Quantitative changes in hydrocarbons in fecal pellets of Incisitermes minor over time may predict the active or inactive status of colonies

Hydrocarbons extracted from fecal pellets of drywood termites are species-specific and can be used to identify termites responsible for damage. When fecal pellets appear after remedial treatment, it can be difficult to determine whether the termites in the structure are alive or dead. We examined hydrocarbons of fecal pellets of Incisitermes minor aged for one week, one month, three months, and one year after collection. The hydrocarbons changed quantitatively over time. Nineteen of the 73 hydrocarbons had significant linear increases or decreases over time. When the sum of the hydrocarbons with significant slopes are regressed over time, an index with a highly significant linear correlation (r2=0.89) results. These quantitative differences between hydrocarbons peaks that are increasing or decreasing in abundance can be used to determine the age of the fecal pellets, and thus help determine whether the colony that produced them is active or inactive.