You Are Here: Management Updates 1999 Archive July 12, 1999

Date: July 12, 1999
Category: Insects
Subject: Hot Temperatures, Beetle Adults, Billbugs

The weather continues to dominate insect activity. Annual bluegrass weevils are beginning their second generation in many locations, with small larvae becoming active. Large larvae (and the next round of damage) should become apparent as early as the week of 12 July in southern New England, and slightly later further north.

Japanese beetle, oriental beetle, and asiatic garden beetle adults are flying in large numbers. We just received a report of oriental beetles in the Ashland/Hopkinton area of Massachusetts. Each of these species has a similar life cycle - females will mate and begin to return to the soil within the next couple weeks to start laying eggs. Eggs must be able to absorb some moisture from soil to begin the maturation process, so unirrigated areas may see less grub activity - at least if the overall "drought" conditions continue in eastern Massachusetts. Young grubs will emerge and begin feeding on tender turf roots early in August, and then wil eat and grow to full size by mid to late September. (Note that the European chafer is a couple weeks ahead of this schedule, and adults have been flying for a couple weeks already.)

Note too that the effectiveness of insecticides varies with species, so check the label and use one that is well suited to your purpose.

With the summer heat and sporadic rainfall, don't forget to look for bluegrass billbugs in areas that look like they are experiencing "drought stress". The symptoms are virtually identical. Small legless larvae can be seen in the thatch and crowns of the plants, and these larvae deposit feces (entomologists call it "frass", at least in mixed company) that looks just like sawdust. If you see sawdust in the thatch, that is virtual assurance that billbugs are present. It may be too late to do anything this year other than manage the stress, but make a note to deal with the population next spring.

- Submitted by: Dr. Pat Vittum