伞裙追寄蝇和双斑截尾寄蝇对草地螟的寄生特性

为认识寄生蝇对草地螟Loxostege sticticalis L.的寄生特性,调查了河北康保田间两种寄生蝇——伞裙追寄蝇Exorista civilis Rondani和双斑截尾寄蝇Nemorilla maculosa Meigen对草地螟各龄幼虫的寄生率、寄生部位及着卵量,并通过室内饲养对寄生蝇的存活率与寄主龄期、着卵部位及着卵量的关系进行了研究。结果表明： 两种寄生蝇在田间主要寄生草地螟5龄幼虫;寄生蝇可在每头寄主幼虫上着1～8粒卵不等,其中以1粒的居多（45.3%）,2粒的次之（33.6%）,但1头寄主幼虫中仅能羽化出1头寄生蝇;寄生蝇以寄生寄主幼虫头部和胸部较多,腹部较少,并且以寄生侧面居多,背面次之,腹面最少。寄生蝇的存活与寄主幼虫着卵量之间呈相关关系,在着卵量为1粒的寄主幼虫中,寄生蝇的存活率仅为66.7%,在着卵量为2粒及以上的寄主幼虫中,单头幼虫羽化出寄生蝇的比例为100%。     

草地螟寄生蝇与寄主间的关系及控害作用

草地螟寄生蝇是草地螟Loxotego stictialisL.的重要天敌,但其发生种类、控害作用尚不明确。通过室内饲养,结合历年田间调查对康保县草地螟寄生蝇种类、田间分布、寄生率及消长规律进行研究,结果表明康保县草地螟寄生蝇发生种类有5种。田间呈聚集分布,种群数量大,寄生率高,控害作用显著。对开展草地螟预测预报,保护利用天敌资源和综合治理提供了科学依据。     

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。     

温湿度对伞裙追寄蝇飞行能力的影响

[目的]草地螟Loxostege sticticalis L.是我国北方天然草原和人工草原上的一种重要害虫,伞裙追寄蝇Exorista civilis Rondani,是草地螟优势性寄生天敌之一,是控制草地螟发生为害及种群动态的重要因素。研究不同温度和湿度对伞裙追寄蝇飞行能力的影响,探索其飞行规律,可为利用伞裙追寄蝇田间寄生防控草地螟提供依据。[方法]通过昆虫飞行磨系统测定了不同温湿度梯度下伞裙追寄蝇雌雄蝇的飞行距离、时间、速度等飞行能力指标。[结果]不同温度条件下,伞裙追寄蝇在21℃飞行能力最佳,飞行距离、飞行时间、平均飞行速度分别为:5.4543 km、2.7392h、2.2469km/h;不同湿度条件下,湿度为40%时寄蝇飞行能力最好,飞行距离、飞行时间、平均飞行速度分别为:5.7043km、2.6594h、1.8327km/h。[结论]在一定温度范围内,伞裙追寄蝇的飞行能力在21℃时较好,随后其飞行能力随温度的升高而下降。在一定湿度范围内,伞裙追寄蝇的飞行能力在湿度为40%时飞最好,不同性别的伞裙追寄蝇飞行能力无显著差异。     

谈谈寄蝇的几种寄生方式

<正> 莫尼(Mesnil)曾主要根据成蝇外部形态同时结合寄生方式,把寄蝇科Tachinidae归纳成三大类: 1.蜉寄蝇族Phorocerini,该族大部分为大卵型寄蝇; 2.撒寄蝇族Salmaciini为微卵型奇蝇; 3.寄蝇族Tachinini(或称Larvaevorini)为伪胎生寄蝇。在他所分的各个族中,除有些个别种类与本族的其他种类迥然不同外,基本上能反映出寄蝇的各主要寄生方式。我们依据寄蝇产卵特性和侵入寄主体腔的途径,择要分两大类五种类型:一、“外侵入”类     

不同生境源的稻飞虱卵寄生蜂对寄主的选择和寄生特眭

稻飞虱重要卵寄生蜂缨小蜂Anagrus flaveolus、A optabilis和寡索赤眼蜂Oligosita aesopi、O.Naias均能在稻田和稻田周围的非稻田生境中生存。而.Ftaveolus为优势种。不同生境来源的卵寄生蜂有着不同的寄生和选择特性。缨小蜂A.Flaveolus能在飞虱科内转换寄主,但需1～2代的适应期。寄主卵对寡索赤眼蜂O.Aesopi的寄生有较大的影响,用褐飞虱和黑尾叶蝉诱集的O.Aesopi呼;不能交叉寄生。稻田内诱集的寄生蜂选择稻飞虱,而杂草地中诱集的缨小蜂则对飞虱T.Pusanus有一定的选择性。非稻田生境对保护稻飞虱卵寄生蜂有很大的作用,但对其寄生特性有较大的影响。     

伞裙追寄蝇的初步研究

近两年在广州郊区、肇庆、阳江、德庆等地调查,松毛虫害蝇主要有六种:伞裙追寄蝇(Exorista civilisRond.)、蚕饰腹寄蝇(Crossocosmia zebina Walk.)、家蚕追寄蝇(Exorista sorbillans Wied.)、松毛虫狭颊寄蝇(Carcelia bombylans rasella Bar.)、红尾追寄蝇(Exori-sta fallax Meig.)和棕尾别麻蝇(Boettcherisca peregrinaR.-D.)。前五种属寄蝇科,后一种属麻蝇科,主要寄生松毛虫的老龄幼虫。在低丘地带,十年生左右的松林中常以伞裙追寄蝇的寄生率为最高。 随着松毛虫生物防治的深入开展,我们对优势种伞裙追寄蝇进行了初步研究。     

伞裙追寄蝇对不同寄主的选择性

通过实验室观察及Y型管选择性试验,对草地螟上的优势种寄蝇-伞裙追寄蝇Exorista civilis Rond.的寄主选择性进行了研究。从这6种供试寄主中筛选出优良繁蝇的替代寄主,为该蝇的大规模繁殖及应用奠定理论基础。试验结果表明:伞裙追寄蝇对6种鳞翅目幼虫和幼虫粪便的趋性顺序相同,依次为草地螟>粘虫>斜纹夜蛾>甜菜夜蛾>玉米螟>苜蓿夜蛾;不同寄主的羽化率结果表明,粘虫的羽化率最高,为70.2%。伞裙追寄蝇对寄主的选择性行为可能与寄主昆虫的活跃程度和其释放的化学信息物质有关。     

冀西北农牧交错区草地螟寄生蜂及其控害作用

【目的】寄生蜂是草地螟Loxostege sticticalis L.卵期和幼虫期的重要天敌,但冀西北地区的发生种类、控害作用尚不明确。【方法】通过1997年以来历年田间调查,结合多年室内饲养。【结果】明确了当地草地螟寄生蜂共14种,其中卵期1种,幼虫期13种,1~5龄幼虫各龄期均有不同种寄生蜂寄生,寄生蜂种类多,种群数量大,寄生率高,控害和压低草地螟种群作用显著。【结论】该调查研究为开展草地螟预测预报,保护利用天敌资源和综合治理提供了科学依据。     

中国菲寄蝇属分类研究(双翅目: 寄蝇科)

经研究发现中国菲寄蝇属现共有9种,其中包括4新种：金额菲寄蝇Phebellia aurifrons sp. nov.,褐粉菲寄蝇Ph. fulvipollinis sp. nov.,宽叶菲寄蝇Ph. latisurstyla sp. nov.和毛基节菲寄蝇Ph. setocoxa sp. nov.。我国新记录3种：叶蜂菲寄蝇Ph. clavellariae (Brauer & Bergenstamm),灰粉菲寄蝇Ph. glauca (Meigen)和拟灰粉菲寄蝇Ph. glaucoides Herting。本文除详细描述新种特征及绘制特征图外,还提供中国菲寄蝇属已知种类的分种检索表。     

Parasitoid complex of the bird cherry ermine moth Yponomeuta evonymellus in Korea

The parasitoid complex of Yponomeuta evonymellus L. (Lepidoptera: Yponomeutidae), the bird cherry ermine moth (BCEM), was sought in South Korea with the goal of identifying its potential biological controls. Thirteen primary and two secondary parasitoids were found. Diadegma armillatum (Grav.), Herpestomus brunnicornis Grav. (Icheumonidae), and Zenillia dolosa (Meigen) (Tachinidae) were the most important parasitoids causing 3.5%, 7.1%, and 7.7% of the combined parasitism of the host larvae and pupae, respectively. The composition of parasitoid species was more diverse in larvae than in pupae; 10 species were reared from larvae, compared to six from pupae. The parasitoid complex contributed to the relatively low mortality levels of Yponomeuta evonymellus with the combined total rate of parasitism of 29.6% for the host larvae and pupae. This level is below that found in some European populations (50%) and is not greater than the larval rate of parasitism (31%) found in the congeneric apple ermine moth in Korea. This low rate of parasitism is partly attributed to the parasitism by Ageniaspis fuscicollis (1%) detected in Yponomeuta evonymellus, which is similar to that detected in Yponomeuta evonymellus in European reports. This is the first report of the parasitoid complex attacking the BCEM in Korea.     

Seasonal phenology and stage-specific parasitism of the apple ermine moth, Yponomeuta malinellus Zeller, in Korea

The apple ermine moth, Yponomeuta malinellus Zeller (Lepidoptera: Yponomeutidae), is a tent caterpillar that feeds on Malus spp. in Korea. Populations of the moth in native areas appeared to be regulated by the assemblage of parasitoids. Phenological associations between host stages and parasitoids, susceptible stage(s) of the host for each parasitoid, and stage‐specific parasitism were studied. The egg larval parasitoid Ageniaspis fuscicollis (Dalman) had highest parasitism of first instar larvae (24%), with 14% parasitism of other larval stages. Dolichogenidea delecta (Haliday) was recovered from all larval instars with the highest parasitism rate of second instar larvae (20.1%), followed by 19.9% parasitism of mid‐larval hosts. Herpestomus brunicornis Gravenhorst was reared from second instar larvae through to pupal collection, and had the highest parasitism rate (29.9%) at the pupal stage. The larval pupal parasitoid Zenillia dolosa (Meigen) was recovered from mid‐larval to pupal stages with the highest parasitism rate (5.5%) occurring in third to fourth instar larvae. The host stages for developing A. fuscicollis completely overlap with those of D. delecta, and with those of H. brunicornis to some degree. A statistically significant negative correlation exists between A. fuscicollis and these dominant parasitoids, indicating competitive interaction within the host.     

Suitability of the maize weevil and angoumois grain moth as hosts for the parasitoidsAnisopteromalus calandrae andPteromalus cerealellae

Two parasitoids,Pteromalus cerealellae (Ashmead) andAnisopteromalus calandrae (Howard) (Hymenoptera: Pteromalidae), were compared for their ability to parasitize two important internally-developing insect pests of stored maize (Zea mays L.). Parasitism byP. cerealellae was greater on Angoumois grain moth,Sitotroga cerealella (Olivier), than on maize weevil,Sitophilus zeamais Motschulsky, in no-choice experiments.Anisopteromalus calandrae parasitized more maize weevils than didP. cerealellae. The former parasitoid parasitized only a few Angoumois grain moths successfully in maize, but parasitized many in wheat if the hosts were younger than 3 weeks old. Thus, both host age and type of grain affect suitability for parasitism. The effects of parental host (species on which the female developed) and experimental host (species exposed to parasitism) on parasitism rate ofP. cerealellae were tested in a host-switching experiment. Parasitism by parasitoids reared on maize weevils was 23% lower than that of parasitoids reared on Angoumois grain moth. This effect was independent of which host the filial generation of parasitoids was tested on. However, the experimental host species had a much greater effect on parasitoid fecundity than the parental host species. Female progeny had smaller body sizes when emerging from maize weevil than from Angoumois grain moth, which may explain the parental host effect on fecundity. There was also a slight intergenerational effect of host species on parasitoid body size.     

Parasitoids of the arctiid mothPareuchaetes pseudoinsulata (Lep.: Arctiidae), an introduced biocontrol agent against the weedChromolaena odorata (asteraceae), in asia and Africa

The leaf-feeding arctiid mothPareuchaetes pseudoinsulata has been released widely in tropical countries for the control of the weedChromolaena odorata. P. pseudoinsulata is now widespread and locally abundant in Ghana, Indonesia, India, Sri Lanka, Malaysia, Micronesia and the Philippines. In the West Indies where it is native,P. pseudoinsulata is host to 2 species of egg parasitoids, 4 species of tachinid larval parasitoids, 1 larval-pupal parasitoid, and 1 pupal parasitoid, as well as a virulent nuclear-polyhedrosis virus.P. pseudoinsulata is not significantly parasitised where it is established in south-east Asia, Oceania or Africa. No egg parasitoids have been reported, and only 3 larval or larval-pupal parasitoids. Only one of these, the larval-pupal tachinidExorista xanthaspis, is regularly encountered, and rarely exceeds 10% parasitism in the field. These results confirm the pattern that herbivorous insects from families with exposed larvae are unlikely to be heavily parasitised in a new geographic range.     

茶毛虫天敌的研究

本明确了茶毛虫天敌种类及其优势种：寄生性天敌中寄生卵的有赤眼蜂和茶毛虫黑卵蜂,其中茶毛虫绒茧蜂是优势种;寄生幼虫的有茶毛虫绒茧蜂、茶毛虫瘦姬蜂、小孢瘦姬蜂、日本黄茧蜂和寄蝇等,其中茶毛虫绒茧蜂是优势种;捕食性天敌有步行虫、蠼螋、蜘蛛和青蛙等,其中蜘蛛是优势类群,白斑猎蛛为优势种。研究了茶毛虫主要寄生性天敌的寄生率和寄生动态：茶毛虫黑卵蜂的寄生率为１５－２０％,越冬卵可高达４５％左右;茶毛虫绒茧蜂     

Parasitoids in low-level populations ofLymantria dispar [Lep.: Lymantriidae] in different forest physiographic zones

A 2-year study was conducted on the distribution of parasitoids of gypsy moth,Lymantria dispar (L.) (Lep.: Lymantriidae), in mesic and adjacent higher elevation transition and xeric forest habitats in Vermont (U.S.A.). In both years, overall parasitism ranged from 12–18% in each habitat. When analyzed according to the life stage at which the host was collected, parasitism rates of greater than 40% were obtained among the late instars.Parasetigena silvestris (Robineau-Desvoidy) andPhobocampe disparis (Viereck) were recovered most commonly from the mesic habitat, andCotesia melanoscelus (Ratzeburg) andBlepharipa pratensis (= Sturmia scutellata) (Meigen) were most common in collections from the xeric area. Parasitism byCompsilura concinnata (Meigen) occurred at similar levels in all three habitats, and this species was responsible for the highest parasitism rates on the site, reaching 40% among the late instars in 1985. Percent parasitism byC. concinnata increased three-four-fold from 1984 to 1985, while parasitism by other species declined.     

Fecundity of the autumnal moth depends on pooled geometrid abundance without a time lag: implications for cyclic population dynamics

1. The abundance and fecundity-related body size variation of the cyclic autumnal moth Epirrita autumnata were monitored from the early increase phase and throughout the outbreak to the end of the density decline in northernmost Norway during 1999-2006. Another geometrid, the winter moth Operophtera brumata, did not increase in density until the autumnal moth had its post-peak in 2004, and was at its own peak concurrent with the steeply declining autumnal moth abundance in 2005-06. 2. The body size variables measured (forewing lengths of males and females and hind femur lengths of males) of the autumnal moth showed a similar density-dependent response, i.e. increasing density was associated with decreasing body size and fecundity. Nevertheless, regression analyses clearly ranked the pooled geometrid abundance without a time lag as the best predictor for the body size variation, ahead of the abundance of the autumnal moth or past abundance of all geometrids. 3. Nondelayed effects of lowered food quality and absolute shortage of foliage under congested conditions are the most plausible reasons for reduced body size. 4. Two most commonly proposed causal factors of the autumnal moth population cycle, i.e. delayed inducible resistance of the host plant (mountain birch Betula pubescens czerepanovii) and delayed density-dependent parasitism by specialized hymenopteran parasitoids, cannot easily explain the diverging population trends between the autumnal and winter moths. 5. We suggest that either the inducible resistance of the host tree or the host utilization of the most important parasitoids and/or pathogens have to be strictly species-specific between these closely related moth species to produce the population dynamics observed. That fecundity of the autumnal moth was best related to the pooled geometrid abundance weakens support for the former hypothesis, while our lack of host-specific information limits conclusions about the role of natural enemies.     

Larval parasitism of a forest pest, the common pine sawfly Diprion pini (L.) (Hym., Diprionidae), during an endemic density phase

Abstract: Species composition and impact of larval parasitoids during an endemic density phase of a pine forest pest, the common pine sawfly Diprion pini (L.), were investigated by exposure of laboratory-reared larvae of the sawfly to parasitoid attack in natural habitats. Colony-associated host larvae of different instars were exposed continuously from early June until end of September of the years 1994 and 1995 in two pine stands with a different history of pine sawfly outbreaks. Host larvae were exchanged after a defined time interval and those collected up were examined in the laboratory for parasitism. Parasitoid assemblages were shown to be very species poor at both pine stands. The dominant species were the ichneumonid Olesicampe macellator and the tachinid Drino gilva , which reached attack rates on the collected host larvae of 60 and 94%, respectively, during peak activity. The patterns of temporal attack, of multiparasitism, and of superparasitism of these dominant species were studied. In an additional experiment, the response of these species to different host-patch sizes (number of host larvae per colony) were investigated. No aggregative response to higher host-patch densities could be detected. The role and function of these larval parasitoids in the population dynamics of D. pini are discussed.