The following corn hybrids were used in the experiments: fodder corns (Blask, Buran) and sweet corns (Ambrozja, Challenger). The field observations carried out on experimental plots of the IHAR Radzików/Błonie showed that sweet corn hybrids (Ambrozja and Challenger) were better accepted by M. dirhodum. Among the sweet corns less accepted by the rose-grain aphid was Ambrozja, instead in case of the fodder corns plants of the Blask hybrid.

Occurrence of the rose-grain aphid (Metopolophium dirhodum Walk.) on saltspray rose (Rosa rugosa) was studied in Eastern Poland. First fundatrix of the M. dirhodum on the R. rugosa were recorded in the end of March. The rose-grain aphid population development was observed on primary host during the May. Its maximum reached the peak density until the meadle of May. At the third decade of May numerous alatae were formed and spring migration of the aphid to the summer hosts began.

The following rose species: saltspray rose (Rosa rugosa) and wild rosa (Rosa canina) were subjected to the studies on primary host acceptance by rose-grain aphid (Metopolophium dirhodum). The results of performed observations in the estern part of Poland revealed that the species R. rugosa was more preferred as a primary host by rose-grain aphid as compared to R. canina. First fundatrices of M. dirhodum on saltspray rose were recorded in the end of March. The dynamic development of rose-grain aphid populations were observed in May, and its maximum was in the middle of the month. In the third decade of May, numerous alatae of M. dirhodum appeared to start a spring migration to summer secondary host plant.