A molecular tool, focused on the mitochondrial Control Region (CR), was developed to discriminate the two hawthorn-feeding psyllid species, Cacopsylla melanoneura (Förster) and C. affinis (Löw), and to estimate their frequencies in mixed populations. The test was carried out in paired and single-tube amplifications and validated analysing 52 male specimens previously determined by morphological...

The biology of Scaptomyza nigrita on its host plant, a native crucifer (Bittercress) in the Rocky Mountains, is described. Development of each stage in the life history was studied both in the field and in the laboratory. This is the first documentation of a host for S. nigrita. We examined the activity of adult flies in two adjacent habitats, sun and adjacent willow shade. Adult flies were mor...

Pear psylla (Cacopsylla pyricola Foërster) is the most serious pest of the European pear (Pyrus communis L.) in the production regions of Europe and North America. Nine plant germplasm introductions of pear from Central Europe recently released from plant quarantine were evaluated for nymphal feeding antixenosis, a primary mode of resistance known to be correlated with ovipositional antixenosis...

Cacopsylla fraudatrix Labina & Kuznetsova sp.n., collected from Vaccinium myrtillus in Bieszczady Mountains (S. Poland) is described and compared with the most closely related species, C. myrtilli (developing on V. myrtillus) and C. ledi (on Ledum palustre) as well as with a distantly related species C. vaccinii (on V. bracteatum). The identity of the new species is supported by the structure o...