Sphecid wasps, Passaloecus cuspidatus were observed gathering fresh pine resin (Pinus strobus) which they used for creating partitions and closures in their nests. Based upon measurements taken of the cells, and an estimate of the load carried by the wasps, the number of collecting trips made by the wasps was correlated with the quantity of resin contained within the nest partitions and closures.
Fricke, John M.
"Economics of Cell Partitions And Closures Produced by Passaloecus Cuspidatus (Hymenoptera: Sphecidae),"
The Great Lakes Entomologist: Vol. 28
, Article 6.
Available at: https://scholar.valpo.edu/tgle/vol28/iss3/6