The systemic effects of juvenoids on the red firebug Pyrrhocoris apterus and on the pea aphid Acyrthosiphon pisum with data on life table response.
BACKGROUND
A series of juvenoid alcohols and their glycosidic derivatives (juvenogens), synthesized at the Institute of Organic Chemistry and Biochemistry in Prague, commercially used juvenoids and the natural derivatives of juvabione were evaluated for their systemic juvenilizing effect on the red firebug, Pyrrhocoris apterus L., and on the pea aphid, Acyrthosiphon pisum Harris. A life table response experiment was designed, and demographic characteristics were computed for a cohort of A. pisum following chronic exposure to a range of concentrations of the selected trans-isomer of carbamate juvenoid 8 applied via the broad bean (Vicia faba L.) root system.


RESULTS
Using the ratio of topical and per os activities, promising effects were found in two alkyl beta-D-glucopyranosides (3 and 9) and the trans-isomer of carbamate juvenoid 8 in tests on P. apterus. In A. pisum, the highest systemic activity was found in tests with the trans-isomer of carbamate juvenoid 8. The longevity, the number of offspring per female and the number of offspring per reproducing female significantly decreased with concentrations of 0.05 mg mL(-1) and higher. While the net reproductive rate R(0) and the intrinsic rate of natural increase r(m) displayed similar trends, the generation time G varied slightly between 11.6 and 12.8 days.


CONCLUSIONS
Expected systemic activity of glycosidic juvenogens in P. apterus was not confirmed by exposure of the pea aphid on broad bean treated with aqueous solutions of the compounds. Nevertheless, the carbamate juvenoid alcohol 8 displayed a considerable juvenilizing effect on A. pisum in screening tests. Furthermore, this compound indicated a sublethal effect as the realized fecundity U(x) decreased disproportionately to the age-specific survival L(x) with increased concentration. The population parameters are compared with the data in similar demographic studies and are discussed together with the possibilities of using the compounds of this structural type in practice.
Jedlicka
Pavel
P
Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 166 10 Praha 6, Czech Republic. jedlicka@uochb.cas.cz
Hrdý
Ivan
I
Kuldová
Jelena
J
Wimmer
Zdenek
Z
D000818:Animals; D001042:Aphids / Q000187:drug effects*; D005260:Female; D020062:Heteroptera / Q000187:drug effects*; D007605:Juvenile Hormones / Q000032:analysis* / Q000494:pharmacology; D008136:Longevity / Q000187:drug effects*; D012098:Reproduction / Q000187:drug effects
D007605:Juvenile Hormones