Conserving the Past

The 99 year old wasp nest collected in Guyana in 1916.

One of the highlights of my time thus far at the Bruce Museum has been caring for a specimen collected by our first curator, Paul Griswold Howes. The specimen is a mud wasp (Trigonopsis howesi) nest from Guyana. This specimen was collected by Howes in 1916 on an expedition with William Beebe. The nest was found attached to the underside a palm frond in the village of Kartabo at the junction of the Kayuni and Mazaruni rivers in Guyana. 

This species, like other mud wasps, create intricate nests for their eggs and larvae from clay and saliva. The female wasps make small chambers about the width of a pencil. They hunt for prey such as spiders and use their stingers to inject a paralyzing venom. They then place one or more of these a paralyzed prey into a chamber, lay an egg, then seal it up. When the egg hatches the larvae has fresh food to feed on until it metamorphoses into an adult wasp.

Paul Howes' wasp nest in 2015; broken in two pieces and crumbling.

At least one of the five nests that Howes collected contained viable eggs or larvae which later hatched out when brought back to the museum. After the wasp transformed into an adult and chewed out of the nest chamber it was preserved for identification. He originally categorized them as the species Trigonopsis abdominalis and at least one specimen made it into the collections of the United States National Museum of Natural History (Smithsonian Institution). In the mid-1970s, an entomologist, Dr. Colin Vardy, at the Natural History Museum in London as working on a revision of the genus Trigonopsis. Dr. Vardy came across the USMN specimen and noticed it was different and not abdominalis at all. In 1978 he published 'A revision of the Neotropical wasp genus Trigonopsis Perty (Hymenoptera: Sphecidae).'

In this paper he described Paul Howes' wasp as a new species and named it after Howes. After Howes' death in 1984, at least four nests were sent to the University of Connecticut at Storrs. In the early 1990s, three nests were sent back to the Bruce Museum; one for the museum and two for Dr. Vardy in London. 

Slowly dripping resin solution onto the nest.

I recently came across our nest in the collections storage. It was in surprisingly good shape despite being ninety-nine years old and having being shipped around as much as it had. Despite its good condition, a fair amount of deterioration and crumbling had occurred. The decision was made to perform some conservation work in order to further preserve the specimen.  I had to very gently handle the nest and shake of all of the crumbled bits. I then used a resin material dissolved into acetone as a 10% solution to infuse the dried mud structure. This was done by using a hypodermic needle and syringe to drip small amounts of the solution onto the nest in stages to make sure the nest had fully absorbed the liquid and diffused it throughout. The nest is now fully preserved and with a bit of luck may be available to researchers in another ninety-nine years!

- Tim Walsh, Manager of Natural History Collections and Citizen Science

Fully preserved nest of the wasp species Trigonopsis howesi.