白纹雏蝗生物学与生态学特性研究

Biological and ecological characteristics of Chorthippus albonemus Cheng et Tu(Orthoptera: Arcypteridae)

【目的】随着气候和生态环境的变化,近年来草原虫害发生日趋复杂,突发性、暴发性虫灾增多,对草原生态造成了极大破坏,而目前有关宁夏草原主要害虫的基础生物学和生态学特性研究尚属空白,制约了草原害虫监测防控工作的有效开展。【方法】以宁夏典型草原上严重发生的白纹雏蝗Chorthippus albonemus Cheng et Tu为研究对象,通过室内饲养和田间调查相结合,采用笼罩供食法,系统开展其生活史、食性及温度对其生长发育的影响等观察和试验研究。【结果】在宁夏典型草原上,白纹雏蝗越冬虫卵每年有两次孵化期,首批越冬虫卵4月中下旬开始孵化,5月中下旬达到第1次孵化高峰期,6月下旬至7月上旬逐步羽化为成虫后随即交配产卵,此时间段的白纹雏蝗称为＂夏蝗＂;第2批越冬虫卵7月中下旬开始孵化,8月中下旬达到第2次孵化高峰期,9月中下旬羽化为成虫交配产卵,此时间段的白纹雏蝗称为＂秋蝗＂;白纹雏蝗嗜食长茅草,喜食赖草,少食星毛委陵菜、阿尔泰狗哇花、达乌里胡枝子和稗草,偶食冷蒿和猪毛蒿;日食量和近似消化力均随着龄期的增长而增大,且雌成虫的日食量和近似消化力比雄成虫大;高温和低温均不利于白纹雏蝗生长发育,若虫在13℃温度下不能蜕皮发育,成虫在18℃温度下不能交配产卵。在18~33℃的温度范围内,各龄期的发育历期均随着温度的升高而缩短。在温度相差15℃的情况下,18℃白纹雏蝗各龄若虫的发育历期是33℃下的3.09~4.93倍。【结论】掌握了白纹雏蝗的生活史和食性特点,明确了其发育历期、发育起点温度和有效积温等生态学特性,进一步分析了温度对其生长发育的影响,为进一步揭示害虫的发生规律,有效开展其监测预报及防控技术提供依据。

[Objectives] In recent years grassland pests have become increasingly diverse, emergent, fulminant pests have increased, and damage to grassland ecology has increased in association with changes of climate and ecological environment. Much basic biological and ecological research on the main pests of grasslands in Ningxia remains to be done. This has restricted the effective development of grassland monitoring and pest prevention and control work. [Methods] Chorthippus albonemus Cheng et Tu is a major pest of the typical steppe habitat of Ningxia. We studied the life history, feeding and the effect of temperature on the growth of this species through indoor rearing and field investigations combined with covered, feeding experiments. [Results] Overwintering eggs of C. albonemus have two incubation periods every year in typical Ningxia steppe. The first overwintering eggs begins to hatch from early to mid-April and the first hatching peak occurs from early to mid-May. After that, emergence gradually begins, and adults mate and oviposit from late June to early July. During this period these insects are called ＂summer locusts＂. Second overwintering eggs begin to hatch from early to mid-July and the second hatching peak occurs from early to mid-August. The adults mate and oviposit from early to mid-September and are called ＂autumn locusts＂. Grasshoppers fed on Stipa bungeana but prefered Leymus secalinus, fed relatively little on Potentilla acaulis, Heteropappus altaicus, Lespedeza bicolor and Echinochloa crusgalli, and only on occasionally Artemisia frigid and Artemisia scoparia. Consumption and approximate digestion increased with age. In addition, the consumption and approximate digestion of female adults was higher than that of males. Excessively high or low temperatures were unfavorable to survival. Nymphs could not molt at 13 ℃ and adults could not mate at 18 ℃. The developmental duration of every stage was reduced with increasing temperatures from 18 to 33℃. The developmental duration of C.albonemus＇ nymph at 18℃ was 3.09 - 4.93 times longer than that at 33 ℃. [Conclusion] The developmental duration, developmental threshold temperature, effective accumulated temperature and other ecological characteristics of C. albonemus have been determined. In addition, the effect of temperature on growth and development were analyzed. These data could provide the basis for further understanding the occurrence of these pests, and improve monitoring, outbreak prediction, prevention and control.