In some matings of praying mantids, the female will consume the body of the male after mating is complete. Insect biologists have debated whether or not being consumed by his mate is beneficial to the male mantid. Brown and Barry* compared the nutritional state and egg production of female mantids (Tenodera sinensis) that consumed their mate and these that did not. They found significant amounts of amino acids from male somatic tissue in the cannibalistic females coupled with a higher egg number. They conclude that males eaten by their mate can produce more offspring from a single mating than males who escape their female mate uneaten.
*Brown WD, Barry KL. 2016. Sexual cannibalism increases male material investment in offspring: quantifying terminal reproductive effort in a praying mantis. Proc. R. Soc. B 283: 20160656.