|
 |
Photo Library: Insects
Sunflower Stem Weevil
The sunflower stem weevil, Cylindrocopturus adspersus (LeConte)
The economic threshold for the sunflower stem weevil is one adult per three plants. However, sampling for adults is difficult because they may be on both leaf surfaces, the stem, in leaf axils, within dried cotyledons, or in soil cracks at the base of the plant. They also fall from the plants when disturbed and remain motionless. The use of foliar insecticides at the 8 to 14 leaf stage has been effective in reducing larval populations and stalk lodging. Insecticides applied in-furrow at planting also have shown efficacy in reducing numbers of larvae. Delayed planting was valuable in both the northern and southern Plains in lowering larval densities in stalks.
Name: Damaged field
Description: Damaged field due to stem weevil
ID Name: sun811n
Size: 61K
![](/images/dot_clear.gif")
Name: Feeding damage in stalk
Description: Damage in stalk due to feeding of stem weevils
ID Name: sun809n
Size: 67K
Name: Larvae in stalk
Description: Stem weevil larvae inside sunflower stalk
ID Name: sun810n
Size: 51K
|
|
Name: Stem weevil larvae
Description: Multiple stem weevil larvae
ID Name: sun808n
Size: 94K
Name: Sunflower Stem Weevil
Description: An adult sunflower stem weevil on a leaf.
ID Name: SUN026
Credits: NDSU Ext. Bulletin 25
Size: 226K
Name: Sunflower Stem Weevil Larva
Description: Sunflower stem weevil larva on a blue background.
ID Name: SUN027
Credits: NDSU Ext. Bulletin 25
Size: 58K
|
|
|
