Effects of an introduced mosquito on juvenile Tigriopus californicus (Copepoda: Harpacticoidea) in supratidal pools

The distribution of the supratidal copepod Tigriopus californicus overlaps widely with that of larvae of the introduced mosquito Aedes togoi. Overlap in resource use suggests the possibility of negative interactions between the two species. To test this possibility, we manipulated the abundance of mosquito larvae in the field and found that increasing the number of larvae reduced the number of copepodites present 28 days later. A laboratory grazing experiment demonstrated that individual A. togoi (instars 2-3) clear about 25 times more water of algae than similarly sized T. californi­ cus. Laboratory experiments also demonstrated that A. togoi can be a very efficient predator of copepod nauplii. The selection imposed by age-specific predation on cope­ pods may have some life-history consequences.