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

Last time I reported on the Staten Islands Zoo’s use of the Zoo Med 10.0 High Output UVB Lamp (Please see Part I of this article). Today I’d like to provide some specifics concerning tests carried out there.

Test Results
The UVB output readings recorded at the Staten Island Zoo are as follows (note: measurements are expressed in microwatts per centimeter squared, the standard for measuring UVB output):

Zoo Med Reptisun 10.0 High Output UVB Lamp

Zoo Med Reptisun 5.0 UVB Lamp

As you can see, the basking site’s distance from the lamp has a major impact upon UVB exposure, as does the screen cover’s deflection of light rays. With a bit of creativity, basking spots within 6 inches of the lamp can be arranged in most situations, and this is certainly the way to go for many species. Where safe to do so, dispensing with the screen cover is another option.

Using a Separate Basking Enclosure
If a 6-inch basking site or uncovered top are not feasible in your pet’s terrarium, consider the possibility of utilizing a separate basking enclosure for a few hours each day. When keeping young radiated and star tortoises in high-topped zoo exhibits, where adequate UVB exposure was not possible, I rotated the animals into a low, uncovered container every day or so, and achieved excellent results.

If you go this route, be sure to keep your pet’s individual needs and temperament in mind. For example, a simple, open container that might suit a Greek tortoise would likely cause a good deal stress to a flat-rock lizard. High strung or secretive animals must be made to feel secure in the basking enclosure, or you may do more harm than good.

Reflectors and UVB Output
The group UV Guide UK has found that simply mounting the lamp within a metal reflector nearly doubles the UVB light that is available to basking animals. In addition to focusing all of the lamp’s light into the terrarium, I imagine that the reflector also helps by deflecting back some of the light that has bounced off screen tops or other structures.

An informative article on the role of UVB and basking behavior in Vitamin D synthesis is posted at:
http://www.uvguide.co.uk/vitdpathway.htm

Today I’d like to take a look at a much-maligned food insect that can, if used properly, be an important addition to your pets’ diets.

Mealworms (larvae)
A steady diet of mealworms (I refer here to the small mealworm, Tenebrio molitor, not the giant mealworm, Zophobus mario) is not recommended for any reptile or amphibian. These beetle larvae lack essential nutrients, the calcium: phosphorus ratio is not ideal and the exoskeleton is high in chitin. Mealworms also have quite strong jaws, and may injure debilitated or small reptiles and amphibians.

However, newly molted mealworms, which are white in color, are soft, have weak mouthparts and lower chitin levels. I have found them to be an excellent supplementary food for amphibians, tarantulas, scorpions and reptiles and fish.

Mealworms will shed most frequently when fed heavily and kept at 76-80 F. I house my colony in a mix of wheat bran, corn meal and powdered multi-grain baby food, with a bit of Tetramin Flake Fish Food added in, and provide banana skins for moisture.

Mealworm Pupa
Mealworm pupae are a fine food for turtles, newts, aquatic frogs and those lizards that accept non-living food items. They are low in chitin and likely have a different nutrient profile than either the larvae or adults.

Mealworm (Darkling) Beetles
Beetles, comprising the world’s largest animal family, figure prominently in the diets of most insectivorous reptiles and amphibians (based upon stomach content studies). I have long used darkling beetles (adult stage of the mealworm) as a food item, and prefer them over the larvae in most situations.

Beetles newly emerged from the pupae are softer than later-stage animals, and brown in color. To ensure a steady supply, I remove pupae as they form and place them into a bare container. In this way the beetles cannot burrow into the substrate, and are thus easier to harvest. Warm temperatures and a good diet (see above) will ensure a steady supply. Be sure to leave some beetles in the colony for breeding purposes.

You can learn more about the specifics of the mealworm’s life cycle at:
http://lawrencehallofscience.org/foss/fossweb/teachers/materials/plantanimal/tenebriobeetles.html

Image referenced from Wikipedia: http://en.wikipedia.org/wiki/Image:Mealworms_in_plastic_container_of_bran.jpg

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

Introduction
Flour beetles of various types are serious pests in grain product storage facilities, and those discussed here are worldwide in distribution.  However, the traits that make them successful invaders also render them easy to culture in captivity.

The larvae, or grubs, of the beetles offer an easy way to add nutritional variety to the diets of tiny reptiles and amphibians, most of which must subsist on only a few food items in captivity.  The adult beetles release an irritating gas when disturbed, but are none-the-less consumed by some reptiles and amphibians.

Obtaining Flour Beetles
I was first introduced to flour beetles some 20 years ago by Bob Holland, an amphibian expert who was setting longevity records with poison frogs long before most zoos kept any at all.  In those days, we collected our founding stock by searching through old containers of dry dog food and cereal.  Today, cultures of confused and red flour beetles are available from private breeders and biological supply houses.

Culturing Flour Beetles
Although most beetle breeders advise keeping the animals in a mix of flour and yeast, Bob’s method of rearing them in dog biscuits has worked very well for me.  The problem with a flour mix is that the medium must be sifted through a fine net each time larvae are needed, which leaves one with unwanted beetles, pupae and shed skins.

Dog biscuits provide all the food, moisture and shelter needed by the beetles (be sure to crack open the biscuits to give the beetles easy access to the interior).  When larvae are needed, I simply tap a biscuit over a Petri dish.  The larvae can also be concentrated by tapping several biscuits over a separate container, into which only 1 biscuit has been placed.  All the grubs will eventually gravitate to the 1 biscuit, allowing you to collect many in a short time.

Using Flour Beetles
The adult beetles live for approximately 1 year, with the period from egg to adult being 4-6 weeks, depending upon temperature.  The larvae are 3/16th of an inch long when fully grown – an ideal size for poison frogs, harlequin frogs and newly morphed froglets of small species such as spring peepers.  I have also fed them to red-backed and red salamanders, the larvae of various newts and to small granite night lizards.

An article concerning the natural history and pest status of flour beetles is posted at:
http://www.google.com/search?hl=en&as_q=confused+flour+beetle&as_epq=&as_oq=&as_eq=&num=10&lr=&as_filetype=&ft=i&as_sitesearch=&as_qdr=all&as_rights=&as_occt=any&cr=&as_nlo=&as_nhi=&safe=images

As summer winds down, resourceful herp keepers are presented with a unique opportunity to treat their pets to a novel food item – providing, at the same time, a source of important nutritional variety. The waning days of summer bring with them the annual die-off of untold millions of large, juicy insects – the annual and periodical cicadas.

More than 100 of the world’s 2,000+ cicada species make their home in North America, and they are widely distributed. I still hear them regularly in the heart of Manhattan, and various species are quite common in and near other large cities as well. Most have a life cycle of 2-8 years, but 7 species in the eastern USA have a 13 or 17 year cycle and a number reach adulthood in 1 year.

The entire cicada population of a given area expires within a short period, usually at the end of August or in early September in the northeastern USA. This yearly event provides a bonanza (up to 1.5 million periodical cicadas may emerge from a single acre of soil!) of nutritious food for a wide range of creatures – deer mice, wood turtles, box turtles, skunks, flying squirrels, black bears and a host of others have been observed gorging on cicadas. Even adult copperhead snakes, not normally thought of as insect eaters, partake of the feast.

If you are alert at the right time, you may find hundreds of these normally arboreal songsters, spent and about to die, on the ground. Your medium and larger sized reptile, amphibian and invertebrate pets will consume them with gusto, and you can freeze the excess for future use. Cicadas occur on every continent except Antarctica, and pets both native and exotic – American bullfrogs, African mud turtles, red-kneed tarantulas – unfailingly attack them with gusto. You can also collect the nymphs as they emerge from the ground in early summer – this usually occurs at night, and often within as short period of time as 1-7 days.

Dietary variety is an important key to keeping your pets healthy and in breeding condition. Those of us who keep insectivorous herps and invertebrates often face limited food choices. The annual cicada die-off may provide a relatively easy way for some of us to remedy that situation.

One word of caution: I have noticed that populations of annual cicadas near NYC have seemingly declined drastically in recent years. A colleague suggested that the insecticides sprayed to control mosquitoes bearing West Nile Virus may be the culprit. I tend to agree – cicadas, with their largely arboreal lifestyles, are easy targets for insecticides sprayed from airplanes (far easier targets than mosquito larvae, which seem as common as ever). I have not run into secondary poisoning problems when feeding cicadas to captive animals, but suggest that you do not collect in areas that have been commercially sprayed.

Image attributed to wikipedia: http://www.cirrusimage.com/homoptera_cicada_T_linnei.htm