Effects of starvation on survival, cannibalism, body mass, and intestinal protozoan profile in the subterranean termite Reticulitermes lucifugus

摘要

Scarcity or inadequate nutrition can affect biological and behavioural aspects of subterranean termites and their intestinal protozoan profile. The aim of this study was to investigate changes in survival, cannibalism, body mass, and protist community structure of Reticulitermes lucifugus Rossi subspecies "Sicily" following starvation to provide basic knowledge for the development of more specific studies on a possible survival strategy under stressful conditions. In nature, this termite consumes many food sources and its feeding activity is continuous during the year. In a 35-day laboratory experiment, groups of 50 termites (worker/soldier ratio 49:1) were subjected to two diets, starvation (no source of cellulose offered to the termites) and filter-paper feeding (as a control), kept for 35 days with 7-day intervals of inspection, and compared with termites freshly collected from a field colony on May 2017. Under starvation, termite survival decreased to 0% after 35 days for both workers and soldiers, whereas in the fed group (filter-paper diet) it was 83% for workers and 66% for soldiers. Cannibalism was on average 84% on dead workers, 1.7% on survivor workers, and 100% on dead soldiers. The body mass of workers decreased from 3.5 mg/worker (first day of the test) to 2.05 mg/worker (last day of the test). The community structure and abundance of the intestinal protozoa of workers changed in response to starvation. Starvation caused the loss of four, six, and two protist species after 7, 14, and 28 days, respectively, with only one species persisting after 28 days. In most inspection dates, results were significantly different from those of filter-paper-fed and field-collected groups.