TOXICITY OF ALIPHATIC AND AROMATIC ISOTHIOCYANATES TO EGGS OF THE BLACK VINE WEEVIL (COLEOPTERA, CURCULIONIDAE)

Citation
V. Borek et al., TOXICITY OF ALIPHATIC AND AROMATIC ISOTHIOCYANATES TO EGGS OF THE BLACK VINE WEEVIL (COLEOPTERA, CURCULIONIDAE), Journal of economic entomology, 88(5), 1995, pp. 1192-1196
Citations number
32
Categorie Soggetti
Entomology,Agriculture
ISSN journal
00220493
Volume
88
Issue
5
Year of publication
1995
Pages
1192 - 1196
Database
ISI
SICI code
0022-0493(1995)88:5<1192:TOAAAI>2.0.ZU;2-T
Abstract
Plant-derived isothiocyanates are rode to a number of soil organisms; however, the differential toxicity of various isothiocyanates to many soil-borne plant pests has not been determined. We tested the contact toxicity of methyl, propyl, allyl, phenyl, benzyl, and 2-phenylethyl i sothiocyanates to eggs of the black vine weevil, Otiorhynchus sulcatus (F.). Eggs were collected every 2 d from a colony of field-collected w eevils and preconditioned over a 5-d period. To reduce the variability of responses, only eggs with melanized chorions were used for all bio assays. Eggs were clipped into acetone solutions of isothiocyanates fo r 2 min. Controls were treated with acetone alone. Treated eggs were i ncubated for 14 d at 24 +/- 2 degrees C and 100% RH. Mortality respons e curves of black vine weevil eggs were analyzed using probit analysis . AU isothiocyanates tested were toxic to weevil eggs; however, isothi ocyanates containing an aromatic moiety (phenyl, benzyl, and e-phenyle thyl) were considerably more toxic than aliphatic (methyl, propyl, and allyl) isothiocyanates. Average mortality in acetone-treated controls was <6%. These results suggest that soil amendments of Brassica aroma tic isothiocyanates may have greater insecticidal potential than those producing aliphatic isothiocyanates.