Sitobion avenae (F. ) is a cosmopolitan cereal pest, but geographic barriers like the Qinling Mountains in the Shaanxi Province of China may lead to isolation among its populations, thus causing allopatric speciation. We sampled S. avenae populations from areas north (mean annual temperature, ≈9°C) and south (mean annual temperature, ≈14°C) of the Qinling Mountains, and tested them at 20°C in common garden experiments. The results showed that northern populations had reduced developmental time for first-instar nymphs but prolonged for third- and fourth-instar nymphs compared with southern populations. The postreproductive time and total lifespan of adults from southern populations were longer than those from northern populations, but no significant differences were found in reproductive time or age at first reproduction. Southern populations showed higher lifetime and daily fecundities than northern ones. Significant differences were found in correlation of life-history traits between northern and southern populations. Principal component analyses (PCAs) of S. avenae's vital life-history traits showed separation of populations from three southern locations, indicating their local adaptation. The clustering patterns generated by PCA also showed divergence between northern and southern populations. Alatae of S. avenae seemed to be able to disperse across the Qinling Mountains, which was indicated by the clustering together of some individuals from one side of the mountains with those from the other side. The impacts of the Qinling Mountains on the divergence and gene flow among S. avenae populations, as well as the potential of allopatric speciation for this species, are discussed.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 42 • No. 6