| Jilin Province,located in the golden maize belts,is an important grain production base in China.The maize planting areas in this province are about 60 million mus.In recent years,the damage of maize aphids in Jilin Province has been increasing year by year.Maize aphids have risen from secondary pests to major pests,which posed a serious threat to maize yield and quality.Clarifying the population dynamics of pests is an important basis for formulating control strategies.At present,there are relatively few researches on the field population dynamics of maize aphids in Jilin Province.And the research on the migration dynamics of maize aphids has not been reported.It is disadvantage to the development of aphid prediction and prevention and control.In this study,the self-built insect monitoring network of suction traps and authorized patents(insect aerial sampling device and winged aphid trapping device)were applied in coordination to monitor the migration dynamics of maize aphids.The population dynamics of aphids in maize field were investigated systematically.This study clarified the field migration,diffusion and population dynamics of maize aphids.The main findings are as follows:1.The species and quantity composition of maize aphids monitored by suction trapsThrough insect monitoring network of suction traps,a total of 156492 winged aphids were investigated and identified in 2019 to 2022,belonging to 82 species,52 genera and 9 families.A total of 4 species of maize aphids were identified(all belong to Aphididae): Sitobion miscanthi,Aphis gossypii,Rhopalosiphum padi and Rhopalosiphum maidis.The number of maize aphids was 132009,accounting for 84 % of the total number of identifications.Among the four aphid species,R.padi accounted for the highest proportion(93.1%)and was the dominant species,followed by A.gossypii(4.8%),S.miscanthi(1.3%)and R.maidis(0.8%).2.Migration and diffusion dynamics of maize aphids in field(1)Immigration period of S.miscanthi was from early May to mid-June.The S.miscanthi began to spread in the maize field in early May.This time earlier than the other three corn aphids.Diffusion period was from late June to mid-August.Emigration period was from late August to October.(2)Immigration period of A.gossypii was from early May to late June.The date of the first detected immigration was advanced year by year.In mid-May,A.gossypii began to spread in maize fields.Diffusion period was from late July to mid-August,but the main diffusion period was July in fields.Emigration period was from late August to October.(3)Immigration period of R.padi was from early May to mid-June.The initial diffusion period of R.padi was similar to A.gossypii in fields.Diffusion period was from late July to midAugust.Emigration period was from late August to October.The number of winged aphids increased significantly during this period.(4)Immigration period of R.maidis was from mid-July to early August.Diffusion period was from mid-August to early September.In these two periods,the number of winged aphids was less.Emigration period was from mid-September to October.The number of winged aphids was relatively high during this period.3.Damage dynamics of maize aphids in fieldExcept R.maidis,the first appearance time of wingless maize aphis on maize plants was in early June.They all parasitized on the lower part of maize plants.The number of S.miscanthi per plant was less than 1.It was relatively less harmful to maize.In July,the number of A.gossypii increased rapidly and was the dominant species.The main damage position was the lower part of maize plant.The number of R.padi began to increase since July,and rapidly grew in August then became the dominant species.It preferred to parasitize in the female ear,followed by the lower part of the plant.Rhopalosiphum maidis began to appear in mid-July and parasitized in tassels.In August,it was largely transferred to the female ear and mixed with R.padi.At this time,the niche overlap of they in time and space was higher than 0.92.They had a relatively strong interspecific competition relationship.From the aspect of technological innovation,this study independently constructed the insect monitoring network of suction traps in Jilin Province and combined with the self-developed patents of insect aerial sampling device and winged aphid trapping device to monitor the migration dynamics of maize aphids.From the aspect of theorical innovation,this study is the first study on the migration,diffusion and field population dynamics of maize aphids in Jilin Province.The results improved the monitoring and early warning technology of maize aphids in Jilin Province.And it provided a theoretical basis for scientific guidance of maize aphids’ prevention and control work. |
