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

The Domestic or House Cricket is perhaps the world’s most popular herp food, the closely-related locusts, grasshoppers and katydids have been neglected as a food source here in the USA.  However, many are easily collected and bred in captivity, and offer important nutrients lacking in commercially-bred insects.  What’s more, they are colorful, active and extremely interesting to work with – don’t be surprised if you begin keeping them as more than just a food item!

Natural History

Grasshoppers, crickets, locusts and katydids are classified in the Order Orthoptera.  Over 20,000 species, inhabiting environments ranging from deserts to mountain tops, have been described.  The USA is home to 1,000+ species.

Many grasshoppers sport a fantastic array of colors and shapes; some are barely visible to the naked eye, while others, such as New Guinea’s Phyllophora grandis, top 5 inches in length (please see photo of a Hooded Grasshopper). Read More »

Please see Part I of this article for a general discussion regarding the collection of insects and other invertebrates and their use in the diets of captive reptiles, amphibians, birds, invertebrates and fishes. Today I’d like to focus on some areas of special concern.

Toxic and Biting/Stinging Invertebrates

While not involving pesticides per se, for your own safety and that of your collection it is imperative that you learn to identify the toxic or otherwise dangerous invertebrates that you may encounter while collecting. A good field guide (i.e. Audubon, Golden Guide or Peterson series) is indispensable in this regard. Be sure to handle unfamiliar species with plastic tongs.

Please bear in mind that even relatively mild bee venom can cause fatalities in allergic people. And while less than 1% of the world’s 40,000+ species of spiders are considered dangerously venomous to us, a number readily bite both people and animals in self defense. It is best, therefore, to avoid them…the Thin-legged Harvestman or “daddy long-legs”, which are not spiders, are safe to use. Steer clear also of bees, wasps, large ants, stag beetles and others well-equipped to defend themselves.

Bright colors often indicate that an animal is toxic or bad-tasting; ladybugs, fireflies, milkweed bugs and a great many others fall into this category. Unless you are sure of an insect’s identity, the safest course of action is to avoid brightly-colored species.

Native vs. Non-Native Prey Species

In many cases, predators avoid dangerous prey animals that occur naturally within their ranges; this can spare both pet and pet-keeper a good deal of grief!  However, dangerous non-native prey animals may be attacked with abandon if the hunter has no “frame of reference”, so use extra caution in such cases.

I have, for example, housed highly-toxic Marine Toads with Green Anacondas for decades without incident, despite the fact that anacondas consume non-toxic frogs readily. However, Australian monitors and snakes, which have no instinctive or learned toad avoidance behavior, eagerly consume the Marine Toads that have been introduced there, often with fatal results.

Earthworms

Earthworms are one of the most nutritious live foods available. There are, however, situations that warrant precautions.

Earthworms are unique in consuming dirt as they tunnel, and in doing so may concentrate toxins present there. To my knowledge, the only problem that has arisen thus far has involved worms that dwell along golf courses, which are subjected to unusually high degrees of pesticide application. Please see my article Raising Earthworms for details concerning striped skunks and earthworms in NY.

West Nile Control and Related Programs

Avoid collecting invertebrates for 1 week after an area has been sprayed as part of West Nile eradication efforts, and steer clear of farms where pesticides are known to be applied regularly. Avoid also local insects that are considered to be agricultural pests, as they are likely the subject of control measures (this may apply to aphids, caterpillars, Japanese Beetles, etc.).

Enjoy

Despite the precautions that must be taken, invertebrate collecting is a fascinating and thoroughly enjoyable endeavor. Don’t forget to examine your catch closely…several years ago a new species of centipede was uncovered in NYC’s Central Park, on ground trod daily by thousands of people. Like me, you just may wind up keeping some of your discoveries in captivity for their own sake!

Further Reading

For a very interesting account of how toads learn to avoid stinging insects, please see my article Amphibian Learning Abilities.

Please write in with your questions and comments.

Black Widow image referenced from wikipedia and originally posted by Trachemys.

Milkweed Bugs image referenced from wikipedia and originally posted by Greg5030.

Isopods, more commonly known as sowbugs, pillbugs or potato bugs, are a valuable but largely neglected food source for pet amphibians and reptiles. The over 10,000 described species are common in most habitats worldwide, and are therefore an important in the diets many creatures. Ranging in size from .02 to 20 inches, there is an isopod to fit every feeding need (public aquariums pay $600 or more each for giant, deep-sea forms, so don’t plan on feeding these to your monitor lizards!).

Nutritious, Interesting Scavengers
Isopods are crustaceans, and as such provide a variety of nutrients not to be found in insects. Another thing I like about using them has to do with their appetites – they will eat anything, so by feeding them a rich and varied diet you are improving their value as food items for your pets. Furthermore, native sowbugs and pillbugs will live in most terrariums and are valuable scavengers, relishing dead earthworms, crickets and feces. I always include a group in naturalistic habitats that I design for zoos and museums. Finally, they are very interesting to observe in their own right. They do contain quite a bit of chitin, so are not suitable as the sole item in a diet.

Obtaining Isopods
Temperate isopods prefer cool, moist environments, and so are most easily found in spring and fall. You can collect them below rocks and leaf litter. They will also flock to cover such as boards placed on the ground, especially if the area is kept moist and baited with coffee grounds or ripe fruit. Biological supply houses also sell starter cultures.

Keeping and Breeding Isopods
Keep your colony in a vented plastic container with 3-4 inches of R-Zilla Coconut Husk as a substrate. Plastic terrariums by Lee, Tom Aquarium, Hagen and PLA House make ideal isopod homes. Be sure to keep the bedding moist but not wet. A covering of Zoo Med Terrarium Moss will help retain moisture and offer shelter to the isopods, making collection easier.

A mix of R-Zilla Alfalfa Meal Bedding and Tetra Min Flake Fish Food is an excellent basic diet, to which can be added grass clippings, leaf litter, coffee grounds and almost any fruit or vegetable. A cool basement makes an ideal location for the colony, but average room temperatures are fine. Be sure to keep an eye on moisture levels during hot, dry periods. A breeding colony will supply huge numbers of isopods of all sizes.

My Experience
I have always kept an isopod colony for my collection, and have used them in zoos as well. They are easy to maintain, breed readily and are, I think, one of the best-kept secrets (no more!) in herptoculture. Very few insectivorous herps refuse them, and they are readily taken by many fishes and birds as well. Be sure to try a group in your naturalistic terrariums also, as they make fine scavengers and, unlike crickets, they will not attack debilitated pets.

The University of Arizona’s Center for Insect Science Education offers a wealth of information on native invertebrates in the wild and captivity. Read more about isopods at:
http://insected.arizona.edu/isoinfo.htm

Herp enthusiasts are, along with entomologists and exterminators, the only people who actively seek out termites – but we have good reason.  These insects (fascinating in their own right, by the way) are a valuable food source for a number of reptiles and amphibians.  Termites are particularly important for poison frogs, and form a major component of the natural diet of many species.

Termites are a valuable food for small terrarium animals, and for the young of others, because our options are limited with regard to such creatures.  Most consume a wide variety of prey in the wild, but in captivity must make due with pinhead crickets, fruit flies and springtails.  I have used termites to feed the young of a number of reptiles and amphibians (other than poison frogs) including five-lined skinks, flying frogs, marbled salamanders and others too numerous to mention, as well as species which remain small as adults (alpine newts, spring peepers, dusky salamanders etc.).  The rapid decline of many animals imposes upon us an obligation to become more effective in our captive breeding efforts – I urge you to experiment with termites and other insects.

To make a termite trap, simply take a plastic storage box – the shoebox size works well – and cut several holes of 2-3 inches in diameter into the 4 sides.  Stuff the box with damp cardboard and you’re all set (termites relish cardboard – I guess if your normal diet is wood, something softer seems like a treat!).

Search for termite nests beneath rotting logs and under the bark of dead trees.  Your trap should be located about a foot away from the nest, buried so that the top of the box is flush with the ground’s surface.  Cover the lid with a thin layer of earth and secure with a rock.  The termites will establish feeding tunnels to the box.  Remove the termite–laden cardboard from time to time, but leave the box in place so as not to disturb the tunnels.  Those more mechanically skilled than I may wish to construct PVC tube-within-a-tube systems with screw-off tops, but the plastic box works just fine.

For those of you with wide interests – termites are also eagerly consumed by tropical fish, finches, red-crested cardinals, sunbirds, bulbuls and other cage birds, and invertebrates such as whip scorpions, ground beetles and flower mantids.  The termite life cycle is very complex – escaped workers (those individuals that you will catch) cannot establish new colonies in your home – any termites that may infest your home will arrive courtesy of a colonizing queen, so please don’t blame me!

Interesting correspondence between hobbyists using termites as frog food (and a man who has trained his dog to detect termites!) is posted at: http://www.utoronto.ca/forest/termite/Decompiculture/Decompiculture/Termiticulture_emails.htm