ELI SHAAYA, Ph.D

About me

Eli Shaaya, Ph.D
Department of Food Science
The Volcani Center
Bet Dagan 50250
Israel

Phone: 972-3-9683586
Fax: 972-3-9683583
Email: vtshaaya@volcani.agri.gov.il

Academic and Professional Experience:

1966 PhD in Biology and biochemistry
1986 Principal scientist (A+) equivalent to professor at the Volcani Center of Agricultural Research Organization, Bet Dagan, Israel
1992 Nominated professor in insect physiology and grain storage at the Faculty of Agriculture, the Hebrew University of Jerusalem, Rehovot, Israel
1991-1995 Chairman, Dept of stored Products at the Volcani Center, ARO, Israel

Research Activities

The Role of Hormones in Insect Development Mainly go in for the physiological and biochemical studies on insect hormones: ecdysone and juvenile hormone.
The use of Natural Products for Insect Control
A). Studies done with edible oils and fatty acids In our search for environmentally safe alternatives to chemical insecticides for the control of stored product insects we tested the activity of a large number of edible oils and their fatty acids against a number of stored product insects. We found that the activity of the oils is stage and species specific and that there is a close correlation between the chain length of the straight chain fatty acids and their biological activity. C₁₁ was found to be the most effective fatty acid against a number of stored product insects at very low concentrations. We also screened a derivative of C₁₁ which was four times more effective that C₁₁. Also we isolated two active fractions from cotton seed oil: one that acts as a repellent against adults and a second fraction which acts mainly as an ovicide, interfering with the late stages of embryogenesis. Some of these compounds were patented.
B). Studies done with essential oils, activity and mode of action. Our investigations on the effects of essential oils extracted from various spices and herbs grown in Israel for the control of insects infesting dry commodities showed great promise. A number of oils were found to be fumigants at low concentrations against the major stored product insects in laboratory and field studies. In field pilot tests, low concentrations of 50 - 7O g oil/m³ was enough to obtain effective control of the main stored product insects compared with the recommended concentration of methyl bromide of 30 - 50g/m³. Addition of CO₂ increased the activity of the oils and facilitated the penetration of these fumigants in the grain.
The use of insect growth regulators for the control of stored product insects.
A). Comprehensive study was conducted to evaluate the effectiveness of promising insect growth regulators and to study their mode of action.
B). Birational suppression of Lepidopteron pests The overall objective of this research is to promote the effective utilization of chitin synthesis inhibitors (CSIs) for the protection of field crops and stored products from losses caused by pest insects. The aims are to test the " precursor transport" hypothesis for the mode of action of CSIs in target cells in vitro and to assess two possible resistance mechanisms to CSIs, enzymatic detoxification and limited penetration of the gut wall by CSIs. At the present, we have succeeded in showing that benzoylphenyl ureas inhibit chitin synthesis without interfering with amino sugar uptake in imaginal wing disc of Plodia interpunctella; that is the " precursor transportÓ hypothesis does not appear to apply to our in vitro system.
Methyl Bromide alternatives for the control of stored product insects This study is aimed to compare the toxicity of the fumigants, methyl iodide (CH₃I), carbon disulphide (CS₂), benzaldebyde and a number of isothiocyanates against the main stored product insects. The toxicity of CS₂ and CH₃I were assessed against adult, pupae and larvae of six stored product insects. Regarding isothiocyanates, we reported on the isolation and the biological activity of a new compound, which was isolated from crucifer seeds.

Here's a list of my recent principal publications:

Shaaya, E. and Spindler, K.D. (1990) The effect of methoprene on RNA and chitinolytic enzymes synthesis and on ecdysteroid titer in some insects. Pesticides and Alternatives (J. Casida Ed.), Elsevier, pp. 271-282.
Shaaya, E., Ravid, U., Paster, N., Juven, B., Zisman, U. and Pisarev, V. (1991) Fumigant toxicity of essential oils against four major stored products insects. J. Chem. Ecol. 17: 499-501.
Oberlander, H., Silhacek, D., Leach, E., Ishaaya, I. and Shaaya, E. (1991). Benzoylphenyl ureas inhibit chitin synthesis without interfering with amino sugar uptake in imaginal discs of Plodia interpunctella (Hubner). Arch. Insect Biochem. Physiol. 18: 219-227.
Shaaya, E. (1993). Interference of the insect growth regulator methoprene in the process of larval pupal differentiation. Arch. Insect Biochem. Physiol. 22: 233-243.
Shaaya, E., Shirk, P., Plotkin, S., Rees, H. and Silhacek, D. (1993). Declining ecdysteroid levels are temporally correlated with the initiation of vitellogenesis during pharate adult development in the Indianmeal moth, Plodia interpunctella. Insect Biochem. Molec. Biol. 23: 153-158.
Zimowska,G., Shirk, P., Silhacek, D.L. and Shaaya. E.(1995). Termination of vitellogenesis in follicles of the moth, Plodia interpunctella: Changes in oocyte and follicular epithelial cell activities. Arch. Insect. Biochem. Physiol. 29:357-379.
Oberlander, H., Silhacek, D.L., Shaaya, E. & Ishaaya, I. (1997). Current status and future perspectives of the use of insect growth regulators for the control of stored product insects. J. Stored Prod. Res. 33(1): 1-6.
Shaaya, E., Kostjukovsky, M., Eilberg, J. & Sukprakarn, C. (1997). Plant oils as fumigants and contact insecticides for the control of stored product insects. J. Stored Prod. Res. 33(1): 7-15
Shaaya, E. and Kostjukovsky, M. (1998) Efficacy of phyto-oils as contact insecticides and fumigants for the control of stored-product insects. In "Insecticides with novel modes of action:mechanism and applicationsÓ, edited by Degheele, D. Springer-Verlang, Berlin, Germany.
Kostyukovsky, M., Chen, B., Atsmi, S., Shaaya, E. (2000) Biological activity of two juvenoids and two ecdysteroids against three stored product insects. Insect Biochem. Mol. Biol. 30: 891-897.
Shaaya, E., Kostyukovsky, M., Ravid, U. and Rafaeli, A. (2002) The activity and mode of action of plant volatiles for the control of stored product insects and quarantine pests in cut flowers. Workshop on agriculture and quality aspects of medical and aromatic plants. M. Ozguven Ed. Adana, Turkey.
Kosjukovsky, M., Rafaeli, A., Gileadi, C., Demchenko, N. and Shaaya, E. (2002) Activation of octopaminergic receptors by essential oil constituents isolated from aromatic plants: possible mode of toxicity against insect pests. Pest Management Science. 58: 1101-1106.
Shaaya, E., Kostyukovsky, M., Demchenko, N.(2002) Alternative fumigants for the control of stored product insects. 8th Int. Working Conf. Stored Products Protection, York, England.