Submitted to: CDFA Pierce's Disease Control Program Research Symposium
Publication Type: Proceedings
Publication Acceptance Date: October 12, 2004
Publication Date: December 7, 2004
Citation: De Leon, J.H., Fournier, V., Hagler J., Daane K., Jones, W.A. 2004. Development of molecular diagnostic markers for Homalodisca sharpshooters present in California to aid in the identification of key predators. In: Proceedings CDFA Pierce's Disease Control Program Research Symposium, December 7-10, 2004, San Diego, California. p. 326-329.
Interpretive Summary: The glassy-winged sharpshooter (GWSS), is a large leafhopper that is a serious pest because it vectors a strain of bacterium that causes Pierce's disease in grapevines. A biological control program is currently in progress in California against the GWSS. Effective control of GWSS will require an area-wide pest management approach, and a major component of such an approach is the exploitation of the pest's natural enemies which, when utilized to their greatest potential, can increase the effectiveness of other control tactics. Unfortunately, very little is known about GWSS natural enemies; this is especially true for their predators. This study uses sophisticated genetic techniques to develop "markers" for identification of key predators of the GWSS in California. The results will facilitate ongoing efforts to develop more effective biological control programs for the GWSS.
The aim of the present study was to develop molecular diagnostic markers to identify key predators of Homalodisca sharpshooter species present in California, H. coagulata (glassy-winged sharpshooter, GWSS) and H. liturata (smoke-tree sharpshooter, STSS). RAPD-PCR DNA fingerprinting of several sharpshooter species identified specific bands that were excised, sequenced, and SCAR (Sequenced Characterized Amplified Region) markers were designed. The results demonstrated that both GWSS- and Homalodisca-specific markers were specific toward their targets. The GWSS-specific markers amplified only GWSS and the Homalodisca-specific markers amplified only GWSS and STSS. The sensitivity limits for both marker sets was at 50 pg of DNA. The mitochondrial cytochrome oxidase subunit gene II (COII)-specific markers that were developed were each specific for GWSS and Homalodisca sharpshooters. The development of diagnostic markers designed toward Homadisca sharpshooters present in California should aid in finding key predators and therefore enhance biological control efforts against these sharpshooters.