He looks like a sucking-type insect (bug) so while he could damage leaves and fruit, he won't be taking bites out of anything. What type of damage are you seeing?

On passionfruit, look for caterpillars that blend in with the leaves & stems.

The leaves are getting chewed up till there's nothing left.
Have looked for caterpillars but can't seem to find any - but the plants are covered with these little bugs which is why I thought it might be them that were responsible.
Mysterious.

OMG whatôs that? :o

phil.melville, Here is a spot that is perhaps more interesting than helpful.
I was quite surprised that there are so many pests of a quite tough plant.