Is diamondback moth a polyphagous pest?Some thoughts about its host range ezpansion to pea
The diamondback moth(DBM)，Plutella xylsotella L.(Lepidoptera：Plutellidae)，has been recognized as an oligophagous pest feeding on more than 40 wild and cultivated crucifers.However they have occasionally been recorded on some non-erucifers. The first field level observation of this pest on pea was made in the Naivasha region of Kenya in 1999.Furthermore，a population coUected from cabbage was even able to adapt to survive on pea for four generations.Oviposition and larval preference experiments were conducted with na(i)ve field populations collected from cabbage fields in Naivasha with a laboratory-reared pea-adapted population as a check.Both under choice and no-choice conditions，both populations preferred cabbage over pea for oviposition and larval survival.However，under no-choice test condition，the Naivasha population preferred pea for laying 33.7％of the eggs laid on cabbage under similar conditions.Among the pea plant parts，the leaf auricle was preferred for oviposition over the leaf lamina，tendril and stem.Pea leaf discs were also preferred by 26.7％of the neonate larvae of the Naivasha population under no-choice test condition.Under no-choice condition，the pea-adapted population moths and larvae equally preferred cabbage and pea for oviposition and larval survival. The increased oviposition preference on pea，sitedirected oviposition on pea leaf auricles and neonate larval preference for pea indicate that the ability to survive on pea is a characteristic of the Naivasha population.Does the occasional observation on non-cruclfers have any genetic or chemicM basis?Does this ability to survive on pea exist in other DBM populations as well?The results are discussed in light of host range expansion of DBM and its implications on the selection of this insect as a model for further studies on the phenomenon of sympatric speciation.
S.Subramanian Bernhard L(o)hr
Plant Health Division,International Center of Insect Physiology and Ecology(ICIPE),P.O.Box 30772-00100,Nairobi,Kenya
国际会议
北京
英文
63-71
2006-10-24（万方平台首次上网日期，不代表论文的发表时间）