Sunflowers are native to the United States.
Sunflowers are large flowers with colors ranging from yellow to rust. There are both annual and perennial varieties. All require regular water and large species require rich, moist soil. Sunflowers are native to the United States and, according to North Dakota State University, a number of pests that once fed on native plants now feed on cultivated varieties. Does this Spark an idea?
Seedling and Root Feeders
Various larvae feed on the seedlings and roots of the sunflower. These insects include wireworms, cutworms, sunflower root weevils and carrot beetles. Wireworms are the larvae of click beetles and are hard, smooth and thin. They can feed on a plant as larvae for two to three years and overwinter in the soil. There are three species of cutworm: the darksided cutworm, redbacked cutworm and dingy cutworm. These are fly maggots that are more likely to live in areas where grass crops were grown the year before. Sunflower root weevil larvae are about 1/4-inch long with a white body and brown head. Carrot beetle larvae are about 1/4-inch long and are white to bluish with a dark head.
Stem feeders include beetle larvae, Dectes stem borer, sunflower stem weevil and the black sunflower stem weevil. The sunflower maggot is also a known pest and is present throughout the United States. The Dectes stem borer is active in Texas and North and South Dakota. It is yellowish with fleshy protuberances on its first seven abdominal segments. The sunflower stem weevil is found west of the Mississippi and is creamy white with a small brown head. The black sunflower stem weevil looks similar to the sunflower stem weevil but is smaller.
The palestriped flea beetle and the sunflower beetle larvae along with the thistle caterpillar are voracious foliage feeders. The palestriped flea beetle’s life cycle is still not well known, but it feeds on leaves, giving them a lacy appearance. The sunflower beetle larvae are humpbacked and yellowish green with a brown head. Thistle caterpillars are the larvae of the painted lady butterfly. They are brown to black with spines and a pale yellow stripe on each side.
Head and Seed Feeders
Beetle larvae that feed on sunflower heads include the sunflower headclipping weevil, the gray sunflower seed weevil and the red sunflower seed weevil. All three are cream-colored, C-shaped grubs. The larvae of several moths are known to feed on sunflower flowers including the banded sunflower moth, the sunflower bud moth and the sunflower moth. All three cause extensive damage. Fly larvae that feed on the head and seeds of sunflowers include the sunflower midge, the sunflower receptacle maggot and the sunflower seed maggot.