Acquisition of Viral Raw Materials

Screening of Indoor Artificial Diets

Based on the feeding habits of Helicoverpa armigera, 3 to 5 artificial diet formulations are screened. After optimization, the formulation supporting continuous rearing and high egg-laying capacity is selected for production.

Indoor Rearing of Helicoverpa armigera

Wild-caught cotton bollworms are domesticated via a gradual substitution feeding regime: pure vegetable feed → mixed vegetable and artificial feed → full artificial feed, to establish a laboratory strain for mass rearing.

Viral Inoculation

When approximately 80% of larvae reach the 3rd instar, purified virus seeds (free of miscellaneous bacteria) are diluted into a viral suspension with a concentration of 1.0×10⁴ to 1.0×10⁷ PIB/mL, which is mixed into the diet for larval feeding.

Collection of Diseased Dead Larvae

Observation commences 3 days after feeding the virus-contaminated diet. Dead and moribund larvae with swollen bodies and reddish abdomens are collected twice daily (morning and evening) until collection is completed.

Extraction and Preservation of Virus

An appropriate amount of deionized water is added to larval cadavers, and the mixture is ground into slurry using a multi-functional homogenizer. Grinding is terminated once the particle size meets specifications.

Detection and Counting

Identification and quantitative counting are performed using an electron microscope and an optical microscope respectively. Subpackaging is carried out after passing inspection.

Virus Storage

Qualified virus suspensions are filled into sealed plastic drums and stored in a cold warehouse at -10℃ to -20℃ for subsequent use.