Larviposition of Compsilura concinnata (meigen) (diptera: Tachinidae), a parasitoid of the gypsy moth,Lymantria dispar (L.) (lepidoptera: Lymantriidae)

Larviposition of Compsilura concinnata, a polyphagous tachinid parasitoid of Lepidoptera, is described. The conventional assessment, long‐established in the literature, places the site of larval deposition by C. concinnata as directly into the host's gut. New evidence, reported here, contradicts the earlier view. Dissection of 38 freshly parasitized gypsy moth (Lymantria dispar) larvae revealed as many maggots (n = 26) situated in the lumen of the midgut as were free in the hemocoel. Observations on maggot behavior and morphology in dissected hosts are briefly presented.     

Learning in the Generalist Tachinid Parasitoid Exorista Mella Walker (Diptera: Tachinidae)

Many parasitoids have been shown to learn visual and/or olfactory cues associated with hosts. In contrast to the Hymenoptera, learning in dipteran parasitoids is relatively unstudied. This study explores the ability of a polyphagous tachinid, Exorista mella, to learn to associate visual and olfactory cues with hosts. In an experiment involving colored host models, flies trained on models of one color were subsequently attracted more strongly to models of the color that they had not experienced. The unsuitability of these models as hosts suggested that the flies may have engaged in avoidance learning. Flies demonstrated the ability to learn to associate colored disks with hosts. A separate experiment demonstrated that flies responded to volatile plant compounds but failed to find evidence for odor learning. Learning of host-associated cues by E. mella may allow this generalist parasitoid to take advantage of locally abundant host populations and maintain host-searching efficiency in an environment.     

A revision of the genus Trixa Meigen （Diptera： Tachinidae）

The genus Trixa Meigen, 1824 is revised. Dexiotrix Villeneuve, 1936 and Trixella Mesnil, 1980, each of which was sometimes treated as a distinct genus, are treated as junior synonyms of Trixa Meigen. Two species from Sichuan and Yunnan, China, are described as new to science, viz. Trixa chinensis sp. nov. and T. chaoi sp. nov. T. alpina Meigen is treated as a junior synonym of T. caerulescens Meigen. T. nox (Shima) and T.pubiseta (Mesnil) are newly recorded from China. Males of T. pubiseta (Mesnil) and T.longipensis (Villeneuve) are described for the first time. Diagnoses, figures and a key to twelve species in Trixa are given.     

A simplified artificial medium for the in vitro rearing of Exorista larvarum (Diptera: Tachinidae)

The standard artificial medium for the parasitoid Exorista larvarum, composed of skimmed milk, yeast extract, egg yolk, sucrose and gentamicin, was simplified by deleting sucrose. Fecund adults were obtained on both the standard and the simplified medium. No difference was found between them for any of the developmental parameters examined.     

Effect of host deprivation on egg quality,egg load,and oviposition in a solitary parasitoid,Chetogena edwardsii (Diptera: Tachinidae)

Solitary parasitoids are limited to laying one egg per host because larvae compete within hosts. If host encounter rate is low, females should not increase the number of eggs/host in response. The tachinid fly, Chetogena edwardsii,was used to evaluate the effect of host deprivation on egg accumulation, oviposition behavior, and egg quality in a solitary parasitoid. Females deprived of hosts for 2– 7 days accumulate about 1 day's supply of eggs. Egg output of deprived females once hosts are restored does not differ from that of control females. Deprived females retain one egg in the uterus where it undergoes embryogenesis. Maggots emerging from retained eggs are more likely to survive in hosts molting in 40 h or less after receipt of an egg than are maggots emerging from eggs fertilized shortly before oviposition. Egg retention is a consequence of host deprivation that permits females to broaden the range of hosts they can exploit to include soon-to-molt hosts and possibly multiply parasitized hosts.     

Ecological and morphological characteristics of the endoparasitoids of larval Acronicta rumicis (Lepidoptera: Noctuidae)

The Hymenopterans Glyptapanteles liparidis, Microplitis sp. and Diadegma sp. were found to be larval parasitoids and koinobionts of Acronicta rumicis (Lepidoptera: Noctuidae). Mesochorus semirufus is believed to be a new unreported hyperparasitoid of G. liparidis, which, along with M. semirufus, is a gregarious parasitoid. In contrast, the parasitoids Microplitis sp. and Diadegma sp. are solitary. All of the hymenopteran parasitoids are multivoltine insects that emerge from A. rumicis more than once. Compcilura concinnata, Euexorista sp. and Exorista sp. of the Diptera were found to be larval–pupal parasitoids, solitary parasitoids and koinobionts. These three species are univoltine, and emerge only once from A. rumicis. Morphological and life cycle data were collected for G. liparidis, and for the parasitoids of that species found in this study. The major and minor axes of an egg of G. liparidis were 0.10 and 0.02 mm, respectively, while the mean clutch size of G. liparidis was 67.71 ± 39.36 individuals. The body length of female and male G. liparidis were 2.25 ± 0.06 and 2.21 ± 0.12 mm, respectively, and the longevity of an adult was 2.93 ± 0.96 days. Among the parasitoids, the mean body length of an adult Microplitis sp. was 3.5 mm and adults lived for an average of 8.13 ± 3.54 days. The adult Diadegma sp. was larger (mean body length 6.5 mm) but lived for a shorter interval (3.33 ± 1.32 days). The body lengths of female and male M. semirufus were 3.16 ± 0.11 and 3.10 ± 0.23 mm, respectively, greater than the body lengths of female and male G. liparidis. The body lengths of adult C. concinnata, Euexorista sp. and Exorista sp. were 9.5, 9.53 and 8.68 mm, respectively. All of their pupae were dark brown.     

中国新记录属——颊寄蝇属分类研究

Dexiosoma Rondani is a small Old World genus belonging to the Microphthalmini (Tachininae) and parasitic on larvae of Scarabaeidae, and collected in the weeds. In this study Dexiosoma is newly recorded from China, one new species, D. nigricornis sp. nov. from Sichuan, Yunnan and Xizang (Tibet) is described, and D. caninum (Fabricius) from Liaoning and Jilin, China is newly recorded and briefly redescribed, and a key to the five species (males) of Dexiosoma is provided. The specimens of two identified species are housed in the collection of Shenyang Normal University.     

Reproductive biology of the microtype tachinid fly Zenillia dolosa (Meigen) (Diptera: Tachinidae)

Reproductive biology including mating, adult longevity, fecundity and development of the tachinid fly Zenillia dolosa was investigated for optimizing rearing procedures using Mythimna separata as a host in the laboratory. Females lay microtype eggs containing a first instar larva on food plants of the host and then the eggs must be ingested by the host for parasitization. Mating success was 58.5% with mating duration of 80.7 min. Mating was most successful when day 0–1 females were kept with day 2–4 male flies. Female body size was positively correlated with its fecundity but not with longevity. However, females that survived longer produced more eggs during their lifetime. Parasitoids successfully developed in 4th to 6th instar host larvae. Host instars at the time of parasitoid egg ingestion significantly influenced development time of the immature parasitoid, but did not affect body size of the emerging parasitoid. We suggest that pairing newly emerged females with day 2–4 males should result in higher mating success and using the last instar hosts for parasitization should minimize development time of the parasitoid for rearing.     

中国瑟寄蝇属种类纪要（双翅目：寄蝇科）

研究了我国蜗寄蝇族瑟寄蝇属Cyrtophleba(双翅目:寄蝇科)2种,其中茹瑟寄蝇Cyrtophleba ruricola 分布于辽宁,山西,宁夏,新疆;变瑟寄蝇Cyrtophleba vernalis为中国新记录种,分布于辽宁。给出了上述2种的鉴别特征及变瑟寄蝇头和雄性尾器的特征图。研究标本分别保存于沈阳师范大学昆虫标本室(SYNU),中国科学院动物研究所(IZCAS)和国家林业局森林病虫害防治总站(GSFPM)。     

中国宁夏六盘山寄蝇亚科二新种（双翅目：寄蝇科）

记述采自宁夏六盘山区的寄蝇亚科2新种,宁夏透翅寄蝇Hyalurgus ningxiaensis sp. nov.和周氏密克寄蝇Mikia choui sp. nov.,分别隶属埃内寄蝇族Ernestini 和寄蝇族Tachinini。宁夏透翅寄蝇外形与分布中国、俄罗斯和欧洲的亮透翅寄蝇H. lucidus 相似,但新种额较窄,触角和足股节均黑色,翅r4+5室不闭合,无短柄,明显不同于后者;此外,新种也近似于分布我国的黄足透翅寄蝇H. flavipes,但新种额和颊均较窄,触角基节和梗节黑色,足股节也黑色,腹部第3、4 背板均具多对侧心鬃,可区别于后者。周氏密克寄蝇外形与分布我国、印尼及印度的毛缘密克寄蝇M. apicalis 相似,但新种雌、雄胸部背板中鬃均2+3,翅前缘端半部无黑色斑.R4+5脉从基部到r-m脉段全部具小鬃,后足端位背鬃3 根,腹部第1+2 合背板无中缘鬃,可区别于后者。新种模式标本保存在沈阳师范大学昆虫标本室。     

中国新记录属——颊寄蝇属分类研究（双翅目：寄蝇科）

颊寄蝇属Dexiosoma属于寄蝇亚科、Microphthalmini族,该属种类均栖息于草丛中,寄生于土壤中金龟子科幼虫;其外形特征是侧颜宽,具淡色毛,单眼鬃缺,触角芒羽状,后背中鬃3,足黄,前足基节前内侧大部具倒伏的小毛。已知4种颊寄蝇中,3种分布东洋区,1种分布古北区。本文研究了产自上述两动物地理区的颊寄蝇属标本和文献,首次发现该属在我国分布,记述了采自四川,云南和西藏的1新种,暗角颊寄蝇Dexiosoma nigricornis;简述了分布辽宁和吉林的中国新记录种,灰颊寄蝇D.caninum(Fabricius)的主要特征;编制了本属5种雄性检索表;研究标本均保存在沈阳师范大学昆虫研究所。     

Olfactory response of Anagrus,nigriventrls (HYM.: Mymaridae): Effects of host plant chemical cues mediated by rearing and oviposition experience

The egg parasitoid Anagrus nigriventris Girault is an important natural enemy of the beet leafhopper, Circulifer tenellus (Baker) which has a broad host range that includes cultivated sugar beets and the weed, Russian thistle. When parasitoids were reared on leafhopper eggs deposited in sugar beets, females were attracted to sugar beet volatiles and preferred them over a blank control and over Russian thistle volatiles in Y- tube olfactometer tests. No preference was detected for either plant by female wasps that were reared on Russian thistle. Wasps reared on Russian thistle and allowed an oviposition experience on sugar beet showed a strong attraction to sugar beet volatiles; however, wasps reared on sugar beets and allowed oviposition experience on Russian thistle demonstrated no preference between the two plants. The implications of parasitoid response towards plant volatiles and their importance in biological control are discussed.     

Annotated check-list of the family Tachinidae (Diptera: Calyptratae: Oestroidea) in the Canary Islands

Summary

A commented check-list of the tachinid species inhabiting the Canary Islands (Spain) is provided, with special emphasis on hosts species and floral resources. Nine new local records are provided and Cylindromyia rufipes is reported for the first time for the Canary Islands, thus increasing the species number to 52. Zoogeographic analysis of the area revealed that there are differences in chorotype composition among islands, with the easternmost islands being richer in Mediterranean species and poorer in endemics. These differences may be due to ecological differences between the easternmost island and the remaining islands. Relevance regarding influence of tachinid as pollinators is discussed.     

Imperfect oviposition decisions by the pitcher plant mosquito (Wyeomyia smithii)

Summary Wyeomyia smithii mosquitoes distribute their eggs across available oviposition sites (water-holding pitcher plant leaves) of varying quality. I experimentally examined responses to three components of site quality: conspecific larval density, larval density of the pitcher plant midge,Metriocnemus knabi, and pitcher size. Responses to larval treatments were complex and apparently suboptimal. Although mosquito larval performance is better in leaves with fewer conspecific and more midge larvae, females did not lay more eggs in such pitchers. Instead, more eggs were laid in experimental pitchers containing either midge or mosquito larvae, but fewer eggs in pitchers with neither or both. More eggs were laid in larger pitchers, which tend to accumulate more resources and dry out less often. Therefore, although the oviposition decisions made were suboptimal, they were better than random.     

Revision of the subgenus Ceranthia Robineau-Desvoidy of the genus Siphona Meigen of Japan (Diptera: Tachinidae)

Japanese species of the subgenus Ceranthia Robineau‐Desvoidy are revised. Five species are recognized in Japan, three of which are described as new to science: Siphona (Ceranthia) angusta, S. (C.) nigra and S. (C.) setigera. A key to Japanese species is provided and male terminalia are illustrated. Monophyly of this group is discussed.     

Phonotaxis in femaleOrmia ochracea (Diptera: Tachinidae), a parasitoid of field crickets

Gravid females of Ormia ochracealocate their hosts by homing on their hosts' calling songs. At Gainesville, Florida, O. ochraceafemales were attracted in greatest numbers to broadcast sounds that simulated the calling song of Gryllus rubens.Other candidate hosts and the attractiveness of their songs relative to the simultaneous song of G. rubenswere G. fultoni(9%), G. integer(4%), G. firmus(3%), Orocharis luteolira(1%), Scapteriscus borellii(1%), and S. vicinus(0%). The response of female O. ochraceato simulated G. rubenssongs that have different pulse rates changes with temperature in parallel with temperature-induced changes in the pulse rate of natural songs. Speaker stations 16 m apart in an apparently uniform environment produced strikingly different fly counts (e.g., 852 and 2163). The song of G. rubensat 21 °C approximates a continuous sequence of 4.6-kHz pulses at a rate of 45 s ^–1 and with a duty cycle of 50%. When two of these parameters were held constant and the third systematically varied in steps of 0.4kHz, 10s ^–1,and 10–20%, maximum attraction occurred at 4.4 kHz, 45 s ^–1,and 20–80%. Omitting as many as half the pulses in a rubenssimulation (e.g., 1, 2, 4, or 16 pulses followed by an equivalent silence, and repeat) did not significantly reduce the counts of O. ochracea,proving that chirping (producing pulses in brief groups) is no safeguard from call-seeking O. ochracea.Phase shifting of pulses in successive chirps sometimes decreased fly counts. When songs were first broadcast, flies came within seconds. Flies that landed at sound often stayed for minutes, even when the sound was turned off.     

Phylogenetic relationships of subgenera of the genus Exorista Meigen,with a revision of the Japanese species (Diptera: Tachinidae)

Phylogenetic relationships of the subgenera of Exorista Meigen (Diptera: Tachinidae) are inferred from morphological data. Our results show that the genus Exorista is not monophyletic and that members of the subgenus Spixomyia Crosskey are divided into two clades. Each subgenus is redefined based on male and female morphological features. The Japanese species of Exorista are revised and classified into five subgenera: Adenia Robineau‐Desvoidy, Exorista Meigen, Podotachina Brauer and Bergenstamm, Ptilotachina Brauer and Bergenstamm, and Spixomyia Crosskey. Thirteen species are recognized, including two newly recorded species, Exorista (Adenia) cuneata Herting and Exorista (Spixomyia) lepis Chao. Exorista cantans Mesnil is transferred to the subgenus Podotachina from Spixomyia.     

Oviposition behavior of the cabbage root fly,Delia radicum (L.), influenced by host plant extracts

An ethanolic extract of cabbage leaves (Brassica oleraceavar. capitata,Golden Acre)and derived fractions were tested on natural and surrogate leaves in order to study the oviposition behavior of the cabbage root fly Delia radicum(Diptera: Anthomyiidae). On surrogate plastic leaves coated with a thin layer of paraffin wax and treated with 0.1 gram leaf equivalent (gle) of an ethanolic raw cabbage extract, the females displayed the same sequence of behavioral patterns as on a natural host plant. The quantified oviposition behavior correlated well with the actual number of eggs laid. The extract-treated surrogate leaves received at least as many eggs as natural leaves with a similar surface area. Previous exposure to surrogate or natural leaves seemed not to induce a specific preference. The three fractions (hexane, butanol, and water) of the raw extract stimulated the oviposition behavior. This was taken as evidence for the presence of a multicomponent mixture or a chemical pattern in the cabbage leaves stimulating oviposition. At the tested concentration each fraction alone could stimulate in some individuals the complete behavior. No effect of volatile components of the raw extract could be detected. This is thought to be due to the extraction procedure, which limits the production of attractive, volatile compounds, such as isothiocyanates.     

Maintenance of the phenology of the winter moth (Lepidoptera: Geometridae)

Adult winter moths ( Operophtera brumata (L.)) are active in late autumn or early winter. The eggs overwinter in the canopy of trees and hatch simultaneously with the bursting of host tree buds. Many young larvae disperse on the wind on silk strands. Larvae are polyphagus and feed until late spring when they pupate in soil or leaf litter. The duration of the egg and pupal stages is genetically determined and varies with latitude. The egg stage is long in the north and short in the south, while the pupal stage is short in the north and long in the south.
The literature on the ecology and physiology of winter moth is reviewed. The factors maintaining the unusual phenology are discussed. It is concluded that the larval stage is early because mature leaves of many host trees are unsuitable as food, because parasitism against later larvae is more intense, and because summer temperatures may be injurious to larvae. The adult period is late in the year so that the final stages of pupal development occur in cool conditions and so that adults emerge after most insect predators have ceased activity. Throughout most of the range retarding the adult emergence period would cause activity to be impeded by severe winter weather; in the south this is not so and it is suggested that eggs must be on the trees for a minimum period to ensure synchronization of egg hatch with bud burst. The protracted adult emergence period may be an adaptation reducing predation by birds.     

中国贵州长腹寄蝇属三新种记述（双翅目：寄蝇科）

记述采自贵州地区的长腹寄蝇属Dolichocoxys Townsend 3个新种:黄基长腹寄蝇D. flavibasis sp. nov.、黑腹长腹寄蝇D. obscurus sp. nov.和短柄长腹寄蝇D. brevis sp. nov.。文中附所有新种的详细描述、鉴别特征图、近缘关系的讨论及中国长腹寄蝇属分种检索表。新种的模式标本保存于贵州省安顺市疾病预防控制中心医学昆虫研究室。