Salix sepulcralis group Salix sepulcralis group The "Salix sepulcralis" group is a cultivar group containing all cultivars of hybrids between "Salix alba" and "Salix babylonica". The "sepulcralis" or × "sepulcralis" trees are sometimes referred to as white weeping willow or glaucous weeping willow in reference to the mixed appearance from the parent species. It was first described by L. Simonkai in 1890 from trees growing in Romania. The group contains both weeping and nonweeping cultivars, though the best-known of its cultivars is 'Chrysocoma', the most widely grown weeping tree.. Some of the cultivars are hybrids of "S. babylonica" var. "matsudana" 'Tortuosa' and have
Spathius agrili only attracted to select species of "Fraxinus" and to "Salix babylonica". In natural settings, "S. agrili" will be unlikely to encounter and parasitize non-target larvae as it does not search other tree species. This, in addition to other tests of host specificity, led to approval of the wasp for controlled releases in specific study sites in the United States for further research. Spathius agrili Spathius agrili is a parasitic non-stinging wasp of family Braconidae which is native to North Asia. It is a parasitoid of the emerald ash borer ("Agrilus planipennis" Fairmaire), an invasive species which has destroyed tens of