Evaluation of the susceptibility of new low nicotine tobacco cultivars to phosphine resistant and susceptible populations of Lasioderma serricorne (F.) (Coleoptera Anobiidae)

Nicotine is believed to be a key factor limiting the ability of arthropods to infest tobacco leaves and their products. The present study investigates the susceptibility of seven inherently low nicotine content tobacco cultivars (lines) to infestation by the cigarette beetle Lasioderma serricorne (F.) (Coleoptera: Anobiidae) via population growth studies of the insect under laboratory conditions. Two populations of L. serricorne, one susceptible, and one resistant, to the fumigant phosphine, were used in the study. Progeny production by L. serricorne differed significantly among the different tobacco lines. An increase in temperature (from 25 °C to 30 °C) increased population growth rate of the insect on susceptible tobacco lines, causing severe infestations in a short period of time. Four tobacco lines (TLB, TLC, TLE and TLF) showed noticeable delay in L. serricorne development, as compared with beetles reared on control tobacco and grain-based rearing media. Both phosphine resistant and susceptible strains of the beetle produced lower numbers of offspring in the low-nicotine tobacco lines (TLB and TLE). Hence, certain low-nicotine tobacco lines may be effective for the control of cigarette beetles, regardless of their susceptibility to phosphine.