The responses of cucumber plants subjected to different salinity or fertilizer concentrations and reproductive success of Tetranychus urticae mites on these plants.

The plant stress hypothesis posits that a herbivore's reproductive success increases when it feeds on stressed plants, while the plant vigor hypothesis predicts that a herbivore preferentially feeds on more vigorous plants. We examined these opposing hypotheses by growing spider mites (Tetranychus urticae) on the leaves of stressed and healthy (vigorous) cucumber plants. Host plants were grown under controlled conditions at low, moderate, and high concentrations of NaCl (to induce salinity stress), at low, moderate, and high fertilizer concentrations (to support growth), and without these additions (control).

Deciphering the metabolic changes associated with diapause syndrome and cold acclimation in the two-spotted spider mite Tetranychus urticae.

Diapause is a common feature in several arthropod species that are subject to unfavorable growing seasons. The range of environmental cues that trigger the onset and termination of diapause, in addition to associated hormonal, biochemical, and molecular changes, have been studied extensively in recent years; however, such information is only available for a few insect species. Diapause and cold hardening usually occur together in overwintering arthropods, and can be characterized by recording changes to the wealth of molecules present in the tissue, hemolymph, or whole body of organisms.