Feeding live silkworms to Bearded dragons

Silkworms, also called ‘silkies’, are the larval (or caterpillar) stages of the Mulberry silkmoth (Bombyx mori). They are generally cultured privately on a small scale or commercially on farms for their ability to produce silk. With their high protein and relatively low-fat content, silkworms are considered to be amongst the best insect foods for Bearded dragons.

Although their natural life cycle is seasonal, silkworms are easy and relatively cheap to keep and culture. Other than food items for Bearded dragons and other reptiles, silkworms are popularly cultured on large scale for their ability to produce silk.

In some countries, silkworms are readily available from specialized pet shops and online retailers (Buy live silkworms from Amazon.com ). Silkworms are quiet, slow-moving, fairly odorless, and need little maintenance and relatively small amounts of space.

Feeding live silkworms to Bearded dragons

Silkworm nutritional values*

Silkworms offer great value as food for Bearded dragons. When looking at their nutritional composition, they are high in protein, vitamins, calcium, and other minerals and low in fat:

  • Moisture 20% (5)
  • Total protein 59% (5) (17)
  • Total fat 17% (5) (17)
  • Calcium: Phosphorus ratio 1:2 (13)

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

When comparing silkworms with other crawling food such as mealworms (T. molitor), they have similar amounts of protein (ca. 59% (5) (17) vs. 54% (1) (2) (4) (5) (6) (8) (9) (14) ), less fat (ca. 17% (5) (17) vs. 30% (1) (2) (5) (6) (7) (8) (9) (14) ), more usable calcium (Ca:P ratio of about 1:2 (13) vs. 1:14 (5) (6) (8) (9) (11) (14) (18) ) and are just as tasty. When compared to crickets (A. domestica)silkworms have similar protein levels (ca. 64% (3) (5) (6) (8) vs. 59% (5) (17) ), less available calcium (ca. 1:5 (6) (8) (18) vs. 1:2 (13) ) and similar amounts of fat (21% (3) (5) (6) (8) vs. 17% (5) (17) ).

Silkworm sizes

  • Hatchling / first instar 3 mm
  • Second instar 9 – 19 mm / 3/8  – 3/4 ” (small silkworms)
  • Third Instar 19 – 31 mm  / 3/4 – 1 1/4″ (medium silkworms)
  • Fourth instar 31- 44 mm / 1 1/4 – 1 7/8 ” (large silkworms)
  • Fifth instar 50 – 75 mm / 2 – 3 ” (x-large silkworms)
  • Moth has a wingspan of 40 to 50 mm / 1.5 “

Feeding silkworms to Bearded dragons

When available, silkworms can be fed to any size and age Bearded dragon. They are considered palatable (tasty) and are readily accepted by Bearded dragons and other insectivorous reptiles (making them a great choice for picky eaters too). Silkworms have soft bodies that make them easy and safe to swallow and digest. Because of their high protein and available calcium levels, they are popularly fed to gravid female and growing Bearded dragons.

Silkworm life cycle

Silkworms hatch from eggs produced by Mulberry silkmoths. After hatching, a silkworm will grow through several larval stages before pupating and emerging as a silkmoth again.

The life cycle of silkworms (Bombyx morio). Image by B kimmel (CC BY-SA 4.0)

Newly hatched silkworm larvae are very tiny and will eat for anything between 12 and 56 days, consuming large amounts of mulberry leaves. The time it takes a silkworm to grow is dependent on the environmental temperature and the availability of food. Colder temperatures will prolong this period and vice versa. During their growth period, they will molt four times. The times between their moltings are called instars. The larvae of all four of these stages (collectively called silkworms), can be fed to Bearded dragons.

After the last molting and being about 50 to 75 mm / 2 to 3 “, the silkworm will stop eating and create a cacoon from its own silk. Metamorphosis (changing into a moth) will take two to three weeks to complete. Moths that emerge from the cocoon will not eat at all. Their only goal is to find a moth of the opposite sex, breed, and lay eggs again. A female silkmoth can lay anything from 200 to 500 eggs. Silkmoths are generally not fed to Bearded dragons.