparing to go into a pupa, it would need to build up a fat store. So does it build up that fat store throughout the larval stage, or does it only create fat reserves shortly before entering the pupal stage?
I'd be fascinated to see a comparison of the fat content of the hornworms early in the larval stage and towards the end of the larval stage.

But logically I'd still expect the same principles to apply to silkworms. Wouldn't silkworms also need a fat store before becoming pupa? If so, wouldn't silkworms be considered 'fatty' feeders prior to pupating?

I guess the scientists are all still working on answers to these questions.
There probably hasn't been much demand for nutritional analysis of insects, probably because no one in the cultures you spoke of that still eat insects, have ever worried about stuff like that. Only cultures that are silly enough to stuff themselves with things like McDonalds need to worry about nutritional (sic) content...