The Collaborative International Dictionary
Tritovum
Tritovum \Tri*to"vum\, n.; pl. Tritova. [NL., fr. Gr. ? third + L. ovum egg.] (Zo["o]l.) An embryonic insect which has twice cast its skin previous to hatching from the egg.
Wiktionary
tritovum
n. (context zoology English) An embryonic insect which has twice cast its skin before hatching from the egg.