How does the personality of Earthworm contrast with the others in James and the Giant Peach?

The Earthworm has the most pessimistic personality of any of the insects in the giant peach, and he often argues with the Centipede because the Centipede has such an optimistic nature. As the Ladybird, who differs from the Earthworm in being much more motherly, says of him to James:

"He hates to be happy. He is only happy when he is gloomy."

As he himself says:

"The problem is that there is no problem."

He is also the opposite of the Centipede because he seems a bit cowardly while the Centipede is brave and sometimes too rash. He is different from Miss Spider because she is outwardly friendlier.
The Earthworm, being a pessimist, doesn't like to take too many risks. However, underneath it all, the Earthworm is a gentle creature who gets along with everyone.
The Earthworm shows he has courage when he allows himself to be used as bait to lure the seagulls.