Making the Most of the Mealworm: some tips on enhancing the nutritional value of this pet trade staple

Hi, Frank Indiviglio here. 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)
MealwormsA 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.

Please write in with your own tips and questions. Thanks, until next time, Frank.

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

Research Update: Gray Treefrog (Hyla versicolor) Calls are Influenced by Social Factors, Concave-Eared Torrent Frogs (Odorrana tormota) Call in the Ultrasonic Range

Socially Influenced Mating behavior
Hi, Frank Indiviglio here. Ever wonder how a male frog might draw the attention of a female when he is calling amid hundreds of others? Research published in the August, 2008 “Journal of Comparative Psychology” has revealed that gray treefrogs vary their calls in response to social situations. When alone or in small groups, males utilize the species’ usual call. However, when trying to attract a mate amid large groups, males will vary the rhythm of their calls, in order to stand out from the crowd.

The Only Ultrasonic-Sensitive Frog
Concave-eared torrent frogs have, as one might guess from their name, recessed eardrums. Biologists looking into why this species’ eardrums are not level with the skin, as in most other frogs, discovered that these natives of central China emit and hear ultrasonic mating calls. This is likely because noise from the rushing streams along which they dwell would drown out calls emitted in the lower sound ranges (which are used by most frogs). Until now, only bats, whales and certain insects were thought to utilize ultrasonic calls.

Unusual Ears
And why the recessed eardrums? As stated in an article published in the May, 2008 issue of “Nature”, the torrent frogs eardrums are only 1/30th as thick as the eardrums of other frogs (which are, I imagine, quite thin themselves!) – an adaptation to allow the detection of ultrasonic sound. Their recessed location is thought to confer some protection against injury.

A new fact turns up on one creature or another every day – please help me to stay abreast and write in with those you find interesting. Thanks, until next time, Frank Indiviglio.

You can learn more about the concave-eared torrent frog’s natural history at:
http://amphibiaweb.org/cgi/amphib_query?where-genus=Odorrana&where-species=tormota

Image referenced from Wikipedia, http://en.wikipedia.org/wiki/Image:Hyla_versicolor.jpg, and taken by LA Dawson

The Green Anole (Anolis carolinensis carolinensis) in the Wild and Captivity; – Natural History – Part 2

Click:The Green Anole (Anolis carolinensis carolinensis) in the Wild and Captivity; – Natural History – Part 1 to read the first part of this article.

Introduced Anoles
Green AnoleThe green anole is the only anole native to the USA, but eight other species, originating as escaped or released pets, have established breeding populations here. The most common and widespread is the brown anole (A. sagrei), now found throughout Florida and in southern Georgia, Alabama, Louisiana, Texas and Hawaii. In many areas it is now more commonly encountered than the green anole.

The knight anole (A. equestris), bark anole (A. distichus), large-headed anole (A. cybotes), Hispaniolan anole (A. chlorocyanus), Cuban green anole (A. porcatus) and Jamaican giant anole (A. gormani) are limited to the vicinity of Miami and Miami-Dade County at this time.

Ill Fated Pets
Green anoles were sold by the millions at carnivals, circuses and through the mail in the 1960’s and early 70’s. Termed “chameleons” due to their color changing abilities, most were fed “sugar water” and expired in short order.

Color Change – not as obvious as it seems
Color change in the green anole has little to do with the background upon which the animal rests (although the colors it exhibits are usually cryptic). Cool or stressed anoles are brown in color, while warm, resting individuals are pale green and warm, active animals are bright green. Anoles involved in aggressive displays develop a black patch behind the eyes.

Unique Climbing Aids
Green anoles are assisted in climbing by transverse lamellae on the bottoms of the toes and feet. These thin structures are divided by thousands of grooves, and provide excellent traction against tiny irregularities in the surface upon which the lizard is moving. Utilizing the lamellae, anoles can even grip dirt particles lodged on glass, and hence climb window panes and aquarium sides easily.

Cold Tolerance and its Conservation Implications
Research has demonstrated that anoles from south Florida lack the cold tolerance exhibited by those in north Florida, and could not survive the winters there. Information such as this is vital in planning reintroduction and captive breeding programs for animals with large ranges. Inter-breeding animals that originate in widely different parts of their range can have disastrous consequences, despite the fact that they are of the same species.

In one case, ibex (mountain dwelling goats) from several European countries were released in the Pyrenees Mountains, to bolster the local population. The animals reproduced, but the offspring resulting from the crossing of native and non-native ibex were genetically programmed to give birth in mid-winter, and the population eventually became extinct.

Onto captive care next time. Until then, please write in with your questions and comments. Observations from those of you who live in anole territory would be most appreciated. Thanks, Frank Indiviglio.

An interesting summary of research being conducted on free-living green anoles by students at UT Knoxville is posted at:

http://eeb.bio.utk.edu/echternacht.asp

The Green Anole (Anolis carolinensis carolinensis) in the Wild and Captivity; – Natural History – Part 1

The green anole has long been a pet trade staple, but these active, attractively-colored little lizards have quite an interesting natural history as well. Today we’ll take a look at how they live and cope with people, and point out some of their special traits. Next week I’ll cover their care in captivity. Classification

Family Iguanidae, Subfamily Polytrotinae.

Note: some authorities have reclassified certain Anolis species as Norops.

Green AnoleAt least 370 anole species range throughout southern North America, Central America, South America and the Caribbean. All are fairly small, slender, egg-laying lizards. Males possess a large, colorful throat fan (dewlap) that is used in territorial displays and other forms of communication; depending upon the species, the female’s dewlap is smaller or vestigial.

 The foot pads of most are equipped with lamellae (please see below) to assist in climbing. Nearly all are arboreal, with the tails of the “bush anoles” (Genus Polychrus) being prehensile. Several species, however (i.e. Genus Pristidactylus), are largely terrestrial.

Anoles feed mainly upon insects, spiders and other invertebrates. Several species have been observed to lap nectar and sap, and the Puerto Rican anole (A. cristatellus wileyae) sometimes consumes fruit.

 The green anole is the only species native to the USA, although a number of others have been introduced here (please see below). The green anole population in southwestern Florida has recently been designated as a distinct subspecies, the pale-throated green anole, A. carolinensis seminolus.

Physical Description

The green anole is slenderly built, possessed of a long tail, and reaches 6 -7.5 inches in length. The color of each individual varies from light and dark brown to pale and bright green (please see below).

 Males are larger and stockier than females and have a thicker tail base and a wider, more colorful dewlap (throat fan). The dewlap of the male is pink to pale red in color (white or cream-colored in A. c. seminolus), and is vestigial or absent in females.

 Anoles clad in various shades of blue are sometimes available in the pet trade. Arising from a genetic mutation, they are quite striking.

Range

Green anoles are found from southern North Carolina west to eastern Texas and southeastern Oklahoma and south to the Florida Keys. They also live in the Bahamas, Grand Cayman Islands, Anguilla and Cuba. There are disjunct populations in Mexico.

Green anoles have been introduced to Belize, southern Japan and Hawaii, and have established breeding populations in those areas.

Habitat

Woodland edges, pine-palmetto scrub, cypress swamps, open forests, overgrown fields, farms, parks, backyards and gardens; highly arboreal.

Status in the Wild

Green anoles adapt well to some human disturbance and may even be drawn to gardens by high insect populations and the humidity generated by frequent plant-watering. They are, however, declining across parts of their range due to over-collection and to the effects of introduced Anolis species that occupy the same habitats and compete with (the brown anole) or prey upon (the knight anole) them.

Diet

Caterpillars, tree crickets, grasshoppers, flies, beetles, moths, ants, roaches, spiders and other invertebrates; they occasionally lap over-ripe fruit, nectar and sap.

Reproduction

The breeding season extends from April to September, although it is shorter in the northern part of the range. Males are highly territorial and battle interlopers. The male’s courtship display consists of vigorous head-bobbing with continued extensions of the dewlap. The dewlap reflects ultraviolet light and is perceived by the female as brilliantly colored.

Males chase females about and grasp them behind the neck during copulation. The first eggs, 1-2 in number, are laid 2-4 weeks after mating occurs. They may be buried in soil or secreted below leaf litter or even left the surface, along a log or other structure. Eggs are sometimes deposited in substrate that has accumulated among air plants or in tree knot-holes above-ground. Additional clutches of 1-2 eggs are laid throughout the breeding season, to a total of 8-10 eggs per female. The eggs hatch in 30-45 days.

Check back on Monday for the conclusion of this article.

Until than,

Frank

Uncommon Facts about a Common Pet Lizard: The Prehensile-tailed Skink, a/k/a Monkey-tailed or Solomon Island Skink (Corucia zebrata)

Monkey Tailed SkinkThe 1,200+ skink species form the largest lizard family, Scincidae, and among them we find quite a number of unusual animals. Yet the prehensile-tailed skink manages to distinguish itself as unique in not one, but many ways.Largely unknown in the pet trade until the late 1980’s, these arboreal skinks became widely available when logging in the Solomon Islands brought their formerly inaccessible treetop homes crashing to the ground, and left the lizards in reach of collectors. I and others noticed right away that they were quite different than anything we had run across previously.

A Highly Social Lizard
The limited field studies suggest, and our captive observations support, that prehensile-tailed skinks live in hierarchal colonies (a reptilian social group is known as a circulus) and exhibit a variety of highly-developed social behaviors. Group members seem to recognize one another by scent, and mark their territories with waxy secretions. Although often found in pairs, up to 10 individuals have been collected from a single tree hollow, but the functioning of these groups is not understood.

A Placenta and a Giant Offspring
Females, which average 24 inches in length, have a true placenta. They produce 1, rarely 2, huge (to 13 inches) offspring after an amazingly long gestation period of 6 – 8 months. Esteemed veterinarian and herpetologist Dr. Kevin Wright has likened this feat to that of a woman giving birth to a 6 year old child!

Complex Parental Care
The young stay close to their mothers for some time and the females become very aggressive towards people and other skinks after giving birth. Although we do not as yet understand the interactions between adults and young, it is quite clear that those reared in isolation exhibit, if you will, “anti-social” behavior (they are noticeably more aggressive than other skinks, to the point of charging people opening the door of their cages).

Coprophagy (eating of feces) is common, and some believe that this provides the young with important intestinal flora. Breeding occurs year round in the wild and captivity. The young begin feeding at about 10 days of age, and reach sexual maturity in 10 months to 1 year.

Much More to Learn
All told, a strange and fascinating beast. Although captive longevities approach 25 years, we have yet to scratch the surface when it come to understanding prehensile-tailed skink social interactions. This is definitely an animal to focus on; I’ll cover captive care in the future…until then, please write in with your observations and questions.

The American Association of Zookeepers has posted an informative article on this species’ fascinating social structure at:
http://www.aazk.org/forum/viewtopic.php?pid=1320

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