Why Are My Captive Bred Mantises Always Smaller than Wild Ones

[Mantis Man13]

I have had Chinese mantises many times, yet I never see them achieve the length of their wild counter parts. My Chinese females are always 3 and 2/8 in. long, yet the wild females are always 4 in. long. My Chinese males are always 2 and 4/8 in. long, yet the wild males are 3 and 2/8 in. long, the same size as my captive females! Another example of this is with my Brunner's stick mantises. I have had them a good number of times, yet these asexual females always get to 3 and 2/8 in. long. The wild ones can get about 7 inches long, with proof from photos and videos of encounters. I just want to know if I am doing something to stunt their growth or something because I always keep my mantises in a 10 gallon cage, feed them every other day,(Because my mantises refuse to eat every day) and also put pollen/honey mantis supplement on their food. I also give them a diet of flies/ moths for more safety of bacteria,(Such as crickets and grasshoppers, which have made a few of my mantises throw up and die). Please tell me if you know anything I am doing anything wrong or why my captive mantises are so small in size comparison to the wild mantises.

 

[kunturman]

Temperature/humidity is a key to large growth. All mantis that I keep outdoors (during the Floridian summer) grow to larger adults, eat more, and live less. The higher the environmental temperatures the higher metabolic life rate, hence burn out is quicker.

 

[Ranitomeya]

A varied diet can greatly affect their growth and most insects in the wild come gut-loaded and filled with additional nutrients. With wild-caught crickets, grasshoppers, and other herbivorous insects you can count on some of that gut-loading to contain a variety of toxic plants, parasites, soil pathogens, and any variety of man-made chemicals.

There's also the fact that most flying insects a wild mantis would encounter would tend to be feeding on nectar and that chitin, the main component of an insect skeleton, is derived from glucose. The insects we raise tend not to have diets composed of mainly sugars and that would result in our mantises having to getting easy sources of glucose--they would need to undergo the relatively more difficult process of breaking down the fats and proteins they ingest into useable glucose.

It's also unknown if natural light has an effect on mantises--maybe they attempt to mature faster at the expense of greater adult size if they're kept in darker environments that mimic the decreased daylight hours experienced nearing the end of their survivable seasons.

 

[Mantis Man13]

So how do I mimic the outside environment and humidity? I spray all my mantises cages every other day, is that not enough humidity? And how would I make it hotter for my mantises, they are usually in room temperature. Also, what would be the best diet to achieve maximum growth? I just like to have big mantises because I think it is a lot more interesting to have a giant insect, which is why I prefer females over males.

 

[Ranitomeya]

Warmth can be provided by heating the room, using a space heater, using a heat lamp, using a ceramic heater, or using a heat pad. Humidity shouldn't be too big of a problem if you're already spraying them every other day and your house isn't bone dry. The optimal diet would be insects that have been fed a good diet prior to being fed to your mantis.

 

[kunturman]

Need to convert your enclosure into a green house, use sheet plastic, incandescent lights 60 W - 40 W, and a computer fan.

 

[Mantis Man13]

Do I need a heat pad or light? Also, does a mantis need heat as well as light? Is it for sure that these factors will make a larger mantis?

 

[Argusdad]

There are many unknowns in your scenario. Here are some likely views. Some keepers are of the belief that varied diet is key; others, would suggest lack of a specific food source (not readily available in captivity) prevents optimum growth; a step further, there are those that feel a specific type of bacteria (see fruit fly lab culture studies with flies raised on yeast medium vs non-yeast medium) from their native environment is not available and thus, leads to malnutrition. Stress (i.e., handling) is also a potential source of stunted growth or in some cases, the reason they will skip an instar and turn into adults faster. There is also a camp that blames inbreeding as the cause for smaller sized animals; however, this does no seem to fit into your inquiry. I would imagine that one or possibly all of these things may have affected your experiences. I would only add "sun light" to the idea pool as I feel it is often very missing in discussion. While the possibility of mantids actually using sunlight for energy currency exchange is conjecture that leaves much to be desired, we can not underestimate solar influence upon health and optimum growth of captive species in artificial environments.

"Photosynthesis-like process found in insects"

NATURE, 17 August 2012

http://www.nature.com/news/photosynthesis-like-process-found-in-insects-1.11214

 

[Mantis Man13]

So how do I give it sunlight without going outside with it. Can I use a lamp?

 

[soundspawn]

You can get a UV-B lamp. Check the reptile section of a pet store, or ask a reptile keeper, as it's actually a very important aspect of keeping snakes and lizards. I don't have one, and my Chinese mantids are freaking huge - so I'm going to say it's all about heat and diet. Feed them nothing but the finest, and you'll get just that back.

 

[Mantis Man13]

what do you consider the finest? I feed mine moths

 

[soundspawn]

Anything wild caught and healthy looking (if you catch a grasshopper and it's acting half dead, steer clear), or anything you captive breed and feed fresh produce. Our main staple is fruit flies and/or springtails followed by crickets and mealworms (I have a specific thread for my set ups: http://mantidforum.net/forums/index.php?showtopic=33518) and we supplement with regular wild caught insects.

Think of the feeder as a shell, it doesn't really matter what they are, it matters what they ate. Keep your captives gut loaded with nutrition, and grab healthy wild caughts (which will be naturally gut loaded).

 

[jday]

I'm pleased by these responses. I asked this very same question a few years ago, and all I got was some dude saying something along the lines of "mine are just as big...you're doing something wrong"!

I don't know all of the factors, but I tend to think it's humidity and light. This year we raised Chinese and Carolina mantises outside, but on a porch with a roof, so there was no direct rain. We also put them where direct sunlight hit them, but only for a few hours in the early morning. And we raised them in mesh cages rather than deli cups. We fed them wild-caught food like crickets, moths and flies, but we always did this with our indoor mantises as well. During the entire season, we had no bad moults, and the mantises are generally as large as the wild mantises we caught at the end of the season.

One incredibly fun thing about raising mantises this way is that--after the females reached maturity--we found wild mantises nearby almost every morning. Sometimes there would be a wild male mantis just hanging out on a female's cage! The Chinese also seemed to attract wild Carolina mantises, so I'm guessing the phermones are similar. Our breeding stock increased with almost no effort. In fact, next year I think we'll release most of the males and just catch a few at the end of the season, which will save tremendously on the time we spend catching food. Also, canibalism was minimal and my son (we're a Pop & Jr team) was a lot less distressed the one time a female munched a wild male while mating, since it was a stranger to him.