Here are all the bugs and fish that you won't be able to catch any more from May 1, split into separate tables for the northern and southern hemispheres, which have different creatures available at any given time. 

The big change this month is really that tarantulas and scorpions are swapping round, with the northern hemisphere now getting scorpions instead of the spiders. They operate the same way, attacking at night, and are worth 8,000 bells each. If you want to grab either before they go, follow our guide to finding a tarantula island (which should work for scorpions too).

Fish and bugs leaving the northern hemisphere

Type Name Location Size Value Time
Bug Tarantula On ground N/A 8,000 7 p.m. - 4 a.m.
Fish Dab Sea Medium 300 All day
Fish Tuna Pier Largest 7,000 All day
Fish Blue Marlin Pier Largest 10,000 All day

Fish and bugs leaving the southern hemisphere

Type Name Location Size Value Time
Bug Yellow Butterfly Flying N/A 160 4 a.m. - 7 p.m.
Bug Bell Cricket On ground N/A 430 5 p.m. - 8 a.m.
Bug Red Dragonfly Flying N/A 180 8 a.m. - 7 p.m.
Bug Darner Dragonfly Flying N/A 230 8 a.m. - 5 p.m.
Bug Banded Dragonfly Flying N/A 4,500 8 a.m. - 5 p.m.
Bug Ladybug On flowers N/A 200 8 a.m. - 5 p.m.
Bug Violin Beetle On tree stumps N/A 450 All day
Bug Scorpion On ground N/A 8,000 7 p.m. - 4 a.m.
Fish Snapping Turtle River X Large 5,000 9 p.m. - 4 a.m.
Fish Catfish Pond Large 800 4 p.m. - 9 a.m.
Fish Tilapia River Medium 800 All day
Fish Angelfish River Small 3,000 4 p.m. - 9 a.m.
Fish Betta River Small 2,500 9 a.m. - 4 p.m.
Fish Rainbowfish River Small 800 9 a.m. - 4 p.m.
Fish Moray Eel Sea Narrow 2,000 All day
Fish Ribbon Eel Sea Narrow 600 All day
Fish Giant Trevally Pier Large 4,500 All day
Fish Mahi-mahi Pier Large 6,000 All day