Gorse, Ulex europaeus, is a serious weed of agriculture and forestry in New Zealand. The mite Tetranychus lintearius feeds on gorse in Europe and was released in New Zealand during autumn 1989 as a potential biological control agent. The aim of my laboratory study was to increase available knowledge on its development and aggregation. As the quality of gorse declined as a food resource (as indicated by chlorophyll content) a significant decline in egg production, and an increase in development time of mites was found. Mean egg production at 15℃ ranged from 37.8 to 45.2 eggs/female over 10 days in the experimental treatments and development time from 39.2 to 43.3 days. Density of adult female mites (1, 2, 5, 10, 15, 20/spine) also had a significant effect on the number of eggs produced/female over ten days (mean daily egg production/female, 0.78-0.88). Mean development time from egg to adult decreased from 40.6 to 39 days as density increased from 1 to 50 mites/spine. The resident New Zealand strain of T lintearius, imported originally from Cornwall, is now widely established but has not established successfully on the west coast of the South Island or in the north of the North Island. Four new strains recently introduced from coastal Portugal and Spain, areas climatically similar to these New Zealand regions, may be more successful. Thus, although egg production and survival of all strains were significantly reduced when subjected to daily periods of simulated rainfall in laboratory experiments, those of the newly introduced strains were least affected. Laboratory experiments with the resident New Zealand and Cambados strains also showed that individuals aggregated actively at 10-20℃, but the latter aggregated more strongly at these temperatures. This strong aggregation behaviour may increase survival in warm, wet climates and suggests that Cambados strain mites could become established and so increase gorse control in Westland and Northland.

No description available.

No description available.

No description available.

Gorse, Ulex europaeus, is a serious weed of agriculture and forestry in New Zealand. The mite Tetranychus lintearius feeds on gorse in Europe and was released in New Zealand during autumn 1989 as a potential biological control agent. The aim of my laboratory study was to increase available knowledge on its development and aggregation. As the quality of gorse declined as a food resource (as indicated by chlorophyll content) a significant decline in egg production, and an increase in development time of mites was found. Mean egg production at 15℃ ranged from 37.8 to 45.2 eggs/female over 10 days in the experimental treatments and development time from 39.2 to 43.3 days. Density of adult female mites (1, 2, 5, 10, 15, 20/spine) also had a significant effect on the number of eggs produced/female over ten days (mean daily egg production/female, 0.78-0.88). Mean development time from egg to adult decreased from 40.6 to 39 days as density increased from 1 to 50 mites/spine. The resident New Zealand strain of T lintearius, imported originally from Cornwall, is now widely established but has not established successfully on the west coast of the South Island or in the north of the North Island. Four new strains recently introduced from coastal Portugal and Spain, areas climatically similar to these New Zealand regions, may be more successful. Thus, although egg production and survival of all strains were significantly reduced when subjected to daily periods of simulated rainfall in laboratory experiments, those of the newly introduced strains were least affected. Laboratory experiments with the resident New Zealand and Cambados strains also showed that individuals aggregated actively at 10-20℃, but the latter aggregated more strongly at these temperatures. This strong aggregation behaviour may increase survival in warm, wet climates and suggests that Cambados strain mites could become established and so increase gorse control in Westland and Northland.

Balaustium medicagoense (Acari: Erythraeidae) and Bryobia spp. (Acari: Tetranychidae) have recently been identified as emerging pests of winter crops and pastures by the Australian grains industry. The relative importance of these mites and damage caused by them in Australia has markedly increased in the last decade, and pest reports indicate extensive damage to a variety of winter grain crops and pastures. Furthermore, pest reports suggest that these mites have been difficult to control in the field, with some pesticides described as being ineffective. Despite this, there is very little information about the biology and control of these species, making it difficult to devise effective and sustainable management strategies. This thesis addresses some of these concerns by investigating various aspects of the biology, ecology and genetics of these mites in broad acre agriculture in southern Australia. / Laboratory bioassays were undertaken to examine the response of Ba. medicagoense and B. sp. I (along with the redlegged earth mite (Halotydeus destructor) as a point of reference) to several currently registered pesticides against earth mites. Balaustium medicagoense and B. sp. I generally had a much greater level of tolerance to the pesticides tested than H. destructor. These mites therefore have a high natural tolerance to currently registered pesticides and may prove difficult to control in the field. These findings suggest other strategies that are not reliant on chemicals should be considered for control of Ba. medicagoense and B. sp. I. / The effects of different crop plants on the survival and reproduction of Ba. medicagoense and Bryobia spp. (B. sp. VIII and B. sp. IX) and the plant damage caused by these mites were investigated under shade-house conditions. In addition information from field surveys and pest report bulletins was collated to test for outbreak patterns. The findings showed that these mites were polyphagous, attacking a variety of agriculturally important plants as well as numerous weeds within southern Australia. Therefore, these mites have the potential to be important pests on several winter grain crops and pasture, but there are important differences in host responses that might assist in management strategies such as targeted crop rotations and weed management. / The distribution, life cycle, seasonal abundance patterns and the pest status of Ba. medicagoense and Bryobia spp. were examined in southern Australia. Both mites are widely distributed throughout Mediterranean-type climate areas within southern Australia. Balaustium medicagoense has two generations per year and was active from March until December, with a likely diapause period in summer. There were differences in the seasonal abundance and life cycle of two species of Bryobia (B. sp. IX and B. sp. I). Bryobia sp. IX had two generations per year, was active from March until December, and was likely to be in diapause over the summer months. Bryobia sp. I did not have a diapause stage, was active year round and had approximately four generations per year. Seasonal abundance patterns of Ba. medicagoense and B. sp. IX overlapped with those of the major pest mite species H. destructor and Penthaleus major. A survey of pest outbreaks and chemical control failures showed that while H. destructor and the Penthaleus species remained important pests, outbreaks and control failures involving Ba. medicagoense and Bryobia spp. had increased over the last decade. / The species/strain status of Balaustium and Bryobia mites from broad acre environments was examined in southern Australia using a combination of mitochondrial and nuclear DNA sequence data. In addition, the reproductive mode and genetic diversity of Ba. medicagoense was examined using the amplified fragment length polymorphism (AFLP) method. Findings showed that Ba. medicagoense is the only species present in grain crops, pastures and roadsides within southern Australia, and at least seven species of Bryobia mites are present. The AFLP data revealed that Ba. medicagoense reproduces asexually and that genetic diversity was low with only 10 genotypes found from 16 populations. / Overall, the data presented in this thesis helps to explain why Ba. medicagoense and Bryobia spp. are emerging pests and points to ways in which these mites may be controlled in the future. The results show that these mites are difficult to control with currently registered pesticides, have a widespread distribution, can potentially increase in abundance rapidly under favourable conditions and persist across a wider range of seasonal conditions than other major pest earth mites. However, there are differences in pesticide susceptibilities and plant host responses that have the potential to be exploited when developing targeted control options for these pest mites.

Thesis (B.Sc.(Hons.)) -- University of Adelaide, Dept. of Entomology, 1972.

Submitted by JANDIR CRUZ SANTOS null (jandir_jc@hotmail.com) on 2017-05-15T18:13:46Z No. of bitstreams: 1 Tese_Jandir_Cruz Santos.pdf: 5587068 bytes, checksum: acb65ead4a03782c42c7fb8d0228224b (MD5) / Approved for entry into archive by Luiz Galeffi (luizgaleffi@gmail.com) on 2017-05-16T14:46:03Z (GMT) No. of bitstreams: 1 santos_jc_dr_jabo.pdf: 5587068 bytes, checksum: acb65ead4a03782c42c7fb8d0228224b (MD5) / Made available in DSpace on 2017-05-16T14:46:03Z (GMT). No. of bitstreams: 1 santos_jc_dr_jabo.pdf: 5587068 bytes, checksum: acb65ead4a03782c42c7fb8d0228224b (MD5) Previous issue date: 2017-04-20 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Em diversos países, muitas empresas têm investido valores significativos na viabilização do uso do controle biológico de pragas, em função da demanda do mercado por produtos alimentícios saudáveis, livres de resíduos químicos. O uso de ácaros predadores tem crescido significativamente nos últimos anos principalmente com ácaros das famílias Phytoseiidae, Laelapidae e Macrochelidae, no entanto outras famílias como Ascidae, Blattisociidae e Melicharidae têm demonstrado bons resultados em laboratório no controle de pragas. Dentro da linha de trabalho priorizada pelas instituições em que o presente trabalho foi conduzido (FCAV/UNESP e ESALQ/USP), o objetivo deste trabalho foi conhecer a fauna de ácaros das famílias Ascidae, Blattisociidae e Melicharidae nas diferentes regiões do Brasil e estabelecer bases de dados sobre a ocorrência destes no Globo Terrestre. Espécimes disponíveis na Coleção de Referência de Ácaros da ESALQ/USP e coletados pelo autor deste documento foram analisados e identificados, descrevendo-se três espécies novas para a ciência e redescrevendose uma espécie (Leioseius basis Karg, 1994). Foram também criadas bases de dados sobre a distribuição de ácaros destas três famílias e sobre os substratos em que foram encontrados, para disponibilização “on-line”. No total, foram examinados 1657 exemplares, de 76 espécies de 19 gêneros. Vinte e seis espécies e três dos gêneros encontrados eram novos para a ciência e destes taxa, três espécies novas (uma de Leioseius e duas de Cheiroseius) foram descritas. Duas chaves dicotômicas taxonômicas foram elaboradas, uma para as espécies de Leioseius do Globo e uma para as espécies de Cheiroseius conhecidas no Brasil. As bases de dados estabelecidas correspondem a uma complementação das informações taxonômicas constantes do catálogo destas famílias publicado em 2016. Cerca de 820 publicações foram obtidas e analisadas, correspondendo a cerca de 1,3 vezes o número de publicações citadas naquele catálogo. As bases de dados permitem o rápido acesso às informações sobre a distribuição por país (por estado ou divisão política correspondente nos sete maiores países) e sobre os substratos em que estes ácaros foram relatados. As bases constam de aproximadamente 2200 registros, cada um correspondente ao número de pontos de constatação citados em cada publicação de dados primários, para cada uma das quase 1000 espécies distribuídas em 45 gêneros destas famílias. Os países com maior diversidade conhecida em cada família são: Ascidae – Rússia (56), Estados Unidos da América (42), China (37) e Polônia (36); Blattisociidae – China (47), Estados Unidos da América (41), Equador (38), Índia (33) e Polônia (32); Melicharidae – Estados Unidos da América (46), Brasil (23), Equador (20) e Polônia e Alemanha (15). No entanto, nenhuma espécie destas famílias é conhecida em cerca de 44% dos países. / In several countries, many companies have invested significant amounts in making viable the use of biological control of pest organisms, due to the demand for healthy food products, free of chemical residues. The use of predatory mites have grown significantly in recent years especially with mites Phytoseiidae families, and Laelapidae Macrochelidae, however other families like Ascidae, Blattisociidae Melicharidae and have shown good results in the laboratory to control pests. In line the research priorities of the institutions in which this work was conducted (FCAV/UNESP and ESALQ/USP), the objective of this work was to investigate the mite fauna of the families Ascidae, Blattisociidae and Melicharidae in different regions of Brazil and to establish databases on the world occurrence and substrates of these mites. Specimens available at ESALQ/USP Mite Reference Collection and specimens collected by the author of this document were analyzed and identified, describing three species new to science and redescribing a species (Leioseius basis Karg, 1994). The work also involved the establishment of databases on the distribution of mites of these three families and on substrates that have been found, for online availability. In total, 1657 specimens from 76 species of 19 genera were examined. Six species and three genera found were new to science and from these taxa, three new species (one Leioseius and two Cheiroseius) were described. Two dichotomous taxonomic keys were elaborated, one for the species of Leioseius of the world and one for the species of Cheiroseius known in Brazil. The established databases correspond to a complementation of the taxonomic information included in the catalog of these families published in 2016. About 820 publications were obtained and analyzed, corresponding to about 1.3 times the number of publications cited in that catalog. The databases allow rapid access to information on the distribution by country (by state or corresponding political division in the seven largest countries) and on the substrates in which these mites have been reported. The bases contain approximately 2200 records, each corresponding to the number of observation points in each publication of primary data, for each of the nearly 1000 species in 45 genera of these families. The countries with the highest known diversity in each family are: Ascidae - Russia (56), United States of America (42), China (37) and Poland (36); Blattisociidae - China (47), United States of America (41), Ecuador (38), India (33) and Poland (32); Melicharidae - United States of America (46), Brazil (23), Ecuador (20) and Poland and Germany (15). However, no species of these families is known in about 44% of the countries.

The history, management and ecology of the European red mite, Panonvchus ulmi Koch, and two important phytoseiid predators, Typhiodromus caudiglans Schuster and Typhiodromus occidentalis Nesbitt were reviewed. The roles and interactions of dispersal, predation and weather in the orchard mite system were examined. Field experiments in an apple orchard with well-established phytoseiid and European red mite (ERM) populations showed that Typhiodromus rarely move among or between trees and the ground cover, either by air or via the trunk. They were incapable, within a single season, of repopulating trees from which phytoseiids had been removed by early-season carbaryl application, even though these trees supported high prey populations and were interspersed among unsprayed trees well-populated with Typhiodromus and the ERM. Large numbers of sticky traps captured very few aerially dispersing phytoseiids. In contrast, their ERM prey actively dispersed within trees and throughout the orchard. Mite densities were uncorrelated with leaf chlorophyll content; within-tree dispersal was not directly determined by leaf condition. Adult females were greatly over-represented in aerially-dispersing ERM emigrants in comparison with populations on the apple trees. No density threshold effect on ERM dispersal was discernible on a per-tree basis. Aerial dispersal was extensive and appeared to depend on the weather more mites disperse on warm and calm days than on cool or windy days. ERM dispersal via the tree trunk was minimal and the presence of weeds resulted in only a slight increase in ERM density on the trees. The phytoseiids affected the ERM by reducing population densities, by reducing the proportion of immatures, and by decreasing the degree of prey aggregation (as represented by frequency distribution of leaf counts). The consequences of low predator dispersal and high prey dispersal in a weather-dependent system are discussed. Results of computer simulation of the development, predation, and dispersal are presented. Dispersal (immigration and emigration) allow the phytoseiid populations in the single-tree model to persist and control the ERM. In simulations of the interaction of Typhlodromus with the ERM, the interaction of dispersal and temperature-related processes is strong and non-linear, and may operate through several processes. / Land and Food Systems, Faculty of / Graduate

Doctor of Philosophy / Department of Entomology / David C. Margolies / James R. Nechols / Foraging traits such as prey consumption rate and the efficiency with which predators convert their prey into offspring are important determinants of local predator-prey dynamics. However, in environments with patchy prey distribution, predator dispersal and aggregation in response to prey-induced volatile cues becomes more critical. My dissertation addressed predator-prey population dynamics in response to variation in four foraging traits in the predatory mite, Phytoseiulus persimilis (Acari: Phytoseiidae): consumption rate, conversion efficiency, dispersal, and olfactory response related to prey. The dispersal response and olfactory sensitivity in predatory mites is modified by prey-related cues. For example, the dispersal response increased with decreasing prey density in a patch and increasing prey-related volatiles from outside the prey patch. The olfactory response of predatory mites also increased with increasing numbers of prey per plant or with the length of time a plant was infested by prey. These results formed the basis for development of bioassays used to examine genetic variation in dispersal and olfactory response of predatory mites. Through artificial selection I documented additive genetic variation in all four traits. After relaxation of selection, high-level phenotypes were stable compared to their low counterparts. There were significant genetic correlations between some of the foraging traits. However, there were no correlations between foraging traits and life-history traits. The existence of genetic variation and covariation among the foraging traits suggests that predatory mites must be able to adopt different foraging strategies in the evolution of prey-finding in a tritrophic system. High consumption, high conversion efficiency and high dispersal response phenotypes interacted differently with prey in a spatially complex landscape. All foraging traits were comparable in terms of predator-prey densities and plant damage; but they were lower than the unselected control. Spatial association and correlation analysis showed that all foraging traits were positively associated with prey; but the strongest association was observed for the high conversion efficiency and dispersal lines. The variability in foraging behaviors of the predatory mite affects its ability to locate patchily distributed prey, thereby influencing foraging efficiency and population dynamics. This research provides new information about the critical link between predator foraging and population dynamics relevant to biological control.