Get 20M+ Full-Text Papers For Less Than $1.50/day. Start a 14-Day Trial for You or Your Team.

Learn More →

Field Efficacy of Pea Leaf Weevil Aggregation Pheromone Combined With Contact Insecticide as an Attract-and-Kill Method, 2020

Field Efficacy of Pea Leaf Weevil Aggregation Pheromone Combined With Contact Insecticide as an... Pea | Pisum sativum Pea leaf weevil | Sitona lineatus cyantraniliprole, spinetoram, isocycloseram A field experiment was conducted to assess the efficacy of an aggregation pheromone combined with a contact insecticide as an attract-and-kill method to reduce adult pea leaf weevil (PLW) populations. The attractant, PLW aggregation pheromone (4–methyal-3,5-heptanedione), was provided by ChemTica International (Heredia Province, Santo Domingo, Costa Rica), as plastic pellet and rubber septa formulations. DeltaGard G Insecticide Granules (0.1% deltamethrin) were used as a contact insecticide. The objective of this field experiment was to assess and demonstrate the potential of an attract-and-kill strategy as a new PLW management tactic to reduce pest pressure using adult aggregation pheromone. The field site was located at the Montana State University Arthur Post Agronomy Farm, Bozeman, Montana, where field peas have been grown with a consistent history of PLW infestation. As a low-cost approach, pheromone baits and granular insecticide were placed in the bottom of small circular pits dug into the soil measuring 5 cm deep and 6 cm in diameter. Six treatments were placed in the bottom of these simple pit fall traps: 1) one pheromone pellet plus insecticide; 2) three pheromone pellets plus insecticide; 3) five pheromone pellets plus insecticide; 4) one pheromone rubber septum plus insecticide; 5) one pheromone rubber septum and no insecticide; and 6) insecticide only. Treatments with insecticide received 0.3 g of DeltaGard G Insecticide Granules. Treatments were replicated four times in a Complete Randomized Block Design (CRBD) during the 2020 field season. An experimental block consisted of six pitfall traps spaced 10 m apart along a linear transect, with four parallel transects separated by 10 m representing the four replicated blocks. The first treatments were placed in the field on 11 May 2020 and evaluated every 8–10 d from 18 May to 19 June 2020. During each evaluation, PLW adults were collected from the pitfall traps and stored in the lab in 95% ethanol, counted, and identified. The male:female ratio was approximately even. PLW counts were entered and analyzed in R studio cloud version 4.0.3 (R Studio Team, 2020). The response variable, the total number of adult PLW collected, was transformed on a log scale (Total+1) to meet the assumptions of normality and constant variance for linear modeling. ANOVA, followed by a post hoc Tukey HSD test, was performed. Treatment and assessment date were statistically significant factors in this experiment, P < 0.001 (Table 1). Experimental block was not a significant factor. Treatment 5, pheromone rubber septum only, trapped the fewest PLW while Treatment 4, pheromone rubber septum plus granular insecticide trapped the highest number of PLW (Table 2), significant at P = 0.05, Tukey HSD test. Treatment 5 results can be explained by attraction of PLW to the pheromone rubber septum, and subsequent dispersal away in the absence of a contact insecticide. However, Treatment 4 resulted in higher mortality and higher numbers of adult PLW recovered from the pitfall traps. PLW counts in Treatment 6, insecticide only, reflect incidental trap catches from adults crawling on the ground. After the first incidental catch, Treatment 6 pitfall traps may have become attractive if the trapped PLW emitted pheromone naturally. The number of PLW adults trapped using the pheromone pellets was more variable. Only Treatment 2, three pheromone pellets plus insecticide, was significantly different from Treatment 5, pheromone rubber septum alone (P = 0.05, Tukey HSD test) and it was not significantly different from Treatment 6, insecticide only. In general, PLW trap catches were the highest on the first assessment date and declined in number each successive collection date (Table 2). Field observations of PLW feeding damage and mating adults indicated that activity extended well into June. The successive decline in PLW adult counts can be explained by degradation of the pitfall traps that were not replenished with pheromone and insecticide. Declining pheromone levels, degradation of the simple soil pits by weather erosion and declining insecticidal activity could all explain sequentially lower trap catches during the experimental period. Better performance of pitfall traps baited with larger pheromone rubber septum suggests higher pheromone release rates may enhance PLW attract-and-kill strategies. Results from this preliminary study have demonstrated the potential of PLW aggregation pheromone as an attract-and-kill method under field conditions. Future research is needed to determine optimal field application methods to dispense the pheromone attractant and insecticide treatments for suppression of adult populations below economically damaging levels. Combining attract-and-kill and push-pull strategies to concentrate adult PLW populations migrating into emerging field pea crops may be an effective approach.1 Table 1. ANOVA factor . Sum of squares . Degrees of freedom . F-value . P-value . Treatment 24.891 5 10.9 1.78e-08 Date 17.710 4 9.67 1.02e-06 Block 1.685 3 1.23 0.3 ANOVA factor . Sum of squares . Degrees of freedom . F-value . P-value . Treatment 24.891 5 10.9 1.78e-08 Date 17.710 4 9.67 1.02e-06 Block 1.685 3 1.23 0.3 Open in new tab Table 1. ANOVA factor . Sum of squares . Degrees of freedom . F-value . P-value . Treatment 24.891 5 10.9 1.78e-08 Date 17.710 4 9.67 1.02e-06 Block 1.685 3 1.23 0.3 ANOVA factor . Sum of squares . Degrees of freedom . F-value . P-value . Treatment 24.891 5 10.9 1.78e-08 Date 17.710 4 9.67 1.02e-06 Block 1.685 3 1.23 0.3 Open in new tab Table 2. Treatment number . Materials . Total PLW count . Average PLW counts per sampling date (n = 4)a . Weekly PLW counts (average, n = 4) . . . . . . . . . 18th May . 26th May . 2nd June . 10th June . 19th June . 1 1 Pheromone pellet + insecticide 7 0.35bc 0.5 0.75 0 0 0.5 2 3 Pheromone pellets + insecticide 53 2.65b 6.0 3.75 3.5 0 0 3 5 Pheromone pellets + insecticide 24 1.21ab 4.0 1.0 0.75 0 0.25 4 Pheromone septum + insecticide 157 7.85a 22.05 12.25 2.75 1.75 0 5 Pheromone septum only 1 0.05b 0 0.25 0 0 0 6 Insecticide only 20 1.0b 1.5 1.5 0.5 1.5 0 Treatment number . Materials . Total PLW count . Average PLW counts per sampling date (n = 4)a . Weekly PLW counts (average, n = 4) . . . . . . . . . 18th May . 26th May . 2nd June . 10th June . 19th June . 1 1 Pheromone pellet + insecticide 7 0.35bc 0.5 0.75 0 0 0.5 2 3 Pheromone pellets + insecticide 53 2.65b 6.0 3.75 3.5 0 0 3 5 Pheromone pellets + insecticide 24 1.21ab 4.0 1.0 0.75 0 0.25 4 Pheromone septum + insecticide 157 7.85a 22.05 12.25 2.75 1.75 0 5 Pheromone septum only 1 0.05b 0 0.25 0 0 0 6 Insecticide only 20 1.0b 1.5 1.5 0.5 1.5 0 Means followed by the same letter within a column are not significantly different (P > 0.05, Tukey HSD). aLog(X + 1)-transformed data used for analysis, presented data are nontransformed means. Open in new tab Table 2. Treatment number . Materials . Total PLW count . Average PLW counts per sampling date (n = 4)a . Weekly PLW counts (average, n = 4) . . . . . . . . . 18th May . 26th May . 2nd June . 10th June . 19th June . 1 1 Pheromone pellet + insecticide 7 0.35bc 0.5 0.75 0 0 0.5 2 3 Pheromone pellets + insecticide 53 2.65b 6.0 3.75 3.5 0 0 3 5 Pheromone pellets + insecticide 24 1.21ab 4.0 1.0 0.75 0 0.25 4 Pheromone septum + insecticide 157 7.85a 22.05 12.25 2.75 1.75 0 5 Pheromone septum only 1 0.05b 0 0.25 0 0 0 6 Insecticide only 20 1.0b 1.5 1.5 0.5 1.5 0 Treatment number . Materials . Total PLW count . Average PLW counts per sampling date (n = 4)a . Weekly PLW counts (average, n = 4) . . . . . . . . . 18th May . 26th May . 2nd June . 10th June . 19th June . 1 1 Pheromone pellet + insecticide 7 0.35bc 0.5 0.75 0 0 0.5 2 3 Pheromone pellets + insecticide 53 2.65b 6.0 3.75 3.5 0 0 3 5 Pheromone pellets + insecticide 24 1.21ab 4.0 1.0 0.75 0 0.25 4 Pheromone septum + insecticide 157 7.85a 22.05 12.25 2.75 1.75 0 5 Pheromone septum only 1 0.05b 0 0.25 0 0 0 6 Insecticide only 20 1.0b 1.5 1.5 0.5 1.5 0 Means followed by the same letter within a column are not significantly different (P > 0.05, Tukey HSD). aLog(X + 1)-transformed data used for analysis, presented data are nontransformed means. Open in new tab Footnotes 1 This research was supported by a MT Specialty Crop Block Program through award Grant 19SCG04712, United States Department of Agriculture (NIFA). © The Author(s) 2022. Published by Oxford University Press on behalf of Entomological Society of America. This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial License (https://creativecommons.org/licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact journals.permissions@oup.com http://www.deepdyve.com/assets/images/DeepDyve-Logo-lg.png Arthropod Management Tests Oxford University Press

Field Efficacy of Pea Leaf Weevil Aggregation Pheromone Combined With Contact Insecticide as an Attract-and-Kill Method, 2020

Kiju, P; Wanner, K W; Reddy, G V P
Arthropod Management Tests , Volume 47 (1): 1 – Jan 1, 2022
Download PDF
2 pages

Loading next page...
 
/lp/oxford-university-press/field-efficacy-of-pea-leaf-weevil-aggregation-pheromone-combined-with-X7HYRoHAxL

References (0)

References for this paper are not available at this time. We will be adding them shortly, thank you for your patience.

Publisher
Oxford University Press
Copyright
Copyright © 2023 Entomological Society of America
eISSN
2155-9856
DOI
10.1093/amt/tsac053
Publisher site
See Article on Publisher Site

Abstract

Pea | Pisum sativum Pea leaf weevil | Sitona lineatus cyantraniliprole, spinetoram, isocycloseram A field experiment was conducted to assess the efficacy of an aggregation pheromone combined with a contact insecticide as an attract-and-kill method to reduce adult pea leaf weevil (PLW) populations. The attractant, PLW aggregation pheromone (4–methyal-3,5-heptanedione), was provided by ChemTica International (Heredia Province, Santo Domingo, Costa Rica), as plastic pellet and rubber septa formulations. DeltaGard G Insecticide Granules (0.1% deltamethrin) were used as a contact insecticide. The objective of this field experiment was to assess and demonstrate the potential of an attract-and-kill strategy as a new PLW management tactic to reduce pest pressure using adult aggregation pheromone. The field site was located at the Montana State University Arthur Post Agronomy Farm, Bozeman, Montana, where field peas have been grown with a consistent history of PLW infestation. As a low-cost approach, pheromone baits and granular insecticide were placed in the bottom of small circular pits dug into the soil measuring 5 cm deep and 6 cm in diameter. Six treatments were placed in the bottom of these simple pit fall traps: 1) one pheromone pellet plus insecticide; 2) three pheromone pellets plus insecticide; 3) five pheromone pellets plus insecticide; 4) one pheromone rubber septum plus insecticide; 5) one pheromone rubber septum and no insecticide; and 6) insecticide only. Treatments with insecticide received 0.3 g of DeltaGard G Insecticide Granules. Treatments were replicated four times in a Complete Randomized Block Design (CRBD) during the 2020 field season. An experimental block consisted of six pitfall traps spaced 10 m apart along a linear transect, with four parallel transects separated by 10 m representing the four replicated blocks. The first treatments were placed in the field on 11 May 2020 and evaluated every 8–10 d from 18 May to 19 June 2020. During each evaluation, PLW adults were collected from the pitfall traps and stored in the lab in 95% ethanol, counted, and identified. The male:female ratio was approximately even. PLW counts were entered and analyzed in R studio cloud version 4.0.3 (R Studio Team, 2020). The response variable, the total number of adult PLW collected, was transformed on a log scale (Total+1) to meet the assumptions of normality and constant variance for linear modeling. ANOVA, followed by a post hoc Tukey HSD test, was performed. Treatment and assessment date were statistically significant factors in this experiment, P < 0.001 (Table 1). Experimental block was not a significant factor. Treatment 5, pheromone rubber septum only, trapped the fewest PLW while Treatment 4, pheromone rubber septum plus granular insecticide trapped the highest number of PLW (Table 2), significant at P = 0.05, Tukey HSD test. Treatment 5 results can be explained by attraction of PLW to the pheromone rubber septum, and subsequent dispersal away in the absence of a contact insecticide. However, Treatment 4 resulted in higher mortality and higher numbers of adult PLW recovered from the pitfall traps. PLW counts in Treatment 6, insecticide only, reflect incidental trap catches from adults crawling on the ground. After the first incidental catch, Treatment 6 pitfall traps may have become attractive if the trapped PLW emitted pheromone naturally. The number of PLW adults trapped using the pheromone pellets was more variable. Only Treatment 2, three pheromone pellets plus insecticide, was significantly different from Treatment 5, pheromone rubber septum alone (P = 0.05, Tukey HSD test) and it was not significantly different from Treatment 6, insecticide only. In general, PLW trap catches were the highest on the first assessment date and declined in number each successive collection date (Table 2). Field observations of PLW feeding damage and mating adults indicated that activity extended well into June. The successive decline in PLW adult counts can be explained by degradation of the pitfall traps that were not replenished with pheromone and insecticide. Declining pheromone levels, degradation of the simple soil pits by weather erosion and declining insecticidal activity could all explain sequentially lower trap catches during the experimental period. Better performance of pitfall traps baited with larger pheromone rubber septum suggests higher pheromone release rates may enhance PLW attract-and-kill strategies. Results from this preliminary study have demonstrated the potential of PLW aggregation pheromone as an attract-and-kill method under field conditions. Future research is needed to determine optimal field application methods to dispense the pheromone attractant and insecticide treatments for suppression of adult populations below economically damaging levels. Combining attract-and-kill and push-pull strategies to concentrate adult PLW populations migrating into emerging field pea crops may be an effective approach.1 Table 1. ANOVA factor . Sum of squares . Degrees of freedom . F-value . P-value . Treatment 24.891 5 10.9 1.78e-08 Date 17.710 4 9.67 1.02e-06 Block 1.685 3 1.23 0.3 ANOVA factor . Sum of squares . Degrees of freedom . F-value . P-value . Treatment 24.891 5 10.9 1.78e-08 Date 17.710 4 9.67 1.02e-06 Block 1.685 3 1.23 0.3 Open in new tab Table 1. ANOVA factor . Sum of squares . Degrees of freedom . F-value . P-value . Treatment 24.891 5 10.9 1.78e-08 Date 17.710 4 9.67 1.02e-06 Block 1.685 3 1.23 0.3 ANOVA factor . Sum of squares . Degrees of freedom . F-value . P-value . Treatment 24.891 5 10.9 1.78e-08 Date 17.710 4 9.67 1.02e-06 Block 1.685 3 1.23 0.3 Open in new tab Table 2. Treatment number . Materials . Total PLW count . Average PLW counts per sampling date (n = 4)a . Weekly PLW counts (average, n = 4) . . . . . . . . . 18th May . 26th May . 2nd June . 10th June . 19th June . 1 1 Pheromone pellet + insecticide 7 0.35bc 0.5 0.75 0 0 0.5 2 3 Pheromone pellets + insecticide 53 2.65b 6.0 3.75 3.5 0 0 3 5 Pheromone pellets + insecticide 24 1.21ab 4.0 1.0 0.75 0 0.25 4 Pheromone septum + insecticide 157 7.85a 22.05 12.25 2.75 1.75 0 5 Pheromone septum only 1 0.05b 0 0.25 0 0 0 6 Insecticide only 20 1.0b 1.5 1.5 0.5 1.5 0 Treatment number . Materials . Total PLW count . Average PLW counts per sampling date (n = 4)a . Weekly PLW counts (average, n = 4) . . . . . . . . . 18th May . 26th May . 2nd June . 10th June . 19th June . 1 1 Pheromone pellet + insecticide 7 0.35bc 0.5 0.75 0 0 0.5 2 3 Pheromone pellets + insecticide 53 2.65b 6.0 3.75 3.5 0 0 3 5 Pheromone pellets + insecticide 24 1.21ab 4.0 1.0 0.75 0 0.25 4 Pheromone septum + insecticide 157 7.85a 22.05 12.25 2.75 1.75 0 5 Pheromone septum only 1 0.05b 0 0.25 0 0 0 6 Insecticide only 20 1.0b 1.5 1.5 0.5 1.5 0 Means followed by the same letter within a column are not significantly different (P > 0.05, Tukey HSD). aLog(X + 1)-transformed data used for analysis, presented data are nontransformed means. Open in new tab Table 2. Treatment number . Materials . Total PLW count . Average PLW counts per sampling date (n = 4)a . Weekly PLW counts (average, n = 4) . . . . . . . . . 18th May . 26th May . 2nd June . 10th June . 19th June . 1 1 Pheromone pellet + insecticide 7 0.35bc 0.5 0.75 0 0 0.5 2 3 Pheromone pellets + insecticide 53 2.65b 6.0 3.75 3.5 0 0 3 5 Pheromone pellets + insecticide 24 1.21ab 4.0 1.0 0.75 0 0.25 4 Pheromone septum + insecticide 157 7.85a 22.05 12.25 2.75 1.75 0 5 Pheromone septum only 1 0.05b 0 0.25 0 0 0 6 Insecticide only 20 1.0b 1.5 1.5 0.5 1.5 0 Treatment number . Materials . Total PLW count . Average PLW counts per sampling date (n = 4)a . Weekly PLW counts (average, n = 4) . . . . . . . . . 18th May . 26th May . 2nd June . 10th June . 19th June . 1 1 Pheromone pellet + insecticide 7 0.35bc 0.5 0.75 0 0 0.5 2 3 Pheromone pellets + insecticide 53 2.65b 6.0 3.75 3.5 0 0 3 5 Pheromone pellets + insecticide 24 1.21ab 4.0 1.0 0.75 0 0.25 4 Pheromone septum + insecticide 157 7.85a 22.05 12.25 2.75 1.75 0 5 Pheromone septum only 1 0.05b 0 0.25 0 0 0 6 Insecticide only 20 1.0b 1.5 1.5 0.5 1.5 0 Means followed by the same letter within a column are not significantly different (P > 0.05, Tukey HSD). aLog(X + 1)-transformed data used for analysis, presented data are nontransformed means. Open in new tab Footnotes 1 This research was supported by a MT Specialty Crop Block Program through award Grant 19SCG04712, United States Department of Agriculture (NIFA). © The Author(s) 2022. Published by Oxford University Press on behalf of Entomological Society of America. This is an Open Access article distributed under the terms of the Creative Commons Attribution-NonCommercial License (https://creativecommons.org/licenses/by-nc/4.0/), which permits non-commercial re-use, distribution, and reproduction in any medium, provided the original work is properly cited. For commercial re-use, please contact journals.permissions@oup.com

Journal

Arthropod Management Tests – Oxford University Press

Published: Jan 1, 2022

There are no references for this article.