The morphological ontogeny of Pilogalumna tenuiclava (Berlese, 1908) is redescribed and illustrated. The prodorsal setae of juveniles are of medium size or long and barbed, and bothridial seta is ...fusiform, with thick, barbed head. Larva has 11 pairs of gastronotal setae, including h2, most are short and smooth, except for longer and barbed c2, c3, dp, h1 and h2. The nymphs have 15 pairs of these setae, most are short and smooth, except for longer and barbed c3. Gastronotal shield of juveniles is poorly developed, with setae of d-, l-series, and h1 in the larva, and d-, l-, h-series and p1 in the nymphs, setae of c-series, p2 and p3 are inserted on unsclerotized integument. In all juveniles, a humeral organ is present.
Wheat production and sustainability are steadily threatened by pests and pathogens in both wealthy and developing countries. This review is focused on the wheat curl mite (WCM),
, and its ...relationship with wheat. WCM is a major pest of wheat and other cereals and a vector of at least four damaging plant viruses (
,
,
, and
). The WCM-virus pathosystem causes considerable yield losses worldwide and its severity increases significantly when mixed-virus infections occur. Chemical control strategies are largely ineffective because WCM occupies secluded niches on the plant, e.g., leaf sheaths or curled leaves in the whorl. The challenge of effectively managing this pest-virus complex is exacerbated by the existence of divergent WCM lineages that differ in host-colonization and virus-transmission abilities. We highlight research progress in mite ecology and virus epidemiology that affect management and development of cereal cultivars with WCM- and virus-resistance genes. We also address the challenge of avoiding both agronomically deleterious side effects and selection for field populations of WCM that can overcome these resistance genes. This report integrates the current state of knowledge of WCM-virus-plant interactions and addresses knowledge gaps regarding the mechanisms driving WCM infestation, viral epidemics, and plant responses. We discuss the potential application of molecular methods (e.g., transcriptomics, epigenetics, and whole-genome sequencing) to understand the chemical and cellular interface between the wheat plant and WCM-virus complexes.
In strawberry production, western flower thrips (WFT) and two-spotted spider mites (TSSM) inflict feeding damage and reduce the yield. Biological control for these pests often includes phytoseiid ...predatory mites and entomopathogenic fungi. The hemipteran family Nabidae have been reported as prominent predators in open-field strawberry.
Carayon is a new biocontrol agent developed in Canada. This study examined if this species was a good candidate for integration with biological control for greenhouse strawberry production. The laboratory trials showed that
Athias-Henriot and
Athias-Henriot were compatible with
, especially when alternative food was available. In contrast, the nabid was not compatible with the
(Balsamo) GHA strain. A greenhouse cage study was conducted to determine if it was beneficial to add
to the phytoseiid-mites-based biological control program for WFT and TSSM in greenhouse strawberry. The release of
on a banker plant together with the placement of sachets of
(Oudemans) and
(McGregor) was beneficial, not only potentially reducing the number of sachet applications, but also providing better pest control than phytoseiid mites alone. Neither the phytoseiids nor the
numbers were significantly affected by the presence of each other.
A prevailing hypothesis for the evolution of parasitism posits that the fitness benefits gained from parasitic activity results in selection for and fixation of parasitic strategies. Despite the ...potential fitness advantage of parasitism, facultative parasites continue to exhibit genetic variation in parasitic behaviour in nature. We hypothesized that evolutionary trade-offs associated with parasitic host-attachment behaviour maintain natural variation observed in attachment behaviour. In this study, we used replicate lines of a facultatively parasitic mite, previously selected for increased host-attachment behaviour to test whether increased attachment trades off with mite fecundity and longevity, as well as the phenotypic plasticity of attachment. We also tested for potential correlated changes in mite morphology. To test for context-dependent trade-offs, mite fecundity and longevity were assayed in the presence or absence of a host. Our results show that selected and control mites exhibited similar fecundities, longevities, attachment plasticities and morphologies, which did not provide evidence for life history trade-offs associated with increased attachment. Surprisingly, phenotypic plasticity in attachment was maintained despite directional selection on the trait, which suggests that phenotypic plasticity likely plays an important role in maintaining attachment variation in natural populations of this facultative parasite.
Dispersal shapes the dynamics of populations, their genetic structure and species distribution; therefore, knowledge of an organisms’ dispersal abilities is crucial, especially in economically ...important and invasive species. In this study, we investigated dispersal strategies of two phytophagous eriophyoid mite species:
Aceria tosichella
(wheat curl mite, WCM) and
Abacarus hystrix
(cereal rust mite, CRM). Both species are obligatory plant parasites that infest cereals and are of economic significance. We investigated their dispersal success using different dispersal agents: wind and vectors. We hypothesised that in both mite species the main mode of dispersal is moving via wind, whereas phoretic dispersal is rather accidental, as the majority of eriophyoid mite species do not possess clear morphological or behavioural adaptations for phoresy. Results confirmed our predictions that both species dispersed mainly with wind currents. Additionally, WCM was found to have a higher dispersal success than CRM. Thus, this study contributes to our understanding of the high invasive potential of WCM.
A new species of spider mite, Tetranychus algarrobus n. sp., is described and illustrated from Peru. It was found damaging the foliage of the native forest tree Neltuma piurensis (Fabaceae) in Piura, ...northwestern Peru.
Two new species of predatory cunaxid mites belonging to the genus Dactyloscirus are described: Dactyloscirus sumatranus Corpuz-Raros and Naredo sp. n. and D. ladangjagung Corpuz-Raros and Lit sp. n. ...Both inhabit soil in corn fields in Sumatra Island, Indonesia. Dactyloscirus. sumatranus closely resembles D. dolichosetosus Den Heyer, 1979, but differs in having the basal half of chelicera strongly inflated, about four times thicker than in the distal half (vs. slender and gradually tapered), hysterosomal setae f1 and h1 at least twice as long as the anterior pairs c1-e1 (vs. only slightly longer), and famulus of tarsus I only ¾ the length of the closely associated asl (vs. longer). Dactyloscirus ladangjagung resembles D. hoffmannae Swift, 1996, but differs by the number of setae on some leg segments, namely, basifemora (5-5-3-2 vs. 5-5-3-1 sts) and tibiae (5-5-5-4 vs. 4-5-4-2 sts), and in having setae g4 the longest of genital setae (vs. setae g3). An updated key to 30 known Dactyloscirus species is provided.
Initial data on the prevalence of storage mites in dry-stored food products and estimates of the presence of mites in human stool in the city of Minia, Egypt are provided. In total, 847 samples were ...collected randomly from houses and retail stores between March 2017 and February 2018. In addition, 1,000 human stool samples were collected for the detection of the presence of mites. Mites were extracted from 285 of 840 (33.9%) samples, and mite contamination was found to be most prevalent in wheat flour (73.3%). In total, 11 mite species belonging to six families were identified, with the pest species Tyrophagus putrescentiae (Schrank) (Acari: Acaridae) (TP) being the most prevalent (91.2% of samples). The seasonal density distribution showed the highest storage mite density in March–April, followed by October, and the lowest in January. In addition, mites were detected in 87 (8.7%) human stool samples, with significant associations between certain occupations and some personal characteristics. Therefore, more attention needs to be paid to intestinal acariasis arising from mite infestation of dry-stored food products.
In the context of sustainable forest management and climate change, increasing tree richness has been proposed as a possible strategy to reach both ecological and productivity goals. This review ...focuses on the effects of mixed stands and increasing tree richness on soil fauna in temperate forests. Effects on earthworm and microarthropod (Collembola and Oribatid Mites) species diversity and abundance and community structure are examined, and clues to the main factors affecting soil communities in these stands are proposed.
Our statistical analyses showed no evidence of any general trend for the effect of mixture either on earthworm or microarthropod diversity or on their abundance. Indeed, positive, negative and non-significant effects have all been reported. Nevertheless, the majority of the studies did find that increased tree richness or the introduction of broad-leaves had a positive effect. In addition, our review shows that soil organism abundance and diversity can be strongly affected by the presence of certain tree species and that the soil organism community structure is, in most cases, significantly affected by an increase in tree richness or by a mixing effect. Litter features appear to be important drivers of soil fauna community composition, while mixture effect seems to have less impact on soil biota. Soil fauna are directly affected by the physical characteristics (microhabitats) and chemical composition (resource quality) of the litter specific to each tree species. Soil communities are then indirectly affected by the subsequent humus characteristics. We conclude our review with some guidelines for forest management and further research.
•Abundance and diversity of soil biota can be strongly affected by tree diversity.•A positive trend of increased tree diversity or when broad-leaves are introduced was found.•Soil community structure is systematically modified in mixed vs pure stands.•Tree species traits, rather than tree species richness, are the most important factor.
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