Spread and potential host range of the invasive oak lace bug [Corythucha arcuata (Say, 1832) – Heteroptera: Tingidae] in Eurasia

1. The North American oak lace bug feeds on leaves of ‘white oaks” in its native range. In Europe, it was first discovered in northern Italy in 2000. In recent years, it has subsequently spread rapidly and population outbreaks have been observed in several European countries. In the present study, we summarize the steps of its expansion.
2. To predict its potential host range, we checked 48 oak species in 20 sentinel gardens in seven countries between 2013 and 2018.
3. In total, 27 oak species were recorded as suitable hosts; 13 of them are globally new ones, 23 out of the 29 in section Quercus (～ white oaks, an intrageneric taxonomic unit within genus Quercus), including Asian oaks, native to Japan, Korea and China, and four out of five in section Cerris (another intrageneric unit of the same genus), were accepted as hosts. None of the species in section Lobatae (red oaks) or in the Ilex group was accepted.
4. Host records were also collected in forest stands of 10 countries. We found 11 oak species that were infested. Outbreak populations were most commonly found on Quercus robur, Quercus frainetto, Quercus petraea and Quercus cerris, comprising widespread and outstandingly important oaks species in Europe.
5. Based on our findings, we conclude that suitable hosts for oak lace bug are present in most of Europe and Asia. This means that a lack of hosts will likely not restrict further range expansion.

     

Defensive Secretions in Callipodella fasciata (Latzel, 1882; Diplopoda,Callipodida, Schizopetalidae)

The small millipede Callipodella fasciata secretes an earthy smell when disturbed. This secretion was obtained by CH₂Cl₂ extraction from specimens of both sexes and was identified by GC/MS analyses to be composed of p‐cresol (96.5%), phenol (3.5%), and p‐ethylphenol (traces). This is the first identification of these compounds in an epigean European callipodidan species and the first report of intergeneric differences in the chemical composition of defensive secretions in callipodidans. These compounds have repellent, antimicrobial, and antifungal properties.     

Assessment of the habitat conditions of a rare and endangered inland saline wetland community with Bolboschoenus maritimus (L.) Palla dominance in Southeastern Europe: the effects of physical–chemical water and soil properties

Wetlands Ecology and Management - Continental inland saline wetlands are among the most endangered habitats in Europe. In the Danube-Tisza-Danube canal network (Serbia, Southeastern Europe), which...     

Photochemical evidence for the presence of histidyl residue in the active site of alkaline mesentericopeptidase.

The photosensitized oxidation of alkaline mesentericopeptidase in the presence of methylene blue results in a first-order rate of inactivation. The loss of enzymatic activity towards casein and N-acetyl-L-tyrosine ethyl ester closely correlates with the destruction of one histidyl residue. A pK value of 6.8 is determined from the sigmoid pH-dependence of the photoinactivation rate. This suggests the involvement of a normal titrating imidazole group in the active site of mesentericopeptidase. The competitive inhibitor Na-benzoyl-L-arginine protects the enzyme from photoinactivation. A conclusion is made that the active site histidyl residue is modified. Circular dichroism spectra show no change in the protein conformation during the photodynamic treatment.