Comparative Toxicity of Neem and Peppermint Oils Nano Formulations against Agrotis ipsilon (Hufn.) Larvae (Lepidoptera: Noctuidae)

 Applications of nanotechnology in agriculture will result in the development of efficient and potential approaches towards the management of insect pests. The toxicity effects of four essential oils peppermint, thyme, camphor and sage oils were tested against the fourth instar larvae of A. ipsilon to select the most effective essential oil to be converted to the nano form. According to the results obtained, peppermint oil was the most toxic compound. The toxicity of  bulk and nano- formulations of neem  and pepper mint oils were tested  against  2nd and 4th instar  larvae of A. ipsilon . The  activity based on LC50  values revealed that the LC50 of loaded neem or pepper mint were lower (0.62 and 36.47 ppm) compared with neem  or pepper mint oil nano-emulsion and bulk neem  for the second larval instar. The different formulations of neem are more potent than in case of pepper mint oil as LC50 and LC90 values were significantly less. The same trend was found concerning the 4th larval instar . Age of treated larvae had a detrimental effect on the response to the compounds tested. It was noticed that the younger larvae were much more sensitive to the prepared compounds compared to the older ones. The least LC50  value for loaded  neem  nano-emulsion was 6.68 ppm compared with the highest value for  bulk neem oil ( 16.68 ppm ) for the fourth instar larvae.  Also,   LC 90  values followed the same trend as in  case ofLC50.  Again, the toxicity of loaded peppermint oil had the most insecticidal activity as expressed by the lowest LC50  value ( 51.9 ppm) with more insecticidal effect than the bulk( 125.43 ppm)  or nano-emulsion (85.43 ppm). The present results indicated that these novel systems could be used in integrated pest management program for A. ipsilon control