Author
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Blackmer, Jacquelyn |
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Byers, John |
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Submitted to: Environmental Entomology
Publication Type: Peer Reviewed Journal Publication Acceptance Date: 7/27/2008 Publication Date: 2/1/2009 Citation: Blackmer, J.L., Byers, J.A. (2009). Lygus spp. (Heteroptera: Miridae) host-plant interactions with Lesquerella fendleri (Brassicaceae), a new crop in the arid southwest. Environmental Entomology, 38:159-167. Interpretive Summary: Lesquerella is a new crop being cultivated in the arid Southwest for fatty acids found in its seed oils. These fatty acids have many commercial and industrial uses that may make this crop important in the near future. 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 of current agricultural pests in Arizona. Lygus bugs are some of our most important pests in the Southwest. In the early spring, these insects 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 bioassays that demonstrated a significant attraction by lygus females to volatiles associated with lesquerella. These volatiles were collected and identified by gas chromatography-mass spectrometry (GC-MS), and phenylacetaldehyde (PAA) was found to be the major component. In the field, we examined the lygus bug. complex, as well as the prevalence of other herbivores and key 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 bugs (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. beetles, 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. Technical Abstract: Lesquerella fendleri is a new crop being cultivated in the arid Southwest for the hydroxy fatty acids found in its seed oils. These fatty acids have a variety of commercial and industrial uses that may make this crop extremely important in the near future. 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. Lygus spp. are some of our most important agricultural pests in the arid Southwest. In the early spring, lygus bugs 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 demonstrated a significant attraction by L. hesperus females to volatiles associated with lesquerella. Headspace volatiles were collected and identified by GC-MS, and phenylacetaldehyde (PAA) was found to be the major component. In the field, we examined the Lygus spp. complex, as well as the prevalence of other herbivores and key 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. |
