Submitted by Edisangela Bastos (edisangela@ufpa.br) on 2013-02-01T20:25:56Z No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_MetodosColetasMosquitos.pdf: 3989932 bytes, checksum: e2eb87c0013bd429a0c794c17179b3c6 (MD5) / Approved for entry into archive by Ana Rosa Silva(arosa@ufpa.br) on 2013-02-04T14:07:40Z (GMT) No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_MetodosColetasMosquitos.pdf: 3989932 bytes, checksum: e2eb87c0013bd429a0c794c17179b3c6 (MD5) / Made available in DSpace on 2013-02-04T14:07:40Z (GMT). No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_MetodosColetasMosquitos.pdf: 3989932 bytes, checksum: e2eb87c0013bd429a0c794c17179b3c6 (MD5) Previous issue date: 2007 / Vários métodos de captura de mosquitos foram desenvolvidos, demonstrando que houve uma evolução dos tipos de armadilhas ao longo do tempo, porém nenhum se comparou à coleta direta por Atração Humana (AH). Este trabalho teve por objetivo, testar métodos alternativos, desenvolvidos para coletar mosquitos, incluindo o desenvolvimento de novas técnicas, que podem substituir o método tradicional de captura direta em humanos. O estudo foi desenvolvido próximo ao Parque Ambiental de Belém, Pará, Brasil. Os métodos utilizados foram: armadilhas CDC, CDC UV, Shannon, armadilha desenvolvida por J. A. Rocha, armadilha desenvolvida por I. S. Gorayeb e coleta por AH. As armadilhas foram instaladas em seis pontos, por seis noites consecutivas. Foram capturados 13.099 espécimes de Culicidae distribuídas em sete gêneros e 27 espécies, sendo Anopheles trianulatus a mais abundante. Os dados foram tratados estatisticamente pelos métodos ANOVA, Análise multivariada – distâncias euclidianas. A coleta por AH direta foi o método que coletou maior diversidade e abundância de mosquitos, seguidos da armadilha de Shannon para abundância e armadilha de Gorayeb para diversidade. / Some methods capture of mosquitoes already had been developed, demonstrating that it had an evolution of the types of the trap to the long one of the time, however none has shown to be comparable to the direct human attraction (AH). This work had for objective, to test the methods alternative, developed to collect mosquitoes, including the development of new techniques, that can substitute the traditional method of direct human attraction. The study it was developed next to “Parque Ambiental de Belém”, Pará state, Brazil. The used methods were: traps CDC, CDC UV, Shannon, trap developed by Rocha, trap developed by Gorayeb and collect for AH direct. The traps were installed in six points, for six consecutive nights. Were captured 13,099 specimens of Culicidae of seven genera and 27 species, being Anopheles trianulatus the most abundant. The direct human attraction, what it collected greater diversity and abundance of mosquitoes, followed of the Shannon’s trap for abundance and Gorayeb’s trap for diversity.

Made available in DSpace on 2015-04-22T22:06:15Z (GMT). No. of bitstreams: 1 tullio.pdf: 2981239 bytes, checksum: d6f78923df4523264147690fa8713589 (MD5) Previous issue date: 2013-08-29 / CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Insects from the subfamily Phlebotominae (Diptera: Psychodidae) are of medical interest because they are vectors of protozoa of the genus Leishmania transmitted when the insect feeds. Approximately 500 species are known in the Americas and 133 registered in the state of Amazonas. Caused by different species of Leishmania, cutaneous leishmaniasis (ACL) affects humans and other animals, affecting skin and mucosa. This work is part of the project " Condições de vida e saúde de populações indígenas na Amazônia", PRONEX, which has an interdisciplinary approach to study eco-epidemiological and anthropological aspects of leishmaniasis in the Middle Purus, funded FAPEAM / CNPq, and is in progress in the municipality of Lábrea, where there are records of cases and suspected underreporting. Therefore, it was thought appropriate to the study sand flies of the municipality as a contribution to the knowledge of the epidemiology of ACL. The aim of this study was to investigate the entomological aspects related to the epidemiology of ACL in an indigenous area of the municipality of Lábrea. The collection of sand flies was carried out in February 2012 in the Aldeia Castanheira, Indian Reserve Caititú, municipality of Lábrea using light traps. After identification of insects, we performed detection and identification of Leishmania present in the collected sand flies using a molecular approach. A total of 1,267 sandflies was collected, 819 (64.6%) females and 448 (35.4%) males, distributed in 10 genera and 32 species. The most abundant genera were Psychodopygus, Nyssomyia and Trichophoromyia, the species Trichophoromyia ubiquitalis was the most abundant with 235 (18.5%) specimens, followed by Psychodopygus davisi with 228 (18%) and Nyssomyia antunesi with 135 (10.7%) individuals. The presence of Leishmania was detected in six species: Sciopemyia servulolimai, Trichophoromyia ubiquitalis, Evandromyia apurinan, Nyssomyia umbratilis, Nyssomyia yuilli yuilli, Psychodopygus davisi, the estimated minimum infection rate was 0.84%.The Leishmania species were: Leishmania (L.) amazonensis, Leishmania (V.) braziliensis and a sample identified only to the level of subgenus Leishmania (Viannia) sp. The Leishmania infection detected in vector species / suspected vectors found in this work, suggests the involvement of these species in the transmission cycle of leishmaniasis in the municipality. Future investigations should be made to help elucidate the epidemiology of cutaneous leishmaniasis in the municipality of Lábrea as well as the state of Amazonas. / Os insetos da subfamília Phlebotominae (Diptera: Psychodidae) são de interesse médico por serem vetores de protozoários do gênero Leishmania transmitidos no momento da alimentação do inseto. Cerca de 500 espécies são conhecidas paras as Américas e 133 registradas no estado do Amazonas. Causada por diferentes espécies de Leishmania, a leishmaniose tegumentar americana (LTA) acomete o homem e outros animais, afetando pele e mucosa. Este trabalho está inserido no projeto Condições de vida e saúde de populações indígenas na Amazônia , PRONEX, que possui abordagem interdisciplinar para estudar aspectos eco-epidemiológicos e antropológicos da LTA no Médio Purús, financiado pela FAPEAM/CNPq, e em andamento no município de Lábrea, estado do Amazonas onde há registros de casos e suspeita de subnotificações. Por isso, achou-se oportuno o estudo de flebotomíneos do município como contribuição para o conhecimento da epidemiologia da LTA. O objetivo deste trabalho foi estudar os aspectos entomológicos relacionados a epidemiologia da LTA em uma área indígena do município de Lábrea. A coleta de flebotomíneos foi realizada em fevereiro de 2012, na Aldeia Castanheira, Terra Iindígena Caititú, município de Lábrea, utilizando armadilhas com atrativo luminoso. Após a identificação dos insetos, foi realizada a detecção e identificação de leishmânias presentes nos flebotomíneos coletados utilizando uma abordagem molecular. Um total de 1.267 flebotomíneos foi coletado, 819 (64,6%) fêmeas e 448 (35,4%) machos, distribuídos em 10 gêneros e 32 espécies. Os gêneros mais abundantes encontrados foram Psychodopygus, Nyssomyia e Trichophoromyia, já a espécie Trichophoromyia ubiquitalis foi a mais abundante com 235 (18,5%) espécimes coletados, seguida de Psychodopygus davisi com 228 (18%) e Nyssomyia antunesi com 135 (10,7%) indivíduos. Foi detectada a presença de DNA de Leishmania em seis espécies: Sciopemyia servulolimai, Trichophoromyia ubiquitalis, Evandromyia apurinan, Nyssomyia umbratilis, Nyssomyia yuilli yuilli, Psychodopygus davisi, sendo a taxa de infecção mínima estimada foi de 0,84%. As espécies de leishmânias detectadas foram: Leishmania (L.) amazonensis, Leishmania (V.) braziliensis e uma amostra identificada somente ao nível de subgênero Leishmania (Viannia) sp. A infecção por Leishmania detectada em espécies vetoras encontradas neste trabalho, é um indício da participação das mesmas no ciclo de transmissão de LTA no município. Futuras investigações devem ser realizadas para ajudar a elucidar a epidemiologia da LTA não só no município de Lábrea mas para o estado do Amazonas.

Submitted by Jorge Silva (jorgelmsilva@ufrrj.br) on 2018-05-04T17:50:45Z No. of bitstreams: 1 2014 - Paloma Martins Mendon?a.pdf: 5837915 bytes, checksum: 4380ed0e7adefff59205996c112ae7af (MD5) / Made available in DSpace on 2018-05-04T17:50:46Z (GMT). No. of bitstreams: 1 2014 - Paloma Martins Mendon?a.pdf: 5837915 bytes, checksum: 4380ed0e7adefff59205996c112ae7af (MD5) Previous issue date: 2014-10-16 / CNPq / The Order Diptera is composed by about 153 thousand described species, but it is believed that the number of unknown species is much bigger. Adults and immature of some muscoid dipteran groups have little morphological differences, making the identification process more difficult. Besides, the available dichotomous keys are based on adults, but in the case of myiasis and cadaver colonization, only immature are found. These insects are known pathogen vectors, their larvae parasite humans and animais and they play an important role in forensic entomology. Therefore, the correct identification of these species is very important. This study aims to characterize features of medical, veterinary and forensic important dipteran species using two new approaches. The first chapter uses scanning electron microscopy which gives detailed information on the morphological characters that can help identify the immature forms of the flies. Immatures belonging to three muscoids with forensic and sanitary importance were studied using this methodology: Peckia (Eubaettcheria) cal/usar (Diptera: Sarcophagidae) (larvae and puparia), Luc?lia cuprina (larvae and puparia) e Cachliamyia macellaria (eggs, larvae and puparia) (Diptera: Calliphoridae). The size ofthe chorionic cells as well as the absence of spines at the posterior spiracle allowed to differentiate C. mace/faria from C. haminivarax, both myiasis causing species. The maxillary palp complex composed by a group of papillae inside a cavity seem to be specific to the subgenus Eubaeucheria. The anterior spiracular openings displaced in an irregular row are found exclusively in Sarcophagidae. The filiform spines at the anal segments are found only in the genus Lucilia. In the second chapter, barcading is used to provide a gene sequence database of medical, veterinary and forensically important Calliphoridae flies. This technique is based on the sequencing of a portion of the genome of the mitochondrial cytochrome oxidase l (cal) gene. Nine species of flies were collected in four regions in Brazil, corresponding to 346 specimens. Two other gene fragments ( elongation factor 1 alpha and white) were sequenced for the first time for some species. The barcade proposal was successfully achieved for Hemilucilia segmentaria, Hemi/ucilia semidiaphana, Chlarapracla idiaidea, Cachliamyia macellaria, Chrysamya megacephala and Chrysamya albiceps, for which the intraspecific variation was less than 3%. However, for Lucilia eximia, Chrysamya putaria and Chrysamya rufifacies, this methodology brought incipient results. Intraspecific variation among Lucilia eximia samples was 4.6%, suggesting that the threshold proposed should not be used for ali dipteran species without previous analysis of the studied group. Chrysamya putaria is polyphyletic according to nuclear and mitochondrial genes. In addition, a set of samples grouped with samples of C. albiceps and C. rufifacies. Therefore, more studies need to be clone to better explain these taxonomic problems. / A ordem Diptera ? composta por aproximadamente 153 mil esp?cies descritas, mas acredita-se que o n?mero de esp?cies ainda desconhecidas ? muito grande. Alguns grupos de d?pteros musc?ides possuem imaturos e adultos com poucas varia??es morfol?gicas, dificultando muito o processo de identifica??o. Al?m disso, as chaves dicot?micas existentes s?o baseadas nos adultos, entretanto, s?o os imaturos mais encontrados causando mi?ases ou colonizando cad?veres. Estes inselos s?o conhecidos vetores de pat?genos, suas larvas s?o parasitas de humanos e animais e apresentam papel importante como auxilio a entomologia forense. Assim, a correta identifica??o das esp?cies que desempenham estas fun??es ? muito importante. O presente estudo tem como objetivo principal caracterizar esp?cies de d?ptcros mnscoidcs de import?ncia m?dica-veterin?ria e forense, atrav?s da utiliza??o de duas t?cnicas modernas de identifica??o. O primeiro cap?tulo utiliza a microscopia eletr?nica de varredura que permite a visualiza??o e a determina??o de caracteres que possam ser utilizados na identifica??o das esp?cies. Foram estudados imaturos de tr?s esp?cies de d?pteros de duas fam?lias diferentes: Peckia (Eubaettcheria) callusar (Diptera: Sarcophagidae) (larvas e pup?rios), Lucilia cuprina (larvas e pup?rios) e Cachliamyia macellaria (ovos, larvas e pup?rios) (Diptera: Calliphoridae) atrav?s desta t?cnica. O tamanho das c?lulas do exoc?rion permitiu diferenciar entre C. macellaria e C. haminivarax, duas esp?cies causadoras de mi?ases. A aus?ncia de espinhos no espir?culo posterior das larvas de C. macellaria tamb?m a diferencia de C. haminivarax. As papilas do complexo do palpo maxilar em uma cavidade parecem ser espec?ficas do subg?nero Eubaettcheria. As aberturas respirat?rias do espir?culo anterior dispostas em fileiras irregulares s?o exclusivas da fam?lia Sarcophagidae. A presen?a de espinhos filamentosos no ?ltimo segmento larval ? caracter?stica espec?fica do g?nero Lucilia. No segundo cap?tulo, a t?cnica de harcade ? utilizada para a forma??o de um banco de dados contendo sequ?ncias g?nicas de esp?cies de import?ncia m?dica-veterin?ria e forense da fam?lia Calliphoridae. Esta t?cnica baseia-se no sequenciamento de uma por??o do gene mitocondrial citocromo oxidase I (cal). Foram analisadas nove esp?cies de d?pteros, coletadas em quatro regi?es do Brasil, em um total de 346 esp?cimes utilizados. Dois segmentos do genoma nuclear (fator de elonga??o 1 alfa e white) tamb?m foram sequenciados pela primeira vez para algumas esp?cies. A proposta de barcade foi bem sucedida em Hemilucilia segmentaria, Hemilucilia semidiaphana, Chlaraprocta idiaidea, Cachliamyia macellaria, Chrysamya megacephala e Chrysamya albiceps, onde a varia??o intraespec?fica foi menor do que 3%. Entretanto, em Lucilia eximia, Chrysamya putaria e Ch1ysamya rufifacies esta metodologia trouxe resultados incipientes. A varia??o intraespec?fica em Lucilia eximia foi 4,6%, sugerindo que o limiar proposto n?o deve ser aplicado em todos os d?pteros sem an?lise pr?via do grupo estudado. Chrysamya pularia ? uma esp?cie polifi!?tica comprovada tanto pelos genes nucleares quanto mitocondrial, al?m isso, uma parte das amostras forma um agrupamento com as amostras de C. albiceps e C. nijifacies. Assim, acrcditase que mais estudos precisam ser conduzidos com o objetivo de esclarecer melhor estas quest?es taxon?micas.

Graduation date: 1994

Hoverflies are important for their roles in ecological and environmental services, and are also charismatic species of conservation interest in their own right. Almost half of all hoverflies are saprophages, which are organisms that feed on dead or decaying organic matter, and these include saproxylic species that depend on deadwood. Deadwood and its associated community are a rich source of forest biodiversity and are fundamental to forest function, but due to poor management, many saproxylics are threatened or endangered, and techniques for conserving saproxylic species are poorly developed. In this thesis I study the ecology and conservation management of an endangered UK saproxylic fly, the Pine hoverfly, Blera fallax (Linnaeus) (Diptera, Syrphidae) and the dispersal ability of the similarly endangered Aspen hoverfly, Hammerschmidtia ferruginea (Fallén) (Diptera, Syrphidae). My main goals were to clarify methods to support their recovery in active programmes of species conservation in Scotland, UK. For B. fallax, this included experimenting with habitat creation techniques, investigating the best conditions for larval growth and assessing competition effects. In addition, I evaluated the genetic variability of the remaining population in Scotland by comparing it with one in Europe to determine whether genetic constraints may limit recovery. For H. ferruginea, I determined dispersal ability with field experiments involving mark and recapture techniques. By cutting holes at the surface of stumps of Pinus sylvestris, breeding habitat was created artificially for B. fallax at the remaining known locality for this species in the UK. Over 4 years, 81 % of holes were colonized by B. fallax, and by up to six other saproxylic syrphid species. The most successful holes were those cut into the heartwood, seeded with pine chips and sawdust and partially covered, as indicated by a combination of field occupancy monitoring and lab growth experiments. Observations of larval morphology and behaviour within rot holes revealed specializations that largely segregate the species in both time and space, and may mitigate interspecific competition between B. fallax and three more common syrphid species. I further demonstrated that B. fallax has a life history that features facultative semivoltine development, which may be a bet-hedging strategy to cope with fluctuating levels of larval food. Fifty B. fallax larvae were successfully reared and bred in captivity and from these, 430 descendent laboratory reared larvae and adults were released across three relocation sites. After initial success at the first re-location site when a new generation of larvae appeared in holes in 2010, a population crash at all sites occurred in the following year, possibly caused by adverse weather conditions. This disappointing result highlights the vulnerability of small populations to stochastic events, and means that survival of B. fallax may now depend on those larvae that are semivoltine, supplemented by animals currently being reared in captivity. My genetic analyses revealed similarly troubling information that highlights the precarious existence of B. fallax in Scotland: compared with a population in Sweden, Scottish B. fallax had significant less neutral genetic variation, and showed signs of a recent and severe bottleneck that reduced the effective population size to just 12 (CI: 0 - 266) individuals at some point in the last 200 years. Mindful of these challenges, I exploit my new data on the ecology and life history of B. fallax and combine it with techniques for captive rearing and for monitoring the genetic health of B. fallax into specific protocols and general prescriptions for the on-going recovery and management of this species. In order to assess the dispersal ability of H. ferruginea (and therefore its potential for recolonizing newly created habitat), in May to July over two years, adults were marked and released from a central point and subsequently monitored at the breeding site, decaying aspen wood Populus tremula, where adults tend to assemble for mating and oviposition. Adults were resighted visiting logs of decaying aspen set out at 1 km intervals along transects up to 7 km away. Up to 10 % of released individuals were resighted up to 5 km from the central release point. Most dispersing individuals (68 %) were resighted at 1 km, which I propose as the optimal distance for managing aspen for this species. Both of these hoverflies are case studies of techniques for recovering endangered saproxylic flies. Overall, my findings greatly increase fundamental knowledge of the ecology and natural history of these flies, and clarify some of the practical approaches that will be required in their conservation.

Winter gnats of the genus Trichocera are one of the main insect groups found in mild climates during the autumn, winter and spring months and so are unique in their way of adapting to living in colder seasons. Phylogenetic links of the genus Trichocera are examined, taxonomy of the genus renewed, species composition of several regions is ascertained and characters for dividing into subgenuses are specified in this thesis. Based on the material collected in Lithuania by standard entomological techniques and by analysis of literature data, a list of 22 species of winter gnats is given with 9 species new for our country. One new for science species of winter gnats is described from Sardinia, Italy. Based on the selected morphologic characters, phylogenetic analysis was performed and 15 species were transferred from one subgenus to another as a result. Characters of male aedeagal complex were found to be a basis for attributing the species into particular subgenus. For the first time important structures of the females of four species, male of one species and type specimens of 15 more species were illustrated. World catalogue of the 110 recent species of Trichocera is compiled and different structures of 106 species are illustrated. / Genties Trichocera uodai yra viena pagrindinių vabzdžių grupių, aptinkamų vidutinėse platumose rudens, žiemos ir pavasario mėnesiais, ypatinga savo prisitaikymu gyventi šaltuoju laikotarpiu. Disertacijoje nagrinėjami genties Trichocera rūšių filogenetiniai ryšiai, atnaujinta genties taksonomija, išaiškinta atskirų regionų rūšinė įvairovė, patikslinti skirstymui į pogentes naudotini požymiai. Standartiniais entomologiniais metodais Lietuvoje surinktų žieminių uodų mėginių pagrindu bei pagal literatūros šaltinius buvo sudarytas 22 rūšių katalogas, papildant jį 9 naujomis mūsų šalies faunai rūšimis. Aprašyta nauja mokslui žieminių uodų rūšis iš Sardinijos salos (Italija). Remiantis atrinktais požymiais atlikta filogenetinė analizė, kurios pagrindu penkiolika rūšių perkeltos iš vienų pogenčių į kitas. Nustatyta, kad patinų edeaguso komplekso ypatybės yra svarbiausios skirstant rūšis į pogentes. Pirmą kartą iliustruotos keturių rūšių patelių ir vienos rūšies patino svarbios identifikacijai struktūros bei dar penkiolikos rūšių tipiniai egzemplioriai. Sudarytas 110 recentinių Trichocera genties rūšių pasaulio faunos katalogas, pateiktos 106 rūšių įvairių identifikacinių struktūrų iliustracijos.

Efficient disposal methods are needed to manage manure produced by industrial animal production. Saprophagous fly larvae could potentially convert manure into fertilizer and produce protein; however, the process is not well studied. Musca domestica, Hydrotaea aenescens, and Coproica hirtula were investigated to determine the most suitable species and conditions that facilitate efficient poultry manure conversion. The objectives were to (1) develop laboratory protocols and timelines for fly production; (2) identify environmental conditions that affect conversion; and (3) determine the ideal manure moisture content, depth, and fly egg-to-manure ratio for manure conversion and protein production. Mass-production was possible for every species and timelines were established for all species except C. hirtula. The most promising species for use in a conversion system was M. domestica and the presence of C. hirtula facilitated complete conversion. When using these species simultaneously the ideal initial conditions were: 77.5% moisture, 2.9cm deep and 0.82g eggs/kg manure. / OMAFRA/ University of Guelph partnership

The genus Aptilotella Duda (Diptera: Sphaeroceridae: Limosininae) is redefined and revised. The type species, Aptilotella borgmeieri Duda is redescribed, and twenty-one species are described as new: Aptilotella andersoni, A. angela, A. caerulea, A. corona, A. diffisa, A. ebenea, A. gemmula, A. germana, A. gloriosa, A. gracilis, A. involucris, A. macula, A. pennifera, A. pichinchensis, A. pyropanda, A. quadrata, A. quatuorchela, A. radians, A. sphyra, A. umbracatus, and A. vivus. A phylogenetic analysis and key to species are presented, with illustrations and notes on distribution. / NSERC Discovery Grant

The impact of peatland restoration on Diptera assemblages was studied across multiple organizational levels (taxon, size class, trophic group) among abandoned-mined, restored and natural sites of three bogs and the environmental variables affecting those assemblages were determined. More than 22,000 individuals representing 716 species were collected using pan traps, sweeping and Malaise traps. Restored and abandoned sites were similar to each other and both distinct from natural sites as shown by small-size class, acalyptrate and trophic assemblages. However, abandoned sites showed much lower evenness and generally supported lower species richness than restored and natural sites, due to the dominance of one or two saprophagous species. The coverage of bare peat, Sphagnum mosses and ericaceous shrubs explained most of the variance in species composition. Those results suggest that restoration enhanced the recovery of high species diversity, although more than seven years are needed to recover a complete trophic structure or to enable species with low dispersal ability to recolonize to pre-disturbance levels.

Wheat midge, Sitodiplosis mosellana (Géhin) (Diptera: Cecidomyiidae), is a key pest of wheat, Triticum aestivum L. (Poaceae), in the Canadian Prairies. The larvae destroy wheat kernels, resulting in reduction of quality and quantity of wheat. Deployment of antixenotic wheat lines, which suppress oviposition of wheat midge, can reduce damage in wheat fields. The objectives of this thesis were to explore the interactions between wheat midge and spring wheat with emphasis on oviposition behavior and to explore the antixenosis of wheat to oviposition from the point of view of genetics and crop breeding. In this research, a doubled-haploid spring wheat population was studied, which was the progeny of a cross between a susceptible wheat cultivar ‘Roblin’ and a resistant (antixenotic and antibiotic) wheat line ‘Key 10’. Oviposition of wheat midge on wheat spikes in the laboratory was affected by visual and chemical cues. The visual contrast between wheat spikes and the background color in the laboratory was important in modifying oviposition of wheat midge on wheat spikes. Low contrast resulted in low egg density on wheat spikes in the laboratory. The egg density on wheat spikes in the laboratory decreased when the background color of the spikes was red or black; while yellow and blue backgrounds did not decrease egg density on the spikes. The laboratory study provided evidence that wheat midge oviposition was affected by volatiles emitted by wheat spikes. The volatiles of spikes of a post-anthesis susceptible wheat cultivar, ‘Roblin’, and a pre-anthesis resistant wheat line, ‘Key 10’, significantly suppressed the oviposition of wheat midge in the laboratory. It is hypothesized that these volatiles might be a factor in antixenosis of wheat against wheat midge in the doubled-haploid population studied. It is suggested that the differences of oviposition behavior in susceptible and antixenotic wheats, which was observed in the laboratory, might be due to volatiles emitted by wheat spikes. However, other factors such as tactile cues might also be involved. The observation of oviposition behavior in the laboratory on the susceptible wheat cultivar ‘Roblin’ showed that wheat midge started ovipositing sooner, stayed longer, laid more eggs and left the spike sooner after the last oviposition than on the antixenotic line ‘Key 10’. However, the time required for laying one egg was similar when wheat midge was on the susceptible or resistant wheat. The observed antennation behavior of wheat midge while probing the wheat spike might indicate that wheat midge probed for chemical cues emitted by the host plant. The observed ovipositor tapping and dragging on the wheat spike surface while probing the spike suggested that there might be receptors at the tip of the ovipositor which receive tactile cues from the plant surface, guiding oviposition. The correlations between morphological traits of bread wheat spikes and antixenosis in the laboratory were not high enough to conclude that those traits were associated with antixenosis. However, more research on fine scale morphological traits of the spike may reveal relationships with antixenosis. Based on data from a laboratory trial and trials in the field over two field seasons, it was concluded that the antixenosis to wheat midge in the doubled-haploid population was probably conferred by two genes with complementary interactions among genes, and a heritability of 67%. In the two field seasons, the least preferred line received 13% and 11% as many eggs as on ‘Roblin’; ‘Key 10’ received 57% and 20% as may eggs as on ‘Roblin’. Our study did not provide evidence for linkage between antixenosis genes and the antibiosis gene, Sm1, which is associated with death of larvae of wheat midge. The antixenosis of spring wheat against wheat midge can be considered as a promising mechanism for suppressing wheat midge oviposition in the field. More research is required to reveal additional genetic information which would help crop breeders in production of cultivars antixenotic to wheat midge.