Alteration of Termite Locomotion and Allogrooming in Response to Infection by Pathogenic Fungi

Abstract

Termites, being vulnerable to parasitic or pathogenic infections due to large number of individuals living together in colonies, have evolved various behavioral and physiological tactics to resist the infections by those pathogens. Locomotion can help termites collect information on parasites and accordingly exhibit hygienic behaviors. Termites inevitably encounter entomopathogenic fungi during nesting and foraging. However, how these fungal pathogens influence locomotion of termites and how hygienic behavior benefits their survival remains unknown. Here, we examined locomotion alteration of the termite Reticulitermes chinensis (Isoptera: Rhinotermitidae) after infections with different concentrations of the entomopathogenic fungus Metarhizium anisopliae (Hypocreales: Clavicipitaceae). When R. chinensis was isolated, the low concentration (5 × 103 conidia/ml) significantly increased termite locomotion after 6, 12, and 24 h compared with control. However, the high concentrations (5 × 107, 5 × 109 conidia/ml) significantly decreased termite locomotion after 48 h, and termite survival was also significantly lower at 5 × 107 and 5 × 109 conidia/ml compared with the low concentrations and the control. When R. chinensis was in group, however, the locomotion significantly increased 24 h after exposure to 5 × 103 and 5 × 109 conidia/ml but was normalized after 48 h of exposure compared with the control. Allogrooming was significantly higher at 5 × 103 and 5 × 109 conidia/ml compared with the control. The fungal infection did not result in significantly higher mortality of the group termites probably owing to their allogrooming. These findings enhance our understanding on how a termite species copes with biotic stress (i.e., fungal infections) via adaptive behaviors.

Behavioural alterations in femaleAedes aegyptimosquito in response to entomopathogenic fungal infections

“…Any decrease in mosquito lifespan can reduce the average number of blood meals consumed, and any reduction in the number of blood meals consumed can decrease the likelihood of the vector acquiring a disease agent and spreading it to new hosts 11 . The entomopathogenic fungus M. anisopliae is known for its virulence against a number of insect species including mosquitoes 11, 46 and termites 41, 47 . Our survival assay results revealed a significant reduction in mosquito survival after application of medium and high concentrations of fungal conidia.…”

“…11 The entomopathogenic fungus M. anisopliae is known for its virulence against a number of insect species including mosquitoes 11,46 and termites. 41,47 Our survival assay results revealed a significant reduction in mosquito survival after application of medium and high concentrations of fungal conidia. A previous study involving the exposure of the adult Ae.…”

Different strategies between queens and workers against fungal pathogens in the termite Reticulitermes chinensis

“…This is contrary to Hassan, Huang, Xu, et al (2021), who found in R. chinensis Snyder that the locomotion rates of both male and female dealates were significantly higher than soldiers and workers after injection with Phosphofructokinase dsRNA. The same study also found that locomotion rate variation was dose‐dependent: lower concentrations of M. anisopliae increased termite locomotion, whereas higher concentrations resulted in both decreased locomotion and survival (Hassan, Huang, Mehmood, et al, 2021). Decreased velocity and total distance moved by fungal‐infected queens may therefore be linked to the potential benefits of receiving increased grooming from workers in the future.…”

Comparative analysis of adipokinetic hormones and their receptors in Blattodea reveals novel patterns of gene evolution

“…Co‐application of AKH with pathogens could yet further enhance these effects by interfering with the immune response in some insect species (Adamo et al, 2008; Gautam et al, 2020; Ibrahim et al, 2017; Ibrahim et al, 2018), potentially making them more susceptible to pathogen‐mediated control, which in termites has proven difficult to implement, in part due to their social immune defence traits, which prevent the spread of infectious disease (He et al, 2018; Davis et al, 2018; Liu et al, 2019; Hassan et al, 2021).…”