Molecular Identification Of Aphids And Parasitoidi From The Empty Mummy In Wheat Fields

Parasitoids are the important parasitic natural enemies of wheat aphids.The residue of host aphid and parasitoid DNA had been proved to exist in the empty aphid mummies.Targeted on the common aphid species Sitobion avenae(Fabricius),Schizaphis graminum(Rondani),primary parasitoid species,Aphidius gifuensis(Ashmead)and hyperparasitoid Pachyneuron aphidis(Bouch�),we studied the influence of time and different environmental conditions on the the aphid and parasitoid DNA detection rates.The results showed that DNA detection of parasitoids decreased gradually along with the time.Collecting the mummy aphids and empty mummy aphids from the field to DNA detection in 2016,To proved that the empty mummy detection technique could be applied to the aphid-parasitoid trophic analysis.The results were as follows.The DS50 values of A.gifuensis' s DNA detection from mummy shells of S.avenae and S.graminum were 31.9 d and 41.4 d respectively.And the DNA detection DS50 values of P.aphidis in S.avenae and S.graminum were 46.8 d and 55.7 d.There was basically no significant difference on the DNA detection rates of aphids and parasitoids in soaked/not soaked treatments or other different temperature and humidity environmental factor treatments.The DNA detection rates from the empty mummies collected 24 days after parasitoids' emergence varied from 76.7% to 100%.The DNA detection of mummy aphids in 2016,the aphid DNA detection rate was97.6% and they were all S.avenae.The total primary parasitoid detection rate was 98.5%with the Aphidius uzbekistanicus 93.1% and Aphidius gifuensis 5.4%.The Pachyneuron aphidis detection rate was 31.3%.While in the empty mummy detection in 2016,90.7%were detected and they were all S.avenae.In the primary parasitoid DNA detection,A.uzbekistanicus were 60.1% and Aphidius gifuensis was 20.9%.The detection rate of Pachyneuron aphidis was 45.5%.The combined of the indoor experiment and field work verified the stability of aphids and parasitoids residual DNA.It proved the empty mummy detection technique could be applied to the aphid-parasitoid trophic analysis and the assessment of pest control effect.