A novel experimental approach for studying life-history traits of phytophagous arthropods utilizing an artificial culture medium

Authors: KARPICKA-IGNATOWSKA, KAMILA - Adam Mickiewicz University; LASKA, ALICJA - Adam Mickiewicz University; KUCZYNSKI, LECHOSLAW - Adam Mickiewicz University; Rector, Brian; LEWANDOWSKI, MARIUSZ - Warsaw University Of Life Sciences; PUCHALSKA, EWA - Warsaw University Of Life Sciences; SKORACKA, ANNA - Adam Mickiewicz University

Submitted to: Scientific Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 12/1/2019
Publication Date: 12/30/2019
Citation: Karpicka-Ignatowska, K., Laska, A., Kuczynski, L., Rector, B.G., Lewandowski, M., Puchalska, E., Skoracka, A. 2019. A novel experimental approach for studying life-history traits of phytophagous arthropods utilizing an artificial culture medium. Scientific Reports. 9. https://doi.org/10.1038/s41598-019-56801-4.
DOI: https://doi.org/10.1038/s41598-019-56801-4

Interpretive Summary: Studying the biology and life-history of economically important plant-feeding mites is challenging due to their minute size and inclination to hide in crevices between plant parts. As such, methods are needed to facilitate observation of these mites while they feed and reproduce in an exposed setting. In this study, a protocol was developed that utilizes a plant-growth solution (similar to hydroponic horticulture) incorporated into an agar-based medium that allows small fragments of a mite’s host plant to remain fresh and viable for the duration of an experiment, while also preventing mites from walking off the leaf and escaping the test. The protocol was assessed in comparison to current standard rearing protocols for the wheat curl mite (WCM) and two-spotted spider mite (TSSM). The new protocol was found to provide a particularly important improvement over the old standard protocol for WCM, in terms of cost, labor, and rearing efficiency. It will likely be similarly useful for rearing related mite species in the family Eriophyidae, many of which are agricultural pests or weed biological control agents. The new protocol performed similarly to the standard for TSSM for the measured criteria although it may provide advantages in terms of reduced need to interrupt experiments to replace degraded leaf material.

Technical Abstract: Experimental approaches to studying life-history traits in minute herbivorous arthropods are hampered by the need to work with detached host plant material and the difficulty of maintaining that material in a suitable condition to support the animal throughout the duration of the test. In order to address this shortcoming, we developed a customizable agar-based medium modified from an established plant cell-culture medium to nourish detached leaves laid atop it while also preventing arthropods from escaping the experimental arena. The artificial culture medium was tested with two herbivorous mite species: the wheat curl mite (Aceria tosichella; Eriophyidae) and two-spotted spider mite (Tetranychus urticae; Tetranychidae). The proposed approach was a major improvement over a standard protocol for prolonged studies of individual eriophyid mites and also provided some benefits for experiments with spider mites. Moreover, the described method can be easily modified according to the requirements of host plant species and applied to a wide range of microherbivore species. Such applications include investigations of life-history traits and other ecological and evolutionary questions, e.g. mating or competitive behaviours or interspecific interactions, assessing invasiveness potential and predicting possible outbreaks. The approach presented here should have a significant impact on the advancement of evolutionary and ecological research on microscopic herbivores.