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Evidence of Field-Evolved Resistance to Bifenthrin in Western Corn Rootworm (Diabrotica virgifera virgifera LeConte) Populations in Western Nebraska and Kansas.

Pereira AE, Wang H, Zukoff SN, Meinke LJ, French BW, Siegfried BD - PLoS ONE (2015)

Bottom Line: Concentration-response bioassays were performed to estimate the baseline susceptibility.This study provides evidence that resistance to bifenthrin is evolving in field populations that have been exposed for multiple years to pyrethroid insecticides.Implications to sustainable rootworm management are discussed.

View Article: PubMed Central - PubMed

Affiliation: Department of Entomology, University of Nebraska-Lincoln, Lincoln, Nebraska, United States of America.

ABSTRACT
Pyrethroid insecticides have been used to control larvae or adults of the western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte, a key pest of field corn in the United States. In response to reports of reduced efficacy of pyrethroids in WCR management programs in southwestern areas of Nebraska and Kansas the present research was designed to establish a baseline of susceptibility to the pyrethroid insecticide, bifenthrin, using susceptible laboratory populations and to compare this baseline with susceptibility of field populations. Concentration-response bioassays were performed to estimate the baseline susceptibility. From the baseline data, a diagnostic concentration (LC99) was determined and used to test adults of both laboratory and field populations. Larval susceptibility was also tested using both laboratory and field populations. Significant differences were recorded in adult and larval susceptibility among WCR field and laboratory populations. The highest LC50 for WCR adults was observed in populations from Keith 2 and Chase Counties, NE, with LC50s of 2.2 and 1.38 μg/vial, respectively, and Finney County 1, KS, with 1.43 μg/vial, as compared to a laboratory non-diapause population (0.24 μg/vial). For larvae, significant differences between WCR field and laboratory populations were also recorded. Significant differences in mortalities at the diagnostic bifenthrin concentration (LC99) were observed among WCR adult populations with western Corn Belt populations exhibiting lower susceptibility to bifenthrin, especially in southwestern Nebraska and southwestern Kansas. This study provides evidence that resistance to bifenthrin is evolving in field populations that have been exposed for multiple years to pyrethroid insecticides. Implications to sustainable rootworm management are discussed.

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WCR adult mortalities of 32 different field populations from counties throughout the U.S. Corn Belt collected in 2013 (collection date) plus a susceptible laboratory population (non-diapause, Crop Characteristics®) after exposure to diagnostic concentration of bifenthrin (0.77 μg of bifenthrin/vial) corresponding to the LC99 calculated from 10 WCR lab populations.Means and standard errors are result of 10 replicates (vial), with 10 beetles per vial (unless otherwise stated). Means and standard errors are the result of 10 replicates (vials) with 10 beetles per vial (unless otherwise stated). Population means encompassed by the same solid vertical bars are not significantly different and were compared by least squared means with Tukey adjustment at p ≤ 0.05 using PROC GLIMMIX in SAS 9.3.
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pone.0142299.g002: WCR adult mortalities of 32 different field populations from counties throughout the U.S. Corn Belt collected in 2013 (collection date) plus a susceptible laboratory population (non-diapause, Crop Characteristics®) after exposure to diagnostic concentration of bifenthrin (0.77 μg of bifenthrin/vial) corresponding to the LC99 calculated from 10 WCR lab populations.Means and standard errors are result of 10 replicates (vial), with 10 beetles per vial (unless otherwise stated). Means and standard errors are the result of 10 replicates (vials) with 10 beetles per vial (unless otherwise stated). Population means encompassed by the same solid vertical bars are not significantly different and were compared by least squared means with Tukey adjustment at p ≤ 0.05 using PROC GLIMMIX in SAS 9.3.

Mentions: Baseline susceptibility was determined using WCR adults from eight different lab populations that were established from field collected adults from throughout the U.S. Corn Belt and maintained in culture for at least 13 years at the USDA/ARS North Central Agricultural Research Lab in Brookings, SD. The baseline assessment also included a non-diapause population (USDA) [42] reared continuously for more than 30 years in the absence of insecticide exposure. A similar non-diapause population from Crop Characteristics LLC® (CCh) (Farmington, MN) was also tested. The pooled analysis of these 10 lab populations was used to estimate a diagnostic concentration based on the LC99 that was subsequently used to test field populations (Table 1). Thirty-two adult field populations from 26 different locations in nine states were collected during the summer of 2013 (Figs 1 and 2), and 17 populations from 10 different counties in Nebraska and Kansas, including one population from Utah, were collected during the summer of 2014 (Figs 1 and 3), by using collection devices such as aspirators and sweep nets. The number of adults collected in the fields varied from 200–1000, except for Kearny, KS, and Floyd, IA, where only 20 and 58 beetles were collected, respectively. All adults were delivered or shipped overnight to the University of Nebraska-Lincoln, Insect Toxicology Laboratory and maintained in BugDorm® cages (30 x 30 x 30 cm) (MegaView Science Co., Ltd., Taichung, Taiwan) with artificial diet or fresh sweet corn for 24 h before initiating bioassays. With the exception of one collection in 2013 (Kearny-KS) and another in 2014 (Perkins 1-NE), all adult field populations were collected prior to any adulticide spray. All field collections were allowed access by the owners (private or University) and field collections outside of Nebraska were shipped with APHIS-USDA permissions (No. P526P-13-00045 and P526P-14-03957). The field studies in our research did not involve any endangered or protected species.


Evidence of Field-Evolved Resistance to Bifenthrin in Western Corn Rootworm (Diabrotica virgifera virgifera LeConte) Populations in Western Nebraska and Kansas.

Pereira AE, Wang H, Zukoff SN, Meinke LJ, French BW, Siegfried BD - PLoS ONE (2015)

WCR adult mortalities of 32 different field populations from counties throughout the U.S. Corn Belt collected in 2013 (collection date) plus a susceptible laboratory population (non-diapause, Crop Characteristics®) after exposure to diagnostic concentration of bifenthrin (0.77 μg of bifenthrin/vial) corresponding to the LC99 calculated from 10 WCR lab populations.Means and standard errors are result of 10 replicates (vial), with 10 beetles per vial (unless otherwise stated). Means and standard errors are the result of 10 replicates (vials) with 10 beetles per vial (unless otherwise stated). Population means encompassed by the same solid vertical bars are not significantly different and were compared by least squared means with Tukey adjustment at p ≤ 0.05 using PROC GLIMMIX in SAS 9.3.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4643967&req=5

pone.0142299.g002: WCR adult mortalities of 32 different field populations from counties throughout the U.S. Corn Belt collected in 2013 (collection date) plus a susceptible laboratory population (non-diapause, Crop Characteristics®) after exposure to diagnostic concentration of bifenthrin (0.77 μg of bifenthrin/vial) corresponding to the LC99 calculated from 10 WCR lab populations.Means and standard errors are result of 10 replicates (vial), with 10 beetles per vial (unless otherwise stated). Means and standard errors are the result of 10 replicates (vials) with 10 beetles per vial (unless otherwise stated). Population means encompassed by the same solid vertical bars are not significantly different and were compared by least squared means with Tukey adjustment at p ≤ 0.05 using PROC GLIMMIX in SAS 9.3.
Mentions: Baseline susceptibility was determined using WCR adults from eight different lab populations that were established from field collected adults from throughout the U.S. Corn Belt and maintained in culture for at least 13 years at the USDA/ARS North Central Agricultural Research Lab in Brookings, SD. The baseline assessment also included a non-diapause population (USDA) [42] reared continuously for more than 30 years in the absence of insecticide exposure. A similar non-diapause population from Crop Characteristics LLC® (CCh) (Farmington, MN) was also tested. The pooled analysis of these 10 lab populations was used to estimate a diagnostic concentration based on the LC99 that was subsequently used to test field populations (Table 1). Thirty-two adult field populations from 26 different locations in nine states were collected during the summer of 2013 (Figs 1 and 2), and 17 populations from 10 different counties in Nebraska and Kansas, including one population from Utah, were collected during the summer of 2014 (Figs 1 and 3), by using collection devices such as aspirators and sweep nets. The number of adults collected in the fields varied from 200–1000, except for Kearny, KS, and Floyd, IA, where only 20 and 58 beetles were collected, respectively. All adults were delivered or shipped overnight to the University of Nebraska-Lincoln, Insect Toxicology Laboratory and maintained in BugDorm® cages (30 x 30 x 30 cm) (MegaView Science Co., Ltd., Taichung, Taiwan) with artificial diet or fresh sweet corn for 24 h before initiating bioassays. With the exception of one collection in 2013 (Kearny-KS) and another in 2014 (Perkins 1-NE), all adult field populations were collected prior to any adulticide spray. All field collections were allowed access by the owners (private or University) and field collections outside of Nebraska were shipped with APHIS-USDA permissions (No. P526P-13-00045 and P526P-14-03957). The field studies in our research did not involve any endangered or protected species.

Bottom Line: Concentration-response bioassays were performed to estimate the baseline susceptibility.This study provides evidence that resistance to bifenthrin is evolving in field populations that have been exposed for multiple years to pyrethroid insecticides.Implications to sustainable rootworm management are discussed.

View Article: PubMed Central - PubMed

Affiliation: Department of Entomology, University of Nebraska-Lincoln, Lincoln, Nebraska, United States of America.

ABSTRACT
Pyrethroid insecticides have been used to control larvae or adults of the western corn rootworm (WCR), Diabrotica virgifera virgifera LeConte, a key pest of field corn in the United States. In response to reports of reduced efficacy of pyrethroids in WCR management programs in southwestern areas of Nebraska and Kansas the present research was designed to establish a baseline of susceptibility to the pyrethroid insecticide, bifenthrin, using susceptible laboratory populations and to compare this baseline with susceptibility of field populations. Concentration-response bioassays were performed to estimate the baseline susceptibility. From the baseline data, a diagnostic concentration (LC99) was determined and used to test adults of both laboratory and field populations. Larval susceptibility was also tested using both laboratory and field populations. Significant differences were recorded in adult and larval susceptibility among WCR field and laboratory populations. The highest LC50 for WCR adults was observed in populations from Keith 2 and Chase Counties, NE, with LC50s of 2.2 and 1.38 μg/vial, respectively, and Finney County 1, KS, with 1.43 μg/vial, as compared to a laboratory non-diapause population (0.24 μg/vial). For larvae, significant differences between WCR field and laboratory populations were also recorded. Significant differences in mortalities at the diagnostic bifenthrin concentration (LC99) were observed among WCR adult populations with western Corn Belt populations exhibiting lower susceptibility to bifenthrin, especially in southwestern Nebraska and southwestern Kansas. This study provides evidence that resistance to bifenthrin is evolving in field populations that have been exposed for multiple years to pyrethroid insecticides. Implications to sustainable rootworm management are discussed.

Show MeSH
Related in: MedlinePlus