That Reptile Blog – Reptile, Amphibian and Exotic Pet Care and Information

Captive insect-eating reptiles and amphibians (and perhaps invertebrates) are often plagued by nutritional deficiencies. A highly-varied diet is a great way to ensure adequate nutrition, but most keepers have access to only a few feeder-insect species; gut-loading (providing nutritious diets to feeders) is helpful, but detailed studies are lacking. While touring several Japanese zoos a few years ago, I was intrigued by the number of cricket species being bred as herp food, and resolved to investigate the species and diets I saw in greater detail. A recent article in Zoo Biology (2011, V. 30), which provides insights into carotenoid supplementation in three different cricket species, has re-sparked my interest. I’ll summarize below.

Carotenoids

Carotenoids are pigments that occur in plants. Animals, as far as is known, cannot manufacture carotenoids but rather must obtain them through their diet.

Carotenoids benefit the immune system by acting as antioxidants, function in the reproductive and other systems, and are believed partially responsible for the health benefits enjoyed by people who regularly consume fruits and vegetables.  We know little of their role in reptile and amphibian health, but many zoo nutritionists believe them to be important. Read More »

Almost every zoo building in which I’ve worked was home to roach (2-3 species) and House Cricket populations.  In most, pesticide use was not an option. An older animal keeper whom I befriended let me in on his favorite insect pest control technique – the molasses trap.  He was content to let management wonder how he did such a good job so, out of respect for him, I did not share the secret until he retired. Then, for a time, molasses traps became standard in several zoo buildings. Molasses is also useful in outdoor traps, where it never fails to turn up a variety of interesting species. I’ll expand on that below as well.

Pesticide Problems

House Crickets, roaches and other escaped “feeder insects” can be problematic in private collections. In the damp basements favored by amphibian keepers, Spotted Camel Crickets (Ceuthophilus maculatus, please see photo) may also set up housekeeping. These unusual creatures are very interesting in their own right, and I’ve featured them, and a large African relative, in several exhibits. However, most folks find their size, appearance and jumping abilities quite unsettling (please see comments in the article linked below – insect fans will find them very interesting!). Read More »

I’ve covered a number of less-commonly kept food animals in this care guide, along with pet trade staples.  Please consider as many as you can, as dietary variety is critical to the health of most pets.  The extra effort on your part will be very worthwhile…novel foods also inspire enthusiastic feeding responses, and may even stimulate reproduction.

There is an endless supply of useful live foods, so please post your ideas and observations.

Earthworms, Red Wigglers, Nightcrawlers (Lumbricus terrestris, others)

I’d like to see earthworms replace crickets as dietary staples for those species that accept them.  Highly nutritious, they are readily taken by most amphibians and turtles, some lizards, insectivorous snakes, and tarantulas.  Most reproduce rapidly when kept in a screen-covered plastic container with alternating layers of dead leaves and moist topsoil; they can also be stored under refrigeration.  Keep earthworms at 70 F or below if possible (certain species tolerate warmer temperatures). Read More »

Dietary variety is the key to success in rearing many herps and invertebrates.  Unfortunately, options for newly-transformed frogs and salamanders, Poison Frogs and other small species and hatchling spiders are limited. A diet of fruit flies, springtails and pinhead crickets sometimes suffices, but as I learned when rearing the endangered Kihansi Spray Toad, other foods are often necessary.  Praying Mantid Egg cases (properly termed “oothecum”), which may be collected or ordered from commercial dealers, are a useful but under-appreciated resource for those who keep small insectivorous pets.

Foreign Mantids in the USA

The 2 most-commonly encountered mantids (or mantises) in the USA are both introduced (not native).  The largest and most widespread is the Chinese Mantid, Tenodera aridifolia sinensis, brought here in 1896 to battle insect pests.  The European or Praying Mantid, Mantis religiosa, arrived as a stowaway around the same time.  They and the world’s other 2,400+ species, consume vast numbers of beneficial and harmful insects…in fact, a single Chinese Mantid may consume 20,000 or more insects in its lifetime! Read More »

The larvae of the Black Soldier Fly, Hermetia illucens, have recently attracted a great deal of interest as a food item for herps, birds, fishes and invertebrates. Also sold as “Phoenixworms”, “Calciworms”, “Reptiworms” and “Soldier Grubs”, they are reputed to be superior to other insects in nutritional value. However, much of what has been written about them is confusing and contradictory. Today I’ll review the available research and my own and other’s experiences and attempt to sort fact from fiction, science from opinion.

Nutritional Analysis

There has been some work done on the nutritional value of Black Soldier Fly larvae, and the reports are promising. In fact, a number of zoos now use them regularly.

Most importantly, their Calcium:Phosphorus ratio is approximately 1.5:1 – very close the 2:1 ration that is generally accepted as ideal for most reptiles and amphibians (a poor Calcium:Phosphorus ratio is the main reason that calcium supplementation of crickets is recommended). Also, the actual calcium content of Soldier Fly Larvae is extraordinarily high – up to 8,155ppm as opposed to 20-135ppm in mealworms and crickets. Read More »