Morse J G, Rugman-Jones P F, Watson G W, Robinson L J, Bi J L, Stouthamer R
Department of Entomology, University of California, Riverside, CA 92521, USA.
J Econ Entomol. 2009 Jun;102(3):855-67. doi: 10.1603/029.102.0303.
Between 1914 and 2007, a quarantine protected California avocado, Persea americana Mill., groves from pests that might be introduced into the state along with fresh, imported avocados. Soon after Mexican avocados were first allowed entry on 1 February 2007, live specimens of several species of armored scales (Hemiptera: Diaspididae) not believed to be present in California were detected on 'Hass' avocados entering the state from Mexico. Initially, the California Department of Food and Agriculture (CDFA) prevented avocados infested with these scales from entering the state or required that they be fumigated with an approved treatment such as methyl bromide. After a Science Advisory Panel meeting in May 2007, U.S. Department of Agriculture-Animal and Plant Health Inspection Service (USDA-APHIS) reaffirmed its position that armored scales on shipments of fruit for consumption (including avocados) pose a "low risk" for pest establishment. In compliance with APHIS protocols, as of 18 July 2007, CDFA altered its policy to allow shipments of scale-infested avocados into the state without treatment. Here, we report on sampling Mexican avocados over an 8-mo period, September 2007-April 2008. An estimated 67 million Mexican Hass avocados entered California over this period. Based on samples from 140 trucks containing approximately 15.6% of this volume of fruit, we estimate that approximately 47.6 million live, sessile armored scales and an additional 20.1 million live eggs and crawlers were imported. We found eight probable species of armored scales in the samples, seven of these are not believed to occur in California; 89.3% of the live scales were Abgrallaspis aguacatae Evans, Watson and Miller, a recently described species. In contrast to the USDA-APHIS opinion, we believe the volume of shipments and levels of live scales they contain present a significant risk to California's US$300 million avocado industry and to other crops that might become infested by one or more of these exotic species.
1914年至2007年间，一项检疫措施保护了加利福尼亚州的鳄梨（Persea americana Mill.）果园，使其免受可能随新鲜进口鳄梨传入该州的害虫侵害。2007年2月1日墨西哥鳄梨首次被允许进入美国后不久，在从墨西哥进入该州的“哈斯”鳄梨上检测到了几种据信在加利福尼亚州不存在的盾蚧（半翅目：盾蚧科）活标本。最初，加利福尼亚州食品和农业部（CDFA）禁止受这些蚧虫侵染的鳄梨进入该州，或要求对其进行如甲基溴等经批准的处理熏蒸。在2007年5月的一次科学咨询小组会议后，美国农业部动植物卫生检验局（USDA - APHIS）重申其立场，即用于消费的水果（包括鳄梨）运输中的盾蚧对害虫定殖构成“低风险”。按照APHIS的规程，截至2007年7月18日，CDFA改变其政策，允许受蚧虫侵染的鳄梨未经处理就进入该州。在此，我们报告2007年9月至2008年4月这8个月期间对墨西哥鳄梨的抽样情况。在此期间，估计有6700万颗墨西哥哈斯鳄梨进入加利福尼亚州。基于从140辆卡车抽取的样本（这些样本约占这批水果总量的15.6%），我们估计大约有4760万个活的、固定不动的盾蚧以及另外2010万个活卵和若虫被进口。我们在样本中发现了8种可能的盾蚧种类，其中7种据信在加利福尼亚州不存在；89.3%的活蚧是阿氏鳄梨盾蚧（Abgrallaspis aguacatae Evans、Watson和Miller），这是一个最近描述的物种。与USDA - APHIS的观点相反，我们认为运输量以及其中活蚧的数量对加利福尼亚州价值3亿美元的鳄梨产业以及其他可能被这些外来物种中的一种或多种侵染的作物构成了重大风险。
