Study on the Effect of Allylisothiocyanate Formulations on Three Lepidopterous Insect Larvae, the Diamond Back Moth, <i>Plutella xylostella</i> (L.), the Small Cabbage White Butterfly, <i>Pieris rapae</i> (L.) and Tobacco Cut Worm, <i>Spodoptera litura</i> Fabr

Abstract

<b>Problem statement:</b> The toxicity of seven of Allylisothiocyanate (AITC) formulations, AITC pure and in mixture with cypermethrin and chlorpyrifos, was evaluated using spray application and fumigation method against the diamondback moth, <i>Plutella xylostella</i> (L.), the small cabbage white butterfly, <i>Pieris rapae</i> (L.) and the tobacco cut worm, <i>Spodoptera litura</i> Fabr. <b>Approach:</b> Response varied according to insect species, specific formulation and AITC application rates. <b>Results:</b> Fumigant toxicity of the oil based on 9 h exposure was evaluated against the three insect larvae, the diamond back moth, <i>P. xylostella</i> larvae were more susceptible followed by tobacco cut worm, <i>S. litura</i> and cabbage white, <i>P. rapae</i> larvae. To <i>P. xylostella</i> larvae, LC₅₀ value was 1.5 µL L^-1 air, <i>S. litura</i> larvae (LC₅₀, 1.8 µL L^-1 air) and <i>P. rapae</i> larvae (LC₅₀, 2.0 µL L^-1 air). These three insect larvae were killed after 9 h exposure to a dose of 4.3 µL L^-1 air of the oil, showed no significance difference with that of phosphine (40 µg L^-1 air) a recommended dose. On the other hand, on the spray application bioassays, mortality data counted 72h after treatment, the <i>P. rapae</i> larvae were most susceptible to AITC formulations followed by <i>S. litura</i> larvae and <i>P. xylostella</i> larvae. LC₅₀ values, to <i>P. xylostella</i> larvae, HJ(A) and HJ(B) were the most potent toxicant (33 mg L ^-1) and (46 mg L^-1) respectively, while the least toxic was HJ(C) (556 mg L^-1). To <i>S. litura</i> larvae, HJ(B) and HJ(A) were the most efficient (10 mg L^-1) and (22 mg L^-1) respectively, while HJ(D) (LC₅₀, 385 mg L^-1) was found to be the least toxic. The both of HJ (B) and HJ (C) had similar insecticidal activity (LC₅₀, 8 mg L^-1) to <i>Pieris rapae</i> larvae followed by HD (B) (LC₅₀, 22 mg L^-1) and HD (A) (LC₅₀, 82 mg L^-1). <b>Conclusion/Recommendations:</b> It was concluded that the AITC oil showed promise findings and may be a good alternative to old fumigant “phosphine”. The others were found efficient on the spray application bioassays but the mixture of AITC with cypermethrin especially HJ (A) and HJ (B) were found to be better than AITC mixed with chlorpyrifos and AITC pure. So they can be used in the field of crop protection as safer and potential components of an integrated pest management strategy, especially allylisothiocyanate is considered fully biodegradable, less toxic and many cruciferous vegetables daily consumed by humans

The toxicity and physiological effect of essential oil from Chenopodium ambrosioides against the diamondback moth, Plutella xylostella (Lepidoptera: Plutellidae)

“…Among plant-derived compounds, the LC 50 value of a 9-h fumigant allyl isothiocyanate (AITC, 85%, EC) treatment on third-instar DBM larvae was reported to be 1.5 ml/L air (Eltayeb et al, 2010). Although the insect sources and experimental conditions among these studies differ, these data suggest that the C. ambrosioides EO is quite toxic against DBM when compared to commercial pesticides or plant extracts.…”

Volatiles from wasabi inhibit entomopathogenic fungi: implications for tritrophic interactions and biological control

“…The compound is highly toxic to a wide range of organisms including various herbivores (Rask et al 2000;Agrawal & Kurashige 2003;Wittstock et al 2003;Eltayeb et al 2010) and plant pathogens (Mayton et al 1996;Oliver et al 1999). As such, AITC contributes to the plant's defense strategy against herbivores and disease (Chew 1988;Louda & Mole 1991;Rask et al 2000;Wittstock et al 2003).…”