Blatticomposting of food waste, production estimates, chemical composition and CO2 emissions savings: A case study

Abstract

Half of the organic waste generated by mankind is compostable. Many of the traditional methods of food waste treatment generate pernicious efects on ecosystems, such as leachates, greenhouse gases, pathogenic microorganisms or odors. Three cockroach species that are widespread as live food for feeding exotic animals (mainly reptiles) due to their high growth rates, waste consumption, production and quality of blatticompost: the Madagascar hissing cockroach (Aeluropoda insignis Butler), the Guyana spotted cockroach (Blaptica dubia Serville) and the ivory cockroach (Eublaberus sp.) has been evaluated. Neither the weight–length ratios (W–L) nor the body condition index (Krel) of the three species studied were statistically diferent between the control and organic waste treatment groups. Average intakes per animal per day were 0.93 g in Aeluropoda, 2.22 g in Blaptica and 2.58 g in Eublaberus. Blatticompost production rates were 0.11, 0.75 and 0.52 g / animal*day, respectively. Taking into account the diferences in size and density of individuals, this implies an average waste consumption of 1015.9 g/m2 *day, of which 26.7% would be transformed into blatticompost considering the three species together. This is equivalent to 304.8 mt/ha*month of food waste recycled, a blatticompost production of 81.4 mt/ha*month and an estimated greenhouse gas emission savings of 817.2 mt/ha*month. Results indicate that any of the three species studied would be a viable alternative, although the ivory cockroach (Eublaberus sp.) presents ideal characteristics. The massive use of this species in the large-scale treatment of organic waste is proposed. Given the enormous advantages of this treatment and the zero environmental costs (absence of invasive character) could be necessary to adapt the legislation of the European Community to include blatticomposting as a suitable waste treatment as it is done in other parts of the world.