You can grab a harvester off a tree. Just grab at the base of the tree they're on and you'll get them.

The genealogy disappears when they turn 18.
_________________________
2X Intel Pentium4 CPUs, 3.40 GHz
2 GB RAM
232GB-NTFS & 180GB-FAT32
Windows XP Home SP2
DirectX 9.0c (4.09.0000.0904)
NVIDIA GeForce 7600 GS 512.0 MB
Realtek AC97 Audio