Acta Entomologica Sinica ›› 2008, Vol. 51 ›› Issue (7): 728-737.

• RESEARCH PAPERS • Previous Articles     Next Articles

A comparative study of the population fitness of Helicoverpa armigera (Hübner) on two tobacco species,Nicotiania tabacum and N. rustica

FU Xiao-Wei   

  • Online:2008-07-20 Published:2008-07-20

Abstract: Effects of Nicotiania tabacum and N. rustica on the developmentfood utilization and population growth of Helicoverpa armigera (Hübner) under both experimental and natural conditions were studied comparatively. The results showed that(1) In laboratory condition with 26±1℃,relative humidity of 75%±5% and photoperiod of 16L8Dwhen reared on N. rusticathe development duration of  H. armigera larvae significantly prolonged while the survival rate of both 1st and 2nd instar larvae and the fecundity of female adults reduced notablythe net reproductive rate (R0=30.5374) and innate capacity of increase (rm=0.0951) decreased compared with those reared on N. tabacum.(2) There were no significant differences in the approximate digestibility (AD) and the relative growth rate (RGR) of the 6th instar larvae reared in the two tobacco species. Compared to the larvae feeding on N. tabacumboth the efficiency conversation of ingestion (ECI) and digestion (ECD) to N. rustica significantly decreased while the relative consumption rate (RCR) increased significantly. (3) The 2nd generation population of H. armigera in N. tabacum fields (I=1.9922>1) increased faster than that in N.rustica fields which were influenced mainly by tobacco and others"especially in early stage of larvae. The increase of the 3rd generation population slowed down in N. tabacum fields (I=1.5994>1)which declined in N. rustica fields (I=0.6434<1). The early stage larvae were mainly affected by tobacco resistance and rainfallswhile the late stage larvae were infected easily by pathogens. These results showed that N. rustica was less suitable to the reproduction and increase of H. armigera compared to N. tabacum.


Key words: Helicoverpa armigera, tobacco, population fitness, life table, food utilization, food conversion, ecological regulation