Palestriped Flea Beetle Back Again

       

Video   

       


The palestriped flea beetle is back again this year injuring sunflower seedlings
in central South Dakota.

I again have reports of palestriped flea beetles injuring large areas of sunflowers
in Sully and Hand counties.

Thanks to Anthony Bjerke (Centrol), Roger Plooster (Garst/Agripro), Travis
(Cone Ag), and Chad Lebrun (SDSU) for the very timely reports.  Thanks also
to Nathan Kizer (Howard Coop) for reporting the affected alfalfa field near
Howard last season (2002).

Palestriped flea beetles are about one-eighth of an inch long, black in color with
two white stripes on the back, and can both jump and fly -- hence the name "flea"
beetle.

Palestriped flea beetles chew on the true leaves, cotyledons, and hypocotyls
causing the sunflower seedlings to wilt and die. Injured leaves become riddled
with holes giving them a "lacey" appearance.

This is the fourth straight year that palestriped flea beetles have caused injuries
on sunflower seedlings in central South Dakota.

Palestriped flea beetles can cause significant stand losses in sunflower seedlings.

Spraying with an insecticide may be justified if 20 percent of the stand (1 out of 5
seedlings) show extensive feeding by the flea beetles.

Baythroid (2.8 fluid ounces per acre), Sevin XLR Plus (32 fluid ounces per acre),
Warrior (2.56 fluid ounces per acre), and Mustang (2.72 fluid ounces per acre)
were effective in reducing palestriped flea beetles in an SDSU Extension
Entomology research near Onida in 2001-2002.

SDSU Extension Entomology is currently testing various seed treatments and
insecticide sprays for potential use against palestriped flea beetles near
Agar, Selby, and Ree Heights.

Funding for these studies come from the South Dakota Oilseeds Council
and the National Sunflower Association.  Thank you very much.

Palestriped flea beetles overwinter as adults under the soil and plant residues
on the field.  They then resume feeding on weeds in the spring. For some
unknown reason, they have recently started to feed on sunflower seedlings.

Also quite worrisome are reports of palestriped flea beetles causing injuries
in alfalfa, soybean, and corn.

Palestriped flea beetles did not use to be a pest of field crops in South Dakota.
Its transformation into a pest of field crops is an example of the ability of insects
to change hosts over time.

Scientific records do indicate that palestriped flea beetles have always been
in South Dakota.  Their known plant hosts in the United States include various
weeds, potato, tomato, carrot, peanut, corn, oat, cotton, pea, beans, strawberry,
watermelon, grape, and pumpkin.

Palestriped flea beetles are considered an important pest of commercially
grown vegetables in California and North Carolina.

What caused the palestriped flea beetles to start attacking field crops in SD?
Have we been too successful in eliminating their original weed hosts?  These
are indeed very interesting questions that should keep graduate students busy
in the next few years.

On the Web:  http://plantsci.sdstate.edu/ent/entpubs/SEE_020618.htm
                      
                        http://agbionews.sdstate.edu/articles/03fleabeetle.html
 

 Last Updated on Monday, June 23, 2003 by Mike Catangui.