Entomology, Department of


First Advisor

Gary L. Hein

Date of this Version



Knoell, E. A. 2018. Transmission characteristics of Triticum mosaic virus by the wheat curl mite Aceria tosichella Keifer and ecology of the wheat-mite-virus complex on field corn. Thesis. University of Nebraska-Lincoln. 1-113


A THESIS Presented to the Faculty of The Graduate College at the University of Nebraska in Partial Fulfillment of Requirements For the Degree of Master of Science, Major: Entomology, Under the Supervision of Professor Gary L. Hein. Lincoln, Nebraska: May 2018

Copyright (c) 2018 Elliot Andrew Knoell


The wheat curl mite (WCM), Aceria tosichella Keifer, is an economically important pest of winter wheat (Triticum aestivum L.) in the Great Plains of North America due to its ability to transmit three viruses: Wheat streak mosaic virus (WSMV), Triticum mosaic virus (TriMV), and High Plains wheat mosaic virus (HPWMoV). WCM is the only known vector of these plant viruses, making up the wheat-mite-virus complex.

TriMV was recently discovered in 2006, but the transmission characteristics are largely unknown. A study was designed to characterize TriMV acquisition and retention periods for the WCM. For TriMV acquisition, nymphs were placed on TriMV infected wheat and allowed to feed for various time increments. After the allowed feeding time, single mites were then transferred to a series of test plants. For TriMV retention, TriMV-viruliferous adults were transferred to barnyard grass (Echinochloa crus-galli (L.) P. Beauv), a host for the mites and non-host for TriMV, and held for 1 to 12 days. Single mites were then transferred to wheat test plants. Results show that WCM can acquire TriMV within an hour, but poor transmission resulted. Transmission increased with increased acquisition time and peaked after 16 hours. WCM adults can retain TriMV for up to 4 days with a steady transmission rate.

Management of this complex relies on the control of the over-summering alternative hosts known as the green bridge. Corn (Zea mays L.) has been documented as an alternate green-bridge host for the wheat-mite-virus-complex, but much of the literature is 30-50 years old; therefore, a field study was conducted to evaluate the ecology of WCM on reproductive stage corn and the mite’s ability to carry viruses through corn and back to wheat. Corn was manually infested with viruliferous mites of different virus combinations. Results indicate that reproductive stage field corn can support populations of viruliferous WCM, and mites moving off corn are able to carry WSMV and HPWMoV from corn to wheat. TriMV was found to be transmitted at low levels. This study provides a better understanding of corn as a potential green bridge host where corn and winter wheat seasons overlap.

Advisor: Gary L. Hein