EFFECT OF TRAP COLOR, VOLATILE ATTRACTANTS, AND TYPE OF TOXIC BAIT DISPENSER ON CAPTURES OF ADULT CORN-ROOTWORM BEETLES (COLEOPTERA, CHRYSOMELIDAE)

Studies were conducted using sticky traps and corn rootworm traps in f ields of maize (Zea mays L.) after silking had occurred to determine e ffect of trap color, olfactory attractants, and type of toxic bait dis penser on captures of adult corn rootworm beetles (Diabrotica barberi Smith & Lawrence and Diabrotica virgifera virgifera LeConte). Capture of D. barberi (each sex) on sticky traps varied with color but not wit h the presence or absence of attractant (4-methoxyphenethanol [MPE]). Yellow traps captured the greatest numbers of D. barberi. Capture of D . v. virgifera (each sex) on sticky traps varied both with color and a ttractant (4-methoxycinnamaldehyde [MCHO]); interaction between color and attractant was also significant. Saturn yellow and aluminum foil t raps, each baited with MCHO, captured the greatest numbers of D. v. vi rgifera. Tests comparing commercial brands of sticky traps showed that Multigard traps captured more male D. barberi than did Pherocon AM tr aps. Unbaited Multigard traps captured the greatest number of male D. v. virgifera, whereas most female D. v. virgifera were captured on Mul tigard traps baited with MCHO. Capture of D. barberi in corn rootworm traps (vial-type traps baited with toxin and feeding stimulant) did no t vary with color or attractant (MPE). Both color and attractant affec ted capture of D. v. virgifera: traps painted Saturn yellow and baited with MCHO captured the greatest numbers of D. v. virgifera. Capture o f female D. barberi varied with the type of toxic-bait dispenser: mean capture was greatest in traps with tray-type dispensers. Implications are discussed for trapping of adult D. barberi and D. v. virgifera.