Richard L. Hellmich
Iowa State University
Publications 133
#1Steven E. NaranjoH-Index: 33
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#1Jun-Ce Tian (Cornell University)H-Index: 11
#2Xiang-Ping Wang (Yangtze University)H-Index: 3
Last.Anthony M. Shelton (Cornell University)H-Index: 54
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Cabbage looper, Trichoplusia ni (Hubner) is an important lepidopteran pest on many vegetable and greenhouse crops, and some field crops. Although there are no commercial transgenic Bt vegetable or greenhouse crops, T. ni is a target of Bollgard II cotton, which produces Cry1Ac and Cry2Ab. We expand on previous work that examined the effect of Bt crops on parasitoids using Bt-resistant lepidopteran populations as hosts. Cry1Ac/Cry2Ab-resistant T. ni larvae were used to eliminate host quality effe...
2 CitationsSource
#1Victoria M. Pocius (PSU: Pennsylvania State University)H-Index: 3
#2John M. Pleasants (Iowa State University)H-Index: 23
Last.Sue L. Blodgett (Iowa State University)H-Index: 11
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Monarch butterfly overwintering numbers have declined over the past 20 years. Restoring habitat that includes milkweeds, the only host plants for larval monarch butterflies, is necessary to increase monarch numbers within the breeding range. The value of different milkweed species for restoration will depend, in part, on the extent to which they are utilized by ovipositing females. The number of eggs laid on different species over a season will be a function of plant size and phenology as well a...
3 CitationsSource
#1Victoria M. Pocius (Iowa State University)H-Index: 3
#2Richard L. Hellmich (USDA: United States Department of Agriculture)H-Index: 28
Last.Diane M. Debinski (MSU: Montana State University)H-Index: 30
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#2Sue L. BlodgettH-Index: 11
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#1Victoria M. Pocius (Iowa State University)H-Index: 3
#2Diane M. Debinski (MSU: Montana State University)H-Index: 30
Last.Richard L. Hellmich (USDA: United States Department of Agriculture)H-Index: 28
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USDA (1009926, 69-3A75-16-006); Prairie Biotics Inc.; Iowa Native Plant Society; Iowa Monarch Conservation Consortium
5 CitationsSource
#1Victoria M. Pocius (Iowa State University)H-Index: 3
#2Diane M. Debinski (MSU: Montana State University)H-Index: 30
Last.Lincoln P. Brower (Sweet Briar College)H-Index: 49
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8 CitationsSource
#1Victoria M. Pocius (Iowa State University)H-Index: 3
#2Diane M. Debinski (Iowa State University)H-Index: 30
Last.Frances K. Hunter (Iowa State University)H-Index: 1
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Over the past two decades, the population of monarch butterflies east of the Rocky Mountains has experienced a significant decline. Habitat restoration that includes milkweed plants is crucial to boost population numbers in the breeding range. Monarch butterfly larvae use milkweeds as their only host plant, but larval performance on different milkweed species is not well documented. We examined early instar survival and growth on nine milkweed species native to Iowa. These included Asclepias exa...
7 CitationsSource
Silencing genes of a pest with double-stranded RNA (dsRNA) is a promising new pest management technology. As part of the environmental risk assessment for dsRNA-based products, the environmental fate and the potential for adverse effects to on-target organisms should be characterized. In the present study, a nonbioactive dsRNA was spiked into the water column of a water and sediment microcosm to mimic drift from a spray application run off of unbound dsRNA or transport of plant tissues. Dissipat...
5 CitationsSource
#1Huipeng Pan (SCAU: South China Agricultural University)H-Index: 22
#2Xiaowei Yang (UK: University of Kentucky)H-Index: 4
Last.Xuguo Zhou (UK: University of Kentucky)H-Index: 34
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By suppressing the expression of genes with essential biological functions, in planta RNAi can negatively affect the development and survival of target pests. As a part of a concerted effort to assess the risks of RNAi transgenic crops on non-target organisms, we developed an in vivo toxicity assay to examine the impacts of ingested dsRNAs incurred to the monarch butterfly, Danaus plexippus (L.), an iconic eco-indicator in North America. To create the worst case scenario, the full-length v-ATPas...
6 CitationsSource