There was an error published in Eqn 3 (p. 2156) of J. Exp. Biol. 210, 2154-2162 and in Eqn 2 (p. 311) of J. Exp. Biol. 211, 310-316.

In both papers, the following equation was written incorrectly as:
formula
The equation should have read:
formula
The authors apologise for any inconvenience this may have caused but assure readers that the error was typographical and does not affect the data, results, interpretations or conclusions of either paper.