It was confirmed that in the north of Poland winged specimens of Myzus persicae (Sulz.) start to migrate in spring approximately over three weeks later than in the central and sou them regions. It was observed that during the 1981-1990 and 1991-2000 decades, M. persicae started its flights approximately over two weeks earlier than during the 1971-1980 decade. With this respect one may conclude that the changes are permanent. There were also changes in quantity. In some places the M. persicae share in the entire aphid fauna on potato crops was observed to have decreased as the time passed, which, as it seems, may be associated with a decrease in potato crops area in Poland. Such a correlation can also be confirmed by the fact that in the area where M. persicae share increased, the potato crops area also increased extensively.

The work involved assessment of the Myzus persicae (Sulz.) capability to infect successively potato plants with PVY and PVM after a Sunspray 850 EC mineral oil application. The tests were carried out in the greenhouse, with 4-week-old, healthy potato plants possessing low ressistance to viruses, derived from in vitro (test plants). Any time, for each combination and each virus, 10 successive plants were inoculated in 6 repetitions. Virus sources were potato plants infected with PVY or PVM, kept in isolated rooms. As a result of oil application, feeding of the M. persicae specimens on plants previously treated with this oil was delayed. The highest reduction as regards PVY and PVM transmission by M. persicae was obtained in the treatment where both plants constituting virus sources and test plants were protected, because only two of ten plants were infected with PVY, and only one with PVM. Mineral oil application only on potato test plants (healthy ones) reduced to a small degree M. persicae capability to transmit PVY to six successive plants (to seven in control), whereas it was much higher for PVM – to three (to six in control). In the case when only plants constituting virus sources were oil-protected, aphid’s capability to transmit PVY was limited only to four plants, and PVM – to two. These results seem to confirm much more the hypothesis that mineral oil inactivates virus particles in the stylets of aphids while they attempt to acquire it from plants which have been previously protected with mineral oil.

The green peach aphid, Myzus persicae (Sulzer), is a polyphagous and holocyclic aphid which significantly damages agricultural crops. In the current study, the effects of micronutrients on some secondary metabolites of bell pepper (Capsicum annum L.) leaves and their subsequent influence on the life table parameters of M. persicae were investigated under greenhouse conditions. The flavonoid content in bell pepper leaves significantly changed following micronutrient treatments in the wavelength of 270 nm while there were no significant differences in the wavelengths 300 and 330 nm. The highest anthocyanin content was recorded after Fe treatment (3.811 mg ⋅ ml–1) while the total phenolic content in the bell pepper leaves increased after Mn (541.2 mg ⋅ ml–1) treatment compared to Fe (254.5 mg ⋅ ml–1) and control (216.33 mg ⋅ ml–1), respectively. The highest values of intrinsic (r) and finite rates of population increase (λ) of M. persicae were gained with Zn (0.320 and 1.377 day–1, respectively) treatment although the highest and the lowest values of the mean generation time (T) were found with Fe and Zn (14.07 and 12.63 days, respectively) treatments, respectively. Our findings suggest that Mn, more than Zn micronutrients, decreased ecological fitness of green peach aphid and may help enhance the efficiency of pest control techniques.

Knowing the tritrophic interactions between plant-virus-insect is important in developing sustainable pest management practices. Myzus persicae is a well-known plant viral vector which can transmit over 40 plant viruses. We studied the impact of Cucumber mosaic virus (CMV) infection in Nicotiana tabacum on the colony development of M. persicae to understand how plant virus infection can affect vector growth and reproduction. Aphid growth, reproduction and fecundity were significantly affected by the virus infection. The mean relative growth rate of M. persicae on healthy plants was 0.29 mg–1 · mg–1 · day–1 and was significantly higher than that of CMV-infected plants (0.23 mg–1 · mg–1 · day–1). In contrast, the percentage of survival was significantly higher on CMV-infected plants. The estimated survival percentages of aphids at 20 days after introduction to CMV-infected and healthy plants were 55.8 and 25.8%, respectively. Therefore, the total population of aphids on CMVinfected plants was significantly higher on the 25th day after the introduction of aphids. The total population of aphids on the CMV-infected plants was 1,225 compared to that of healthy plants which was 713. Similarly, mean fecundity over a 30 day observation period was 61.25 and 35.65 for aphids grown on CMV-infected and healthy plants, respectively. Jasmonic acid (JA) upstream gene OPR3 and downstream gene COI1 was measured to quantify the changes in JA expression in the plants under the virus infection. Both genes tested were significantly downregulated in CMV-infected plants. From our results, it was evident that the JA related insect resistance was reduced in CMV-infected plants and hence aphid colony development was increased.

The observations on Myzus persicae and Macrosiphum euphorbiae development were carried out on boxthorn (Lycium halimifolium) growing in various places of the city ofWroclaw in 1999-2001. They concerned the following issues: aphid population dynamics and aphid age and morph diversity in population structure. Aphids infested only certain boxthorn bushes and other bushes were free of these insects. M. persicae infested more bushes than M. euphorbiae did. The first species appeared 7-10 days earlier on boxthorn than the second one. Time of the maximum population density of both aphid species was similar. Age structure of M. persicae and M. euphorbiae populations was similar. The youngest larvae (L,-L,) predominated and the least numerous were alatae females. Coccinellids were the most numerous aphid predators on boxthorn.