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The silverleaf whitefly (''Bemisia tabaci'', which is also informally referred to as the sweetpotato whitefly) is one of several whiteflies that are currently important agricultural pests.〔 The silverleaf whitefly is classified in the family Aleyrodidae, and is included in the large sub-order of insects, ''Sternorrhyncha''. A review in 2011 concluded that the silverleaf whitefly is actually a species complex containing at least 24 morphologically indistinguishable species. The silverleaf whitefly thrives worldwide in tropical, subtropical, and less predominately in temperate habitats. Cold temperatures kill both the adults and the larvae of the species. The silverleaf whitefly can be confused with other insects such as the common fruitfly, but with close inspection, the whitefly is slightly smaller and has a distinct wing color that helps to differentiate it from other insects. While the silverleaf whitefly had been known in the United States since 1896, in the mid-1980s a virulent strain appeared in poinsettia crops in Florida. For convenience that strain was referred to as strain B (biotype B), to distinguish it from the milder infestation of the earlier known strain A. Less than a year after its identification, strain B was found to have moved to tomatoes, and other fruit and vegetable crops. Within five years, the silverleaf whitefly had caused over $100 million in damage to Texas and California agriculture industries.〔 == Anatomy and life cycle == During the adult stages of the silverleaf whitefly, the body expands up to 0.8mm in length and has a snow-white color, which is attributed by the secretion of wax across its wings and body. During feeding or resting stages the whitefly adult covers its body over with its wings. When depositing eggs, the females will lay 50 to 400 eggs ranging from 0.10mm-0.25mm on the under part of leaves. Female whiteflies are diploid and emerge from fertilized eggs whereas male whiteflies are haploid and emerge from unfertilized eggs. Eggs are laid in groups, being small in size with dimensions of 0.2 mm wide and .1mm in height. Eggs are initially whitish in color and change to a brown color towards the time of hatching within 5 to 7 days. After the egg stage, the whitefly hatchling develops through four instar stages. In the first instar, commonly called the crawler, the nymph is 0.3mm in size and grows to be 0.6 mm till the fourth instar stage. During the first instar stage the body is greenish in color and flat in body structure.〔 The mobile whitefly nymph walks to find a suitable area on the leaf with adequate nutrients and molts into four other instar or nymphal stages over the span of 40–50 days until it reaches adulthood.〔 During molting, the flies shed silver skins, which are left on the leaves. During the instar phases, the whitefly maintains an opaque white appearance and does not move from the feeding site the crawler originally chooses. At the feeding site the nymphs use parts of their mouth to stab into the plant and consume the plant’s juices.〔 The stage following the nymph stages is the pupal stage when the eyes become a deep red color, the body color becomes yellow, and the body structure thickens. After development is completed, adult whiteflies are approximately four times the size of the egg, with light yellow bodies and white wings.〔 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Silverleaf whitefly」の詳細全文を読む スポンサード リンク
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