Rape generally is defined as
“unlawful sexual activity and usually sexual intercourse carried out forcibly or under threat of injury against a person’s will or with a person who is beneath a certain age or incapable of valid consent because of mental illness, mental deficiency, intoxication, unconsciousness, or deception” (Merriam Webster dictionary)
Since a caterpillar is not a person, the definition misses.
Laying an egg is strictly speaking, not intercourse.
And the concept of consent in the realm of caterpillars doesn’t fit, either.
The wasp may be doing something unwelcome by the caterpillar, but it isn’t rape.