RESUMO
The insecticidal effect of six commercially available plant oils was tested against 4th larval instars of Culex pipiens. Larvae were originally collected from Meit El-Attar, Qalyubia Governorate, Egypt, and then reared in the laboratory until F1 generation. The LC50 values were 32.42, 47.17, 71.37, 83.36, 86.06, and 152.94 ppm for fenugreek (Trigonella foenum-grecum), earth almond (Cyperus esculentus), mustard (Brassica compestris), olibanum (Boswellia serrata), rocket (Eruca sativa), and parsley (Carum ptroselinum), respectively. The tested oils altered some biological aspects of C. pipiens, for instance, developmental periods, pupation rates, and adult emergences. The lowest concentrations of olibanum and fenugreek oils caused remarkable prolongation of larval and pupal durations. Data also showed that the increase of concentrations was directly proportional to reduction in pupation rates and adult emergences. Remarkable decrease in pupation rate was achieved by mustard oil at 1000 ppm. Adult emergence was suppressed by earth almond and fenugreek oils at 25 ppm. In addition, the tested plant oils exhibited various morphological abnormalities on larvae, pupae, and adult stages. Consequently, fenugreek was the most potent oil and the major cause of malformation of both larval and pupal stages. Potency of the applied plant oils provided an excellent potential for controlling C. pipiens.
Assuntos
Culex , Inseticidas , Óleos de Plantas , Animais , Egito , Larva , Dose Letal Mediana , Controle de MosquitosRESUMO
The insecticidal effect of six commercially available plant oils was tested against 4th larval instars of Culex pipiens. Larvae were originally collected from Meit El-Attar, Qalyubia Governorate, Egypt, and then reared in the laboratory until F1 generation. The LC50 values were 32.42, 47.17, 71.37, 83.36, 86.06, and 152.94 ppm for fenugreek (Trigonella foenum-grecum), earth almond (Cyperus esculentus), mustard (Brassica compestris), olibanum (Boswellia serrata), rocket (Eruca sativa), and parsley (Carum ptroselinum), respectively. The tested oils altered some biological aspects of C. pipiens, for instance, developmental periods, pupation rates, and adult emergences. The lowest concentrations of olibanum and fenugreek oils caused remarkable prolongation of larval and pupal durations. Data also showed that the increase of concentrations was directly proportional to reduction in pupation rates and adult emergences. Remarkable decrease in pupation rate was achieved by mustard oil at 1000 ppm. Adult emergence was suppressed by earth almond and fenugreek oils at 25 ppm. In addition, the tested plant oils exhibited various morphological abnormalities on larvae, pupae, and adult stages. Consequently, fenugreek was the most potent oil and the major cause of malformation of both larval and pupal stages. Potency of the applied plant oils provided an excellent potential for controlling C. pipiens.
O efeito inseticida de seis óleos de plantas comercialmente disponíveis foi testado contra larvas de 4ºinstar de Culex pipiens. Larvas foram coletadas originalmente de Meit El-Attar, Qalyubia Governorate, Egito e então cultivadas no laboratório até a geração F1. Os valores LC50 foram 32,42, 47,17, 71,37, 83,36, 86,06 e 152,94 ppm para o feno grego (Trigonella foenum-grecum), amêndoa da terra (Cyperus esculentus), mostarda (Brassica compestris), olíbano (Boswellia serrata), rocket (Eruca sativa) e salsa (Carum ptroselium), respectivamente. Os óleos testados alteraram alguns aspectos biológicos do C. pipiens, por exemplo os períodos de desenvolvimento, estados de crisálida, e emergências de adultos. As concentrações mais baixas de óleo de olíbano e feno grego causaram extraordinário prolongamento da duração larval e pupal. Dados também mostraram que o aumento das concentrações foi diretamente proporcional à redução no estado de crisálida e emergências dos adultos. Notável decréscimo no estado de crisálida foi conseguido com o óleo de mostarda a 1000 ppm. Emergência de adulto foi diminuída no óleo de amêndoa da terra e feno grego a 25 ppm. Além do mais, os óleos de plantas testados, exibiram várias anormalidades morfológicas nas larvas, pupas e estádios adultos. Consequentemente, o óleo de feno grego foi o óleo mais potente e o maior causador de malformação em ambos estádios larval e pupal. Potencial dos óleos de plantas aplicados mostraram excelente resultado no controle do C. pipiens.