Revealing Differences in the Viral Transmission Mechanism Between Viruliferous and Nonviruliferous Tagosodes orizicolus Using Transmission Electron Microscopy
Jaclyn Martin and Keyan Zhu-Salzman
Department of Entomology, Texas A&M University
The rice delphacid, Tagosodes orizicolus, presents a threat to the Texas rice industry by causing direct damage from oviposition and feeding on rice leaves and by transmitting Rice hoja blanca virus (RHBV) to rice. T. orizicolus is the most damaging pest of rice in the tropical regions of Latin America, and, when combined with RHBV, can cause up to 100% yield loss. T. orizicolus was found in the United States in the 1950s, 1960s, and 1980s. This pest was not detected in the US again until 2015 in ratoon rice fields near Houston, TX, when outbreaks caused up to 25% yield loss in rice fields from feeding and oviposition. RHBV is a negative sense single-stranded RNA virus and viral transmission by the insect vector is under genetic control. In addition, RHBV has deleterious effects on T. orizicolus such as decreased life expectancy and reduced oviposition. The details on how and if RHBV affects T. orizicolus are unknown along with transmission barriers RHBV faces in the insect vector. In this study, transmission electron microscopy (TEM) is used to explore potential transmission barriers for RHBV in nonviruliferous T. orizicolus and how RHBV might affect different internal structures and organs of T. orizicolus. Nonviruliferous females and males as well as viruliferous females and males were examined under TEM. Ultimately, this study increases the knowledge of this pathosystem and could lead to future research on control methods against this insect vector and virus threatening the rice industry in Texas and beyond.