Western1 Plant Diagnostic Network First Detector News A Quarterly Newsletter for First Detectors Spring 2010 edition, volume 3, number 2 Dear First Detectors, The WPDN newsletter has In this Issue taken on a new look and method of sending the news. The newsletter will be linked to the WPDN 1. Editor’ Note site. We will email a summary of the newsletter and its link. To view the archived newsletters of the 2-3. Alder Sawfly in AK, WA, & OR NPDN and WPDN, click on www.wpdn.org (or simply google WPDN). You will find the menu on 4. European Grapevine Moth in CA the left side of the homepage: 5. Spinach Severe Curly Top Virus in Newsletters Arizona • NPDN News 6. Small Hive Beetle in Hawaii • WPDN Newsletter archive • First Detector Network News • Pacific Pest Detector Contact us at the WPDN Regional Center at UC Davis: We have also added the Pacific Pest Detector (see the Phone: 530 754 2255 link above) to the WPDN region. The agriculture, Email: [email protected] horticulture, and pests of our Pacific Island members Web: https://www.wpdn.org are so different from the continental WPDN region Editor: Richard W. Hoenisch that the members from Hawaii, Guam, and American ©Copyright Regents of the Samoa have developed an excellent newsletter. University of California All Rights Reserved Western Plant Diagnostic Network News 2 New Pest Spreads in Alaska, Oregon and Washington The Green Alder Sawfly, Monsoma pulveratum (Retzius) In the WPDN July 2009 newsletter, Dr. Jim Kruse of USDA Forest Service in Alaska reported a new insect pest of Alder in Alaska, the green alder sawfly. Dr. Kruse has developed a new pest alert, dated March 31, 2010. His article on a new behavior of the sawfly is found on page 3. http://www.fs.fed.us/r10/spf/fhp/pubs/MonsomaPestAlert.pdf Eric LaGasa, the chief entomologist for WA, now reports that the insect has been found in Vancouver and Olympia WA. Green alder sawfly was first found in the continental U.S. by Andre Karankou, who found adults on understory shrubs beneath red alders at a park in Vancouver, WA, in early April 2010 (view his photos at: http://bugguide.net/node/view/383192 Subsequently adult green Sawfly larva and larvae feeding on alder leaves alder sawflies were collected in Forest Part (Portland, OR) and King County, WA (Seattle area) on April 26. An adult thought to be a green Photo: Ken Zogas alder sawfly was also recently seen, though not collected, near Tillamook on the Oregon coast. The distribution map is below http://oregonstate.edu/dept/nurspest/GAS-R6Summary2010April28.pdf Adult Green Alder Sawfly Photo: Andrei Karandou Western Plant Diagnostic Network News 3 Dr. Jim Kruse reports on the latest observations of Green Alder Sawfly in Alaska During field investigations in south-central Alaska and the Kenai Peninsula on 27-29 April 2010, the Forest Health Protection Team (USDA Forest Service R10 FHP) discovered that mature Monsoma pulveratum larvae find pupation sites in wood of many species and in various states. This habit was reported in Europe (Pieronek 1980) but had not previously been reported from North America, and Pieronek (1980) described burrowing into rotten wood or branch piths, not sound logs or living material. In Alaska, it appears that Monsoma larvae are very capable of utilizing wood materials to an extent not previously described. They have been found overwintering in various tree species including the most rotten stump or logs in the area, various dead branches down to less than one inch in diameter, dead woody debris on the ground, standing dead, and even standing live trees from small shrubby alders to mature birch, spruce, and willow. Larvae easily penetrate decayed, soft wood. Larvae were found several inches into the heart wood of dead cottonwood for example. Sound wood and live wood is penetrated using dead branch nubs where they have broken off from the trunk, through dead material in the process of being grown over, through stem or branch breaks, and via frost cracks. The larvae possess formidable mandibles that they use to chew their way into the wood and then move laterally as much as several inches. Live material is more resistant, and damage is often restricted to hollows just under the bark. Damage to standing wood from larvae were found from the ground level on up as high as 20 feet. Natural enemies: there appears to be at least one parasitoid associated with Monsoma. This parasitoid appears to be Hymenoptera: Ichneumonidae, and judging from the status of the cocoons, emerges in the fall and therefore does not spend the winter with its host. Additionally, at least one species of woodpecker seems to be very interested in them in the standing dead alder ramets (an individual stem within a clump). The woodpecker damage is very noticeable, often entering as far as the center of four inch diameter alder ramets. The tendency is for the birds to work up the cracks in the ramet formed during drying after death. Additionally, the team discovered one instance of a log torn into by a mammal of some kind, smaller than a bear, but larger than a squirrel or similar sized creature. Alder sawfly pupal niches in alder (left) and entrance holes in live birch tree (right) Photos by Ken Zogas Western Plant Diagnostic Network News 4 The European Grapevine Moth Spreads in California The European Grapevine Moth (EGVM), Lobesia botrana, has been detected in 6 counties in California. EGVM was first detected in September 15, 2009 in the Rutherford/Oakville region of Napa County CA. Because the vines were going into winter dormancy at that time, it was hard to detect the presence of the EGVM. The EGVM pupates during the winter under the bark of the vine. With bud break the pupae hatch and the adult begins to mate and lay eggs in the flower clusters of the vine. Detection at the adult stage is done using the California Department of Food and Agriculture (CDFA) and the USDA have placed pheromone traps across the state and have quarantined. “Grapes are our state’s top crop,” said CDFA Secretary A.G. Kawamura. We have set an array of more than 40,000 traps statewide to determine exactly where the infestations exist. Detecting the pest is an important first step toward controlling it, and quarantines are the next step in the process. These regulations allow us to protect surrounding uninfested areas by preventing movement of the insects on crops, harvesting equipment and related articles." Previously quarantined areas in Napa, Solano and Sonoma counties are expanding by approximately 827 square miles. New quarantine areas are being created in Fresno County (approximately 96 square miles) and in Mendocino County (approximately 140 square miles). The state's total EGVM quarantine area now stands at approximately 1395 square miles. Maps are at: http://www.cdfa.ca.gov/phpps/PE/InteriorExclusion/egvm_quarantine.html The EGVM has recently been detected in Monterey Co. (Soledad area) on May 10th and Merced Co. (Snelling) on May 13th. View the video on the home page demonstrating the size and number of EGVMs with Greg Clark http://www.cdfa.ca.gov/phpps/egvm/index.html. This site also has several links about the pest. Learn to identify the moth and learn about the means of control. Overwintering EGVM pupa under vine bark Related Information: • European Grapevine Moth Biology & Management Presentation in English Apr. 21, 2010 • European Grapevine Moth Biology & Management Presentation in Spanish Apr. 21, 2010 • European Grapevine Moth Photographic Identification Aid Feb. 11, 2010 • European grapevine moth: a known olive pest (PDF) • Pest Management Guidelines for European Grapevine Moth (UC IPM) • European Grapevine Moth Mini Risk Assessment (PDF) CDFA technician installing EGVM pheromone traps in a vineyard Western Plant Diagnostic Network News 5 Spinach severe curly top virus, a new curtovirus infecting spinach (Spinacia oleracea) has been identified in Arizona Cecilia Hernández-Garcia and Judith K. Brown (& WPDN member) of the Department of Plant Sciences, University of Arizona, Tucson, report on a new virus affecting spinach in Arizona. They have proposed the name “Spinach severe curly top virus.” The curtoviruslike symptoms, presence of the curtovirus leafhopper vector, together with the isolation of a curtovirus-like genome from symptomatic spinach plants, collectively, are highly suggestive of curtovirus etiology. This is the first report of SSCTV worldwide, and of its association with diseased spinach in Arizona. A During April 2009, a commercial spinach field (250 acres) in south-central Arizona developed Geminivirus-like disease symptoms. Approximately 40 to 50% of the spinach plants exhibited extreme leaf distortion, foliar interveinal chlorosis, shortened internodes, and ~80% yield reduction. The beet leafhopper, Circulifer tenellus, the only known insect vector of curtoviruses in the United States, was observed on spinach plants. Although plant viruses are not nearly as well understood as the animal counterparts, one plant virus has become iconic. The first virus to be discovered was Tobacco mosaic virus (TMV). This and other viruses cause an estimated US$60 billion loss in crop yields worldwide each year. Plant viruses are grouped into 73 genera and 49 families. In order to transmit themselves from one plant to another and from one plant cell to another, plant viruses must use strategies which are usually different than those of animal viruses. Plants do not move, and so plant-to- plant transmission usually involves vectors (such as insects). Plant cells are surrounded by solid cell walls; therefore transport through plasmodesmata is the preferred path for virions to move between plant cells. Plants probably have specialized mechanisms for transporting mRNAs through plasmodesmata, and these mechanisms are thought to be utilized by RNA viruses in order to spread from one cell to another.[1 See http://en.wikipedia.org/wiki/Plant_virus Twinned icosahedra virus coats typical of the genus Curtovirus.