Poophilus costalis (Aphrophoridae), is known for producing a protectivefoam during its nymphal stage. This study investigates the chemical andbiological properties of the biofoam produced by P. costalis nymphs. Stability of the foam decreased significantlyat temperatures above 50°C. For the first time, metabolic waste products suchas urea, uric acid, and creatinine were identified in the biofoam. Insecticidalactivity of the biofoam was assessed using a choice test against three cottonpests: Phenacoccus solenopsis, Dysdercus koenigii, and Aphis craccivora. The froth exhibitedrepellent properties against D. koenigiiand A. craccivora, while P. solenopsis showed attraction at allconcentrations except 0.05%. Antibacterial activity was tested against three phytopathogens (Xanthomonas malvacearum and Xanthomonas citri, Pseudomonas aeruginosa), plant growth promotor (Proteus vulgaris) and four microbes including G⁺ (Bacillussubtilis, Enterococcus faecalis)and G^- (Escherichia coli,  Klebsiella pneumoniae). The froth aloneand in combination with gallic or tannic acid exhibited significant,dose-dependent inhibition activity. Notably, E. faecalis and E. coli showedthe highest growth suppression. Gallic acid combinations enhanced theinhibition of E. faecalis and X. malvacearum, while tannic acid wasmore effective against X. citri.These findings suggest that P. costalisfroth has promising potential as a natural antimicrobial agent against bothhuman and plant pathogens.