New host-plants of ergot pathogen Claviceps purpura (Fr.) Tul. were identified in Poaceae (R. Brown) Barnharth family in Lithuania during the surveys arranged over the period 2001–2006. There were identified 8 new Poaceae family plant species affected by C. purpurea: Melica altissima L., Bromus secalinus L., Deshampsia flexuosa (L.) Trin., Festuca pseudalmatica K., Helictotrichon sempervirens (Vill.) Pilg., Phalaris paradoxa L., Secale montana L., Stipa turkestanica K. The results of previous research as well our findings indicate that 87 Poaceae family plant species are known to be affected by ergot in Lithuania.

The rose flea beetle, RFB (Luperomorpha xanthodera Fairmaire 1888) is a new flower pest in Europe. In 2012, it was brought accidentally to central Poland. To search for this introduced species in the area adjacent to the site of the first finding, 29 plant species belonging to five botanical families (Lamiaceae, Brassicaceae, Asteraceae, Plantaginaceae, Crassulaceae) were monitored over a 3-year-long study (2016−2018). RFB were found on 11 herbaceous/ ornamental plant species (Lamiaceae, Brassicaceae, Asteraceae) along with feeding damage to the flowers. White mustard (Sinapis alba L., Brassicaceae), hyssop (L.), and Monarda spp. (Lamiaceae) were its most preferred host plants. In each season, RFB females preferred host plants which bloomed abundantly and vividly. However, among the examined plant species there was a large variation in the year-to-year RFB abundance. Over the examined period the RFB extended its abundance exponentially, and its population survived and established itself in the area. The general sex ratio of the beetles was strongly female biased. In the female pool, females with conspicuously swollen abdomens predominated. The results of our study provide more insight into RFB behaviour, its establishment and spreading into new areas. To support the evidence for the RFB risk factor as an agricultural/ horticultural pest, further research should focus on the beetles’ biology, reproductive tactics, larval host plant preference, larva-inflicted damage and harmfulness, the impact of the RFB on the native fauna, as well as its further local and distant migration propensity. Presently our knowledge about these aspects is still fragmentary.