Live-trapped voles 1.9 (73) 3.4 (29)
Snap-trapped voles 1.1 (26) 1.3 (27)
[Footnote C: The fleas on the live-trapped voles are all _Ctenophthalmus
pseudagyrtes_ Baker, and those on snap-trapped voles represent several
species (see table 2). The numbers in parentheses are the numbers of
voles examined.]
Table 5 shows the average degree of infestation for ten months of an
eleven month period. The monthly averages for the most part show no
variations. The latter half of February provides an exception in that a
series of 22 snap-trapped voles and 11 live-trapped voles taken at that
time had on the average, 9.7 and 5.3 fleas respectively. Pine mice
(_Pitymys nemoralis_) occurred in small numbers in the area where
_Microtus ochrogaster_ was live-trapped, and _Ctenophthalmus
pseudagyrtes_ was the flea found to be common on both of these voles.