FusionDex

Cactsect climbs up on top of cacti to drain them of water and nutrients. Once the cactus is a dry husk, Cactsect will leap down and wander the desert. If it cannot find another cactus, it will start hunting other Pokémon instead.

Cactsect are known to infest the roots of large trees en masse and drain nutrients. After spending thousands of years in harsh deserts, its blood transformed into the same substances as sand.