ALFALFA WEEVIL LARVAE ARE HATCHING in most areas of Oklahoma, and significant numbers of small larvae are moving into the plant terminals.  According to recommendations for sampling alfalfa to assess the need for sprays to control the weevil, field scouting should begin when numbers of Degree-Days (DD) for weevil development accumulated from January 1st reaches 150.  We are now above the level of 150 DD in nearly all parts of Oklahoma, and it is time to begin checking fields for damaging populations of this pest. 

 

In addition to the potential for damage by the alfalfa weevil, large numbers of COWPEA APHIDS (black in color) and SPOTTED ALFALFA APHIDS are being found in fields across Oklahoma.  These aphids can cause extensive stand loss, especially in seedling stands, if high population densities are not reduced with insecticide applications. 

 

At this time, it appears that 2006 may set a record for the earliest occurrence of damaging populations of alfalfa weevil, combined with the potential for heavy damage by aphids.  It is critical that farmers CHECK ALFALFA FIELDS NOW, and continue to scout fields regularly as growth of the first crop of alfalfa occurs.

 

Richard Berberet

Entomology and Plant Pathology Dept.

Oklahoma State University