<p>The tobacco caterpillar <italic>Spodoptera litura</italic> Fab. a noxious polyphagous pest, attack on several economical crops. Several natural and synthetic compounds were tested for their antifeedant activity against this pest. (<xref ref-type="bibr" rid="bib003">Purwar & Yadav, 2004</xref>). Thus, the present study was made to know the antifeedant activity of commercial formulation (neemazal 1 EC) against <italic>S. litura</italic>.</p><p>The culture of S. litura was maintained in 0.3 ppm based on its azadirachtin concentration, were prepared in tap water, whereas control was kept with water only. The antifeedant activity was evaluated using no choice feeding bioassay method. All the treatments were replicated thrice. Each replication consisted of 4 leaf discs of castor (size: 4 cm<sup>2</sup>) kept on filter paper, moistened with water and placed equidistant in glass Petri dishes (dia 10 cm). Five larvae of <italic>S. litura</italic>, 6 days old were released in each Petri dish and allowed to feed until control leaf were consumed by >50%. The quantitative analysis of feeding deterrency was done follwing the ‘deterrency scale’ Strong (+++): 90.01–100.00, Moderate (++): 70.01–90.00, Slight (+): 50.01–70.00, Poor or nil (-): 0.001–50.00.</p><p>The results indicated a differential feeding activity in all concentrations of neemazal except in the lowest concentration (0.3 ppm). Maximum area of leaf consumed (11.3 cm<sup>2</sup>) was recorded in control and mimimum (2.7 cm<sup>2</sup>) was in highest concentration of neemazal (300 ppm). At the lowest concentration (0.3 ppm), the area of leaf consumed was statistically at par to that of untreated control. Similar results were recorded by Nathala and Dhingra (<xref ref-type="bibr" rid="bib002">2005</xref>) against <italic>Helicoverpa armigera</italic> by extracts of <italic>Melia azedarach</italic>. Minimum% feeding area was recorded in highest concentration and maximum was in control, it ranged from 18.1–70.8 (<xref ref-type="table" rid="tab001">Table 1</xref>). The% protection offered by 300, 150, 30, 5, 3, 1.5 and 0.3 ppm of neemazal 1 EC was 75.8, 69.8, 64.3, 58.1, 55.1, 52.6 and 23.6 over control. A quantitative analysis of feeding deterrency revealed moderate antifeedant activity at 300 ppm and slight at all lower concentrations and poor or nil was at lowest concentration (0.3 ppm). Kaur <italic>et al.</italic> (<xref ref-type="bibr" rid="bib001">2001</xref>) assessed the growth and reproductive performance of <italic>S. litura</italic> by feeding doses of NSKE and observed disrupting effects, delayed development and dose correlated mortality. <table-wrap id="tab001"><label>Table 1</label><caption><p>Antifeedant activity of Neemazal against <italic>Spodoptera litura</italic></p></caption><table><thead><tr><th align="center">Conc. (ppm)</th><th align="center">Mean leaf area consumed (cm<sup>2</sup>)</th><th align="center">Mean% feeding</th><th align="center">Mean% protection</th><th align="center">Anti-feedant activity</th></tr></thead><tbody><tr><td colspan="5"><hr /></td></tr><tr><td rowspan="2" align="center" valign="top">300</td><td align="center">2.74</td><td align="center">18.1</td><td align="center">81.8</td><td align="center">+++</td></tr><tr><td align="center">(1.63)</td><td /><td /></tr><tr><td rowspan="2" align="center" valign="top">150</td><td align="center">3.42</td><td align="center">21.7</td><td align="center">78.2</td><td align="center">++</td></tr><tr><td align="center">(1.83)</td><td /><td /></tr><tr><td rowspan="2" align="center" valign="top">30</td><td align="center">4.04</td><td align="center">25.2</td><td align="center">74.7</td><td align="center">++</td></tr><tr><td align="center">(1.99)</td><td /><td /></tr><tr><td rowspan="2" align="center" valign="top">5</td><td align="center">4.74</td><td align="center">29.3</td><td align="center">70.3</td><td align="center">++</td></tr><tr><td align="center">(2.15)</td><td /><td /></tr><tr><td rowspan="2" align="center" valign="top">3</td><td align="center">5.08</td><td align="center">31.7</td><td align="center">68.2</td><td align="center">++</td></tr><tr><td align="center">(2.20)</td><td /><td /></tr><tr><td rowspan="2" align="center" valign="top">1.5</td><td align="center">5.36</td><td align="center">33.5</td><td align="center">66.5</td><td align="center">++</td></tr><tr><td align="center">(2.27)</td><td /><td /></tr><tr><td rowspan="2" align="center" valign="top">0.3</td><td align="center">8.65</td><td align="center">54.0</td><td align="center">45.9</td><td align="center">-</td></tr><tr><td align="center">(2.91)</td><td /><td /></tr><tr><td rowspan="2" align="center" valign="top">Control</td><td align="center">11.33</td><td align="center">70.8</td><td align="center">29.1</td><td /></tr><tr><td align="center">(3.36)</td><td /><td /></tr><tr><td rowspan="2" align="center" valign="top">SEm±</td><td align="center">1.11</td><td align="center">-</td><td align="center">-</td><td align="center">-</td></tr><tr><td align="center">(0.23)</td><td /><td /></tr><tr><td align="center">CD</td><td align="center">33.85</td><td align="center">-</td><td align="center">-</td><td align="center">-</td></tr><tr><td align="center">(P=0.05)</td><td align="center">(17.38)</td><td /><td /></tr></tbody></table></table-wrap></p></sec></body><back><ref-list><title>References

APPS

Annals of Plant Protection Sciences

0971-3573

Society of Plant Protection Sciences

apps-14-1-070

SHORT COMMUNICATION

Effect of antifeedant activity of azadirachtin against Spodoptera litura

Purwar

J.P.

Sharma

Nagesh B.

Department of Entomology, College of Agriculture, G.B.PU.A. & T., Pantnagar-263 145, India

32006

141243244

<p>The tobacco caterpillar <italic>Spodoptera litura</italic> Fab. a noxious polyphagous pest, attack on several economical crops. Several natural and synthetic compounds were tested for their antifeedant activity against this pest. (<xref ref-type="bibr" rid="bib003">Purwar & Yadav, 2004</xref>). Thus, the present study was made to know the antifeedant activity of commercial formulation (neemazal 1 EC) against <italic>S. litura</italic>.</p><p>The culture of S. litura was maintained in 0.3 ppm based on its azadirachtin concentration, were prepared in tap water, whereas control was kept with water only. The antifeedant activity was evaluated using no choice feeding bioassay method. All the treatments were replicated thrice. Each replication consisted of 4 leaf discs of castor (size: 4 cm<sup>2</sup>) kept on filter paper, moistened with water and placed equidistant in glass Petri dishes (dia 10 cm). Five larvae of <italic>S. litura</italic>, 6 days old were released in each Petri dish and allowed to feed until control leaf were consumed by >50%. The quantitative analysis of feeding deterrency was done follwing the ‘deterrency scale’ Strong (+++): 90.01–100.00, Moderate (++): 70.01–90.00, Slight (+): 50.01–70.00, Poor or nil (-): 0.001–50.00.</p><p>The results indicated a differential feeding activity in all concentrations of neemazal except in the lowest concentration (0.3 ppm). Maximum area of leaf consumed (11.3 cm<sup>2</sup>) was recorded in control and mimimum (2.7 cm<sup>2</sup>) was in highest concentration of neemazal (300 ppm). At the lowest concentration (0.3 ppm), the area of leaf consumed was statistically at par to that of untreated control. Similar results were recorded by Nathala and Dhingra (<xref ref-type="bibr" rid="bib002">2005</xref>) against <italic>Helicoverpa armigera</italic> by extracts of <italic>Melia azedarach</italic>. Minimum% feeding area was recorded in highest concentration and maximum was in control, it ranged from 18.1–70.8 (<xref ref-type="table" rid="tab001">Table 1</xref>). The% protection offered by 300, 150, 30, 5, 3, 1.5 and 0.3 ppm of neemazal 1 EC was 75.8, 69.8, 64.3, 58.1, 55.1, 52.6 and 23.6 over control. A quantitative analysis of feeding deterrency revealed moderate antifeedant activity at 300 ppm and slight at all lower concentrations and poor or nil was at lowest concentration (0.3 ppm). Kaur <italic>et al.</italic> (<xref ref-type="bibr" rid="bib001">2001</xref>) assessed the growth and reproductive performance of <italic>S. litura</italic> by feeding doses of NSKE and observed disrupting effects, delayed development and dose correlated mortality. <table-wrap id="tab001"><label>Table 1</label><caption><p>Antifeedant activity of Neemazal against <italic>Spodoptera litura</italic></p></caption><table><thead><tr><th align="center">Conc. (ppm)</th><th align="center">Mean leaf area consumed (cm<sup>2</sup>)</th><th align="center">Mean% feeding</th><th align="center">Mean% protection</th><th align="center">Anti-feedant activity</th></tr></thead><tbody><tr><td colspan="5"><hr /></td></tr><tr><td rowspan="2" align="center" valign="top">300</td><td align="center">2.74</td><td align="center">18.1</td><td align="center">81.8</td><td align="center">+++</td></tr><tr><td align="center">(1.63)</td><td /><td /></tr><tr><td rowspan="2" align="center" valign="top">150</td><td align="center">3.42</td><td align="center">21.7</td><td align="center">78.2</td><td align="center">++</td></tr><tr><td align="center">(1.83)</td><td /><td /></tr><tr><td rowspan="2" align="center" valign="top">30</td><td align="center">4.04</td><td align="center">25.2</td><td align="center">74.7</td><td align="center">++</td></tr><tr><td align="center">(1.99)</td><td /><td /></tr><tr><td rowspan="2" align="center" valign="top">5</td><td align="center">4.74</td><td align="center">29.3</td><td align="center">70.3</td><td align="center">++</td></tr><tr><td align="center">(2.15)</td><td /><td /></tr><tr><td rowspan="2" align="center" valign="top">3</td><td align="center">5.08</td><td align="center">31.7</td><td align="center">68.2</td><td align="center">++</td></tr><tr><td align="center">(2.20)</td><td /><td /></tr><tr><td rowspan="2" align="center" valign="top">1.5</td><td align="center">5.36</td><td align="center">33.5</td><td align="center">66.5</td><td align="center">++</td></tr><tr><td align="center">(2.27)</td><td /><td /></tr><tr><td rowspan="2" align="center" valign="top">0.3</td><td align="center">8.65</td><td align="center">54.0</td><td align="center">45.9</td><td align="center">-</td></tr><tr><td align="center">(2.91)</td><td /><td /></tr><tr><td rowspan="2" align="center" valign="top">Control</td><td align="center">11.33</td><td align="center">70.8</td><td align="center">29.1</td><td /></tr><tr><td align="center">(3.36)</td><td /><td /></tr><tr><td rowspan="2" align="center" valign="top">SEm±</td><td align="center">1.11</td><td align="center">-</td><td align="center">-</td><td align="center">-</td></tr><tr><td align="center">(0.23)</td><td /><td /></tr><tr><td align="center">CD</td><td align="center">33.85</td><td align="center">-</td><td align="center">-</td><td align="center">-</td></tr><tr><td align="center">(P=0.05)</td><td align="center">(17.38)</td><td /><td /></tr></tbody></table></table-wrap></p></sec></body><back><ref-list><title>ReferencesKaur

J.J.

Rao

D.K.

Sehgal

S.S.

Seth

R.K.

(2001). Effect of hexane extract of neem seed kernel on development and reproductive behaviour of Spodoptera litura. Ann. Pl. Protec. Sci.9: 171–178.Nathala

Dhingra

(2005). Chromic effect of Melia azedarach seed extracts on survival, feeding, growth and development of Helicoverpa armigera. Ann. Pl. Protec. Sci.13: 292–297.Purwar

J.P.

Yadav

S.R.

(2004). Evaluation of age relating response of Spilarctia obliqua to biorational insecticides. Ann. Pl. Protec. Sci.12: 271–274.