Diet composition of larval Leiostomus xanthurus in and about the Mississippi River plume

The diet of the larvae of the sciaenid fish Leiostomus xanthuruscollected within the Mississippi River plume differs from thatof larvae collected in adjacent Gulf of Mexico shelf waters.Larvae collected in plume water had eaten twice as many foodorganisms as had larvae collected in shelf waters. Larvae collectedwithin the plume had eaten mostly small food organisms (tintinnids,copepod nauplii, pelecypod veligers and invertebrate eggs),whereas larvae collected in shelf waters had eaten mostly largerfood items (copepodite and adult copepods). Differences in theabundance of food organisms in and differences in the photicenvironments of these water masses may account for the differencesin diet.     

Grazing by the calanoid copepod Neocalanus cristatus on the microbial food web in the coastal Gulf of Alaska

Neocalanus cristatus feeding on phytoplankton and microzooplanktonwas measured in the coastal Gulf of Alaska during spring andearly summer of 2001 and 2003. Neocalanus cristatus CV fed primarilyon particles >20 µm. Particles in the 5- to 20-µmsize range were ingested in some experiments under nonbloomconditions but not under bloom conditions. Particles <5 µmwere not ingested but increased during incubations because N.cristatus consumed their microzooplanktonic predators. Neocalanuscristatus are sufficiently abundant in nature to induce sucha cascade effect in situ. Microzooplankton provided >70%of the carbon ingested by N. cristatus under nonbloom conditionsbut only     

双斑截尾寄蝇对寄主种类及草地螟幼虫龄期和寄生部位的选择性

双斑截尾寄蝇Nemorilla maculosa Meigen是草地螟和其他鳞翅类昆虫的重要寄生天敌,但国内外对其寄生行为知之甚少。为了明确双斑截尾寄蝇的寄生行为特征及其对草地螟种群动态的影响,在22℃,光照16 h的条件下就其对不同寄主种类及草地螟幼虫龄期、寄主部位的选择性进行了研究。结果显示：在草地螟、甜菜夜蛾和粘虫3种幼虫同时存在的条件下,双斑截尾寄蝇对草地螟的寄生率显著高于甜菜夜蛾和粘虫,而对甜菜夜蛾的寄生率又显著高于粘虫。另外,幼虫被寄生的平均次数也呈现相同的趋势,表明双斑截尾寄蝇喜选择草地螟。在3, 4, 5龄草地螟幼虫同时存在时,双斑截尾寄蝇对5龄幼虫的寄生率和平均寄生次数均显著高于4龄和3龄幼虫的,表明该寄蝇主要选择5龄幼虫为其寄主。在被寄生的草地螟幼虫中,胸部被寄生的比率（66.4%）和次数（4.2）显著高于头部（23.4%,1.0）和腹部（10.9%,1.1）,而腹部及头部被寄生的比例及卵粒数没有显著差异,表明双斑截尾寄蝇主要选择幼虫的胸部进行寄生。最后,就双斑截尾寄蝇对产卵寄主选择的原因和机理进行了讨论。     

紫茎泽兰乙醇提取物对棉铃虫生长发育和繁殖力的影响

采用室内生物测定法研究了紫茎泽兰Eupatorium adenophorum Spreng乙醇提取物对棉铃虫Helicoverpa armigera (Hübner)生长发育和繁殖力的影响。结果表明,当给棉铃虫幼虫饲喂含紫茎泽兰提取物浓度分别为0.088、0.44、2.2和11 g/kg的饲料时,棉铃虫的死亡率显著高于对照,而羽化率和蛹重均显著低于对照（P≤0.05）。在棉铃虫成虫产卵实验中,0.08、0.4和2 g/L紫茎泽兰提取物对产卵有一定引诱作用,而10 g/L则对产卵有驱避作用。取食浓度分别为0.08、0.4、2和10 g/L紫茎泽兰提取物的棉铃虫卵孵化率降低。表明取食紫茎泽兰提取物对棉铃虫的生长发育和繁殖有明显不利影响。     

豆薯种子中的杀虫成分及其毒力测定

为明确豆薯Pachyrrhizus erosus (L.) Urban种子中的杀虫成分及其杀虫毒力,以白纹伊蚊Aedes albopictus 4龄幼虫为目标昆虫,在活性跟踪的基础上,通过多种色谱技术和核磁共振技术分离鉴定其化学成分结构,并通过浸渍法、点滴、夹毒叶碟法等测定各化合物对白纹伊蚊幼虫、棉蚜Aphis gossypii无翅成蚜、甘薯天蛾Herse convolvuli幼虫和小菜蛾Plutella xylostella幼虫的杀虫活性和作用方式。结果表明,从豆薯种子中共分离、鉴定了14个化合物,即12a-hydoxyrotenone,pachyrrhizine,12a-hydoxypachyrrhizone,12α-dehydropachyrrizone,α-naphthoflavone,7-methoxyflavanone,12α-hydroxydolineone,6-methoxyflavone,4′-hydoxyflavanone,quercetin dihydate,5-methoxyflavone,7-hydroxyflavone,3′-hydoxyflavanone和3-hydroxyflavone。上述化合物中的前7个化合物对白纹伊蚊4龄幼虫具有毒杀活性, 处理24 h的LC₅₀分别是25.0,51.1,196.2,48.4,98.9,107.2 和15.6 mg/L;前6个化合物对棉蚜成虫24 h 的毒力分别为1.5,10.9,80.7,8,32.1和112.8 mg/L;前5个化合物以及12α-hydroxydolineone对甘薯天蛾3龄幼虫有毒杀活性;12α-hydoxyrotenone对3龄小菜蛾幼虫24 h的胃毒毒力LD₅₀为17.3 μg/头,7-methoxyflavanone对该虫仅表现出较弱的生长发育抑制活性。首次从豆薯种子中分离得9个化合物,即6-methoxyflavone,4′-hydoxyflavanone,quercetin dihydate,α-naphthoflavone,7-methoxyflavanone,5-methoxyflavone,7-hydroxyflavone,3′-hydoxyflavanone和3-hydroxyflavone;豆薯种子含有7个活性成分,其作用方式因目标昆虫不同而不同,其主要杀虫成分不是鱼藤酮而是12α-羟基鱼藤酮。     

Growth, development and condition of Dendraster excentricus (Eschscholtz) larvae reared on natural and laboratory diets

Feeding invertebrate larvae may be food limited while developingin the ocean. If they are, then their time in the plankton isprolonged, which likely increases mortality. Food limitationcould be due to the quantity and/or quality of the food available.In an effort to answer how food type influences larval nutrition,we compared growth, development and lipid deposition for Dendrasterexcentricus larvae reared in natural seawater from two depths(1 and 20 m) and in filtered seawater on a monoculture laboratorydiet of 6 cells µL^–1 of the green alga Dunaliellatertiolecta (Butcher). Five days post-fertilization, larvaereared on the laboratory diet had developed to the latest stage,were the largest and had lipid deposits. Larvae reared on naturalsurface water were intermediate in size and developmental stage,and larvae reared in the water from 20 m depth were the smallestand developed the slowest. This trend continued at 8 days post-fertilizationwhen surface water diet larvae were similar in size to laboratorydiet larvae, but their juvenile rudiments were significantlysmaller. To assess food availability in each food treatment,we compared the concentration of chlorophyll (Chl) a, b andc in natural seawater from each depth and in D. tertiolectaculture in filtered seawater. Natural seawater collected fromthe surface had the highest concentration of Chl a and c, whereasChl b was not significantly different between treatments. IncreasedChl concentrations in the surface water are likely due to higherconcentrations of diatoms and dinoflagellates, which are typicallynot high-quality food items for echinoid larvae. Our resultssupport a hypothesis that echinoid larvae in the water columnmay be limited by food quality.     

A COMPARATIVE STUDY OF LACUNA VINCTA AND LACUNA PALLIDULA (GASTROPODA: PROSOBRANCHIA) IN LITTORAL ALGAL TURFS

A comparison is made of the number of individuals of Lacunavincta and L. pallidula associated with several red algae betweenJune 1978 and June 1980 at Cooskeen Cove, Bantry Bay, Ireland.Both are annuals and exhibit similar seasonal cycles of abundance.Planktonic larvae of L. vincta settle between eary May and July,resulting in summer maxima followed by heavy mortality. Survivorshipcurves of L. vincta were similar in both 1978 and 1979. Juvenilemortality is very high resulting in less than 2% of the populationsurviving at commencement of the spawning period in January.In L. pallidula hatching occurs from April to July and populationstructure between April and September in G. stellata indicatesa succession of cohorts which remain for only short periodsbefore moving to the adult habitat, Fucus serratus. Sex-ratioand sexual dimorphism in shell height was investigated in bothspecies. Mean growth rate of penis and shell for male L. vinctabetween October and January was compared for the 1978 and 1979populations. Measurements on L. pallidula are also given. Acomparison of the spawn in both species was made. (Received 20 June 1981;     

闹羊花素类化合物对斜纹夜蛾幼虫表皮成分的影响及构效关系

从我国特有的高效杀虫植物闹羊花 Rhododendron molle G. Don中分离提纯了14个活性化合物,并研究了这些化合物对斜纹夜蛾Spodoptera litura幼虫表皮成分的影响及构效关系,为揭示闹羊花素类化合物的作用机制、优化结构及确定先导化合物提供了参考。通过IR,UV, NMR,MS等光谱鉴定了3个新化合物黄杜鹃素A, B, C (rhodomolin A, B,C)。结果表明: 闹羊花素Ⅲ（rhodojaponin Ⅲ）,黄杜鹃素A,羊踯躅素Ⅰ（rhodomollein Ⅰ）,黄杜鹃素B ,黄杜鹃素C,羊踯躅素ⅩⅧ (rhodomollein ⅩⅧ),木藜芦素Ⅲ (grayant oxin Ⅲ)和对照药剂印楝素（azadirachtin）的生长发育抑制活性明显高于其他化合物,以50 mg/L浓度浸渍叶碟饲喂斜纹夜蛾4龄幼虫后,虫重、蛹重以及羽化率均显著低于空白对照。处理后120 h,各化合物处理和空白对照试虫表皮几丁质相对含量为28.15%～35.18%,差异不显著。闹羊花素Ⅲ,黄杜鹃素A, B, C,羊踯躅素ⅩⅧ和印楝素处理显著降低试虫表皮总蛋白的相对含量,提高了表皮总脂肪的相对含量。进一步研究发现,闹羊花素 Ⅲ和印楝素处理后,试虫表皮水溶性蛋白、氢键结合蛋白和共价键结合蛋白相对含量显著降低,弱键结合蛋白相对含量显著提高,而对电价键结合蛋白相对含量无明显影响。闹羊花素 Ⅲ处理试虫表皮水溶性蛋白相对含量为对照的50%。闹羊花素类化合物对昆虫生长发育抑制作用不属于“几丁质合成抑制型”,而属于“内分泌干扰型 ”,显著降低表皮水溶性蛋白是其重要机制之一。构效关系定性分析表明,木藜芦烷类闹羊花素化合物基本结构中的C-2,3环氧基、C-6、C-10和C-14取代基结构对化合物的生长发育抑制活性具有重要意义。还讨论比较了闹羊花素类化合物与印楝素对昆虫生长发育抑制作用机 制的差异。     

不同食料植物对棉铃虫生长发育和繁殖的影响

报道了棉花、烟草、番茄和辣椒4种植物对棉铃虫Helicoverpa armigera生长发育和繁殖的影响。棉铃虫成虫喜欢在番茄上产卵,在辣椒上的着卵量最少。初孵幼虫喜选食嫩棉叶,选食辣椒嫩叶的虫数最少。4组幼虫取食嫩叶时的平均相对生长速率都有显著差异,顺序为棉叶组>烟叶组>番茄叶组>辣椒叶组。幼虫存活率以取食棉花时最高,取食番茄时最低。棉花组成虫的产卵量最高,烟草组的产卵量最低。取食棉花的棉铃虫种群增长的速度约为取食番茄时的14倍。6龄幼虫能有效利用和转化棉铃、烟草蒴果、辣椒果实,而对番茄果实的利用和转化效率较低。棉铃虫可分别以这4种植物的不同器官为食完成世代循环。其中,棉花是最适宜的寄主,辣椒和番茄是较不适宜的寄主。     

虫酰肼及其衍生物0593对家蚕的毒性及作用机理

为明确虫酰肼衍生物0593对家蚕Bombyx mori的毒性,本研究采用食下毒叶法测定了虫酰肼及其衍生物0593对家蚕的毒性,观察了亚致死浓度下对家蚕生长发育的影响,并测定了虫酰肼及其衍生物0593对家蚕幼虫体内保护酶的影响,对虫酰肼0593的作用机理进行了初步探索。结果表明：虫酰肼及其衍生物0593对2龄家蚕96 h的LC₅₀值分别为1.2863和0.3364 mg·L^-1,属高毒级药剂;虫酰肼及其衍生物0593在亚致死剂量下对家蚕的生长发育有明显的不利性,可使幼虫历期缩短0.5～2 d;处理组眠期体重、全茧量、蛹重和化蛹率与对照相比均显著降低;对4龄幼虫体内多酚氧化酶和几丁质酶也有较明显影响,虫酰肼及其衍生物0593处理家蚕,处理后6 h对体内多酚氧化酶有明显激活作用,12 h后表现出显著的抑制作用;虫酰肼及其衍生物0593对家蚕体内几丁质酶均有激活作用。0593对保护酶的影响较虫酰肼明显。结果提示虫酰肼及其衍生物0593对家蚕毒性高,对其生长发育和保护酶类均有不利性,不适合在桑园及其周边农田使用。     

粘虫中肠α-淀粉酶活性测定方法的参数优化

针对粘虫Mythimna separata中肠α-淀粉酶筛选了11种不同参数组合的3，5－二硝基水杨酸活性测定方法，并对其中最适组合的各个参数进行了优化。结果表明：在离体测定条件下，粘虫中肠α-淀粉酶活性的最优化测定参数为0.03 mol/L 磷酸盐缓冲液（pH 8.0，含有55 mmol/L NaCl）、温度45℃、吸收波长480 nm。Ca²⁺对α-淀粉酶活性具有抑制作用。该优化法能够显著降低粘虫、德国小蠊Blattella germanica、黄粉虫Tenebrio molitor、淡色库蚊Culex pipiens pallens和家蝇Musca domestica等昆虫α-淀粉酶的米氏常数K_m值，且粘虫和德国小蠊α-淀粉酶的V_max值增大，但黄粉虫、淡色库蚊和家蝇α-淀粉酶的V_max值均明显减小。结果说明，在该优化体系下，粘虫α-淀粉酶与底物的亲和力增强，最大反应速度增大，测定酶活性的准确性和灵敏度显著提高；同时该优化体系也可作为测定德国小蠊α-淀粉酶活性的优化方法，但不适合作为黄粉虫、淡色库蚊和家蝇α-淀粉酶的最优化测定方法。     

Predation by a carnivorous marine copepod, Euchaeta elongata Esterly, on eggs and larvae of the Pacific hake, Merluccius productus

The predatory behavior of the carnivorous marine copepod, adultfemale Euchaeta elongata Esterly, feeding on eggs and larvaeof the Pacific hake, Merluccius productus, was examined in thelaboratory and in a natural setting. E. elongata did not feedon eggs. Predation on larvae is believed to depend on larvalswimming behavior: (1) predation rates were low on early stageyolk-sac larvae which are inactive swimmers and are relativelyundetected by the predator; (2) rates were high on middle stageyolk-sac larvae which are more active swimmers yet have a poorlydeveloped escape response; and (3) rates were low on largerlarvae which are able to escape the predator effectively. Starvedhake larvae were more vulnerable to predation due to a poorescape ability although they were less active and not easilydetected. The presence of naturally occurring alternative prey,Pseudocalanus sp., depressed the rate of E. elongata predationon hake larvae. In an analysis of field data, hake larvae andE. elongata were found to occupy the same depths in Dabob Bay.A high percentage of E. elongata collected had apparently beenfeeding on hake larvae, as indicated by the presence of pigmentsin their guts. Survival of hake larvae in late spring appearsto be relatively poor compared with early spring; poorer survivalin late spring may be due partly to an increase in the abundanceof invertebrate predators, such as E. elongata. ^*Current address: Northwest and Alaska Fisheries Center, 2725Montlake Blvd, Seattle, WA 98112, USA.     

Avermectin类农药对美洲斑潜蝇的生物活性

Avermectin类农药对美洲斑潜蝇Liriomyzasattvae Blanchard生物活性的室内研究结果表明： 揭阳霉素对美洲斑潜蝇1、2、3龄幼虫的LC₅₀分别是1.54×10^-4 g/L、3.73×10^-4 g/L、1.99×10^-3g/L;害极灭对上述幼虫的LC₅₀分别是1.48×10^-4g/L、3.68x10^-4 g/L和1.97×10^-3 g/L。美洲斑潜蝇幼虫对Avermectln类农药以1龄最敏感,其中揭阳霉素对3龄幼虫的LC₅₀是1龄的12.9倍。揭阳霉素对雌成虫24 h、48 h的LC₅₀分别是3.12×10^-3 g/L和2.08×10^-3 g/L,其对美 洲斑潜蝇取食、产卵拒避持效期分别是4-8天和10天。使用浓度0.005 g/L揭阳霉素处理6天、8天和10天后接虫,幼虫的存活率分别是0、16.13%和28.07%。田间使用浓度0.005 g/L的揭 阳霉素和0.0045 g/L几的害极灭分别处理,6天后的校正虫口减退率分别为91.0%和90.9%,两者差异不显著,而使用浓度0.0067 g/L揭阳霉素处理,6天后校正虫口减退率为93.6%。     

闭弯尾姬蜂与菜蛾盘绒茧蜂寄生菜蛾幼虫时的种间竞争

在室内25℃下,以菜蛾3龄初幼虫作寄主,研究了菜蛾盘绒茧蜂Cotesia plutellae和半闭弯尾姬蜂Diadegma semiclausum的种间竞争。当寄主供2种蜂同时产卵寄生时,2种蜂各自的寄生率与其单独寄生时无显著差异,合计寄生率比一种蜂单独存在时有所提高,但差异不显著。2种蜂均能产卵寄生已被另一种蜂寄生了的寄主幼虫。当寄主被2种蜂寄生的间隔时间很短（少于10 h）时,所育出的蜂绝大部分（80%以上）为绒茧蜂;当寄主先被绒茧蜂寄生,并饲养2天以上再供弯尾姬蜂寄生时,所育出的全为绒茧蜂;当寄主先被弯尾姬蜂寄生,并饲养2天以上再供绒茧蜂寄生时,寄主幼虫绝大部分不能存活,只有少部分能育出寄生蜂,且多为弯尾姬蜂。当2种蜂的幼虫存在于同一寄主体内时,2种蜂的发育均受到另一种蜂的抑制;绒茧蜂1龄幼虫具有物理攻击能力,能将弯尾姬蜂卵或幼虫致死。这些结果表明,菜蛾盘绒茧蜂与半闭弯尾姬蜂在同一寄主中发育时,前者具有明显的竞争优势。     

Morphological and Physiological Responses of Echinoderm Larvae to Nutritive Signals

SYNOPSIS. Echinoid larvae have been found previously to developshorter arms as phytoplankton concentrations increase. In thepresent study, the skeletal dimensions of larvae of the seaurchins Lytechinus pictus and Strongylocentrotus purpuratuswere measured after exposure to dissolved organic compoundsin seawater. The presence of glucose or individual amino acids(at 1 or 2 µM), a mixture of 16 different amino acids(100 nM each), or algal exudate resulted in larvae with shorterarms (by 12 to 88%), relative to larvae in seawater with noadditions. Larvae exposed to mixtures of amino acids also hadchanges in the constituents of their internal free amino acidpools (as determined by HPLC). For another echinoid, Dendrasterexcentricus, amino acid transport (T, from 500 nM) by individuallarvae (n = 47) scaled to arm length (L) as follows: T = 2.06L^0.81(0.81 ± 0.26,95% confidence intervals). Mass (M) andmetabolic rate (MR) did not scale in the same manner (as transport)to arm length for larvae of the echinoid Centrostephanus coronatus(MR = 148L^1.51; M = 1.7L^2.01). These characteristics may scaleto arm length independently from transport rate under certainconditions. Larvae of echinoderms respond morphologically to"signals" in their environment that may indicate the availabilityof dissolved and paniculate nutrients. This in turn will haveconsequences for their ability to take up and metabolize thesenutrients. The response may be mediated by surface receptorsfor dissolved organic compounds, or by changes in the sizesof intracellular substrate pools.     

盐酸吗啡对大头金蝇生长发育的影响及其对死者死亡时间推断的意义

用盐酸吗啡注射家兔,处死后用家兔的不同组织饲养大头金蝇 Chrysomya megacephala初孵幼虫,研究吗啡剂量对大头金蝇幼虫生长的影响及其在法医学中推断死者死亡时间方面的应用。结果显示,在28℃下,取食处理组兔肉和肝脏的大头金蝇幼虫的体长和体重均于孵化后28 h开始在不同程度上大于对照组幼虫,这种趋势一直持续到幼虫末期。在实验的剂量范围内（2.67～10.66 mg/kg）,吗啡可促进大头金蝇幼虫的生长。根据大头金蝇幼虫体长和体重推断死者死亡时间时,吗啡的这种影响可使推断值产生的最大偏差达18h。     

在高CO2浓度下生长的小麦对棉铃虫生长发育和繁殖的影响

通过室内饲养实验研究了在高CO₂浓度（738.8±25.7μL/L）中生长的小麦对棉铃虫 Helicoverpa armigera (Hübner)生长发育,繁殖以及营养效应的影响。结果表明： （1）取食高CO₂浓度大气中生长的麦粒的棉铃虫对食料的取食量和粪便排泄量增加,与对照相比,取食量和粪便排泄量分别增加46.3%（P<0.05）和37.8%;（2）大气CO₂浓度增加影响了麦粒中的营养成分的含量,其中,可溶性蛋白、游离氨基酸、葡萄糖和总糖的含量及碳氮比(C∶N)都显著增加,果糖和粗蛋白的含量都显著降低;（3）大气 CO₂浓度升高所导致的麦粒营养成分的变化影响了棉铃虫幼虫的食物利用效率,与对照组相比,棉铃虫幼虫对食物的毛转化率和净转化率分别降低27.2%和25.4%,对食物的相对取食率则显著提高58.8%（P < 00.1）。据此推测,未来高CO₂浓度的大气环境会降低春小麦的营养价值,从而影响棉铃虫的生长发育,加重其对小麦的危害。     

Unseasonable Latewood and Incrusted Pits are the Cause of Drying in Pinus halepensis and P. eldaricaInfested with Matsucoccus josephi

Mendel, Z. and Liphschitz, N. 1988. Unseasonable latewood andincrusted pits are the cause of drying in Pinus halepensis andP.eldarica infested with Matsucoccus josephi.—J. exp. Bot.39: 951–959. A study was made of the effects of Matsucoccus josephi (Insecta:Homoptcra: Margarodidae) on (a) water transport in Pinus halepensis,using a basic fuchsin solution and (b) the structural changesof the xylem of Pinus halepensis, P. brutia andP. eldarica usinga scanning electron microscope.Examinations were carried outin artificially and naturally infested plants. Transport ofthe fuchsin dye was arrested below the affected zone of heavilyinfested shoots, but reached the shoot apex through sparselyinfested segments or via segments heavily infested with thefirst larval stage. Heavily infested stem sections of P. halepensisand P.eldarica were characterized by narrow pits and incrustedpit membranes. In non-infested shoots and those infested withfirst or early second-scale larvae in both these species andheavily infested P. brutia shoots, there were typical earlywoodpits with wide pit apertures and thin membranes. It is suggestedthat blocking of water ascent in P. halepensis and P. eldaricastarts when female second-instar larvae complete their developmentand only when population density is relatively high. Therefore,it is considered that the accelerated drying of the growth ofP. halepensis and P. brutia is directly related to the narrowingof the pit apertures, which resembled those of latewood pitsalthough produced early in the season. The absence of changesin the xylem of heavily infested P brutia may explain why thisspecies tolerates a high density of M. josephi. The structuralmodification of the xylem caused by the scale may be relatedto imbalance in plant growth hormones which are either transmittedwith the insect saliva or formed in the plant by salivary enzymes. Key words: Xylem, Matsucoccus, Pinus     

两种虫酰肼类新化合物对五种鳞翅目害虫的生物活性

为了比较虫酰肼及其衍生物对鳞翅目 5 种害虫的毒力 ,以虫酰肼为对照药剂,分别采用浸叶法、浸虫法和点滴法测定了虫酰肼衍生物 0593 (Ⅲ f) 和 0673 对甜菜夜蛾 Spodoptera exigua（Hübner）、斜纹夜蛾 Prodenia litura (Fabricius)、小菜蛾 Plutella xylostella (Linnaeus)、棉铃虫 Helicoverpa armigera(Hübner)和玉米螟 Ostrinia furnacalis(Guenée)的毒力;通过浸叶法系统研究了虫酰肼和虫酰肼衍生物 0593 对甜菜夜蛾生长发育的影响。结果表明：0593 和 0673 对甜菜夜蛾 4 龄幼虫的触杀毒力分别是虫酰肼的 11.3 倍和 7.4 倍,对斜纹夜蛾 4 龄幼虫触杀毒力分别是虫酰肼的 30.4 倍和 24.7 倍,对小菜蛾 3 龄幼虫浸虫处理的毒力分别是虫酰肼的 4.7 倍和 4.5 倍 ,对棉铃虫3龄幼虫的触杀毒力分别是虫酰肼的 15.5 倍和 15.2 倍,对玉米螟 4 龄幼虫的触杀毒力分别是虫酰肼的 1.3 倍和 2.0 倍,较虫酰肼的毒力都有很大提高,而0593 和 0673 对 5 种害虫的毒力差异不显著。用虫酰肼和 0593 处理甜菜夜蛾 2 龄幼虫,都能导致存活幼虫陆续死亡;化蛹率和正常蛹数降低;成虫羽化率、单雌产卵量和卵的孵化率显著减少,对后代的繁殖力影响显著;在相同处理浓度下,0593 较虫酰肼对甜菜夜蛾后代繁殖力的不利影响更大。因此,0593 是较虫酰肼杀虫毒力更高、对生长发育和繁殖力不利影响更大的药剂,开发应用价值很大。     

Capelin larvae (Mallotus villosus) and community structure of zooplankton off the coast of northern Norway

Capelin larvae (Mallotus villosus) and mesozooplankton werecollected in May 2001 in the southern part of the Barents Sea.During the period of hatching and first feeding, capelin larvaeexperience high mortality rates. In order to understand theunderlying mechanisms influencing larval survival, we monitoreda selected site for 10 days using a variety of different samplingapproaches. Hydrological parameters conductivity–temperature–depth–fluorescence(CTDF) were recorded and zooplankton samples obtained simultaneouslyusing MOCNESS at three time periods. The mesozooplankton consistedessentially of copepods (85), dominated by Calanus finmarchicus.The zooplankton community consisted of different assemblagesderived from different areas (i.e. different water masses; Atlanticand coastal). Capelin larvae were found in surficial coastalwaters. Copepod nauplii and C. finmarchicus were less abundantin coastal waters where small copepodites (such as Acartia spp.and Temora longicornis) were found together with early stagesof coastal invertebrates that are possible prey for capelinlarvae. We suggest that capelin larvae base their foraging onsmall prey organisms frequently found among the coastal zooplanktonand that these larvae are less dependent on the propagationof the recruiting generation of C. finmarchicus present fromApril to June.