Short-term responses of spider mites inform mechanisms of maize resistance to a generalist herbivore

Plants are attacked by diverse herbivorous pests with different host specializations. While host plant resistance influences pest pressure, how resistance impacts the behaviors of generalist and specialist herbivores, and the relationship to resistance, is less well known. Here, we investigated the behavioral changes of a generalist herbivore, the two-spotted spider mite (TSM), and a specialist herbivore, the Banks grass mite (BGM), after introduction to no-choice Tanglefoot leaf-arenas (2×2 cm2) of three maize inbred lines (B73, B75, and B96). The widely-used inbred line B73 is susceptible to spider mites, while B75 and B96 are known to be mite resistant, especially to TSM. Video tracking was used to record TSM and BGM walking, probing, feeding, resting, web-building and travel distance on arenas of each line. Mite oviposition was also recorded after 72 hours.  B75, a resistant line, decreased the feeding behavior of both mite species compared to B73 (susceptible control) and B96. More..., Maize lines and plant maintenance
Plants were grown at Utah State University’s Research Greenhouse and Laboratory, Logan, UT. Three maize inbred lines were selected for the study (B73, B75, and B96). B73 is susceptible to both BGM and TSM , while B75 and B96 have moderate- and high-level resistance to TSM, respectively.
Two seeds per pot for each maize inbred line (B73, B75, and B96) were sown in 3.5 L pots filled with soil (Sunshine Mix #3, Sun Gro Horticulture, MA), 8 pots per line, distributed in a complete randomized design. Maize plants were grown under greenhouse-controlled conditions (25±2 °C, 60±5% RH, 16:8 hrs. (L:D) photoperiod) and fertigated at a rate of 4.8 kg/100L of 21N-5P-20K Peters Excel Water Soluble Fertilizer mixture (ICL Specialty Fertilizers, SC, USA) by using drip tape (DIG Corporation, CA, USA; 12.7 mm and 6.35 mm diameter tubing with 3.8 L/hr compensating emitters). At 8 weeks of age, plants were used to evaluate spider mite behavior.
Video tracking spider mite..., Data from mite oviposition on maize inbred lines were analyzed using a generalized linear model (Proc Glimmix; SAS 9.4 M4 University edition) within two-way ANOVA that included maize resistance (B73, B75, and B96) and mites (TSM and BGM) as fixed factors. Oviposition data were log transformed to conform to the assumptions of normality and heteroscedasticity. Video recordings (50 min each) were analyzed in 10 min intervals (0 to 10 min, 10 to 20 min, etc.). Proportions of time that each mite spent walking, probing, feeding, and resting within the 10 min intervals were analyzed using a generalized linear model within two-way ANOVA and repeated measures (5 time intervals) with a beta distribution. Data for web-building and travel distance were square-root transformed and analyzed using two-way ANOVA (maize inbred lines) with repeated measures (5 time intervals) using Proc Glimmix., # Short-term responses of spider mites inform mechanisms of maize resistance to a generalist herbivore

Author(s)
Gunbharpur S. Gill1, Hsuan Bonny Lu2, Huyen Bui3, Richard M. Clark4,5, Ricardo A. Ramirez1*
1Department of Biology, Utah State University, Logan, Utah 84322, USA.
2Department of Kinesiology and Health Sciences, Utah State University, Logan, Utah 84322, USA.
3R&S Genetic, ARUP Laboratories, Salt Lake City, Utah 84108, USA.
4School of Biological Sciences, University of Utah, Salt Lake City, Utah 84112, USA.
5Henry Eyring Center for Cell and Genome Science, University of Utah, Salt Lake City, Utah 84112, USA.
*Current address: Department of Entomology, Plant Pathology, & Weed Science, New Mexico State University, Las Cruces, New Mexico 88003, USA.

**File list**
Gill et al. 2023 mite behavior and eggs.xlsx

This data set highlights the spider mite responses of twospotted spider mite and Banks grass mite to maize with varied host plant resistance in the lab. The behavior...