Co-habiting ants and silverfish display a converging feeding ecology.

Background: Various animal taxa have specialized to living with social hosts. Depending on their level of specialization, these symbiotic animals are characterized by distinct behavioural, chemical, and morphological traits that enable close heterospecific interactions. Despite its functional importance, our understanding of the feeding ecology of animals living with social hosts remains limited.

Adaptation of an arthropod predator to a challenging environment is associated with a loss of a genome-wide plastic transcriptional response.

Background: Structural and chemical plant defence traits may reduce the efficacy of biological control agents in integrated pest management. Breeding programmes have shown arthropod predators' potential to acclimate to challenging host plants. However, whether and how these predators adapt to novel plant environments remain unclear.

The host plant strongly modulates acaricide resistance levels to mitochondrial complex II inhibitors in a multi-resistant field population of Tetranychus urticae.

The two-spotted spider mite Tetranychus urticae is a polyphagous pest with an extraordinary ability to develop acaricide resistance. Here, we characterize the resistance mechanisms in a T. urticae population (VR-BE) collected from a Belgian tomato greenhouse, where the grower was unsuccessful in chemically controlling the mite population resulting in crop loss.

Cardinium symbionts are pervasive in Iranian populations of the spider mite Panonychus ulmi despite inducing an infection cost and no demonstrable reproductive phenotypes when Wolbachia is a symbiotic partner.

Maternally transmitted symbionts such as Cardinium and Wolbachia are widespread in arthropods. Both Cardinium and Wolbachia can cause cytoplasmic incompatibility, a reproductive phenotype that interferes with the development of uninfected eggs that are fertilized by infected sperm. In haplodiploid hosts, these symbionts can also distort sex allocation to facilitate their spread through host populations.

Egg provisioning explains the penetrance of symbiont-mediated sex allocation distortion in haplodiploids.

Maternally transmitted symbionts such as Wolbachia can alter sex allocation in haplodiploid arthropods. By biasing population sex ratios towards females, these changes in sex allocation may facilitate the spread of symbionts. In contrast to symbiont-induced cytoplasmic incompatibility (CI), the mechanisms that underpin sex allocation distortion remain poorly understood.

Host adaptation and specialization in Tetranychidae mites.

Composite generalist herbivores are comprised of host-adapted populations that retain the ability to shift hosts. The degree and overlap of mechanisms used by host-adapted generalist and specialist herbivores to overcome the same host plant defenses are largely unknown. Tetranychidae mites are exceptionally suited to address the relationship between host adaptation and specialization in herbivores as this group harbors closely related species with remarkably different host ranges-an extreme generalist the two-spotted spider mite (Tetranychus urticae Koch [Tu]) and the Solanaceous specialist Tetranychus evansi (Te).

The complex II resistance mutation H258Y in succinate dehydrogenase subunit B causes fitness penalties associated with mitochondrial respiratory deficiency.

Background: The acaricides cyflumetofen, cyenopyrafen and pyflubumide inhibit the mitochondrial electron transport chain at complex II [succinate dehydrogenase (SDH) complex]. A target site mutation H258Y was recently discovered in a resistant strain of the spider mite pest Tetranychus urticae. H258Y causes strong cross-resistance between cyenopyrafen and pyflubumide, but not cyflumetofen.

A salivary GMC oxidoreductase of Manduca sexta re-arranges the green leaf volatile profile of its host plant.

Green leaf volatiles (GLVs) are short-chain oxylipins that are emitted from plants in response to stress. Previous studies have shown that oral secretions (OS) of the tobacco hornworm Manduca sexta, introduced into plant wounds during feeding, catalyze the re-arrangement of GLVs from Z-3- to E-2-isomers. This change in the volatile signal however is bittersweet for the insect as it can be used by their natural enemies, as a prey location cue.

Incomplete reproductive barriers and genomic differentiation impact the spread of resistance mutations between green- and red-colour morphs of a cosmopolitan mite pest.

Pesticide resistance represents a clear and trackable case of adaptive evolution with a strong societal impact. Understanding the factors associated with the evolution and spread of resistance is imperative to develop sustainable crop management strategies. The two-spotted spider mite Tetranychus urticae, a major crop pest with worldwide distribution and a polyphagous lifestyle, has evolved resistance to most classes of pesticides.

Intersexuality in a natural population of the terrestrial isopod .

Intersex phenotypes are rarely observed in natural isopod populations and their expression is typically associated with infection of , a reproductive parasite that manipulates arthropod reproduction. During an intensive sampling effort of a natural population of the isopod , an adult individual was isolated that expressed both male and female traits. The intersex individual exhibited clearly developed external male genitalia and carried multiple eggs in its brood pouch.

Interacting host modifier systems control -induced cytoplasmic incompatibility in a haplodiploid mite.

Reproductive parasites such as spread within host populations by inducing cytoplasmic incompatibility (CI). CI occurs when parasite-modified sperm fertilizes uninfected eggs and is typified by great variation in strength across biological systems. In haplodiploid hosts, CI has different phenotypic outcomes depending on whether the fertilized eggs die or develop into males.

Intradiol ring cleavage dioxygenases from herbivorous spider mites as a new detoxification enzyme family in animals.

Background: Generalist herbivores such as the two-spotted spider mite Tetranychus urticae thrive on a wide variety of plants and can rapidly adapt to novel hosts. What traits enable polyphagous herbivores to cope with the diversity of secondary metabolites in their variable plant diet is unclear. Genome sequencing of T.

Genomic diversity across the Rickettsia and 'Candidatus Megaira' genera and proposal of genus status for the Torix group.

Members of the bacterial genus Rickettsia were originally identified as causative agents of vector-borne diseases in mammals. However, many Rickettsia species are arthropod symbionts and close relatives of 'Candidatus Megaira', which are symbiotic associates of microeukaryotes. Here, we clarify the evolutionary relationships between these organisms by assembling 26 genomes of Rickettsia species from understudied groups, including the Torix group, and two genomes of 'Ca.

A H258Y mutation in subunit B of the succinate dehydrogenase complex of the spider mite Tetranychus urticae confers resistance to cyenopyrafen and pyflubumide, but likely reinforces cyflumetofen binding and toxicity.

Succinate dehydrogenase (SDH) inhibitors such as cyflumetofen, cyenopyrafen and pyflubumide, are selective acaricides that control plant-feeding spider mite pests. Resistance development to SDH inhibitors has been investigated in a limited number of populations of the spider mite Tetranychus urticae and is associated with cytochrome P450 based detoxification and target-site mutations such as I260 T/V in subunit B and S56L in subunit C of SDH. Here, we report the discovery of a H258Y substitution in subunit B of SDH in a highly pyflubumide resistant population of T.

Structural and functional characterization of β-cyanoalanine synthase from Tetranychus urticae.

Tetranychus urticae is a polyphagous spider mite that can feed on more than 1100 plant species including cyanogenic plants. The herbivore genome contains a horizontally acquired gene tetur10g01570 (TuCAS) that was previously shown to participate in cyanide detoxification. To understand the structure and determine the function of TuCAS in T.

The G126S substitution in mitochondrially encoded cytochrome b does not confer bifenazate resistance in the spider mite Tetranychus urticae.

Several genetic variants of the cd1- and ef-helices of the Q site of mitochondrial cytochrome b have been associated with bifenazate resistance in the spider mite Tetranychus urticae, an important crop pest around the world. Maternal inheritance of bifenazate resistance has provided strong evidence for the involvement of many of these mutations alone or in combination. A number of populations highly resistant to bifenazate were uncovered that carried the G126S substitution in combination with other target-site mutations.

High-resolution genetic mapping reveals cis-regulatory and copy number variation in loci associated with cytochrome P450-mediated detoxification in a generalist arthropod pest.

Chemical control strategies are driving the evolution of pesticide resistance in pest populations. Understanding the genetic mechanisms of these evolutionary processes is of crucial importance to develop sustainable resistance management strategies. The acaricide pyflubumide is one of the most recently developed mitochondrial complex II inhibitors with a new mode of action that specifically targets spider mite pests.

Genome streamlining in a minute herbivore that manipulates its host plant.

The tomato russet mite, is among the smallest animals on earth. It is a worldwide pest on tomato and can potently suppress the host's natural resistance. We sequenced its genome, the first of an eriophyoid, and explored whether there are genomic features associated with the mite's minute size and lifestyle.

The physiology of movement.

Movement, from foraging to migration, is known to be under the influence of the environment. The translation of environmental cues to individual movement decision making is determined by an individual's internal state and anticipated to balance costs and benefits. General body condition, metabolic and hormonal physiology mechanistically underpin this internal state.

Identification and characterization of new mutations in mitochondrial cytochrome b that confer resistance to bifenazate and acequinocyl in the spider mite Tetranychus urticae.

Background: In spider mites, mutations in the mitochondrial cytochrome b Q pocket have been reported to confer resistance to the Q inhibitors bifenazate and acequinocyl. In this study, we surveyed populations of the two-spotted spider mite Tetranychus urticae for mutations in cytochrome b, linked newly discovered mutations with resistance and assessed potential pleiotropic fitness costs.

Results: We identified two novel mutations in the Q site: G132A (equivalent to G143A in fungi resistant to strobilurins) and G126S + A133T (previously reported to cause bifenazate and acequinocyl resistance in Panonychus citri).

Convergent evolution of cytochrome P450s underlies independent origins of keto-carotenoid pigmentation in animals.

Keto-carotenoids contribute to many important traits in animals, including vision and coloration. In a great number of animal species, keto-carotenoids are endogenously produced from carotenoids by carotenoid ketolases. Despite the ubiquity and functional importance of keto-carotenoids in animals, the underlying genetic architectures of their production have remained enigmatic.

Draft Genome Assembly of the False Spider Mite .

The false spider mite Brevipalpus yothersi infests a broad host plant range and has become one of the most economically important species within the genus . This phytophagous mite inflicts damage by both feeding on plants and transmitting plant viruses. Here, we report the first draft genome sequence of the false spider mite, which is also the first plant virus mite vector to be sequenced.

Long-Term Population Studies Uncover the Genome Structure and Genetic Basis of Xenobiotic and Host Plant Adaptation in the Herbivore .

Pesticide resistance arises rapidly in arthropod herbivores, as can host plant adaptation, and both are significant problems in agriculture. These traits have been challenging to study as both are often polygenic and many arthropods are genetically intractable. Here, we examined the genetic architecture of pesticide resistance and host plant adaptation in the two-spotted spider mite, , a global agricultural pest.

Structural and functional characterization of an intradiol ring-cleavage dioxygenase from the polyphagous spider mite herbivore Tetranychus urticae Koch.

Genome analyses of the polyphagous spider mite herbivore Tetranychus urticae (two-spotted spider mite) revealed the presence of a set of 17 genes that code for secreted proteins belonging to the "intradiol dioxygenase-like" subgroup. Phylogenetic analyses indicate that this novel enzyme family has been acquired by horizontal gene transfer. In order to better understand the role of these proteins in T.