Abstract

The study aims to assess the insecticidal activity, oviposition inhibitory and ovicidal effects of volatile oils from different garlic cultivars on faba bean beetle, Bruchidius incarnatus (Boh.) (Chrysomelidae: Bruchinae). The oils were tested at various concentrations and time intervals.  Results showed that all volatile oils caused significant mortality to the test insects. The effects were time and dose-related. The 72 h median lethal doses (LD50%) of male and female B. incarnatus were 0.03 and 0.006% (Chinese oil); 3.77 and 0.06% (Egyptian oil) and 0.03 and 3.77% (Sudanese). The respective median lethal times (LT50, at 0.01%) for male and female were 55.88 and 57.57 h (Chinese oil); 48.62 and 57.76 h (Egyptian oil) and 79.93 and 84.99 h (Sudanese oil). The results of egg hatchability of B. incarnatus exposed to the lowest concentration (0.01%) were: 31, 32 and 34% for Chinese, Egyptian and Sudanese oils, respectively. The respective median lethal doses (LD50 %) for Chinese, Egyptian and Sudanese oils were 0.025, 0.034 and 0.21%. The results indicated that there were significant differences among the three garlic oils; however, the efficacy of the three types of garlic oils against the test insects can be in this order: Chinese> Egyptian> Sudanese oil.

Key words: Bruchinae, fumigation, faba bean, garlic.