Recently we have found about 6 of the very large tomato hornworms(?) on our 2 tomato plants. They look very similar to the black and white photo on your website. Half of them had white oval fuzzy pieces all over the outside of their bodies. What are those? Eggs? We took them off the plant by either breaking the stems they were on or by picking them off with a Popsicle stick. They are eating our plants down to the stalks!
Those “eggs” you saw were in fact the cocoons of a parasitic Braconid wasp which was devouring the tomato hornworm alive. Nature’s own pesticide.