Investigating Efficacy and Host preference of Bruchidius fulvus (Col.: Bruchidae) for Biological control of Camelthorn in Birjand

Bruchidius fulvus Allard is a biological control agent of camelthorn weed (Alhagi camelorum Fisch.) in Birjand region. Efficiency of B. fulvus for biological control of Camelthorn weed was studied by separate experiments in laboratory and natural conditions based on CRD in 2009. So in average, 35±1.15 and 48±1.04% of the seeds in the legumes destroyed in the spring sampling (Early of May) and in fall (Early of November), respectively. Also the percent of seed germination was 65±2.8, 33.5±2.13 and 27±2.59% in average under the laboratory conditions and control and in spring and fall sampling, respectively. The results of this study indicated that the activity of this seed beetle caused a significant decrease (p≤ 0.001) in the seeds camelthorn and percent of seed germination (viability) rather than the control. The mean percents of parasitism for spring and fall sampling were 12.1±0.52 and 15.16±0.42%, that it can be decrease the efficiency of B. fulvus in biological control programs in natural conditions. The results of host preference experiments that studied under constant temperature of 25±1˚C and relative humidity 65±5% based on Sherratt and Harvey (1993) method indicated that B. fulvus is probably a monophagous species and only hurt to the camelthorn weed