烟粉虱的分类地位及在中国的分布

烟粉虱广泛分布于全球热带和亚热带地区。近20多年，烟粉虱的一些遗传群入侵世界各地，严重危害作物生产。烟粉虱遗传结构的多样性和复杂性早已被关注，但其分类地位，尤其是烟粉虱到底是一个包含多个生物型的种还是一个包含许多隐种的物种复合体，一直颇受争议。近几年，有关烟粉虱种系发生和系统学的研究取得长足进展，有证据推论其是一个包含至少31个隐种的物种复合体，但生殖隔离证据仍显不足，种系发生分析结果也因仅依据COI一个基因而受到质疑。因此，在大多数从事烟粉虱研究的同行接受其为一个物种复合体的概念的同时，仍有同行沿用生物型的概念。在我国境内已先后报道了包括13个本地种和2个全球入侵种在内的15个烟粉虱隐种。本地种主要分布在我国南部及包括海南岛和台湾岛的东南沿海地区，隐种的多样性由南向北逐渐降低。入侵种“中东一小亚细亚1”隐种（MEAMl）（即“B型”）和“地中海”隐种（MED）（即“Q型”）分别于20世纪90年代中后期和2003年前后入侵我国，并在许多地区迅速取代了本地种而占据优势地位。全国范围内的调查数据显示，这2个入侵种可在大部分区域共同存在，但自2005年以来，MED在许多地区陆续取代MEAMl，这很可能与MED对大量使用的新烟碱类杀虫剂有较强抗性有关。本文还讨论了烟粉虱隐种复合体分类所面临的命名等难题以及大范围抽样调查的数据偏差问题。

Species status of Bemisia tabaci complex and their distributions in China

The whitefly Bemisia tabaci is widely distributed in the tropical and subtropical regions of the world. In the last 20 years, some genetic groups of B. tabaci have invaded many parts of the world and caused serious damage to crop production. While the ge- netic diversity and complexity of this whitefly have long been recognized, its species status, in particular whether B. tabaci is one species containing many biotypes or a complex containing many cryptic species, has been a subject of debate. In recent years, sub- stantial progress has been made in studies on the phylogeny and systematics of B. tabaci, and evidence suggests that this whitefly is a species complex containing at least 31 cryptic species. However, data on reproductive isolation are yet insufficient and the results of phylogenetic analyses have been questioned because they relied on only the COI gene. While most scientists in the whitefly sci- ence community have rapidly accepted that B. tabaci is a whitefly species complex, some scientists continue to use the concept that B. tabaci is composed of many biotypes. In China, 13 indigenous and two invasive whitefly species have been recorded. The indige- nous species occur only in the southern and south eastern parts of China and the diversity declined from south to the north. The inva- sive cryptic species Middle East-Asia Minor 1 （MEAM1）, formerly referred to as ＂B biotype＂ , entered China in middle 1990s, and the invasive cryptic species Mediterranean （MED） , formerly referred to as ＂ Q biotype＂ , was first found in China around 2003, and thereafter they displaced rapidly the indigenous whiteflies in many regions. Both MEAM1 and MED whitefly occur sympatrically in most provinces of China. However, data from extensive field surveys indicated that MED has been displacing MEAM1 in many re- gions after 2005, probably due to, at least in part, the higher level of insecticide resistance to neonicotinoids in MED than that in MEAM1. The difficulties in the classification and nomenclature of this species complex and the likely biases of field sampling are al- so discussed.