Biological changes in the Eastern subterranean termite, Reticulitermes flavipes (Isoptera, Rhinotermitidae) and its protozoa profile following starvation

Abstract

The effects of starvation on survival, body mass, movement, other behavior, and the symbiotic protozoan community in Reticulitermes flavipes (Kollar) were investigated in a 40-day assay. Groups of 100 termites in their natural worker/soldier ratio (98/2) were tested. Starvation resulted in significantly greater mortality and induced more cannibalism of workers than in the control. Worker survival rate gradually declined to 58% along with an increasing rate of cannibalism during the first 30 days, and then quickly decreased to 5% along with an increasing rate of necrophagia after 30 days. In contrast, starvation had no significant effect on the survival of soldiers (60%) as compared to the control (90%) and starved workers did not cannibalize soldiers. Ten protozoan species residing in the hindgut were identified. When compared with field termites, the 40-day starvation eliminated 5 species (Trichonympha agilis, Pyrsonympha vertens, and P. major, D. gracilis, Holomastigotes elongatum), significantly reduced the numbers of two species (Dinenympha fimbriata, Spironympha kofoidi), had no effect on two species (Trichomitus trypanoides and Spirotrichonympha flagellata), and led to proliferation of one species (Monocercomonas sp.), whereas feeding on filter paper reduced the populations of five species (T. agilis, D. fimbriata, P. vertens, P. major, and S. flagellata) to different degrees. Workers surviving starvation had similar body mass and short-range movement speed to workers fed on filter paper and workers freshly collected from natural setting. The energy-demanding survival and walking indicated that they might obtain sufficient nutrients from cannibalizing other workers. The observed behaviors are important in helping to understand termite survival strategies and the mechanisms by which termites maintain their social structure under stressful conditions.

Dietary‐driven variation effects on the symbiotic flagellate protist communities of the subterranean termite Reticulitermes grassei Clément

“…It is also suggested that cannibalism is a natural response to the survival struggle, as cannibalism may provide both an additional source of nitrogen and also provide symbiotic fauna to maintain the digestion abilities when food becomes available (Hu et al. ). For these reasons, necrophagy is considered to be a normal behaviour within termite colonies.…”

“…Moreover, cellulose alone (as filter paper) may also impose major alterations to the flagellate protist communities (Cook and Gold ; Hu et al. ).…”

“…Flagellate protists seem to be sensitive to the wood species, possibly due to wood extractives, which may cause the total loss of flagellate protists, as well to high or low weight carbon sources, which may cause changes in the flagellate protist species composition and community structure (Mannesmann 1972;Cook and Gold 2000;Tanaka et al 2006). Moreover, cellulose alone (as filter paper) may also impose major alterations to the flagellate protist communities (Cook and Gold 2000;Hu et al 2011).…”

Communication and Social Regulation in Termites

“…It has even been speculated that the intestinal bacteria of R. speratus may be involved in nestmate recognition (Matsuura 2001). However, the symbiotic community (microbiome), which includes flagellates and bacteria, is poorly described when it comes to its involvement in behavior and caste regulation in intermediate termites (Hu et al 2011;Boucias et al 2013;Dedeine et al in prep). Since stomodeal trophallaxis is relatively common in Reticulitermes (Korb et al 2012), it may play a regulatory role in the transfer of symbiotic fauna.…”

Social Recognition in Invertebrates

“…It has even been speculated that the intestinal bacteria of R. speratus may be involved in nestmate recognition (Matsuura 2001). However, the symbiotic community (microbiome), which includes flagellates and bacteria, is poorly described when it comes to its involvement in behavior and caste regulation in intermediate termites (Hu et al 2011;Boucias et al 2013;Dedeine et al in prep). Since stomodeal trophallaxis is relatively common in Reticulitermes , it may play a regulatory role in the transfer of symbiotic fauna.…”