blow vb.1 (2 not pre-S., but ‘blowing’=‘flies’ eggs' is earlier)
1.
to inflate,
swell, puff up Tw.N. II. v.
49,
Ant. IV. vi. 34
“This blows my
heart.”
2.
(of flies) to deposit
their eggs (on) and so make foul Tp. III. i. 63, LLL. V. ii. 410,
Oth. IV. ii. 66
“summer flies . . . That
quicken even with blowing.”