Answer
For frogs: 45 (30+15) minutes total per frog, 10 joules per frog=13.3 joules per hour. (1 1/3 frogs per hour)
For crickets: 15 (12+3) minutes total per cricket, 2 joules per cricket=8 joules per hour (4 crickets per hour)
The stream is still the best place to hunt.
Work Step by Step
Here add the search and subdue/consume times for each kind of prey and use the data to find energy obtained per hour to decide where it is best to hunt.