Biofoam of Spittlebug, Poophilus costalis (Walker): Preferential Sites, Temperature Regulation, Chemical Composition and Antimicrobial Activity

SIMPLE SUMMARY: Spittlebugs produce foam in either nodes or internodes on stems of Theporsia purpurae (100%) and Mimosa pudica (100%), to establish and protect their young. However, this reduces the photosynthetic capacity of the plants. The surface area of the foam is higher for Lawsonia inermis (18.15 cm(2)) than other plants. The number of nymphs in each piece of foam varied from 1 to 3 in this study. The foam was cooler than the external environment for all the tested plants (p < 0.0001), except T. purpurae and M. pudica (p > 0.05). The biofoam consists of carbohydrates, amino acids, proteins and fatty acids. A saturated fatty acid, octadecanoic acid, was more abundant (88.33%) in the biofoam of Poophilus costalis. The biofoam showed strong antibacterial activity against Staphylococcus aureus than that of other species, similar to that of chloramphenicol against Pseudomonas fluorescens. ABSTRACT: The foam produced by nymphs of Poophilus costalis on eleven different host plants belonging to eight families on St. Xavier’s College campus in India was studied over five months. The chemical composition and antimicrobial activity of these biofoams were investigated. The results revealed that P. costalis preferred Theporsia purpurea and Mimosa pudica for laying their eggs and producing foam, over the other tested plants. P. costalis produce their foam on either nodes or internodes on monocotyledons (30%) (p < 0.05), whereas on dicotyledons, they produce more foam on the stems (63.8%) than on the leaves (6.2%) (p < 0.01). The number of nymphs in each piece of foam from P. costalis varied from 1 to 3 (mean = 1.8 per plant). They produced their foam (5.7 to 45.2 cm) from the ground level on a plant. The length and breadth of a piece of foam ranged from 1.0 to 3.9 cm and 0.6 to 4.7 cm, respectively. The foam tended to be cooler than the environment. Qualitative profiling showed that the foam consists of carbohydrates, including maltose; trypsin; amino acids; protease. The foam was also analyzed using a spectrophotometer, Fourier transform infrared spectroscopy (FT-IR), gas chromatography–mass spectroscopy (GC-MS), and high-performance liquid chromatography (HPLC). The antimicrobial activity of the biofoam was the greatest against Staphylococcus aureus, the growth of which was reduced by 55.9 ± 3.9%, suggesting that the foam could be used as an antimicrobial product. However, no activities were observed against Fusarium oxysporum and Candida albicans.