Occurrence Dynamics of Agrotis ypsilon(Rottemberg)in Weifang

Hongping Tian,Guocai Lu,Fujun Li

Weifang Academy of Agricultural Sciences,Weifang 261071,China

Abstract [Objective]The paper was to monitor the occurrence dynamics of Agrotis ypsilon in Weifang and to clarify its occurrence regularity.[Method]High-altitude trap lamp and ground trap lamp were used to trap insects respectively.The lamps were automatically turned on at 19:00 every day,and monitored for 12 h until 7:00 am.The species of insects trapped by lamps was recorded every day,and the number of each species was counted.[Result]The peak periods of A.ypsilon caught by high-altitude trap lamp were basically consistent with those caught by ground trap lamp,indicating that A.ypsilon was more likely to immigrate from local area of Weifang.[Conclusion]The study provides theoretical support for migration prediction and early warning of A.ypsilon in Weifang.

Keywords Trap lamp;Agrotis ypsilon(Rottemberg);Monitor

Agrotis ypsilon(Rottemberg),belonging to Noctuidae,Lepidoptera,also known as black silkworm,wireworm,etc.[1],is a national important omnivorous agricultural pest[2].It mainly harms the seedlings of vegetables,corn and cotton,and cuts off the stem of seedlings near the ground,causing the death of the whole plant,sparse seedlings and seedlingless ridges,or even destruction of the whole field[3].Phototaxis is one of the important biological characteristics of nocturnal insects,and it is an instinct formed during long-term selection and adaptation of insects to environmental conditions[4-5].The trap lamp developed according to this character of insects is an important tool in the field of insect research,and plays an important role in insect diversity,occurrence dynamics,classification monitoring and pest control[6].In this study,A.ypsilon in Changyi area of Weifang was monitored by trap lamp,in order to provide theoretical support for migration prediction and early warning of A.ypsilon in Weifang.

1 Materials and Methods

1.1 Selection of monitoring points Changyi monitoring site is located in Changyi experimental field in Weifang Academy of Agricultural Sciences in Shandong Province.The major crops are wheat,corn,peanuts,soybeans,etc.,which are under double cropping condition.

1.2 Trap lamp Trap lamps were manufactured by Shandong Jinan Xiangchen Technology Co.,Ltd.,and the main parameters are shown in Table 1.

Table 1 Parameters of high-altitude trap lamp and ground trap lamp

1.3 Monitoring method The trap lamps were turned on from April 3,2020 to November 1,2020.The lamps were automatically turned on at 19:00 every day,and monitored for 12 h until 7:00 am.The species of insects caught every day were recorded,and the number of each species was counted.

2 Results and Analysis

Since April 3 when the lamps were turned on,175 331 pests were caught by high-altitude trap lamp,and 1 146 of which were A.ypsilon,accounting for 0.65% of the total;3 066 pests were caught by ground trap lamp,and 76 of which were A.ypsilon,accounting for 0.25%of the total.

As shown in Fig.1,there were three peaks of A.ypsilon caught by high-altitude trap lamp.The first peak was in early June,which was the highest in the whole year.The peak date was June 9,and the number of moths trapped per day was 100.The second peak was in early August,which was the second highest of the year.The peak date was August 10,and the number of moths trapped per day was 70.The third peak was in late July,which was the last peak of the year.The peak date was July 26,and the number of moths trapped per day was 60.

There were two peaks of A.ypsilon caught by ground trap lamp(Fig.2).The first peak was in early June,which was the second highest of the year.The peak date was June 5,and the number of moths trapped per day was 4.The second peak was in early August,which was the highest in the whole year.The peak day was on August 10,and the number of moths trapped per day was 10.

Fig.1 Occurrence dynamics of Agrotis ypsilon caught by high-altitude trap lamp in Changyi area of Weifang

Fig.2 Occurrence dynamics of Agrotis ypsilon caught by ground trap lamp in Changyi area of Weifang

3 Discussion

A.ypsilon is an omnivorous obligate migratory insect that occurs widely in the world.In the east Asian migratory field,A.ypsilon find suitable habitats and host plants by long-distance migration across wintering areas and different agro-ecological zones,so as to complete annual life cycle and population reproduction.Due to long-distance migration of adults and the concealment of larval damage,A.ypsilon often breaks out suddenly,resulting in great loss of crop production.The peak periods of A.ypsilon caught by high-altitude trap lamp were basically consistent with those caught by ground trap lamp,indicating that A.ypsilon was more likely to immigrate from local area of Weifang.Therefore,a series of measures can be taken in advance to prevent and control A.ypsilon.Physical measures,such as placing poplar branches in the field,hanging sex attractants,setting black lamp,can be adopted.Due to incomplete records of early meteorological data and other reasons,some of the results have not been reasonably explained. Relevant monitoring records will be continued in the future,in order to provide scientific reference for production practice.