If the frass does not fall, is it important to the forest?

Concentrations of twenty-three elements obtained from pinewood were compared with the frass produced by insects representing the following taxa: Reticulitermes spp. (Rhinotermitidae), Zootermopsis spp. (Termopsidae), Incisitermes spp. (Kalotermitidae), Hylotrupes spp. (Cerambycidae), Heterobostrychus spp. (Bostrichidae), Lyctus spp. (Bostrichidae), and the family Ptinidae (formerly Anobiidae). Twenty elements (Al, B, Ba, Ca, Cd, Co, Cr, Cu, Fe, K, Mg, Mn, Mo, Na, Ni, P, Pb, Si, Sr, and Zn) were measured using ICP-OES, while carbon, hydrogen and nitrogen percentages were measured using a CHN autoanalyzer. Multiple Kruskal-Wallis (non-parametric ANOVA) tests were used to determine statistically significant differences between all pairwise comparisons. Only one element, Cr, was present at a statistically different concentration (lower) in all frass types compared to pinewood. A comparison of ICP-OES results from pinewood to pine-feeder insect frass revealed that Reticulitermes frass contained significantly higher levels of 15 elements, Zootermopsis 11, Ptinidae 5, Incisitermes 4 and Hylotrupes 1. Only Incisitermes frass showed a significantly higher concentration of percent carbon then pinewood, and Reticulitermes, Zootermopsis, and Ptinidae showed significantly higher percent nitrogen than pinewood. This survey of elements in frass indicates that saproxylic insects are, for the most part, not sequestrating but recycling the store of micronutrients in wood biomass, with the greatest potential contribution to soil nutrient cycles attributable to subterranean termites.