The essential oils from five plants, Mentha spicata, Ocimum basilicum, Cymbopogon schoenanthus, Juniperus phonicea and Matricaria chamomilla were obtained by hydrodistillation and their chemical composition was identified based on spectral analysis of chromatography/mass spectrometry (GC/MS). The insecticidal potential of oils against the larvae of Trogoderma granarium was tested using contact and fumigant toxicity bioassays. Based on GC/MS analysis, the main compounds of essential oils were carvone (66.17 %) in M. spicata, methyl cinnamate (44.28 %) in O.basilicum, piperitone (63.35%) in C. schoenanthus, α-pinene (44.57 %) in J. phoniceaand bisabolol oxide A (56.71 %) in M. chamomilla. It was also clear that the essential oils are rich with monoterpenes, either oxygenated or non-oxygenated ones except the essential oil of M. chamomilla which contains a high concentration of oxygenated sesquiterpenes. The oil of M. spicata displayed the highest fumigant toxicity against T. granarium as, it induced 71.67 and 91.67% larval mortality at 50 and 100 µl/l, respectively, while the essential oil of J. phonicea revealed a weakest toxicity. Among the five tested oils, M. spicata (LC50 = 0.07 mg/cm 2 ), O. basilicum (LC50 = 0.08 mg/cm 2 ) and C. shoenanthus (LC50 = 0.09 mg/cm 2 ) essential oils showed a remarkable contact toxicity against T. granarium. The values of LC50 it is almost half of deltamethrin (0.04 mg/cm 2 ), as one of the recommended insecticides to control stored insect pests. The essential oils of M. chamomilla and J. phonicea displayed moderate and weak contact toxicity, respectively. It was obvious that the essential oils were more active as contact toxicants than as fumigant toxicants. Therefore, M. spicata, O. basilicumand C. shoenanthus essential oils could be implemented in T. granarium management programs.
Reduction infestation percentages of spiny bollworm (SBW), Earias insulana (Boisd.), and pink bollworm (PBW), Pectinophora gossypiella (Saund.), on cotton treated with some chlorpyrifos and cyhalothrin formulations alone or/and mixed with Top Film or Tritone K adjuvants were investigated under field conditions. Adjuvants/insecticides mixtures enhanced the reduction percentages of E. insulana infestation, compared with individually applied insecticides. Mixtures of Top Film with chlorpyrifos or cyhalothrin formulations gave the highest reduction percentages of infestation, where general reduction average ranged between 81% and 89.7%, and between 86.5% and 93.2%, respectively. Moreover, Tritone K mixed with cyhalothrin formulations displayed adequate infestation reduction, as general reduction averages ranged between 80.6% and 88.1%. In general, tank mixing of both adjuvants with cyhalothrin formulations enhanced the efficiency of formulation greater than mixing adjuvants with chlorpyrifos formulations against E. insulana. On the other hand, the infestation percent of P. gossypiella was lower than that of E. insulana in untreated cotton plants. The formulations alone or their mixtures with adjuvants gave good reduction of infestation, where the general reduction averages ranged between 88% and 93.5%, and between 70.6% and 87.1% for formulations/adjuvants mixtures and formulations alone, respectively.
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