2: Predatory mites, free living and plant parasitic nematodes: Association and predation mechanism

While it  has been reported in lab and greenhouse studies that species of soil predatory mites (SPMs) feed on free-living nematodes (FLNs), little is known on the association of species of predatory mites and free-living nematodes in agricultural systems. Furthermore, the functional morphology of the gnathosomal appendages involved in nematode predation has yet to be described.
Standardized methods were streamlined and developed to collect, incubate and extract mites and nematodes. High resolution digital images were taken to determine morphotaxa, which were then used to record taxon abundance. Taxa were identified using morphological and molecular tools. To document SPM predation behavior and to study gnathosomal functional morphology we utilized digital, confocal, low temperature scanning electron (LT-SEM) and transmission electron microscopes.
A short Incubation period (17 days) of soil samples yielded substantially higher abundances of SPM and FLN than samples processed directly from the field. This process facilitated the molecular and subsequent morphological identifications. It also provided the opportunity to conduct LT-SEM imaging followed by barcoding of the three dominant mite species. These high-resolution images were then used to add morphological details to existing descriptions.
Digital recording of SPM showed mites snatching individual nematodes at mid-body level with palps, rolling them compactly like spaghetti on a fork, and puncturing the cuticle with chelicera. LT-SEM imaging of the surface of these arenas revealed the remnants of nematode cuticles following feeding. LT-SEM imaging of mites feeding on nematodes showed the labrum between the protracted chelicera, extending from the dorsal surface of the deutosternal groove.