The Effect of Plant extracts on Potato Tuber Moth, Phthorimaea operculella (Zeller) under Lab Conditions

Mahmoud Al-Ssedo
General Commission for Scientific Agricultural Research-
Homs Research Center
Al-Furat University, Faculty of Agriculture
 2007

Abstract

The bio-agent effects of some plant extracts: Melia azedarach L., Lantana camara L., and Schinus molle on leaves and fruits are tested by using acetone and ether petroleum as organic solvents in different life stages of potato tuber moth Phthorimaea operculella.Zeller at Insect Lab of Homs Research Center in 2003- 2006.
The results show the efficiency of Lantana camara leaves acetonic extracts, and Schinus molle fruits extracts when it treated on newly eggs, where the decrease rate in hatching of treated eggs 80.16, 88.75% and 59.8, 65,17% at 2.5%, 5% concentrations respectively for two extracts.
The acetonic and petroleum extracts of Lantana camara and Melia azedarach leaves have high efficiency on larva population and moth emergence when eggs treated, so we don’t observe any pupation case at 5% acetonic Lantana camara leaves, and the petroleum extract of Lantana camara leaves causes decreasing the pupation and emergence rates (80.95, 90.23%) and (91.06, 95.78%) respectively, whereas causes decreasing the pupation (95.76, 90.94%) for Melia azedarach extract acetone and (82.12, 86.94%) for petroleum at 2.5, 5% respectively, and Schinus molle leaves extract has the less efficacy among tested extracts.
When tubers treated by Melia azedarach fruits extract, S. molle fruits extract and Melia azedarach leaves extract acetone the mortality rates recorded significant decrease and apparent mortality percentage (AM%) reached (73.78, 85.79%) and  (64.42, 81.05%) and (62.1, 78.63%) at 2.5, 5% concentrations respectively.
The total fecundity (Mx) values were 12.29, 17.62 and 22.75 egg/female when larvae were fed on tubers treated with acetonic extracts for Melia azedarach fruits and S. molle fruits and Melia azedarach leaves respectively whereas it was 99 eggs/female at control treatment.
Using life table parameters, we find that doubling rate of one generation (RO) Net reproductive rate values in F2 decrease very significantly 0.40, 0.91, 0.93 female/female when larvae feed on tubers which treated by acetonic extracts of Melia azedarach fruits and S. molle fruits and Melia azedarach leaves respectively; control reach 36.40 female/female, and The intrinsic rate of increase (Rm) which means ability of sum total to increase free from outside factors was decreased, so it reached 0.0056, 0.0131, 0.0136 one/female/day respectively compared with 0.579 for control while the doubling time (DT) increase significantly, it was duplicated one time every 175.9, 271.6, 772 days compared to 1.5 days in control.
Linear correlation was present between bio-agents effects for plant extracts and concentrations to the same solvent, and the same matter. The acetonic extracts were more effective than ether petroleum.
The results of biological evolution for studied plant extracts by ether petroleum as repellence substances calculating the percentage of repellency value in lab conditions show the efficiency of all plant extracts by disparate rates ranged between 58.17, 70.59% for S. molle leaves extract, 81.7, 98.04% for Melia azedarach fruits extract at 2.5, 5% concentration respectively.
Treatments with Melia azedarach fruits, Lantana camara leaves surpass others at the same concentration by significant differences so the percentage of repellency value for Melia azedarach fruits 81.70, 98.04% and Lantana camara leaves extract 70.59, 96.08% at 2.5, 5% concentrations respectively.
For acetonic extracts we find the efficiency of Lantana camara leaves, Melia azedarach leaves and fruits, S. molle fruits if rates ranged between 71.24, 90.85% for schinus fruits at 2.5, 5% and 86.27, 96.73% for Melia azedarach leaves at same concentrations respectively.
The extract of S. molle leaves was the less efficient acetonic among tested; the repellency value equal 19.6, 22.88% at 2.5, 5% respectively.