Skip to main content
Have a personal or library account? Click to login
Laboratory and Greenhouse Assessments of Steinernema Carpocapsae With Three Adjuvants on Chrysodeixis Includens Cover

Laboratory and Greenhouse Assessments of Steinernema Carpocapsae With Three Adjuvants on Chrysodeixis Includens

Journal of Nematology
Volume 57 (2025): Issue 1 (February 2025)
By: ,  ,   and    
Open Access
|Sep 2025
Figures & tables

Figures & Tables

Figure 1:

(A) A cage containing soybean plants used for the trials in the greenhouse; the circle over the plants shows where the survival of entomopathogenic nematodes (EPNs) on soybean leaves was examined. (B) A larva of Chrysodeixis includens killed by Steinernema carpocapsae (ALL strain) within 24 hr in the greenhouse; the color change began from the anus, and EPNs were found after dissection. (C) Adults of Steinernema carpocapsae (ALL strain) in the body cavity of a Chrysodeixis includens larvae taken from the greenhouse trial.

Table 1:

Mortality (% ± SEM) of fifth instars of Chrysodeixis includens caused by Steinernema carpocapsae (ALL strain) with adjuvants at 24 and 72 hr under laboratory conditions (25 °C, 85% RH).

Insect dead (hr)2472247224722472
EPNa5.0 ± 2.2 ab38.3 ± 4.8 b8.3 ± 4.0 bc40.0 ± 6.8 b0.0 ± 0.0 b63.3 ± 1.2 a23.3 ± 4.9 b98.3 ± 1.7 a
EPN+S8.3 ± 4.0 ab48.3 ± 6.5 ab16.7 ± 3.3 b61.7 ± 7.9 a15.0 ± 7.2 a80.0 ± 5.8 a21.7 ± 5.4 b98.3 ± 1.7 a
EPN+S+O10.0 ± 6.3 a61.7 ± 7.0 a23.3 ± 4.2 a66.7 ± 6.1 a23.3 ± 5.6 a76.7 ± 6.7 a51.7 ± 4.0 a100.0 ± 0 a
EPN+SAg5.0 ± 3.4 ab38.3 ± 5.4 b11.7 ± 6.0 abc55.0 ± 7.6 ab10.0 ± 2.6 a75.0 ± 6.2 a25.0 ± 3.4 b98.3 ± 1.7 a
Water0.0 ± 0.0 b0.0 ± 0.0 c0.0 ± 0.0 c0.0 ± 0.0 c0.0 ± 0.0 b0.0 ± 0.0 b0.0 ± 0.0 c1.7 ± 1.7 b
Water+S0.0 ± 0.0 b0.0 ± 0.0 c0.0 ± 0.0 c1.9 ± 1.6 c0.0 ± 0.0 b0.0 ± 0.0 b0.0 ± 0.0 c0.0 ± 0.0 b
Water+S+O0.0 ± 0.0 b1.7 ± 1.7 c0.0 ± 0.0 c0.0 ± 0.0 c0.0 ± 0.0 b3.5 ± 2.2 b0.0 ± 0.0 c0.0 ± 0.0 b
Water+SAg0.0 ± 0.0 b1.7 ± 1.7 c0.0 ± 0.0 c0.0 ± 0.0 c0.0 ± 0.0 b1.9 ± 1.9 b0.0 ± 0.0 c0.0 ± 0.0 b
F-Value (7, 40)4.1958.8712.0864.5611.7442.1740.71457.83
P-Value0.0015<.0001<.0001<.0001<.0001<.0001<.0001<.0001

{ label (or @symbol) needed for fn[@id='j_jofnem-2025-0034_tfn_001'] } Mean values within a column followed by the same letter are not significantly different at P > 0.05 (Tukey’s HSD test).

a EPN = Entomopathogenic nematode, S = 0.125% dish soap, S + O = 0.125% dish soap combined with 0.25% vegetable oil, SAg = 0.066% Southern Ag Surfactant.

Table 2:

Mortality (% ± SEM) of fifth instars of Chrysodeixis includens caused by Steinernema carpocapsae (ALL strain) with adjuvants under greenhouse conditions.

TrialFirstSecondThird
Temperature (°C)a19 (10–32)24 (22–39)24 (22–38)
RH (%)a81 (74–90)81 (44–95)70 (32–83)
Plant stage3rd trifoliolateFull floweringBeginning pod
High (cm)7.640.643.2
Insect dead (hr)7224722472
EPN 40b100.0 ± 0.0 a19.0 ± 13.2 ab80.1 ± 8.8 b7.4 ± 3.7 b63.0 ± 9.8 b
EPN+S 40100.0 ± 0.0 a48.1 ± 19.6 a100.0 ± 0.0 a18.5 ± 13.4 ab77.8 ± 6.4 ab
EPN+S+O 40100.0 ± 0.0 a38.4 ± 3.2 a100.0 ± 0.0 a48.1 ± 13.4 a88.9 ± 0.0 a
EPN+SAg 40100.0 ± 0.0 a43.5 ± 6.0 a96.7 ± 3.3 a11.1 ± 6.4 ab74.1 ± 7.4 ab
EPN+SAg 2095.8 ± 7.2 a14.9 ± 3.7 ab70.1 ± 4.4 b3.7 ± 3.7 b59.3 ± 3.7 bc
EPN+SAg 1080.0 ± 17.3 b13.2 ± 8.3 ab61.4 ± 5.0 b0.0 ± 0.0 b32.6 ± 3.4 c
Water0.0 ± 0.0 c0.0 ± 0.0 b0.0 ± 0.0 c0.0 ± 0.0 b0.0 ± 0.0 d
Water+S0.0 ± 0.0 c0.0 ± 0.0 b0.0 ± 0.0 c0.0 ± 0.0 b0.0 ± 0.0 d
Water+S+O0.0 ± 0.0 c0.0 ± 0.0 b0.0 ± 0.0 c0.0 ± 0.0 b0.0 ± 0.0 d
Water+SAg0.0 ± 0.0 c0.0 ± 0.0 b0.0 ± 0.0 c0.0 ± 0.0 b0.0 ± 0.0 d
F-Value (9, 20)205.577.80171.925.5083.39
P-Value<.0001<.0001<.00010.0007<.0001

Mean values within a column followed by the same letter are not significantly different at P > 0.05 (Tukey’s HSD test).

a Numbers outside parentheses were the temperature or RH at the beginning of the application, and numbers inside parentheses were the lowest-highest temperature or RH during the first 24 hr of the trial.

b EPN = entomopathogenic nematode, 40 = 40 IJs/cm2, 20 = 20 IJs/cm2, and 10 = 10 IJs/cm2. S = 0.125% dish soap, S + O = 0.125% dish soap combined with 0.25% vegetable oil, SAg = 0.066% Southern Ag Surfactant.

Figure 2:

Entomopathogenic nematode (EPN) suspensions after application on soybean leaves. EPN suspension with water only (A) displays numerous water droplets on the leaf. EPN suspensions with dish soap (B), dish soap combined with vegetable oil (C), and Southern Ag Surfactant (D) show the suspensions evenly distributed on the leaves due to the use of adjuvants.

Table 3:

Number (± SEM) of viable Steinernema carpocapsae (ALL strain) per soybean leaf after application under greenhouse conditions.

TrailFirstSecondThird
Sampling time (hr)2448120168244896244896
Temperature (°C)a10–328–325–325–3222–3920–3920–3922–3821–3820–42
RH (%)a74–9042–9042–9042–9044–9544–9944–9932–8326–8824–94
EPN 40b19.7 ± 3.4 a3.7 ± 0.9 ab0.0 ± 0.0 b0.0 ± 0.0 a51.7 ± 5.8 ab10.3 ± 8.1 ab4.8 ± 1.3 ab50.0 ± 10.2 a13.3 ± 7.5 a0.8 ± 0.4 a
EPN + S 4020.3 ± 10.9 a13.5 ± 3.0 a0.5 ± 0.3 b0.5 ± 0.3 a28.8 ± 6.7 ab12 ± 5.5 ab4.8 ± 3.1 ab35.2 ± 25.8 ab4.7 ± 1.6 ab0.3 ± 0.2 a
EPN + S+O 4064.2 ± 36.5 a15.3 ± 5.7 a10. 3 ± 4.6 a0.0 ± 0.0 a65.2 ± 19.0 a45.8 ± 5.4 a9.0 ± 2.8 a44.8 ± 12.6 a3.2 ± 1.5 ab1.2 ± 1.2 a
EPN + SAg 409.5 ± 1.8 ab2.0 ± 0.5 bc0.5 ± 0.5 b0.0 ± 0.0 a33.7 ± 12.9 ab9.0 ± 3.5 ab3.7 ± 2.0 ab21.3 ± 12 ab5.5 ± 2.4 ab0 ± 0 a
EPN + SAg 208.3 ± 4.4 ab0.0 ± 0.0 c0.0 ± 0.0 b0.0 ± 0.0 a7.5 ± 4.5 b4.5 ± 3.0 b0 .0 ± 0.0 b6.7 ± 2.4 ab1.0 ± 0.3 ab0 ± 0 a
EPN + SAg 100.7 ± 0.7 b0.0 ± 0.0 c0.0 ± 0.0 b0.0 ± 0.0 a4.7 ± 2.4 b2.8 ± 1.6 b0.0 ± 0.0 b1.8 ± 1.4 b0.0 ± 0.0 b0 ± 0 a
F-Value (5, 12)6.5922.4116.453.325.414.158.404.963.601.14
P-Value0.0036<.0001<.00010.04120.00780.02020.00130.01080.03210.3938

Mean values within a column followed by the same letter are not significantly different at P > 0.05 (Tukey’s HSD test).

a Lowest-highest temperature or RH.

b 40 = 40 IJs/cm2, 20 = 20 IJs/cm2, and 10 = 10 IJs/cm2.

b EPN = entomopathogenic nematode, S = 0.125% dish soap, S + O = 0.125% dish soap combined with 0.25% vegetable oil, SAg = 0.066% Southern Ag Surfactant.

DOI: https://doi.org/10.2478/jofnem-2025-0034 | Journal eISSN: 2640-396X | Journal ISSN: 0022-300X
Journal RSS Feed
Language: English
Submitted on: Mar 1, 2025
Published on: Sep 17, 2025
Published by: Society of Nematologists, Inc.
In partnership with: Paradigm Publishing Services
Publication frequency: 1 issue per year
Keywords:
adjuvant,
Chrysodeixis includens,
soybean looper,
Steinernema carpocapsae
Related subjects:
Life sciences,
Life sciences, other

© 2025 Minling Zhang, Nathan R. Spaulding, Gadi V.P. Reddy, David I. Shapiro-Ilan, published by Society of Nematologists, Inc.
This work is licensed under the Creative Commons Attribution 4.0 License.

Volume 57 (2025): Issue 1 (February 2025)
Previous article
Next article