Arthropod symbioses: a neglected parameter in pest- and disease-control programmes

Abstract

Summary1. Arthropods are important players in biological control as pests, control agents and transmitters of invertebrate diseases. Arthropods are frequently infected with one or several micro-organisms, serving as micro-ecosystems in which multiple interactions can take place. These micro-organisms include disease agents and symbiotic micro-organisms. The latter are usually vertically transmitted and can have a broad spectrum of effects on their hosts, ranging from reproductive manipulations to protection against natural enemies. These interactions may directly or indirectly alter the biology of many arthropods in agriculturally, medically and ecologically relevant ecosystems. 2. Symbiotic micro-organism-induced reproductive manipulations such as cytoplasmic incompatibility and parthenogenesis induction can substantially affect the rearing of biological control agents. Many insects, and recently also mites and nematodes, have been found to be infected, displaying a wide range of effects. We discuss examples of arthropod-micro-organism interactions and effects, which could have consequences for the practical application of arthropods in biological control. 3. Symbiotic micro-organisms can also be involved in host protection against natural enemies such as parasitoids, pathogenic bacteria, fungi and viruses. 4. Symbiotic bacteria can influence the vectorial capacity of disease-vectoring arthropods and may be very helpful in decreasing the transmission of disease agents. 5. Synthesis and applications. The effect of micro-organisms on the outcome of biological control programmes is usually not considered in risk assessments and failure analyses. This review emphasizes the importance of endosymbiotic micro-organisms in comprehensive biological control programmes and provides recommendations on how to recognize, avoid or benefit from these influential tenants.

Endosymbionts and honey bee colony losses?

“…Interactions between viruses, ectoparasitic mites and microsporidian endoparasites are most likely key factors [3][4][5], but the underlying mechanisms are not well understood. Although it is known that maternally-inherited, facultative bacterial endosymbionts such as Wolbachia or Rickettsia can significantly interfere with viral and fungal infections of arthropods [6], they have so far been neglected in this regard. Here we propose to evaluate the potential role of such endosymbionts for colony losses.…”

“…via providing protection against viruses or fungi [6]. For example, Wolbachia can protect the host against several vectored RNA viruses [9] and can be regarded as part of host immunity [6].…”

“…However, endosymbionts such as Spiroplasma and Hamiltonella can also be beneficial for their host's vectorial capacity, e.g. in the whitefly Bemisia tabaci-Tomato yellow leaf curl virus system, Hamiltonella protects viral particles in the vector [6,10].…”

Francisella-Like Endosymbionts and Rickettsia Species in Local and Imported Hyalomma Ticks

“…Several endosymbiotic bacteria in arthropod vectors were shown to interact with pathogens and affect their host's susceptibility to infection, including in tick hosts (12)(13)(14). These symbiotic interactions can lead to the development of novel vector-borne disease control (15), as in the case of dengue virus (www.eliminatedengue.com). The potential symbiosis between FLE bacteria and Hyalomma ticks can serve as a target for the novel development of Hyalomma-borne disease control; however, there is no current study testing the nature of FLE in these vectors or its interaction with potential pathogens, such as Rickettsia species.…”

Bacterial Symbionts of a Devastating Coffee Plant Pest, the Stinkbug Antestiopsis thunbergii (Hemiptera: Pentatomidae)

“…Such phenotypic aspects of the Sodalis symbiont, the Spiroplasma symbiont, and the Rickettsia symbiont in A. thunbergii may be of interest to applied scientists and deserve future studies (48)(49)(50). The causal agent of potato taste associated with Antestiopsis-infested coffee cherries has not been identified, and the possibility that these symbiotic bacteria may be involved in the development of potato taste in some way is worth pursuing.…”