栎旋木柄天牛取食与产卵选择性研究

栎旋木柄天牛Aphrodisium sauteri(Matsushita)是南方地区栎林的重要害虫之一。对三清山高海拔栎林中栎旋木柄天牛Aphrodisium sauteri Matsushita幼虫危害状况、成虫补充营养习性、成虫的产卵选择等情况进行了调查。结果表明,栎旋木柄天牛对寄主树木的危害具有明显的区域性,海拔、坡向、温湿度等对虫害发生有较大影响。主要危害小叶青冈(Cyclobalanopsis myrsinaefolia),轻度危害多脉青冈(C.multinervis)、甜槠(Castanopsis eryei)、木荷(Schima superb)等。野外调查和室内试验发现,成虫有取食液体物质的习性,不同营养液对成虫的取食次数具有显著影响。室内产卵选择试验,成虫在8种供试树种的自然枯枝疤痕凹陷处或枝皮裂缝间隙内产卵,不同树种上的产卵量存在显著差异。栎旋木柄天牛对枝条选择性的室内、外研究结果存在差异:室内试验表明,3种寄主树木的不同枝径水平上的产卵量没有显著差异。林间调查表明,栎旋木柄天牛产卵处的高度与小叶青冈胸径之间存在显著的线性相关,成虫更趋向于在枝径15～25mm、皮厚1～2mm的枝条产卵。对小叶青冈测量分析表明,枝条直径与枝皮厚度间存在着极显著的线性相关。     

油茶新害虫南方锦天牛形态特征和生物学特性研究(英文)

南方锦天牛Acalolepta speciosa属鞘翅目天牛科沟胫天牛亚科锦天牛属昆虫,是近年在油茶Camellia oleifera上新出现的一种蛀干害虫.本文首次对该天牛的形态特征,包括雌雄生殖器结构进行了详细的描述,以期为该虫的鉴定提供可靠的依据,并首次报道了该虫生物学特性.     

云斑天牛对补充营养寄主的选择性

通过林间调查和室内选择性试验,研究云斑天牛Batocera horsfieldi(Hope)成虫在补充营养阶段对多种寄主植物的选择性。林间调查结果表明,云斑天牛成虫对法国冬青(V.awabuki)和光皮桦(B.luninifera)有较强的嗜食性,林间最高取食选择率分别为100%和92.4%。利用"Y"型嗅觉仪测定云斑天牛成虫对法国冬青、核桃(Jugians regia L.)、光皮桦和杨树(Populus tomentosa)等寄主挥发物的行为反应,生测结果与林间调查及室内选择结果一致,法国冬青和光皮桦的挥发物对云斑天牛引诱效果明显,并且枝条挥发物引诱力高于叶片挥发物,引诱效果最佳的组合为:采用蒸馏法,用二氯甲烷提取的冬青枝叶粗提物;采用浸提法,用乙醚提取的冬青和光皮桦枝叶粗提物和二氯甲烷分别提取的冬青枝和叶的粗提物。     

松褐天牛产卵刻痕在黑松树干上分布规律的研究

调查和分析了松褐天牛Monochamus alternatusHope的产卵刻槽在寄主植物黑松上的分布情况,结果表明：产卵刻槽分布与寄主胸径和树高有一定的相关关系,黑松树干胸径在9～15 cm之间,树高在4～7 m之间最适合天牛产卵危害,其中在胸径9～13 cm范围内产卵刻槽数量最多,在此范围的寄主受天牛为害最重。天牛在胸径＞17 cm或树高＞7 m时,没有产卵刻槽分布。产卵刻槽集中分布于树干1～2 m位置,3 m以上很少有刻槽分布,同时,天牛产卵多在光线充足的地方,其中南面产卵刻槽数量最多。     

黄斑星天牛成虫下颚须和下唇须的化学感受器

<正> 黄斑星天牛 Anoplophora nobilis Gang-lbauer是我国西北地区,尤其是陕、甘、宁三省(区)杨树的毁灭性蛀干害虫。由于该虫成虫对寄主树有着明显的选择性,并且,越来越多的研究表明,该虫成虫下颚须和下唇须在寄主选择(取食和产卵)上起着重要作用。另     

杨树和核桃树两种寄主植物上云斑天牛产卵刻槽的分布

为了对比杨树和核桃树两种寄主植物上云斑天牛成虫产卵方式的差异,本研究于2013年通过林间定期调查的方法得到了云斑天牛成虫在两种寄主植物上的产卵规律。杨树上,产卵刻槽沿树干一周,卵产于韧皮部或者木质部;核桃树上,产卵刻槽沿着树干上下排列,卵产于树皮缝内。两种寄主植物上,产卵刻槽的数量均随着树干高度的增高而减少,但在不同高度范围内没有差异(df=2,6,F=0.866;df=2,15,F=0.071),且在不同方向上也没有差异(F1=0.691;F2=0.646;F3=0.994)。另外还调查了寄主植物胸径与产卵刻槽数量之间的关系,结果表明,产卵刻槽不会随着寄主植物胸径的增大而增多。这些研究结论为进一步完善云斑天牛的生物学特性提供了理论依据。     

星天牛成虫的取食节律及对两种苦楝粗提物行为趋性

星天牛(Anoplophora chinensis Forster)是林业上危害性极大的一种蛀干害虫,行为调控是控制星天牛的重要手段。为了研发星天牛成虫植物源诱杀剂,观测了星天牛的取食行为节律,通过Y型嗅觉仪行为生测、笼养法选择趋性试验及林间诱捕试验测定了不同苦楝粗提物对星天牛成虫的引诱效果。结果表明:星天牛成虫在光照及黑暗条件下(光周期15L∶9D)均存在取食行为,且两种条件下的取食量差异不显著(P>0.05);在光照条件下,雌成虫取食高峰出现在13:00—14:30,雄成虫无明显的取食高峰期。在室内,索式抽提法所得粗提物对星天牛成虫引诱效果较好,星天牛在经索式抽提法所得粗提物处理的滤纸上的平均停留时间(15.19±2.09 min)显著长于水蒸气蒸馏法所得粗提物(8.94±1.26 min,P<0.05);两种粗提物在林间均诱捕到星天牛成虫,其中索式抽提法所得粗提物平均每个诱捕器诱到2.0±0.58头,水蒸蒸馏气法所得粗提物平均每个诱捕器诱到3.0±1.15头,二者差异不显著(P>0.05)。     

桃红颈天牛成虫的交配行为及对不同寄主植物的栖落和产卵选择性

【目的】桃红颈天牛Aromia bungii是一种钻蛀性害虫,主要以蔷薇科果树和观赏树木为寄主。本研究旨在搞清楚桃红颈天牛成虫的交配产卵行为及其对不同寄主植物的栖落和产卵选择性。【方法】选择苹果Malus pumila、山樱花Prunus serrulata var. spontanea、桃Prunus persica、西府海棠Malus micromalus、毛樱桃Prunus tomentosa、秋子梨Pyrus ussuriensis、杏Prunus armeniaca和红叶李Prunus cerasifera var. atropurea 8种寄主植物木段,构建为成虫的活动场所,观察桃红颈天牛成虫的交配和产卵行为,并测定桃红颈天牛成虫在不同寄主木段上的栖落数量和产卵量。【结果】桃红颈天牛成虫的交配行为分为避让、打斗和交配3种行为。交配过程可分为相遇抱对、插入输精、交配后陪护3个阶段。桃红颈天牛雌虫产卵时无刻槽行为,喜欢将卵产于较为狭窄的缝隙中。雌虫偏好在桃树木段上栖落,雄虫则偏好在毛樱桃木段上栖落。李亚科李属的桃是桃红颈天牛最喜欢的产卵寄主木段,而雌虫在苹果亚科的苹果、海棠和秋子梨木段上产卵极少。相关性分析结果表明雌虫在寄主木段上的栖落数量与产卵量占比间存在正相关性,雄虫在寄主木段上的栖落数量与雌虫在寄主木段上的栖落数量之间也存在正相关性。【结论】桃红颈天牛雌成虫最喜欢桃树木段,雄虫对寄主植物的选择性与雌虫并不完全相同。     

B型烟粉虱为害烟草后对斜纹夜蛾成虫产卵和幼虫取食行为的影响

为明确外来入侵害虫B型烟粉虱取食诱导的烟草防御反应对斜纹夜蛾的影响,探讨其与斜纹夜蛾的种间竞争机制,在室内条件下研究了B型烟粉虱取食后的烟草对斜纹夜蛾成虫产卵选择、幼虫取食选择、拒食作用和其他取食行为指标的影响.结果表明:斜纹夜蛾成虫在B型烟粉虱为害后的植株上的落卵量较对照植株降低了40.9%.B型烟粉虱为害的虫体叶对斜纹夜蛾初孵化幼虫具有明显的驱避作用,而中间叶和系统白脉叶有一定的吸引作用,心叶不影响幼虫对寄主的选择性.B型烟粉虱为害叶片对斜纹夜蛾幼虫具有显著的拒食作用,虫体叶拒食作用明显大于系统白脉叶片.与对照相比,B型烟粉虱为害的虫体叶和系统白脉叶降低了斜纹夜蛾幼虫单位时间取食次数或取食比例,虫体叶还显著延长了幼虫开始取食时间,总取食面积显著减少.表明B型烟粉虱为害烟草对斜纹夜蛾成虫产卵和幼虫取食行为均产生不利影响.研究结果对了解烟田害虫种群变动规律和指导害虫治理具有较大意义.     

松墨天牛在秦巴林区不同寄主上的危害规律

松墨天牛Monochamus alternatus是次期性蛀干害虫,也是松材线虫病的主要传播媒介,廓清该害虫在秦巴林区不同寄主上的危害程度和发生规律,对于控制松材线虫病的扩散蔓延具有重要意义.本研究对秦巴林区遭受松材线虫病严重危害的3种主要松树(油松Pinus tabuliformis、华山松P.armandii和马尾松P.massoniana)进行了冬季疫木野外解析,并在统计不同胸径、不同高度疫木树干上松墨天牛侵入孔和幼虫数量的基础上,采用聚集度指标分析方法,对该害虫在不同寄主上的危害差异进行了比较研究.结果表明,松墨天牛在3种寄主上的危害程度具有显著差异,以华山松受害最重,其次分别为马尾松和油松;越冬幼虫在油松上主要危害皮下1～2 cm的边材;在华山松和马尾松上危害比较多样,以髓心部位受害最重,其后依次为心材、边材和树皮;在油松和华山松上,松墨天牛主要在树干7m以下部分危害,而在马尾松上主要危害树干7m以上部分,且虫口数量均与寄主胸径呈显著正相关.松墨天牛侵入孔和越冬幼虫在不同寄主树干上均呈聚集性分布.本研究揭示了松墨天牛在秦巴林区3种主要寄主上的危害规律,对于进一步开展大尺度地理范围松墨天牛的寄主选择性及危害规律研究提供了基础信息,也为秦巴林区松墨天牛的有效防治和松材线虫病的蔓延控制提供了新的重要信息.     

Egg and larval load assessment and its influence on oviposition behaviour of the leaf beetle Galerucella nymphaeae

The oviposition behaviour of the water-lily beetle Galerucella nymphaeae was examined. This species is a specialist herbivore on the floating leaves of nymphaeids Nymphaeaceae and especially on the yellow water-lily, Nuphar lutea. Females lay their eggs in clutches on the leaves, and after hatching, the larvae feed on the leaves. The quality of the leaves decreases quickly after the larvae hatch, and eventually the leaves will sink below the water surface, whereupon the eggs, 1st-instar larvae and pupae are killed by drowning. The influence of conspecific eggs, larvae and feeding tracks on the oviposition preferences of the beetles was tested. Females were allowed to choose between fresh leaves and leaves with conspecific eggs and larvae as well as between leaves with larvae and leaves with feeding tracks but no larvae. An attempt was also made to determine whether eggs and larvae affect the oviposition rate of females when they are not given the opportunity to oviposit on untouched leaves. The results indicate that females tended to avoid leaves with conspecific larvae or to exhibit a decreased oviposition rate on such leaves. Females also avoided conspecific eggs, although the oviposition rate was not influenced by the presence of conspecific eggs. When females were allowed to choose between leaves with larvae and leaves with feeding tracks, possible discrimination against leaves with larvae just fails to reach the 5% level.     

Feeding damage by larvae of the mustard leaf beetle deters conspecific females from oviposition and feeding

Herbivorous insects may be informed about the presence of competitors on the same host plant by a variety of cues. These cues can derive from either the competitor itself or the damaged plant. In the mustard leaf beetle Phaedon cochleariae (Coleoptera, Chrysomelidae), adults are known to be deterred from feeding and oviposition by the exocrine glandular secretion of conspecific co-occurring larvae. We hypothesised that the exocrine larval secretion released by feeding larvae may adsorb to the surface of Chinese cabbage leaves, and thus, convey the information about their former or actual presence. Further experiments tested the influence of leaves damaged by conspecific larvae, mechanically damaged leaves, larval frass and regurgitant on the oviposition and feeding behaviour of P. cochleariae. Finally, the effect of previous conspecific herbivory on larval development and larval host selection was assessed. Our results show that (epi)chrysomelidial, the major component of the exocrine secretion from P. cochleariae larvae, was detectable by GC-MS in surface extracts from leaves upon which larvae had fed. However, leaves exposed to volatiles of the larval secretion were not avoided by female P. cochleariae for feeding or oviposition. Thus, we conclude that secretion volatiles did not adsorb in sufficient amounts on the leaf surface to display deterrent activity towards adults. By contrast, gravid females avoided to feed and lay their eggs on leaves damaged by second-instar larvae for three days when compared to undamaged leaves. Mechanical damage of leaves and treatment of artificially damaged leaves with larval frass or regurgitant did not affect oviposition and feeding of P. cochleariae. Since no adverse effects of previous herbivory on larval development were detected, we suggest that female P. cochleariae avoid Chinese cabbage leaves damaged by feeding larvae for other reasons than escape from competition or avoidance of direct negative effects that result from consuming induced plant material.     

Could hosts considered as low quality for egg-laying be considered as high quality for host-feeding?

When parasitoid females encounter a host, they can either lay an egg and thus invest in current reproduction or feed on the host and thus invest in future reproduction. However, hosts could have different values according to their parasitized status. Whereas already parasitized hosts represent poor quality for egg-laying, they could have a high nutritive value for feeding. Moreover, the optimal strategy adopted generally depends on the females’ physiological state. In this study, the impact of the females’ physiological state on their reproductive strategies was investigated in the solitary parasitoid Anisopteromalus calandrae. We analysed how their age and diet influenced (i) the use of hosts (feeding vs. oviposition) and (ii) host selection (previously parasitized vs. unparasitized). Our results show that both age and diet influence the reproductive strategy of A. calandrae females: old females fed with the poorer diet laid fewer eggs and made more host-feeding than others. Females also showed a preference for already parasitized hosts for feeding. This strategy cannot be explained by the nutritive value of haemolymph, as parasitized hosts carry fewer lipids. However, as parasitized hosts are also paralyzed, it could be less costly to feed on them than on unparasitized hosts.     

Effects of leaf damage on oviposition choice in an invasive paropsine beetle

In 2007, an invasive paropsine beetle, Paropsisterna nr. gloriosa Blackburn, caused severe defoliation of Eucalyptus in mixed‐species foliage plantations in south‐west Ireland. At many of the plantations, Eucalyptus parvula L.A.S. Johnson & K.D. Hill was the most heavily damaged species while Eucalyptus pulverulenta Sims was generally resistant to the beetle. However, at the most heavily damaged site beetles moved to feed on E. pulvarulenta presumably during periods when suitable foliage (new leaves) of E. parvula had been severely depleted. The present study examines factors underlying shifts in oviposition from the preferred to non‐preferred host. In choice and no‐choice experiments, P. nr. gloriosa laid more eggs directly on new E. parvula foliage compared with new E. pulverulenta foliage. However, in choice experiments where new E. parvula foliage was unavailable (but old foliage available), more eggs were laid on new E. pulverulenta foliage. The potential for prior feeding damage to stimulate or deter oviposition on either host was also examined. Prior damage to new and old E. parvula leaves increased egg‐laying directly on the damaged foliage; however, prior damage to E. pulverulenta may have inhibited oviposition. The results suggest that in mixed‐species plantations, facilitation of oviposition on preferred hosts through prior feeding damage helps maintain the relative resistance of E. pulverulenta against P. nr. gloriosa, even under high beetle densities. However, the vulnerability of E. pulverulenta will increase where suitable age‐classes of preferred‐host foliage are severely depleted or unavailable.     

绿盲蝽成虫的产卵行为与习性

本文观察记录了绿盲蝽Apolygus lucorum(Meyer-Dür)雌性成虫的产卵行为,并研究了其产卵习性。结果发现,绿盲蝽卵主要产在植物组织中,单次产卵平均历时31.4 s;产卵主要在夜间进行,白天的产卵量仅占全天的6.6%。成虫交配后主要产可育卵,后期偶产不育卵;而未交配个体大部分能产不育卵。在25℃下,成虫从7日龄起开始产卵,16日龄前产卵量占总产卵量的48.9%;17～40日龄间产卵量约占40%。在棉株上,约65%卵分布在中部(第4到第7果枝),同时94.3%卵集中在叶柄、叶脉、蕾柄和铃柄上。     

柳蓝叶甲的生物学特性室内观察

在实验室条件下(27±0.5℃,12 D:12 L)研究了柳蓝叶甲Plagiodera versicolora的生物学特性。结果表明,幼虫每隔2~3 d蜕皮1次,共蜕皮2次。成虫产卵前期4 d,世代周期17 d。产卵具有一定的周期性,约10 d为1个周期。叶龄对幼虫的生长发育和成虫的产卵行为有极显著的影响。当幼虫以成熟叶为食料时,其生长发育速率明显减慢,各龄期延长,蛹重较轻;成虫以成熟叶或老叶为食料时产卵几乎完全被抑制,而以幼叶为食料时几乎每天均能产卵。此外,柳蓝叶甲产出卵表面化合物对产卵行为有极为显著的影响。卵表面的有机提取物对成虫产卵具有显著的引诱作用;相反,卵表面的水提取物对产卵有一定的驱避作用。     

Preference for plants damaged by conspecific larvae in ovipositing cabbage root flies: influence of stimuli from leaf surface and roots

In laboratory dual-choice assays females of the cabbage root fly, Delia radicum, prefer for oviposition plants with roots damaged by conspecific larvae to undamaged controls. Cauliflower and kale plants were inoculated with root fly eggs (25 per plant) and the hatching larvae were allowed to feed on the roots for various periods of time (1–17 days). After 4 (cauliflower) or 5 (kale) days of larval feeding the oviposition preference was most pronounced and flies laid between 64% and 68% of their eggs near plants with damaged roots. Later, with increasing damage but fewer surviving, and thus actively feeding, larvae, the magnitude of the preference declined. The preference for plants already damaged by conspecific larvae may contribute to the previously observed aggregated distribution of D. radicum eggs in Brassica crop fields.Further experiments revealed that the sensory cues inducing this oviposition preference originate from the complex consisting of the damaged roots, the surrounding substrate (soil) and associated microbes, rather than from the aerial plant parts. In choice assays using the root-substrate complex of damaged and control plants (aerial parts removed), the observed preference for damaged roots was similar to that found for the entire plant but was more pronounced. The damaged roots alone, compared to control roots, received up to 72% (cauliflower) and 75% (kale) of the eggs. By contrast, surrogate leaves sprayed with methanolic leaf surface extracts from the most preferred plants which had been damaged were not discriminated from surrogate leaved sprayed with extracts of the respective control plants. Analysis of glucosinolate levels in methanolic leaf surface extracts revealed that root damage resulted in enhanced concentrations of indole-glucosinolates on the leaf surface in kale but not in cauliflower. Although indole-glucosinolates are oviposition stimulants for the cabbage root fly, the induced changes were apparently too small to influence oviposition behaviour.     

Sex allocation in a field population of an autoparasitoid

Autoparasitoid wasps lay fertilized eggs in homopteran nymphs, and these eggs develop into female primary parasitoids. Unfertilized, male-producing eggs are laid in immatures of the wasps' own or another primary parasitoid species; males then develop as secondary or hyperparasitoids. In the population of Encarsia pergandiella studied in Ithaca, NY, fertilized eggs were laid in the nymphs of the whitefly Trialeurodes packardi (primary hosts) and unfertilized eggs were laid almost exclusively in pupal females of their own species (secondary hosts). In the two years the population was studied, secondary hosts were always much less abundant than primary hosts at both sites. However, secondary hosts were parasitized at a significantly greater rate than primary hosts. In a laboratory experiment, the encounter rate of females with primary and secondary hosts was not significantly different. Moreover, there was no evidence from the field that wasps found leaves bearing secondary hosts more frequently than leaves without secondary hosts. Dissections of field-collected females showed them to be mated, and thus capable of laying both unfertilized and fertilized eggs. These results suggest that wasps did not encounter secondary hosts at a greater rate, nor were they constrained to lay unfertilized eggs, but rather secondary hosts were preferred. The oviposition sex ratios were influenced by the proportion of secondary hosts, but were less female-biased than would be predicted from the proportion of secondary hosts alone. The results do not support the predictions of Godray and Waage (1990) for either strictly host-limited autoparasitoids (sex ratio should reflect the proportion of secondary hosts) or for egg-limited autoparasitoids (sex ratio should be equal, and independent of the proportion of secondary hosts).     

Impact of mating status on egg-laying and superparasitism behaviour in a parasitoid wasp

Most parasitoid female wasps can distinguish between unparasitized and parasitized hosts and use this information to optimize their progeny and sex allocation. In this study, we explored the impact of mating on oviposition behaviour (parasitism and self‐ and conspecific superparasitism) on both unparasitized and already parasitized hosts in the solitary parasitoid wasp Eupelmus vuilleti (Crw.) (Hymenoptera: Eupelmidae). Virgin and mated females had the same oviposition behaviour and laid eggs preferentially on unparasitized hosts. The sex ratio (as the proportion of females) of eggs laid by mated females in parasitism and conspecific superparasitism was 0.67 ± 0.04 and 0.57 ± 0.09, respectively. Likewise, females laid more eggs in conspecific superparasitism than self‐superparasitism under our experimental conditions. These experiments demonstrate that E. vuilleti females can (i) discriminate between unparasitized and parasitized hosts and adapt the number of eggs they lay accordingly, and (ii) probably discriminate self from conspecific superparasitized hosts. Finally, mating does not appear to influence the host discrimination capacity, the ovarian function, or the oviposition behaviour.     

Diamondback moth oviposition: effects of host plant and herbivory

The oviposition behaviour of Plutella xylostella L. (Lepidoptera: Plutellidae) on Chinese cabbage (Brassica rapa L. Pekinensis, cv. Wombok), canola (Brassica napus L. cv. Thunder TT), and cabbage (Brassica oleracea L. Capitata, cv. sugarloaf) (Brassicaceae) was studied in the laboratory. In no‐choice experiments moths laid most eggs on the stems and lower three leaves of cabbage plants, the lower three leaves of canola plants, but on the upper three leaves of Chinese cabbage plants. The effects of conspecific herbivore damage to foliage could be replicated by mechanical damage. When foliage was damaged, injured cabbage and canola plants were preferred for oviposition over intact conspecifics, whereas injured Chinese cabbage plants were less preferred than intact conspecifics. However, when root tissue was damaged, intact cabbage and canola plants were preferred over injured conspecifics, whereas moths did not discriminate between root‐damaged and intact Chinese cabbage plants. Injury to upper leaves significantly affected the intra‐plant distribution of eggs. In cabbage and canola plants, injury to leaf 6 significantly increased the number of eggs laid on this leaf, resulting in a significant decrease in the number of eggs laid on the lower foliage/stem of plants, whereas in Chinese cabbage plants it significantly decreased the number of eggs laid on leaf 6. Following oviposition on intact plants, neonate larvae established the vast majority of feeding sites on leaves 5–8 in all three host plants, indicating that larvae moved a considerable distance from preferred oviposition sites in cabbage and canola plants. The growth rate of neonates fed on leaf‐6 tissue was significantly greater than that of those fed on leaf‐1 tissue; >90% of larvae completed development when fed exclusively on leaf‐6 tissue but no larvae completed development when fed exclusively on leaf‐1 tissue. The study demonstrates the complex and unpredictable interactions between P. xylostella and its host plants and provides a basis from which we can begin to understand observed distributions of the pest in Brassica crops.