the relationship between female oviposition preference and offspring performance is a key area of study on the evolution of host specificity. this study investigates host prefer-ence of the polyphagous hover fly syrphus ribesii (diptera: syrphidae) and compares it with some components of its offspring`s performance. females and offspring were tested on six naturally used aphid hosts (blackberry...

fusarium solain is the most important pathogen of huge range of plant hosts, especially potato in the word, which causes tuber rot in storage and root rot of potato plants in fields. fifty four isolates from potato, bean, chickpea and cucurbit (melon, watermelon and cucumber) was subjected in a study through analysis of vegetative compatibility groups (vcgs) and rep-pcr dna fingerprinting. nit ...

Brown spot disease caused by Alternaria alternata (Fr.: Fr.) Keissl is a serious problem forproduction of tangerines and tangerine hybrids in Iran. The Tangerine pathotype causes brownspot disease on young leaves and immature fruits of limited varieties of mandarins and tangerines(Citrus. reticulata Blanco). Specificity in the interaction between tangerine and the pathogen isdetermined by a hos...

brown spot disease caused by alternaria alternata (fr.: fr.) keissl is a serious problem forproduction of tangerines and tangerine hybrids in iran. the tangerine pathotype causes brownspot disease on young leaves and immature fruits of limited varieties of mandarins and tangerines(citrus. reticulata blanco). specificity in the interaction between tangerine and the pathogen isdetermined by a hos...