Catch insects here and there (3)
I believe the answer is:
net
'catch' is the definition.
(net can mean to catch)
'insects here and there' is the wordplay.
'here and there' indicates alternate letters (here and then can mean regularly).
The alternate letters of 'insects' are 'NET'.
(Other definitions for net that I've seen before include "What separates court opponents" , "After taxes" , "Meshwork" , "Open-meshed material (used for catching things?)" , "Catch -- after all deductions" .)