Study On Biological Characteristics Of The Spotted Pupa Strain Of Helicoverpa Armigera(Hübner)

Helicoverpa armigera(HUbner) seriously harms the crops like cotton. Helicoverpa armigera is very common in Chinese agricultural districts. Helicoverpa armigera is a polyphagous pest. It is also a migratory and diapause pest. It has a high rate of reproduction. It can easily adjust to changes in the environment. In this study, the normal type of Helicoverpa armigera (HAW) only produce normal offspring of type. The spotted pupa of Helicoverpa armigera (HAB) is a mutant strain of normal type. In this study, the biological characteristics of HAB and HAW are compared and analysed. And the color inheritance mode of the spotted Pupa of Helicoverpa armigera is explored. Pupation and eclosion regularity of HAB and HAW were observed, too. The main consequence are followed:1. HAB and HAW have no difference during the eggs, larvae and adults time. HAB and HAW only have differences in pupa.1-2spots appears at the Wing bud site of HAB pupa but HAW has no. Critical period of the formation of spots is about8h after the molt.2. It is found that the mating rate, the average single female mating frequency and the average fecundity of HAB were significantly less than HAW. The index of population trend of HAB is far lower than HAW. Overall, HAB has lower fitness.3. There is no reproductive isolation between HAB and HAW. Genetic pupa plaque mutant does not accord with Mendel’s laws of inheritance. It does not follow the cytoplasmic inheritance, either. But the pupae spots in the proportion of offspring mutants have been relatively stable. Maybe this color inheritance is a complex genetic controlled by multiple genes.4. Temperature does not affect the formation of spots in HAB. Pupation and eclosion regularity of HAB and HAW were similar.