Agrotis ipsilon larvae known as black cutworm is one of the most destructive and serious underground insect pests. Which attacks various field crops and causes great damage especially it prefers attacking the young plant in the growing stages. The extensive used of insecticides to control it to protect the yield from reduction led to build-up resistance to these insecticides. So, field experiments were approved to evaluate the effectiveness of certain photosensitizer compounds methylene blue, safranin, bromophenol blue belonging to various chemical groups against Agrotis ipsilon larvae in potato crop in El- Giza Governorate in Egypt for the duration of two successive seasons, February 2020 and 2021 under field conditions using double values of LC₅₀ and LC₉₀ of these compounds. A highly significant decrease in the population of A. ipsilon post 3 days of treatment with all tested photosensitize using poisonous baits and a significant difference between the two seasons. On the light of the median and quarter lethal effects of the three tested photosensitizer compounds, methylene blue, bromophenol blue and safranin on the total proteins, total lipids, cholinesterase, acid and alkaline phosphatase in the 4^th larval instars of the black cutworm, A. ipsilon the results proved that all tested compounds caused decreased in these biochemical contents except bromophenol blue treatment slightly increase in acid phosphatase at LC₂₅ and methylene blue increased in total lipids content at both LC₂₅ and LC₅₀ relative to control.