  Charles Suh and his colleagues at the Agricultural Research
Service (ARS) Areawide Pest Management Research Unit in College
Station, Texas, have found a pheromone formula that is
attractive to a major milkweed pest, the milkweed stem weevil.
The discovery stems from research originally designed to help
improve pheromone lures used in Texas to monitor the boll
weevil, a major pest of cotton. The lures haven't always been
effective, so the researchers worked with the pheromone
manufacturer to improve the pheromone lure used in the traps.
The researchers set up traps along roads in Texas to compare the
standard and experimental lures for attracting boll weevils.
They checked the traps once a week from mid-May to mid-June,
replacing the lures every other week.  They soon found that the
experimental lures were attracting a type of weevil distinctly
different from boll weevils. The weevils were identified as
milkweed stem weevils, Rhyssomatus lineaticollis. The
researchers initially discounted the number of mil