Comparative study on the embryonic development of three mud crabs Scylla spp.

Morphological changes in the embryos, egg size and development, incubation period and morphological structures of newly hatched zoea of three mud crab Scylla species were determined. The three species exhibited similar embryonic development composed of 10 stages. The mean egg diameter of Scylla serrata was significantly larger (P<0.05) at the prehatch stage. The mean egg diameters of Scylla tranquebarica and Scylla olivacea were similar (P>0.05). The incubation period was the longest in S. serrata and the shortest in S. olivacea. There was a positive relationship between egg size and larval size, as S. serrata exhibited the largest egg size and first zoea. However, no correlation was detected between egg size at prehatch and lengths of the morphological structures of the newly hatched zoea. The three species exhibited similar lengths of cephalic structures, but S. olivacea had significantly shorter (P<0.05) abdominal structures. The duration of spawning from ablation was the shortest in S. tranquebarica and the longest in S. olivacea. The study is relevant to aquaculture and fisheries management of Scylla species.     

浙江菜区斜纹夜蛾对几类杀虫剂的敏感性

为明确浙江菜区斜纹夜蛾对主要杀虫剂的抗药性发展趋势,采集了浙江三门和萧山地区田间斜纹夜蛾,监测其对11种杀虫剂的敏感性水平。结果表明,三门种群和萧山种群对这些杀虫剂的敏感性存在明显差异,且萧山种群对测试药剂的敏感性高于三门种群。参考抗性诊断剂量（田间推荐浓度）处理后存活率和11种杀虫剂LC99致死浓度与田间推荐浓度的比值,推断三门种群对氯虫苯甲酰胺和溴虫腈敏感,对茚虫威、甲氨基阿维菌素苯甲酸盐、啶虫隆、丁醚脲和多杀菌素的敏感性下降,对虫酰肼、乙基多杀菌素、阿维菌素和高效氯氰菊酯已产生抗性;同样,萧山种群对氯虫苯甲酰胺、溴虫腈和多杀菌素敏感,对甲氨基阿维菌素苯甲酸盐、丁醚脲、啶虫隆、乙基多杀菌素、茚虫威、阿维菌素敏感性下降,对虫酰肼和高效氯氰菊酯产生抗性。因此,浙江菜区斜纹夜蛾对大部分监测杀虫剂的抗性正在形成,已产生抗性的高效氯氰菊酯、阿维菌素、虫酰肼应暂停使用1~2年;其余药剂则需要控制用药次数和采用不同种类杀虫剂轮用、混用的方式以延缓抗药性的产生。     

棕榈红棕象甲防治技术研究

[目的]及时有效地控制棕榈红棕象甲在广西南宁的发生与为害。[方法]在广西南宁展开棕榈红棕象甲分布及为害情况的调查,同时进行传播途径的检测,再进行灯光诱杀试验、人工结合药剂防治和药剂防治试验。[结果]目前南宁市70%的苗圃及景区已有红棕象甲分布;在已栽种的棕榈科植物中,受害品种达80%。带虫棕榈苗木输出是扩散为害的主要途径。采用频振式诱虫灯诱杀成虫,有效可行。采用药剂喷施寄主喇叭口（即心叶处）,然后用老叶鞘或农用薄膜包扎寄主茎杆的叶鞘,可达到防治红棕象甲的目的。[结论]对红棕象甲的防治策略,应以防治树苗和树龄在10年以下的植株为主;对高龄树和高大植株,必要时采用药剂挑治,综合防治。     

3种查耳酮类化合物对斜纹夜蛾的杀虫活性

在室内测定了查耳酮、二氢查耳酮和4-甲氧基查耳酮3种查耳酮类似物对斜纹夜蛾的杀虫活性。结果表明,3种查耳酮类似物对斜纹夜蛾幼虫拒食活性大小依次为:4-甲氧基查耳酮查耳酮二氢查耳酮,处理后24 hAFC50值分别为0.452、0.524、1.072 mg/mL;对斜纹夜蛾幼虫还有一定的胃毒作用,在2 mg/mL的供试浓度下,处理后12 d的死亡率分别为67.78%、57.41%和53.33%;此外,查耳酮类化合物对斜纹夜蛾幼虫还具有一定抑制生长发育的作用,主要表现在幼虫体重、化蛹率和羽化率均显著低于对照。     

9种药剂对斜纹夜蛾的室内毒力与田间应用效果

通过室内毒力测定和田间药效试验,测定当前9种主流杀虫剂产品对斜纹夜蛾的防治效果。结果表明,甲维盐、茚虫威、虫螨腈和虫酰肼对斜纹夜蛾具有优良的防效,可作为防治斜纹夜蛾的首选药剂。Bt与多杀菌素的效果次之。阿维菌素、高效氯氰菊酯和毒死蜱对斜纹夜蛾已逐渐失去控制作用,在生产中应尽量少用、慎用。     

辣椒碱对斜纹夜蛾细胞增殖及凋亡的影响

采用3-(4,5-二甲基-2-噻唑)-2,5-二苯基溴化四唑(MTT)检测法、荧光显微镜细胞形态观察法和流式细胞仪(flow cytometry,FCM)技术,研究了辣椒碱对离体培养斜纹夜蛾Spodopt-era litura(SL)细胞增殖及凋亡的影响。结果表明:辣椒碱对SL细胞24 h的IC50值为46.89μg/mL,与鱼藤酮差异不显著。40μg/mL辣椒碱处理SL细胞24h后,细胞形态明显不规则,呈现出凋亡的典型症状。10、20和40μg/mL辣椒碱处理SL细胞48h后,细胞早期凋亡率分别为13.56%、18.61%和3.81%,而晚期凋亡和坏死率分别为23.78%、34.28%和61.72%。辣椒碱处理细胞48h后,细胞周期变化明显,细胞生长阻滞于G2/M期。表明辣椒碱对斜纹夜蛾细胞具有良好的抑制作用,能致细胞凋亡并有一定的浓度依赖性。     

四斑小毛瓢虫生物学特性初探

本文观察了四斑小毛瓢虫Scymnus frontalis各虫态的形态特征和生活习性,比较了其在不同温度下的发育历期,取食桃蚜Myzus persicae、大豆蚜Aphis glycines、麦长管蚜Macrosiphum avenae和刺槐蚜A.robiniae对其捕食量和幼虫发育历期的影响。在182、02、32、62、9℃条件下,四斑小毛瓢虫卵到成虫的发育时间分别为32.91、27.18、22.23、17.25、14.93d。四斑小毛瓢虫幼虫对桃蚜、大豆蚜、麦长管蚜、刺槐蚜的捕食量分别为82.97、64.70、58.57、76.11头;相应发育历期分别为9.80、10.901、0.86、9.86d。在26℃、RH70%的条件下,用桃蚜饲养四斑小毛瓢虫效果最好,成虫获得率达88%。四斑小毛瓢虫的卵期、幼虫期、蛹期及产卵前期的发育起点温度和有效积温分别为12.875、.45、11.72、14.41℃和40.94、210.915、8.54、54.42日度。     

大华丽蜾赢的筑巢和育幼行为观察与视频记录

通过直接观察和摄像机同步记录的方式．观测大华丽蜾赢[Deltapetiolata（Fabricius）]的筑巢与育幼行为,包括选址、取水、取泥、筑巢、产卵、捕虫和封口等环节。结果表明,大华丽蜾赢一天的活动时间为8：00～18：00．完成1穴需要制作和搬运15～18个泥球,单次取泥时间为33～75s,单次取水时间为15～22s。筑巢耗费1个泥球的时间为41～209s,单穴储存2～4只夜蛾幼虫;每天筑l穴,连筑8穴,每穴产卵1粒．共8粒,幼虫发育30d左右,2只破巢而出,羽化为成虫,其余被寄生而未能完成发育。同时,成功地获得了包括巢内行为在内的视频记录。     

Cross‐resistance,mode of inheritance and stability of resistance to emamectin in Spodoptera litura (Lepidoptera: Noctuidae)

BACKGROUND: Spodoptera litura (F.) is a cosmopolitan pest that has developed resistance to several insecticides. The aim of the present study was to establish whether an emamectin‐selected (Ema‐SEL) population could render cross‐resistance to other insecticides, and to investigate the genetics of resistance. RESULTS: Bioassays at G₁ gave resistance ratios (RRs) of 80‐, 2980‐, 3050‐ and 2800‐fold for emamectin, abamectin, indoxacarb and acetamiprid, respectively, compared with a laboratory susceptible population Lab‐PK. After three rounds of selection, resistance to emamectin in Ema‐SEL increased significantly, with RRs of 730‐fold and 13‐fold compared with the Lab‐PK and unselected (UNSEL) population respectively. Further studies revealed that three generations were required for a tenfold increase in resistance to emamectin. Resistance to abamectin, indoxacarb, acetamiprid and emamectin in UNSEL declined significantly compared with the field population at G₁. Furthermore, selection with emamectin reduced resistance to abamectin, indoxacarb and acetamiprid on a par with UNSEL. Crosses between Ema‐SEL and Lab‐PK indicated autosomal and incomplete dominance of resistance. A direct test of a monogenic model and Land's method suggested that resistance to emamectin was controlled by more than one locus. CONCLUSION: Instability of resistance and lack of cross‐resistance to other insecticides suggest that insecticides with different modes of action should be recommended to reduce emamectin selection pressure. Copyright © 2010 Society of Chemical Industry     

斜纹夜蛾的人工饲养技术

介绍了斜纹夜蛾的人工饲养技术,结果表明:室内饲养的斜纹夜蛾平均蛹重达473 mg,幼虫成活率、羽化率均在95%以上。该饲养方法可用于室内大量饲养斜纹夜蛾,但为减少霉菌的污染,应在人工饲料中加入适量的甲醛。