Larval growth inhibition of the spiny bollworm, Earias insulana, by some steroidal secondary plant compounds

Abstract

The effect of 23 secondary plant compounds including a series of steroidal aglycones and glycosides, on larval growth and pupation of Earias insulana (Boisd.) was investigated. Larvae did not develop when fed on artificial diets containing 0.2% solamargine, solasonine, tomatine, digitonin, saponin, nomilin, lawsone or coumarin. Some growth‐retarding activity was found with diets containing 0.2% ajmalicine, capsaicin, quercetin, glycyrrhizin and glycerrhetic acid. The eight compounds highly active at 0.2% were also bioassayed at 0.1, 0.05 and 0.01%: larvae did not pupate when fed on diets containing 0.1% solasonine, tomatine or nomilin, whereas solamargine and coumarin were active even at 0.05%. Preliminary structure‐activity relationships were evaluated for the active steroidal glycosides. Zusammenfassung Larvale Wachstumshemmung des ägyptischen Baumwollkapselwurms, Earias insulana, durch einige Steroide sekundäre Pflanzeninhaltstoffe Es wurde die Wirkung von 23, einem künstlichen Nährmedium einverleibten, sekundären Pflanzeninhaltstoffen, unter ihnen eine Reihe steroider Aglucone und Glycoside, auf das Larvenwachstum und die Verpuppung von Earias insulana untersucht. Larven entwickelten sich nicht in mit 0.2% Solamargin, Solasonin, Tomatin, Digitonin, Saponin, Nomilin, Lawsone und Coumarin versetzten Nährmedien. Auf Medien, die 0.2% Ajmalicin, Capsaicin, Quercetin, Glycyrrhizin and Glycyrrhetinsäure enhielten, war das Larvenwachstum verzögert. Die 8 bei 0.2% hoch wirksamen‐Substanzen wurden auch bei 0.1, 0.05 und 0.01% getestet. Die Larven verpupten sich nicht auf 0.1% Solasonin, Tomatin und Nomilin und auf 0.05% Solamargin und Coumarin. Vorläufige Struktur‐Wirksamkeit‐Beziehungen wurden für die aktiven Steroiden Glycoside vorgeschlagen.

Substrate specificity and promiscuity of horizontally transferred UDP-glycosyltransferases in the generalist herbivore Tetranychus urticae

“…Capsaicin (capsaicinoids) is found solely in hot peppers (Capsicum spp.) and is known to 469 deter oviposition (Cowles et al, 1989), inhibit feeding (Hori et al, 2011) and delay larval growth 470 (Weissenberg et al, 1986) in insects. Glycosylation has been linked with the detoxification of 471 capsaicin by the Lepidopteran species Helicoverpa armigera, H. zea and H. assulta, resulting in 472 capsaicin glucoside, a more water-soluble compound than its aglycone and subsequently easier to 473 excrete (Ahn et al, 2011).…”

Metabolic detoxification of capsaicin by UDP‐glycosyltransferase in three Helicoverpa species

“…There are several studies on the effects of capsaicin on insects. Capsaicin is known to deter oviposition in the onion fly Delia antiqua (Diptera: Anthomyiidae) (Cowles et al, 1989), to inhibit the feeding of a ladybird beetle Henosepilachna vigintioctomaculata (Coleoptera: Coccinellidae) (Hori et al, 2011), and to retard larval growth in the spiny bollworm Earias insulana (Lepidoptera: Noctuidae) (Weissenberg et al, 1986). Capsicum extracts have larvicidal activity to two species of mosquitoes, Anopheles stephensi and Culex quinquefasciatus (Madhumathy et al, 2007), and synergistic effects with insecticides on the green peach aphid, Myzus persicae (Edelson et al, 2002).…”

Toxic Activity of Salicylic and Tannic Acids on some Biological Parameters of Spiny Bollworm, Earias insulana and Glassy Clover Snail, Monacha cartusiana

“…Added that this acid in general increased the developmental period of insects and decreased the pupal weight. Moreover, Weissenberg et al (1986) stated that the larvae of E. insulana did not pupate when fed on diets containing 0.10% coumaric acid. At the same trends, Zhu et al (2012) showed that the sub lethal concentrations of hexaflumuron reduced the larval survival of Spodoptera littura.…”