Seasonal occurrence of aphids and natural enemies in wheat and associated crops

We monitored experimental plantings of winter wheat and 12 other grain and forage crops for aphids and aphid natural enemies throughout the growing season of each crop for three years. Sorghum (Sorghum vulgare Prescott), cotton (Gossypium hirsutum L.), and winter canola (Brassica napus L.) hosted aphids and predators and parasitoids of cereal aphids during summer months. Winter canola also harbored aphids and predators and parasitoids cereal aphids during autumn and winter. Legumes harbored aphids and natural enemies nearly the entire year. However, parasitoids that attacked aphids in legumes did not parasitize cereal aphids in winter wheat except for the English grain aphid. Sitobion avenae (F.), which was an uncommon species in winter wheat.