Energy Flow through Tropic Levels - Hocus Pocus Locusts

An activity for GCSE pupils to illustrate the flow of energy through trophic levels using live locusts. This is a practical where students follow the change in mass of animals over time, and then compare it to the mass of food they are given.
Locusts make superb study animals for a wide range of topics at A-level. Living locusts can be used for a variety of respiration experiments whilst dissecting locusts is a fascinating way of illustrating an invertebrate gas exchange mechanism. It is less obvious, however, how locusts could be used at KS4. This resource introduces a new way of incorporating a display of live locusts into a GCSE topic: the flow of energy through trophic levels. This resource provides direct experimental and observational evidence of the inefficiency of energy transfer. Locusts are ideal animals for this protocol as they are easy to keep, grow very rapidly (hoppers become adults in only 3 weeks) and their food is either free (grass) or cheap (lettuce).