Complex sentence: No level of radiation treatments completely sterilized the adult males, but fecundity was reduced 33-40%; fertility (% hatched) was dramatically reduced, greater dose of radiation resulted in a sex imbalance that lowered the proportion of female progeny.
Split into simpler sentences: No level of radiation treatments completely sterilized the adult males, but fecundity was reduced to 33-40%. Fertility (% hatched) was dramatically reduced, and greater doses of radiation resulted in a sex imbalance that lowered the proportion of female progeny.