Matthew J. Johnson
Dan W. Bean
Charles van Riper III
Levi R. Jamison
2018
<p><span>Timing and spatial dynamics of tamarisk (</span><i>Tamarix</i><span> spp. L.) defoliation by the biological control agent </span><i>Diorhabda carinulata</i><span> (Desbrochers) were evaluated. Relative abundance of </span><i>D. carinulata</i><span> and the phenology of tamarisk along the San Juan and Colorado rivers were recorded in 2011–2012. </span><i>D. carinulata</i><span> began reproducing in the spring when temperatures were >15°C. Variation in spring temperature-rise affected the timing of development of larvae of the first summer generation and initial defoliation of tamarisk at each site. Shortening day lengths in mid- to late-summer cued </span><i>D. carinulata</i><span> to enter reproductive diapause resulting in cessation of defoliation. The critical day length for inducing reproductive diapause was 33–47 minutes shorter than that of populations of </span><i>D. carinulata</i><span> released into North America in 2001. Variation in spring temperature-rise combined with timing of shortening day length resulted in differences in </span><i>D. carinulata</i><span> voltinism per site. During the active season, larvae were less likely to establish in areas where defoliation was >70%. Lack of reestablishment of larvae led to temporary loss of </span><i>D. carinulata</i><span> from the locations and allowed tamarisks to sprout new canopies. Defoliation of tamarisk was dictated by environmental cues and abundance of </span><i>D. carinulata</i><span>, and in turn large amounts of defoliation negatively affected abundance of </span><i>D. carinulata</i><span>.</span></p>
application/pdf
10.3958/059.043.0302
en
Society of Southwestern Entomologists
Phenology and abundance of Northern Tamarisk Beetle, Diorhabda carinulata affecting defoliation of Tamarix
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