After years of waiting – finally!
When visiting Roi-Et in Esan (northeastern Thailand) I took the opportunity of going to their national museum. This was unusually rich in artefacts and information, well worth a visit. I saw the raw lac, i.e. the scarlet clumps excreted by the insect Kerria lacca (Homoptera/Coccoidae) and used for making shellac as a wood varnish. It has also been used as an important pigment for silk, as a cosmetic, for leather tanning and as a fruit wax. Lac and indigo gave purple colours.
I asked where I could buy it, as it would be interesting to show such a famous and formerly important natural chemical. An experienced Thai lady said with sad eyes that the days of the lac are gone, everything is synthetic now. I spoke to friends about where to find the lac insect, indicating I should like to introduce it to Dokmai Garden for educational purposes. People said that they had seen lac harvesters working in the rain trees (Samanea saman, Fabaceae) on the road to Lampang.
Anyhow, yesterday afternoon when I tied some orchids to a young Shorea roxburghii (a very important and local timber tree of the Dipterocarpaceae family, now much reduced due to logging) I jumped of joy! Here and there I could see scarlet clumps of real lac, guarded by weaver ants!
If you abandon pesticides and fire, and introduce many plant species (currently 1046 plant species) you get many new guests such as fireflies (yesterday evening at 19.30 was spectacular), birds, butterflies and now the lac insect!
Harvested sticklac (the raw lack on a stick) is ground and purified into seedlack (look like grains). Highly purified lac dissolved in alcohol becomes shellac. Lacquer is a totally different substance, based on the sap from the lacquer tree Gluta usitata (Anacardiaceae). Lacquer was a sticky insecticidal substance used to coat bamboo baskets to make them last longer.
Updated on April 1, 2012: Apparently the search function does not include words and names included in comments. I shall contact WordPress about that, but to overcome the problem in this case I here mention that tung oil from Vernicia fordii, Vernicia montana and Aleurites moluccana (Euphorbiaceae) are mentioned in a comment below.
Welcome on Sunday to listen to Pavlos’s talk and to behold the lac, an important industrial product and trading commodity for thousands of years until the mid 1800’s when synthetic chemicals were invented.
Lac production as seen at Dokmai Garden. The sticklac is a protection for the insects. By excreting sugars they also attract the Praetorian Guard (weaver ants, Oecophylla smaragdina).
Lacquerware, here Chiang Mai style, is based on the sap from the lacquer tree which also grows at Dokmai Garden.
Text & Photo: Eric Danell