What is the size and time for the 3rd instar maggot stage?

• A. 5 mm long after 1.8 days
• B. 10 mm long after 2.5 days
• C. 14-16 mm long after 4-5 days
• D. 2 mm long after 3 days

Answer: (C)

The 3rd instar is the final larval stage before pupation, and it represents the largest size achieved before metamorphosis. At moderate temperatures, blowfly larvae reach about 14–16 mm in length by roughly day 4 to 5 after egg hatch, which is why the pairing of 14–16 mm with 4–5 days best fits this stage. The smaller sizes and shorter times point to earlier instars (first or second), not the last larval stage, so those options don’t match the typical growth pattern for the 3rd instar.