Based on the study done by the Japanese Centre for Applied Entomology and Zoology the tobacco beetle eggs will experience an 80% Hatch rate at 68degrees but all eggs will die withing 6 weeks at 62.5 degrees.
The study is somewhat interesting and what I used to base my freezing process around.
The archive of the article can be found here
http://www.jstage.jst.go.jp/article/aez/41/1/87/_pdf