Can sulfur fertilisation improve the effectiveness of trap crops for diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae)?
BACKGROUND
The effect of sulfur fertilisation on chemical constituents of yellow rocket, Barbarea vulgaris (R. Br.), was studied with regard to its potential use as a trap crop for the diamondback moth, Plutella xylostella (L.) (Lepidoptera: Plutellidae). Two types of B. vulgaris var. arcuata were used: the G-type, resistant to P. xylostella and proposed as a 'dead-end' trap crop, and the P-type, not resistant to P. xylostella and used as a control.


RESULTS
In G-type B. vulgaris, sulfur fertilisation increased the content of the dominant glucosinolate (S)-2-hydroxy-2-phenylethylglucosinolate by 20%. Sulfur fertilisation did not significantly change levels of the saponins 3-0-beta-cellobiosylhederagenin and 3-0-beta-cellobiosyloleanolic acid, known to act as feeding deterrents for P. xylostella larvae. In P-type B. vulgaris, the same levels of sulfur fertilisation did not change the glucosinolate content significantly. Two-choice oviposition preference tests with B. vulgaris plants showed that P. xylostella laid 144% and 45% more eggs on G- and P-type plants with sulfur fertilisation respectively.


CONCLUSIONS
The studies suggest that sulfur fertilisation could increase the effectiveness of G-type B. vulgaris as a trap crop for P. xylostella. The effect of plant sulfur fertilisation on P. xylostella oviposition preference is associated with a quantitative glucosinolate increase, but other compounds could also be involved.
Badenes-Perez
Francisco R
FR
Max Planck Institute for Chemical Ecology, Department of Entomology, Jena, Germany. frbadenes@ccma.csic.es
Reichelt
Michael
M
Heckel
David G
DG
D000818:Animals; D031216:Barbarea / Q000737:chemistry / Q000187:drug effects*; D005247:Feeding Behavior / Q000187:drug effects; D005308:Fertilizers; D005961:Glucosinolates / Q000032:analysis / Q000302:isolation & purification / Q000494:pharmacology; D009036:Moths / Q000187:drug effects / Q000502:physiology; D010058:Oviposition / Q000187:drug effects; D010572:Pest Control, Biological / Q000379:methods*; D012503:Saponins / Q000032:analysis / Q000302:isolation & purification / Q000494:pharmacology; D013455:Sulfur / Q000494:pharmacology*
D005308:Fertilizers; D005961:Glucosinolates; D012503:Saponins; D013455:Sulfur