Monday, March 8, 2010

Stick Bug Feeding

During the 11 years since the opening of the Ackerly Family Gallery, Pacific Science Center has maintained exhibits of Australian Prickly Sticks (Extatosoma tiaratum) and Vietnamese Stick Insects (Baculum extradentatum). They are visually and behaviorally interesting and have been very popular with the public.

For most of that time we have fed both on blackberries (Rubus spp.). Blackberries have the advantage of growing locally year round, making them relatively easy to obtain. Not surprisingly, however, they are not too popular with the staff taking care of the stick bugs. Aside from the obvious problem of thorns, they have a tendency to wilt rather quickly which requires changing out the feeding material in the cages weekly.

A short while ago, we learned that a colleague in another institution was having some success feeding his Australian Sticks Wax Myrtle (Myica californica). This shrub, like the blackberries, has the advantage of growing year round in the northwest and Pacific Science Center has the advantage of having a good deal of it in the plantings on our grounds. In addition, it seems to have a longer “shelf life” on exhibit so it doesn’t need to be changed out as often. Best of all – NO THORNS!!

We decided to give it a try. The Australian Sticks took to it like a duck to water. We have now successfully reared them from egg to adult and seen eggs from insects raised on the new diet.

But, the Vietnamese Sticks did not seem to care for it nearly as much. They would nibble on the myrtle but did not seem to be thriving. To meet their dietary preferences and maintain some of the advantages of the myrtle, we now dress the Vietnamese Stick Insect cage with a large bunch of myrtle, for appearance, and place a smaller bunch of blackberries in a container behind it where it is easily accessible from the cage opening. This way, we can change out the blackberry branches more often while leaving the myrtle in place until it begins to look wilted which generally is much longer that the blackberries. In addition to its good looks, the myrtle provides ample climbing surfaces so that younger stick insects can spread out without risk of thorns.

Bottom line, happy stick bugs and happy caretakers!

-Dan Warner, Animal Caretaker


  1. Stick insects also like to eat English ivy. That's what we used to feed ours and they thrived and reproduced on that diet.

  2. Several years ago PSC Animal Care staff tested various kinds of evergreen foliage on our stick insects as an alternative to blackberry. We tested Mountain Ash, Hawthorne and various Rosacea. We even tried English ivy which is fed to Indian or Laboratory stick insects (Carausius morosus). The only foliage that our Australian sticks devoured was Salal (Gaultheria shallon), a northwest evergreen groundcover that is not as abundant as blackberry.

    Ironically, we didn't try Wax Myrtle which literally grows under our noses!