Friday, April 18, 2014

Alfalfa weevils

Alfalfa weevil adults are about 3/16 of an inch in length, brown with a dark brown stripe down the back.  Weevils are a group of beetles that often have a long snout.  Larvae are legless, plump and yellow to green in color with a dark head. Both adults and larvae have chewing mouthparts.

Females lay eggs in the stems of alfalfa where the larvae develop throughout the spring.  Pupation takes place in the soil. There is one generation per year and the adults can survive 10-14 months.

Host plants include alfalfa, vetch and various clover.

So why am I, an urban agent, writing about what seems to be a field crop pest?  Well, these little guys and gals have been emerging from overwintering sites and making their way into homes and other structures.  I spoke with a Master Naturalist in Williamson county who said that someone brought in a bag full that was collected from the inside of a home.

If you are dealing with alfalfa weevils invading your house, work on exclusion techniques.  Some ideas include:

  1. reduce outdoor lighting at night or use yellow bug bulbs
  2. make sure weather stripping is in good repair around doors & windows
  3. make sure screens are in good repair
  4. seal any crack & crevices with sealant that will expand with temperature change we get throughout the year
  5. seal any pipe/ wire penetrations
If you want, you can do an outdoor treatment with pesticide around the foundation to create a barrier.  Indoor pesticide treatments are unnecessary.  Clean up any weevils found indoors with a dustpan and broom or a vacuum.

On another note....WEBINAR INFORMATION:

If you missed the webinar on ticks from the All Bugs Good and Bad series, you can find the recording here:
https://learn.extension.org/events/1381

Next month, on the first Friday....May 2nd there will be a new webinar.  This webinar will be titled "Are Those Itsy Bitsy Spiders Good or Bad?"  The 45 minute webinar will be presented at 1PM CDT and given by Dr. Nancy Hinkle and moderated by Charles Pinkston.  The webinar will highlight good qualities of spiders and their usefulness.

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