Stems bearing egg masses of the western tent caterpillar (Malacosoma californicum), collected in Arizona and northern New Mexico during 1977–1980, had mean diameters between 2.9 and 4 mm. Mean lengths of the egg masses were consistently between 11 and 14 mm.
Schmid, J. M.; Farrar, P. A.; and Ragenovich, I.
"Length of western tent caterpillar egg masses and diameter of their associated stems,"
Great Basin Naturalist: Vol. 41
, Article 14.
Available at: http://scholarsarchive.byu.edu/gbn/vol41/iss4/14