转换寄主对马尾松毛虫生长发育与繁殖的影响

在室内条件下,分别用马尾松针叶(Pinus massoniana Lamb.)、湿地松针叶(Pinus elliottii Engelm)、以及在不同的幼虫龄期从用马尾松针叶转移到用湿地松针叶饲养马尾松毛虫Dendrolimus punctatus Walker,观察转换寄主对马尾松毛虫生长发育与繁殖的影响。结果表明:(1)从用马尾松针叶饲养转换到用湿地松针叶饲养,可显著影响马尾松毛虫生长发育和繁殖参数;而且当在马尾松毛虫幼虫老龄期进行转换寄主饲养比低龄期转换寄主饲养,可显著缩短马尾松毛虫幼虫的发育历期,降低死亡率,同时,可显著增加幼虫体重、蛹重和化蛹率;对食物的营养效应也越强。(2)取食马尾松的松毛虫较取食湿地松的马尾松毛虫发育历期短,死亡率低,幼虫及蛹重增加,产卵量高。结果说明,马尾松毛虫从马尾松转换移到湿地松上取食对其生长发育与繁殖是不利的。     

松树受害后一些化学物质含量的变化及其对马尾松毛虫种群参数的影响

通过探讨松树受害后松针的一些化学物质变化与马尾松毛虫Dendrolimus punctatus 种群参数的相互作用关系。结果表明：松针被马尾松毛虫为害后,针叶的氨基酸含量减少、单宁和总酚含量增加;马尾松毛虫取食被害松针后,体内的2种解毒酶(过氧化氢酶、羧酸酯酶)活性增加,其种群参数表现出发育历期延长、体重减轻、死亡率增加、生殖力下降的变 化。     

马尾松诱导抗性对马尾松毛虫幼虫生长发育的影响

利用不同受害方式和受害程度的马尾松 (PinusmassonianaLamb.)针饲养马尾松毛DendrolimuspunctarusWalker虫幼虫 ,研究受害松针对幼虫生长发育的影响。结果表明 :马尾松毛虫取食受害松针后 ,幼虫的取食量下降 ,排粪量减少 ,对食物的消耗和利用指数降低 ,幼虫发育速率缓慢 ,死亡率增加 ,从而影响马尾松毛虫的种群动态     

天敌对马尾松毛虫自然种群的影响

马尾松毛虫 Dendrolimus punctatus Wlaker分布于我国南方十三个省,是毁害森林的大害虫。近年来每年发生虫害面积达3000—4000万亩,损失木材达500—700余万立方米。在广西为害也极严重。广西钦州县红卫林场有4万亩马尾松纯林,营造于六十年代中期,是广西马尾松毛虫为害的常灾区、重灾区。马尾松毛虫在该林场每年发生三     

不同松林内马尾松毛虫种群动态的特征

通过对1992-2001年5种不同混交林型的马尾松林内各代幼虫发生量,受害面积和有虫株率的系统调查,研究了各种不同林型的松林对马尾松毛虫种群动态的影响。结果表明,不同树种混交的马尾松林对马尾松毛虫的种群动态有较大的影响。马尾松毛虫在马尾松纯林中发生量多,为害最严重。暴发周期最短;在与杉木等混交的马尾松林中发生次之;而在与阔叶树混交的马尾松林中平均每株虫口数少,发生与危害率及有虫株率均较其它林型小,不易引起松毛虫暴发为害。     

马尾松毛虫自然种群生命表

<正> 马尾松毛虫Dendrolimus punctatus Walker是马尾松的主要害虫,大发生过后,林木如同火烧,严重影响马尾松的生长。笔者于1983年在华云山天池林场对马尾松毛虫自然种群生命表进行了研究,旨在为马尾松毛虫的预测预报提供资料。     

广东省马尾松毛虫发生规律的研究

马尾松毛虫在广东省北部地区每年发生3代,南部每年发生4代。根据历年不同地区马尾松毛虫的发生情况进行分析,中部地区发现面积小,年间波动小,其发生呈下降趋势,西南部则是发生面积大,年间波动很小,发生呈增长,趋势一种中间形式的类型区是一个狭长的带。分布于西部边缘地区和中部与东部、北部的过渡区。     

马尾松毛虫危害马尾松造成经济损失评价

马尾松毛虫 Dendrolimus punctatus ( Walker)是松树的主要害虫 ,对其防治指标的研究已有不少报道[1、2 ] ,但该虫对危害马尾松造成材积和松脂等损失量的定量比研究问题 ,未见详细报导。为此 ,本文通过人工剪叶模拟马尾松毛虫危害 ,采割不同剪叶量松树的松脂 ,利用回归分析 ,建立马尾松材积损失率、产脂损失量分别与失叶率的回归方程。并根据这些方程推算出马尾松毛虫各种虫口密度造成材积、松脂和经济上的损失量 ,为综合防治马尾松毛虫提供科学依据。1　试验地概况试验地设在福建省诏安县桥东镇林家村 ,地处东径 1 1 7°1 2′2 4″～ 1 1 …     

马尾松毛虫的光周期反应

马尾松毛虫Dendrolimus punctatus Walker和油松毛虫 Dendrolimus tabulaeformisTsai et Liu都属于长日照型昆虫。它们的光周期反应却存在着明显的差开。马尾松毛虫初龄幼虫对光照时数虽然敏感,可是只有在整个幼虫期都处在短光照周期条件下才能维持幼虫的滞育。 而且, 幼虫的滞育强度明显较弱,解除滞育所要求的条件也不如油松毛虫严格。在较高温度条件下,幼虫的滞育更不稳定,一般仅表现为生长的短暂停滞和幼虫历期的相对延长。温度和光周期还可影响到幼虫的存活和性比。马尾松毛虫幼虫呈典型的浅滞育现象。正是由于这一特性,在环境条件的影响下,长江沿岸省份不同年份马尾松毛虫二、三代分化的比例才有较大的波动,这直接关系着当地的种群动态,也是当年当地高虫口区二代虫能否成灾的关键。     

马尾松毛虫种群消长与寄主受害程度的关系

研究不同受害程度松林与马尾松毛虫Dedrolimuspunctatus(Walker)种群发育阶段的关系。结果表明,松毛虫大面积发生时松林的受害程度可以很好地标示着松毛虫种群的发生阶段。松林点片受害显示松毛虫种群进入上升开始阶段;松林受害程度中等时,松毛虫仍处于上升种群阶段;当松林的针叶被吃光,表明松毛虫已处暴发阶段。松毛虫暴发种群在自然情况下,将出现典型的蛹期和下一代卵期的寄生率大幅度升高、雌性比、蛹重和产卵量等种群参数大幅度下降等特征;其后代会自然转入下降种群或进入低虫口期。但这些暴发种群的卵转入在保证充足饲料的可控条件下饲养时,其后代的生长发育、存活率、性比、蛹重等主要种群参数没有明显差异。即没显示出上升种群和暴发种群的特征差异,说明暴发种群的终止主要是受外界环境的限制而不是松毛虫本身的内因所致。     

Ten polymorphic microsatellite markers developed in the masson pine moth Dendrolimus punctatus Walker (Lepidoptera: Lasiocampidae)

A set of 10 polymorphic di‐ and trinucleotide microsatellite loci were developed for the forestry pest insect, masson pine moth, Dendrolimus punctatus Walker. The expected heterozygosity at these loci ranges from 0.285 to 0.859, and the observed allele numbers from five to 19. Cross species amplification of these loci in four other congeneric pine moth species indicates variable levels of loci conservation and thus cross‐applicability. Therefore, the microsatellite loci reported here should be useful for population genetic and other related studies in the masson pine moth and other closely related species.     

马尾松毛虫越冬代滞育与非滞育幼虫过冷却点的研究

测定了在恒温和自然温度处理下饲养的马尾松毛虫滞育与非滞育幼虫的过冷却点。结果表明 ,2 7℃恒温饲养的滞育幼虫的平均过冷却点较非滞育幼虫的平均过冷却点低 ,但无显著差异 ;而自然温度下饲养的滞育幼虫的过冷却点较非滞育的过冷却点也低 ,然而 ,滞育开始时差异不显著 ,之后差异显著。相应滞育状态下 ,自然温度下饲喂的幼虫较 2 7℃恒温下饲喂的平均过冷却点低 ,但在滞育开始阶段和结束阶段两者之间的差异显著。自然温度下滞育和非滞育幼虫的抗寒能力都随气温的降低而增强 ,而 2 7℃下滞育与非滞育幼虫的抗寒能力均出现先增后减的趋势     

马尾松毛虫2、3代分化和干旱对种群时间动态的影响

通过对安徽冬至县金寺山林场27年中马尾松毛虫Dendrolimus punctatus Walker发生面积的时间序列和2、3代分化率及干旱记录进行相关分析,进一步探讨2、3代分化和干旱对马尾松毛虫种群时间序列动态的影响。马尾松毛虫2、3代分化率有一定的周期性,而且波动的幅度很大,大致可以分成低、中、高三个等级,三个等级的分化率范围分别为1%～10%,11%～40%和41%～100%。大致每隔5～6年出现一次高分化率,高分化率的前后往往是低分化率,高分化率之间一般是中等的分化率和低分化率交替出现。通过分析马尾松毛虫2、3代分化对种群时间序列动态的影响,说明2、3代分化主要影响当代的数量,与以后各代数量无明显相关。2、3代分化前的种群数量与2、3代分化也无明显的相关。中等以上的分化率常引起松毛虫的发生。影响2、3代分化的主要气候因子是7月份的气温,7月份的气温越高,卵孵化的高峰期越早,更多幼虫于分化的临界光周期以前孵化,分化率就高。干旱与2、3代分化有微弱的相关,对松毛虫时间动态的影响具有延迟作用,影响最明显的是第二年的第1代,这说明干旱不仅影响当代松毛虫的动态,更重要的是通过影响寄主,从而影响到以后世代的松毛虫动态。     

Effect of pine foliage damage on the incidence of larval diapause in the pine caterpillar Dendrolimus punctatus (Lepidoptera: Lasiocampidae)

The pine caterpillar Dendrolimus punctatus (Walker) with a larval facultative diapause is one of the most destructive insect pests of the pine tree Pinus massoniana in China. The larvae feeding on pine trees with different damage levels were studied to determine the induction of diapause under both laboratory and field conditions. Developmental duration of larvae before the third instar was the longest when fed with 75%–90% damaged needles, followed by 25%–40% damaged needles and intact pine needles, whereas mortalities did not differ among different treatments under the conditions of 25° and critical photoperiod 13.5:10.5 L:D. At 25°, no diapause was induced under 15:9 L:D, whereas 100% diapause occurred under 12:12 L:D regardless of the levels of needle damage. Incidences of larvae entering diapause when they were fed with intact, 25%–40% and 75%–90% damaged pine needles were 51.7%, 70.8% and 81% under 13.5:10.5 L:D, respectively. Similar results were obtained in the field experiment. Incidence of diapause was significantly different among the pine needle damage levels of pine trees when the photoperiod was close to the critical day length, indicating that the effect of host plants on diapause induction was dependent on the range of photoperiod. The content of amino acid and sugar decreased and tannin increased in pine needles after feeding by the pine caterpillars, suggesting that changed levels of nutrients in damaged needles or a particular substance emitted by damaged pine trees was perhaps involved in the diapause induction of the pine caterpillar.     

马尾松毛虫幼虫的捕食天敌及其捕食作用的研究

根据林间调查和室内观察资料,分析了江西省万年县不同松林中马尾松毛虫不同发生代别低龄幼虫期的主要捕食天敌种类及数量。结果表明低龄幼虫期捕食无敌有13科31种,其中以蜘蛛类最多,其次为蚂蚁类。不同林型中捕食天敌的种类和数量在年份间代别间均存在一定差异,数量差异尤其显著。在室内研究了几种主要捕食无敌对马尾松毛虫低龄幼虫的捕食作用及其功能反应,结果表明功能反应为S型,由此建立了它们的功能反应模型。     

Stimulation of sex pheromone production by PBAN-like substance in the pine caterpillar moth, Dendrolimus punctatus (Lepidoptera: Lasiocampidae)

Sex pheromone production in the female pine caterpillar moth, Dendrolimus punctatus is controlled by a PBAN-like substance located in the head of female moth. Pheromone titer was significantly decreased by decapitation of female moth, and restored by injection of either Hez-PBAN or head extract prepared from male or female moth. Stimulation of pheromone production by head extract followed a dose-dependent pattern from 0.5 to at least 4 head equivalent. A gland in vitro assay was used to study the relationship between gland incubation time and pheromone production as well as calcium involvement in the stimulation of pheromone production by head extract. Maximum pheromone production was occurred at 60 min after pheromone gland was incubated with two equivalents of head extracts. In vitro experiments showed that the presence of calcium in the incubation medium was necessary for stimulation of pheromone production. The calcium ionophore, A 23187, alone stimulated pheromone production. The pheromone components (Z,E)-5,7-dodecadienol and its acetate and propionate were produced in these experiments but in addition to the aldehyde, (Z,E)-5,7-dodecadienal was also found. This indicates that females are capable of producing four oxygenated functional groups. The PBAN-like substance control of the pheromone biosynthetic pathway was investigated by monitoring the incorporation of the labeled precursor into both pheromone and pheromone intermediates.