Lygus spp. (Heteroptera: Miridae) host-plant interactions with Lesquerella fendleri (Brassicaceae), a new crop in the arid southwest.
Lesquerella fendleri is a new crop being cultivated in the arid Southwest for the hydroxy fatty acids found in its seed oils; however, little is know about the agricultural pests that will affect the seed production of this crop or the role the crop may have as a possible source or sink for current agricultural pests in the Arizona landscape. In the early spring, lygus bugs, some of our most important agricultural pests, are normally found in relatively small numbers on weeds; however, as lesquerella production increases, it may serve as an important early-season host for lygus. Here we present results from olfactometer bioassays that showed a significant attraction by Lygus hesperus females to volatiles associated with flowering lesquerella. Headspace volatiles of flowering lesquerella were collected and identified by gas chromatography-mass spectrometry, and phenylacetaldehyde (PAA) was found to be the major component, followed by benzaldehyde and Z-3- hexenyl acetate. In the field, we examined the Lygus spp. complex, as well as the prevalence of other herbivores and select predators, and monitored their responses to unbaited sticky traps of various colors and PAA-baited green and blue sticky traps. Green, blue, and clear sticky traps captured significantly more Lygus spp. (L. elisus in particular) than opaque yellow and red traps, but PAA-baited blue and green traps did not capture more lygus than unbaited traps. Collops spp., however, were collected in higher numbers on PAA-baited traps, suggesting that this compound might provide a means of recruiting and/or retaining this particular natural enemy.
U.S. Arid-Land Agricultural Research Center, USDA-ARS, 21881 North Cardon Lane, Maricopa, AZ 85238, USA.
Jacquelyn L
JL
Blackmer
John A
JA
Byers
D000818:Animals; D019607:Brassicaceae / Q000469:parasitology*; D003116:Color; D005260:Female; D020062:Heteroptera / Q000502:physiology*; D007300:Insect Control / Q000295:instrumentation / Q000379:methods; D009812:Odorants; D015206:Southwestern United States