Catalyzes juvenile hormone hydrolysis. Degrades juvenile hormone III (JH III) about 3 times and 5 times slower than juvenile hormone I (JH I) and II (JH II), respectively. Degrades cis-stilbene oxide and trans-stilbene oxide about 18 and 43 times slower than JH III, respectively. cis-stilbene oxide + H2O = (1R,2R)-hydrobenzoin 1-(4-methoxyphenyl)-N-methyl-N-[(3-methyloxetan-3-yl)methyl]methanamine + H2O = 2-{[(4-methoxybenzyl)(methyl)amino]methyl}-2-methylpropane-1,3-diol Optimum pH is 7.5-8.0. Activity decreases rapidly below pH 7.0 and above pH 9.0. Activity increases as temperature increases from 0 to 37 degrees Celsius. Homodimer. Expressed in fat body, foregut and midgut but not in brain, subesophageal ganglia or silk gland of larvae on day 1 of fifth instar. Expressed in fourth and fifth instar larvae. Initial levels decline until day 2 of fourth instar but increase sharply on day 3. Levels do not significantly change on days 0 and 1 of fifth instar, increase on day 2 before falling again on days 3-4 to the level seen at day 2 of the fourth instar. Expression then remains low until the end of the instar. Belongs to the peptidase S33 family.