DY: R’ Shlomo Zalman said (I think R’ Shachter said he heard this straight from him, I think) very much like R’ Dessler. Basically, Chazal knew they were Muttar. They thought the reason was that they’re not Pare V’rave. They got that wrong. The real reason is… eggs are too small? Slifkin basically follows this line. He says that Chazal’s Mesorah on the Halachah is indisputable (he admits the Pachad Yitzchak is a minority). They definitely got the Halachah right. He just holds that they can get the scientific reason wrong.
(Now, this leads to a Chiluk that if Chazal say a scientific fact and extrapolate a Halachah from that, maybe we have to worry about the Halachah being incorrect. But as long as they are only using science to explain what they know the Halachah to be, then he can say that the science is wrong but the Halachah doesn’t change.)
By the way, the T’shuvos Nezer Kohen (very new) says Chazal were actually right. He says they mean that it’s Muttar to kill any insect that reproduces via parthenogenesis.