Try to follow one old lady bug (5)
I believe the answer is:
imago
'bug' is the definition.
(I know that imago is a type of bug)
'try to follow one old lady' is the wordplay.
'try' becomes 'go' (both can mean an attempt).
'to follow' is a charade indicator (letters next to each other) (some letters go after or follow others).
'one' becomes 'i' (Roman numeral).
'old lady' becomes 'ma' (both can informally mean mother).
'i'+'ma'='ima'
'go' put after 'ima' is 'IMAGO'.
(Other definitions for imago that I've seen before include "Beetle, for example" , "Winged insect -- amigo (anag)" , "Final stage of an insect's development" , "butterfly, for example" , "idealised figure" .)