hmm your aperture is way too low for macro to work well - you really want something greater than f8 and many here seem to use f13 as a good place to set the aperture for macro insects.
This will give you a greater depth of field thus letting you get more of the insect in focus - and should be doable with the 100macro handheld - boost your ISO up to something like 400 or even 800 to keep the shutter speed up.