Rearing Ambrosia Beetles in Tubes

Fig: Peter Biedermann’s brood of Xyleborinus saxeseni inside a tube with artificial medium.

One of the coolest features of ambrosia beetles is that you can rear them on artificial media and observe them as they go about their lives. Like an ant farm in a test tube.

This is a technique perfected mostly by Dale Norris and his colleagues in the 70’s (Norris & Chu, 1985, among many of their publications). Peter Biedermann has also tested various approaches (Biedermann et al., 2009)

Recipe

Ingredients: 75 grams of sawdust, 40 grams of refined mycological agar media, 500 ML of water. Optional: 0.35g of streptomycin.

Mix the sawdust and refined mycological agar media and heat them to 125 °C for twenty minutes. Pour the mixture in tubes, autoclave, allow them to cool down to room temperature. Introduce ambrosia beetles.

The optional streptomycin is an antibiotic that we use sometimes when we know that the beetle to be reared is likely to come in with a lot of bacteria on its body and we want to prevent that bacteria from thriving in the media before the natural beetle fungus can become established. If you opt to use streptomycin, add it after autoclaving but before you add the beetles.

With luck and sterile handling, ambrosia beetles will start a gallery in the tube and the tunnels with brood and fungus should be visible through the glass. The trick is to pick the right beetle and keep the rearing tubes clear of fast-growing opportunistic fungi.

So far, we’ve had the best luck with Xylosandrus germanus. Peter Biedermann has also had good success with the more picky Xyleborinus saxeseni. Dr. Norris with his team did most of their experiments on Xyleborus ferrugineus.

With a bit of further development, these techniques may eventually facilitate the establishment of even more species of fascinating and genetically unique ambrosia beetles as a laboratory model system for the study of symbiosis (Norris, 1993).

Fig: Artificial diets can be used for rearing large numbers of ambrosia beetles. Each of the tubes below houses a gallery of Xylosandrus germanus. Photo J.H.

References

Norris, D.M. (1993) Xyleborus ambrosia beetles – a symbiotic ideal extreme biofacies with evolved polyphagous privileges at monophagous prices. Symbiosis, 14, 229-236.

Biedermann, P., Klepzig, K.D., & Taborsky, M. (2009) Fungus Cultivation by Ambrosia Beetles: Behavior and Laboratory Breeding Success in Three Xyleborine Species. Environmental Entomology, 38, 1096-1105.

Norris, D.M. & Chu, H. (1985). Xyleborus ferrugineus. In Handbook of Insect Rearing (ed. by P. Singh & R.F. Moore), pp. 303-315. Elsevier, Amsterdam.