Insect boy picked up beside one road (8)
I believe the answer is:
Here is my best explanation:
'insect' is the definition.
(ladybird is a kind of insect)
'boy picked up beside one road' is the wordplay.
'boy' becomes 'lad' (lad is a kind of boy**).
'picked up' says the letters should be written in reverse.
'beside' becomes 'by'.
'one' becomes 'i' (Roman numeral).
'road' becomes 'rd' (abbreviation).
'by' backwards is 'yb'.
(Other definitions for ladybird that I've seen before include "Red beetle with black spots", "Garden beetle", "Spotted beetle", "imprint", "Beetle spotted by black", "spotted one that flies", "Beetle (or the late Mrs LBJ)", "Black-spotted red beetle", "Small flying beetle, red with black spots" and "Common insect".)