We’ve been talking lately about how we seem to be two to three weeks ahead of schedule weatherwise. Alfalfa has really been growing and will likely be turned to hay as soon as weather allows.
Because of degree days, the alfalfa weevil is a little ahead of schedule too. A mild winter didn’t hurt this insect much since they overwinter in debris on top of the ground. The good news is that it’s usually only an issue for the first growth.
Female weevils deposit their eggs in alfalfa litter, stubble and fresh stems. A yellowish legless larva with a black head emerges from the egg and climbs up to feed on the end of the plant. As the larva develops, it becomes green.
A full-grown larva is about 3/8” long. Normally, it takes about three weeks for the weevil to go through the larval stages. When fully grown, the larva spins a cocoon on the leaves of the alfalfa plant or among debris on the ground. The larva pupates within this cocoon and the adult weevil emerges in about 10 days.
After feeding for a time, it flies from the field and remains inactive during the summer. The adult will return to an alfalfa field in the fall. It will lay some eggs in the fall and most of them the following spring.
Alfalfa weevil larvae are active from late April though early June. Initial symptoms are tiny holes in the terminal leaves. As the larvae grow, they move down the stems and feed along the edges of the fully expanded leaves. If many leaves are eaten, the field can take on a gray or frosted appearance.
Weevil feeding not only reduces crop yield, but also lowers quality. Leaf loss greatly reduces the protein content and digestibility of the harvested crop. The alfalfa weevil is normally a first cutting pest, but occasionally damage regrowth with resulting losses on the second crop.
The best alfalfa weevil management decisions are based on stem sampling procedures. If this information is not available then control is recommended when 25-50 percent of the tips are being skeletonized and three or more larvae can be found per stem.
Routine stubble sprays are not justified. If early harvest was used as a weevil management tool, there occasionally may be sufficient larvae or newly-emerged adults present to justify an insecticide application. Watch such fields carefully for the normal green-up that indicates active regrowth.
Surviving larvae may feed on developing leaves and new adults can cause “notch-like” feeding holes on leaves giving them a feathery appearance. To protect honeybees, do not make insecticide applications when the crop or weeds are blooming.
The 54th annual Whitaker Bank Farm/City Banquet is this Thursday night, April 19.
The banquet is at the Capital Plaza Hotel, Wilkinson Blvd., beginning at 6 p.m. with an opportunity to mingle and visit the various sponsors’ booths. Dinner will be served around 6:45.
Tickets are $10 with a portion going to the local high school FFA chapters. Stop by the Farm Bureau Office on Wilkinson Boulevard or the Frankfort Chamber of Commerce on the corner of Capital and Second Streets for your tickets. Monday is the last day to pick up tickets.
The other half of the Farm/City Banquet as you know is the Farm/City Field Day. This year the Field Day is July 12 in the Forks of Elkhorn area at the Peyton Farm. We look forward to seeing you at the banquet and again, Thursday July 12 for a farm tour and another fine meal. For more details contact the Extension Office at 695-9035.
Bob Ricks retires
Many of you have worked with Bob Ricks through the NRCS. He is retiring from his job as a Soil Conservation Technician. There will be an open house on Thursday, April 26, 2-5 p.m. at the Frankfort Service Center, 103 Lakeview Court. Light snacks and drinks will be provided. Come by and visit with Bob and remember old times.