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Collecting Live Food for Reptiles and Amphibians: an Entomologist’s Technique

Wild-caught insects and other invertebrates are valuable, and often essential, additions to the diets of many captive reptiles and amphibians.  During the warmer months, I have utilized them for 50-100% of the diets of many animals in my own collection, and for those under my care in zoos.

Beating the Bushes for Insects

Tent CaterpillarsOne of the simplest and most effective collecting techniques was developed by entomologists (insect scientists) who needed to sample large habitats quickly.  Here it is: a white, un-patterned sheet is spread below a bush or tree, and the foliage is then beaten with a stick.  That’s it!

An incredible assortment of caterpillars, beetles, ants, tree crickets, katydids, spiders and other tasty morsels will rain down upon the sheet, where they can be easily collected.  The majority will be arboreal species – healthful additions to the diets of tree frogs, flying geckos, smooth green snakes and other tree-dwelling creatures, and to all other insectivorous herps.

Identifying Potentially Troublesome Species

Eyed Click BeetleDo not collect fireflies, “hairy” caterpillars (please see photo), and brightly colored insects that you cannot identify (due to possible toxicity).  Unless you are well-acquainted with local spiders, it is best to avoid them as well…harvestmen, or “daddy long-legs”, however, are harmless.

Use our plastic tongs to handle any specimens that may bite or sting.  A Peterson or Audubon Society field guide will help you to learn about the innumerable interesting creatures that you will encounter.

A World of Possibilities

You’ll have quite a selection to choose from, wherever you live.  Over 2,000 types of insects live right within New York City, and it is estimated that 30 million species inhabit the planet.  A single tree in Panama has yielded 130 species of beetle, 100 of which were new to science!

Last summer I was pleasantly surprised to find the spectacular eyed click beetle (Alaus oculatus) pictured below in my haul (this fellow was released).

Insect Traps and Canned Insects

The Zoo Med Bug Napper is another very useful insect-collecting tool.  An alternative means of introducing variety to your pets’ diets is through the use of canned invertebrates.

Further Reading

An amusing story involving the “bush beating” technique is given in fabulous book To the Zoo in a Plastic Box (Newmark, 1965; Random House).  A hilarious and informative account of two brothers’ adventures collecting insects and herps for the London Zoo, the book is a true gem…please read it if possible.

Please see my other insect-collecting articles as well – Leaf Litter Invertebrates and Building a Termite Trap.




  1. avatar

    Thank you for the very interesting article. I wish I would have known about this technique 4 years ago and maybe I wouldn’t have spent all that time catching insects individually by hand! Actually, I got quite good at it! I’m glad I know about this now, and I’ll be sure to try it out.

    There are plenty of tent caterpillars around here, but I never thought about feeding them to my reptiles. Interesting.

    • avatar

      Hi Sarah, Frank Indiviglio here.

      Nice to hear from you again. I’m glad you enjoyed the article, thanks for letting me know. Collecting insects with this technique is very rewarding – provides a great catch and is quite allot of fun.

      I’m sorry, I should have been clearer concerning the tent caterpillar photo…I meant to use it to illustrate some of the “hairy” caterpillars that are best avoided as pet food. I did experiment with them a bit…African bullfrogs take them right down, but I’m not sure how safe it would be to use them long term. Most lizards and frogs refuse them, due to the irritating hairs.

      Tent caterpillars are not, by a long shot, the most noxious meals taken by African bullfrogs…for a few strange-but-true stories, please see my article An Appetite for Cobras.
      Happy hunting…please let me know how it goes.

      Best regards, Frank Indiviglio.

  2. avatar

    Hi Frank, great article. Just curious. In all of these articles devoted to catching bugs outside to feed herps, I’ve never heard you mention the ever-abundant Japanese beetle. Is this not a viable food source for herps? I’ve never seen information on it anywhere one way or another. I’d imagine that they’re pretty high in chitin and/or has some kind of unfavorable taste or toxin to herps based on its bright(er) coloration and extreme abundance. Either way, there are lots of standard japanese beetle traps out there that you could really clean up with IF they could be used as food. Can they be? Thanks!

    • avatar

      Hello Matt, Frank Indiviglio here. Thanks for your kind words and interest in our blog; much appreciated.

      Well, in Japanese beetles you’ve hit on an insect that is in somewhat of a gray area for me…surprised and happy that you brought them up, as have been meaning to address the matter in a short note.

      Due to a lack of natural predators and competitors in North America, these introduced beetles do build up huge populations. I’m not aware of any toxins/disagreeable taste, and indeed have fed them to monitors, tegus, plated lizards, wood turtles and other robust reptiles. Chitin levels are likely within the normal range for beetles, which should be fine unless they formed the bulk of an animal’s diet. Pheromone-based traps are an ideal collection method.

      One problem is that there are a great many insecticides geared specifically for Japanese beetles. While secondary poisoning is supposedly not a concern with the latest generation of insecticides, I’m not quite convinced (not at all as regards rodenticides, incidentally). Collecting in pesticide-free areas is safe as regards most insects. but Japanese beetles disperse widely and cover great distances with their powerful wings, so there may be a concern.

      An incident occurred some 15-20 years ago that again set off some warning bells re these insects. A colleague reported losing 2 frogs, both long term captives (African clawed frog, 15 years, American bullfrog, 7 years) within a few hours after having fed them Japanese beetles (6 and 12 beetles, respectively). He refrigerated the bodies, but only after they had been exposed to warm temperatures for a time. I retrieved the animals and had them autopsied at the Bronx Zoo. Unfortunately, the heat compromised the results, but it seemed clear hat toxicity was not an issue. However, both frogs bore cuts and other injuries along their digestive tracts, perhaps caused by the beetles’ strong, spiny legs.

      Odd in a way, as bullfrogs occassionally consume tooth-bearing rodents, bats and other formidable prey, and other species (African bullfrogs) consume scorpions, centipedes and venomous snakes. However, Japanese beetles are not native, and certainly are better protected by spines and vigorous escape behaviors than are native beetles. Perhaps it was just the wrong combination of size, prey mobility and such that rendered them fatal in this case.

      Lizards and turtles tend to crush/tear insects before swallowing, while frogs take most prey down while it is still very much alive (cicadas continue their distress calls for a few seconds after being swallowed by bull and green frogs). Their digestive enzymes are quite strong, and quickly subdue normal prey species, but again perhaps the Japanese beetles are somehow resistant, at least for a time.

      Years later, a co-worker reported that his beagle expired after having consumed approximately 1,500 Japanese beetles!

      So, I’m left uncertain, but suggest erring on the side of caution and avoiding Japanese beetles – meaty and abundant as they may be – until we learn a bit more (or you learn a bit more!).

      Thanks for spurring my thoughts on this interesting topic.

      Good luck and please keep me posted.

      Best regards, Frank Indiviglio.

  3. avatar

    Sorry, but I disagree with this unique piece of writing. I actually do really enjoy your personal web-site however and may keep on coming once again for the latest.

    • avatar

      Hello Coretta

      Thanks for your interest and comment. I’ve had lots of similar feedback over time…I assume pesticides, toxic species and the like are at the root of your concerns? I’ve written a 2 Part article that addresses these and related issues; please look it over and let me know what you think when you have a chance. Care is needed, but there are many benefits as well. During my years at the Bronx Zoo, wild caught invertebrates were a regular part of the diets of many of our reptiles, amphibians and birds, and the same holds true in other major zoos…please see this article for further details.

      Please let me know if you need any further information. Good luck, enjoy and please keep me posted.

      Best regards, Frank Indiviglio.

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  5. avatar

    Hi Matt,

    I just found several caterpillars eating my parsley, I believe its the caterpillar that becomes the monarch butterfly. My eastern box turtle loves caterpillars. Do you know if these are poisonous for a turtle.


    • avatar

      Hello Vicki,

      You need to be careful with caterpillars, as several concentrate plant toxins as a defense. Monarchs are toxic (but they are usually found on milkweed, and have gen transformed by this time of year. Best, Frank

  6. avatar

    mantises are good for chameleons

About Frank Indiviglio

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Being born with a deep interest in animals might seem unfortunate for a native Bronxite , but my family encouraged my interest and the menagerie that sprung from it. Jobs with pet stores and importers had me caring for a fantastic assortment of reptiles and amphibians. After a detour as a lawyer, I was hired as a Bronx Zoo animal keeper and was soon caring for gharials, goliath frogs, king cobras and everything in-between. Research has taken me in pursuit of anacondas, Orinoco crocodiles and other animals in locales ranging from Venezuela’s llanos to Tortuguero’s beaches. Now, after 20+ years with the Bronx Zoo, I am a consultant for several zoos and museums. I have spent time in Japan, and often exchange ideas with zoologists there. I have written books on salamanders, geckos and other “herps”, discussed reptile-keeping on television and presented papers at conferences. A Master’s Degree in biology has led to teaching opportunities. My work puts me in contact with thousands of hobbyists keeping an array of pets. Without fail, I have learned much from them and hope, dear readers, that you will be generous in sharing your thoughts on this blog and web site. For a complete biography of my experience click here.
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