بررسي بيواكولوژي سفيد بادك زبان گنجشك SIPHON INUS PHILLYREAE در استان فارس

Bioecology of ash whitefly, Siphoninus phillyreae (Halliday) (Horn: Aleyrodidae) in the Fars province, Iran

Ash whitefly , Siphoninus phillyreae , is one of the important pests of fruits and shade trees in the Fars province.The adult appears much like a typical whitefly with a light dusting of white wax on wings and the whole body. Lateral areas of the pupal case are light beige and are covered with two longitudinal tufts of white wax. The dorsal surface has 40-50 long glassy tubercles. The vasiform oriffice is surrounded by dark brown derm, with the anal area appearing as a dark brown spot. Over seventeen plant species (including acer, ash, elm, apple, quince, pear, sweet lime, sure lime, orange, tangerine, peach, nectarine, apricot, hawthorn, plum, almond and pomegranate) were identified in Fars provinc as its host plants that ash was the most important. Adult and nymphs of the pest feed on sap from late May to late November and cause direct economic damages to host plants. The population of the pest on ash trees in Shiraz reach to its peak in late July. One of the most active parasitoids is Encarsia inaron (Walker) (Hym. Aphelinidae). Body length in adult is 0.6-0.7 mm, female abdomen is yellow, but it is black in male. Parasitism started from, late July and continued till late November. The parasitoid prefers third and fourth instars of ash whitefly and its highest parasitism about 85.9%, was observed on pear trees in Shiraz (Badjgah). Sex ratio of the parasitoid wasp was 1:1.44 on ash trees in natural conditions.