Potomac Hoppers - Spray or Harvest?

POTOMAC - Multiple species of grasshoppers are throughout Potomac Valley this summer in hayfields, gardens, roadways and lawns. Some residents were concerned enough about crop and other plant damage to request more information and reached out to Missoula County Extension office.

In response, a Potomac hopper survey was completed in June. Richard (Joe) Merenz, Gary Adams and Shayne Galford from the USDA presented a grasshopper management workshop July 11 at the Blackfoot Church of Potomac where more than 23 people attended.

Resident Denny Iverson has dealt with hoppers in the past. Although he has some at the upper end of the valley, it is not as bad up there as past years nor did it harm that area hay crop this year.

"They seem to be worse in the lower end of the valley where they hatched," said Iverson, where he does see some hay crop damage from the hoppers.

One management option is disposal by 'zapping.' Potomac resident Jeff Wilson expressed an interest in this hopper harvesting method which involves a truck or ATV-towed driven electronic mesh implement that zaps the hoppers. This method is used in Canada and some Wyoming fields and is known to be somewhat effective to try and control the hoppers.

Reduced Area and Agent Treatment (RAATs) is dispersed by ATV. According to the University of Wyoming, this method uses Integrated Pest Management or IPM strategies for hopper infestations in rangeland.

The goal of the USDA is not to eradicate all grasshoppers but keep them within controllable numbers. Merenz explained the RAAT/ATV method uses chemical control in swaths on rangeland and rough ground which the ATVs can easily navigate.

Within the swaths created by the chemical treatment dispersed by the ATV, the grasshoppers are treated. Grasshoppers can move into untreated areas outside the swaths that remain biologically balanced.

Preventative tactics were discussed. Information was provided on preventative products including Diflubenzuron, Malathion and Carbaryl and different sprayers and nozzles.

Another resident Jody Wills said the hoppers are still bad on the dryland areas and thinks the hoppers are about the same as previous years.

For management, Wills has sprayed Malathion mixture without success and now has another plan.

"We are going to try the Carbaryl bait the [USDA] suggested just to see what result we might have," she said.  

Insecticides and other treatments can be expensive. The use of RAATs mean the cost is reduced and more than 50 percent less insecticide is applied for hopper control due to a reduced area of treatment.

Some Potomac landowners are discussing the benefits versus the risks of purchasing certain mixtures as a group and bringing it to Potomac. The benefit would be more treated acreage (for hoppers) if neighbors worked together, according to Adams. Risks involve more chance for infestation of hoppers moving into the untreated areas of other landowners' property.

For more information contact the USDA at aphis.usda.gov or Missoula County Extension at 406-258-4200 or visit their website http://www.missoulaeduplace.org/