Feeding butterworms (Chilecomadia moorei) to Bearded dragons

Butterworms, also known as tebo worms, trevo worms, or wood worms are the larval stage of the Chilean moth (Chilecomadia moorei). Due to their scent and bright colouration, butterworms are known to be a popular choice for Bearded dragons, but contain high levels of fat, making them better for offering as snacks.

Butterworms are native to Chile and will not be available in many other countries. Because they are difficult to culture in captivity, the majority of countries that have butterworms to trade will only have them available as an imported product. Butterworms are quiet, slow-moving, fairly odourless, need little maintenance and relatively small amount of space. They are popularly used as reptile and other pet food and for fishing.

Butterworms are considered an invasive species and are often radiated to kill bacteria and prevent them from pupating and breeding. They are also sold in a stage where they won’t eat or need to eat. Although they can be kept in this stage for long periods of time, they do start to lose some of their nutritional value after longer periods. The shelflife of butterworms can be extended with up to four months by keeping them refrigerated at temperatures of 5 – 10 °C / 40 – 50 °F. They need dry conditions to survive. If available, butterworms will be sold by specialised pet shops, bait shops and online retailers (Buy live butterworms from Amazon.com ).

Butterworm nutritional values*

As a food, butterworm larvae contain high amounts of fat and a low Ca:P ratio:

• Moisture 60% ^{(18) (19)}
• Total protein 39% ^{(8) (18) (19)}
• Total fat 74% ^{(9) (18) (19)}
• Calcium:Phosphorus ratio 1:18 ^{(18) (19)}

* Values are averages calculated from sources. Expressed as %DM except moisture.

When comparing butterworms with other crawling food such as Mealworms (T. molitor) and  Superworms (Z. morio), they have more or less the same protein (ca. 39% ^{(8) (18) (19)} vs. 49% ^{(4) (5) (8) (9) (14) (18)} & 54% ^{(1) (2) (4) (5) (6) (8) (9) (14)} ), even more fat (ca. 74% ^{(9) (18) (19)} vs. 36% ^{(5) (7) (9) (14) (18)} & 30% ^{(1) (2) (5) (6) (7) (8) (9) (14)} ), are considered more tasty and has less available calcium levels (Ca:P ratio of 1:18 ^{(18) (19)} vs. 1:9 ^{(8) (9) (14) (18)} & 1:14 ^{(5) (6) (8) (9) (11) (14) (18)} ). When compared to crickets (A. domestica), butterworms are just respectible for their fat content.

Feeding butterworms to Bearded dragons

Butterworms are typically bright orange with brick-red colouration on the back. This, together with their smell and taste, makes them very appealing to Bearded dragons. On average they measure 2 to 2.5 cm / 3/4″ to 1″ in length (var. 1.2 to 3 cm / 1/2 to 1 1/4″) making them a better-sized choice for adult Bearded dragons.

Their high fat and low Ca:P ratio makes them a poor choice as a staple for Bearded dragon food and will lead to obesity and poor growth, especially in growing Bearded dragons.

If the occasional butterworm is fed, they should be fresh. Butterworms can be fed in a shallow, escape-proof dish with calcium supplementation to stimulate its intake. Uneaten butterworms should be removed immediately after feeding is over. Other higher protein feeder insects such as crickets, silkworms, and/or Dubia roaches should make out the bulk of a Bearded dragon’s food.

Additional butterworms can be offered to breeding female Bearded dragons on a daily basis to improve the body condition between egg batches.

Butterworm life cycle

Not a lot of information is available about the life cycle of butterworms. They are the larval stages of the Chilean moth (Chilecomadia moorei), which, after mating, produces eggs, which hatches into larvae. The larvae eat vegetation (including Trevo Bush (Trevoa trinervis) leaves and dry wood) allowing them to grow and pupate again.