| Nombre científico |
Tipo de plaga |
| Oat golden stripe virus |
Virus |
| Oat sterile dwarf virus |
Virus |
| Oculimacula yallundae (Wallwork & Spooner) Crous & W. Gams |
Hongo |
| Odoiporus longicollis (Olivier) |
Insectos |
| Oidium heveae B.A. Steinm |
Hongo |
| Okra mosaic virus |
Virus |
| Olive latent ringspot virus |
Virus |
| Omphisa anastomosalis Guenée |
Insectos |
| Onion yellow dwarf virus |
Virus |
| Ootheca mutabilis Sahlberg |
Insectos |
| Operophtera brumata Linnaeus |
Insectos |
| Ophiomyia phaseoli Tryon |
Insectos |
| Ophiostoma piceae (Munch) H. Sydow & Sydow |
Hongo |
| Opisina arenosella Walker |
Insectos |
| Opogona sacchari Bojer |
Insectos |
| Opuntia aurantiaca Lindl |
Maleza |
| Orgyia postica (Walker) |
Insectos |
| Ornithogalum mosaic virus |
Virus |
| Orobanche spp. (Excepto: Orobanche crenata Forssk.; Orobanche minor Sm.) |
Maleza |
| Orseolia oryzae (Wood-Mason) |
Insectos |
| Orseolia oryzivora Harris & Gagné |
Insectos |
| Oryctes boas Fabricius |
Insectos |
| Oryctes monoceros (Olivier) |
Insectos |
| Oryctes rhinoceros Linnaeus |
Insectos |
| Oryza longistaminata A. Chev. & Roehr |
Maleza |
| Oryza punctata Kotschy ex Steud |
Maleza |
| Ostrinia nubilalis Hübner |
Insectos |
| Otiorhynchus ovatus Linnaeus |
Insectos |
| Oulema melanopus (Linnaeus) |
Insectos |
| Oulema oryzae Kuwayama |
Insectos |