哈尔滨市郊区亚洲玉米螟发生规律与卵块空间分布研究

Occurrence rules of Ostrinia furnacalis (Guenée) and the spatial distribution of egg masses in the suburbs of Harbin

通过田间玉米罩笼观察法研究了亚洲玉米螟在哈尔滨市郊区的发生规律和其卵块在玉米植株上的分布特点。结果表明,该地区为一、二代亚洲玉米螟混合发生区,有10%左右个体发生二代。越冬代化蛹盛期为6月下旬,化蛹持续时间为54~58d。越冬代成虫盛发高峰期为7月初,羽化期为45~52d。一代卵出现的始盛期为6月末,高峰期为7月上旬,产卵期约为40d。二代产卵高峰期为8月上旬末,产卵期约为20d。一代卵孵化率显著高于二代卵,卵粒被寄生率和被捕食率均明显低于于二代卵。随着玉米植株的生长,成虫有向玉米植株上部集中产卵的趋势,前期羽化的越冬代成虫产卵高度主要集中在1.2~1.6m,主要分布在玉米上部第3~6片叶上,后期羽化的成虫产卵高度主要集中在1.8m以上,主要分布在玉米上部第1~4片叶上,一代卵在玉米植株0.8m以下高度没有分布。二代卵块分布较一代卵块分散,产卵高度较一代卵有所降低。亚洲玉米螟卵块主要分布在玉米叶背近中脉2cm内,距叶腋20~50cm处。研究结果对当地开展玉米螟的测报调查和释放赤眼蜂防治玉米螟具有重要指导意义。

Observational method of corn cage in field was used to study the occurrence rules of Asian corn borers Ostrinia furnacalis（Guenée）and the distribution characteristics of the egg masses on corn plants in the suburbs of Harbin.The results showed that the first and the second generations of this pest occurred simultaneously in this region,and about 10% of individuals had the second generation.The peak period of pupation of overwintering generation occurred in late June,and the pupation period could last for 54 to 58 days.The full incidence peak of overwintering generation adults occurred at the beginning of July and the emergence period could last for 45 to 52 days.The full egg period of first generation occurred in late June and the peak period of eggs occurred in early July.The ovipositing duration of Asian corn borers was about 40 days.The peak egg period of the second generation occurred at the end of early August,and the ovipositing period lasted for about 20 days.The percentages of parasitized or preyed eggs in the second generation were higher than those in the first generation,while the hatching rate of the first generation egg were higher than that of the second generation significantly.There was no first generation eggs on corn plants below 0.8 m.Overwintering adults＇ eggs concentrated 1.2 m to 1.6 m above the ground,and mainly distributed on the top third-to the sixth-leaf of corn.With the growth of corn plants,adults tended to lay eggs on the upper of corn plants.The eggs laid by later emerged adults mainly concentrated on the top first-tothe fourth-leaf（〉1.8 m）.The egg masses of the second generation distributed much dispersive and the position of eggs were lower than that of the first generation.The egg masses mainly distributed on the underside of corn leaves 2 cm near the midrib and 20 to 50 cm away from leaf axil.The results of the survey provided important information for the prediction of local Asian corn borer and the release of Trichogramma spp.to control this pest.