Effect of pea lectin expressed transgenically in oilseed rape on pollen beetle life-history parameters

When investigating resistance to herbivorous insects in transgenic plants, it is primarily the damaging stage of the insect that is targeted. In our study, we showed that small effects of the transgenic plant on the pest performance might lead to a clear effect on the pest population level. Pollen beetle, Meligethes aeneus (Fabricius) (Coleoptera: Nitidulidae), larvae were reared on three transgenic lines of Brassica napus L. (Brassicaceae) expressing pea (Pisum sativum L.) lectin at 0.2, 0.6, and 0.7% of total soluble protein in anthers, and then monitored until the adult stage. Two lines without the gene construct and consequently containing no pea lectin were used as controls. The egg viability, larval weight, development time, and survival rate were recorded. In a separate experiment, the development time from egg to adult, adult weight, and winter survival of pollen beetles developed on intact plants were recorded. Survival of larvae to adult stage was significantly lower on the transgenic plant lines, independent of lectin level. Survival during hibernation was only 2.4% and was not affected by plant line. Combining previously published results from adult feeding and oviposition assays with the new data on larval development we summarize the effect of the transgenic oilseed rape on the pollen beetle, from oviposition in spring to overwintered adults of the new generation. Net reproductive rate was then shown to be reduced by half on the transgenic oilseed rape compared to the control plants.