Distribution of cryptic blue oat mite species in Australia: current and future climate conditions

• 1 Invertebrate pests, such as blue oat mites Penthaleus spp., cause significant economic damage to agricultural crops in Australia. Climate is a major driver of invertebrate species distributions and climate change is expected to shift pest assemblages and pest prevalence across Australia. At this stage, little is known of how individual species will respond to climate change.
• 2 We have mapped the current distribution for each of the three pest Penthaleus spp. in Australia and built ecological niche models for each species using the correlative modelling software, maxent . Predictor variables useful for describing the climate space of each species were determined and the models were projected into a range of future climate change scenarios to assess how climate change may alter species‐specific distribution patterns in Australia.
• 3 The distributions of the three cryptic Penthaleus spp. are best described with different sets of climatic variables. Suitable climate space for all species decreases under the climate change scenarios investigated in the present study. The models also indicate that the assemblage of Penthaleus spp. is likely to change across Australia, particularly in Western Australia, South Australia and Victoria.
• 4 These results show the distributions of the three Penthaleus spp. are correlated with different climatic variables, and that regional control of mite pests is likely to change in the future. A further understanding of ecological and physiological processes that may influence the distribution and pest status of mites is required.

     

The Jean Gutierrez spider mite collection

The family Tetranychidae (spider mites) currently comprises 1,275 species and represents one of the most important agricultural pest families among the Acari with approximately one hundred pest species, ten of which considered major pests. The dataset presented in this document includes all the identified spider mites composing the Jean Gutierrez Collection hosted at the CBGP (Montferrier-sur-Lez, France), gathered from 1963 to 1999 during his career at the Institut de Recherche pour le Développement (IRD). It consists of 5,262 specimens corresponding to 1,564 occurrences (combination species/host plant/date/location) of 175 species. Most specimens were collected in Madagascar and other islands of the Western Indian Ocean, New Caledonia and other islands of the South Pacific and Papuasia. The dataset constitutes today the most important one available on Tetranychidae worldwide.     

Biology, ecology and control of the Penthaleus species complex (Acari: Penthaleidae)

Blue oat mites, Penthaleus spp. (Acari: Penthaleidae), are major agricultural pests in southern Australia and other parts of the world, attacking various pasture, vegetable and crop plants. Management of these mites has been complicated by the recent discovery of three cryptic pest species of Penthaleus, whereas prior research had assumed a single species. The taxonomy, population genetics, ecology, biology and control of the Penthaleus spp. complex are reviewed. Adult Penthaleus have a dark blue-black body approximately 1 mm in length, and eight red-orange legs. Within Australia, they are winter pests completing two or three generations a season, depending on conditions. The summer is passed as diapausing eggs, when long-distance dispersal is thought to occur. The Penthaleus spp. reproduce by thelytokous parthenogenesis, with populations comprising clones that differ ecologically. The three pest Penthaleus spp. differ markedly in their distributions, plant hosts, timing of diapause egg production and response to pesticides, highlighting the need to develop control strategies that consider each species separately. Chemicals are the main weapons used in current control programs, however research continues into alternative more sustainable management options. Host plant resistance, crop rotations, conservation of natural enemies, and improved timing of pesticide application would improve the management of these pests. The most cost-effective and environmentally acceptable means of control will result from the integration of these practices combined with the development of a simple field-based kit to distinguish the different mite species.     

The biology of Penthaleus species in southeastern Australia

Earth mites are major pests of pastures and crops within southern Australia. While the biology and ecology of the redlegged earth mite (Halotydeus destructor) have been studied extensively, the blue oat mite (Penthaleus major) and its recently discovered relative, Penthaleus falcatus, have received little attention. The distribution of H. destructor, P. major and P. falcatus is described in Victoria, Australia, and the inland borders in central New South Wales are re-described. A new undescribed Penthaleus species identified from mallee samples is recognized, and its restricted distribution in Victoria is mapped. Electrophoretic data and the complete absence of males indicate that all Penthaleus species are obligate thelytokous parthenogens. The three Penthaleus species differ in clonal diversity. All species are pests of pastures and/or crops, however the preferred plant hosts of P. major and P. falcatus differ. Tolerance of a commonly used pesticide (omethoate) differs between the species. P. falcatus shows the highest LC₅₀, and may be responsible for pesticide control failures. Rearing methods for P. major and P. falcatus are described. The large differences between these blue oat mite species point to difficulties in interpreting early published data that failed to distinguish them.     

Amensalism via webs causes unidirectional shifts of dominance in spider mite communities

Competitive displacement is considered the most severe consequence of interspecific competition; if a superior competitor invades the habitat of an inferior species, the inferior species will be displaced. Most displacements previously reported among arthropods were caused by exotic species. The lack of investigation of displacement among native species may be due to their apparently harmonious coexistence, even if it is equivalent to an outcome of interspecific association. A seasonal change in the species composition of spider mites, from Panonychus ulmi to Tetranychus urticae, is observed in apple trees worldwide. Previous laboratory experiments have revealed amensal effects of T. urticae on P. ulmi via their webs. Using manipulation experiments in an orchard, we tested whether this seasonal change in species composition occurred as the result of interspecific competition between these spider mites. Invasion by T. urticae prevented an increase in P. ulmi densities throughout the experimental periods. Degree of overlap relative to the independent distribution on a leaf-surface basis (ω _S) changed from positive to negative with increasing density of T. urticae. T. urticae invasion drove P. ulmi toward upper leaf surfaces (competitor-free space). The niche adjustment by P. ulmi occurred between leaf surfaces but not among leaves. Our findings show that asymmetrical competition between T. urticae and P. ulmi plays an important role in this unidirectional displacement and that the existence of refuges within a leaf produces the apparently harmonious coexistence of the mites and obscures their negative association.     

Life-history of predatory mites Neoseiulus californicus and Phytoseiulus persimilis (Acari: Phytoseiidae) on four spider mite species as prey, with special reference to Tetranychus evansi (Acari: Tetranychidae)

The commercially available strains of Phytoseiulus persimilis Athias-Henriot, the biological control agent of Tetranychus urticae Koch, perform poorly in the Western Mediterranean, probably because they are not well adapted to local climatic conditions. For that reason, efforts are being focused on the development of a biological control programme using native phytoseiid mites. Four species of red spider mites can be found in vegetable crops in eastern Spain: T. urticae, Tetranychus turkestani Ugarov and Nikolski, Tetranychus ludeni Zacher and the recently introduced Tetranychus evansi Baker and Pritchard. To evaluate their potential role as biological control agents, the present study evaluates the life-history of local populations of Neoseiulus californicus (McGregor) and P. persimilis when fed on T. urticae, T. turkestani, T. evansi, and T. ludeni in the laboratory. Results indicate that N. californicus and P. persimilis are able to feed and complete their development on the four tested red spider mite species. The predators may exhibit a particularly high capacity for population increase when fed on T. urticae, T. turkestani, and T. ludeni, thus may be able to provide effective control of these species in the field. When fed T. evansi, however, predator performance was poor; significant increase in development and preoviposition times, and a reduction in oviposition period and fecundity were recorded. The resultant low capacity for population growth suggests poor ability of the two tested predators to suppress T. evansi populations on commercial crops. It is unlikely therefore that P. persimilis and N. californicus, now being widely used to control T. urticae in greenhouse crops in Central Europe, will be able to halt any spread of T. evansi to greenhouse crops in temperate areas.     

Distribution, host specificity, and overwintering of Celatoria bosqi Blanchard (Diptera: Tachinidae), a South American parasitoid of Diabrotica spp. (Coleoptera: Chrysomelidae: Galerucinae)

The genus Diabrotica (Coleoptera: Chrysomelidae) includes a great number of pest species, including some of the most important crops pests of the Americas. However, only five parasitoid species have been recorded for it. The parasitoid Celatoria bosqi Blanchard was the first parasitoid described from Diabrotica spp. in South America, where substantial parasitism has been observed. C. bosqi has been collected almost throughout the South American distribution of its main host, Diabrotica speciosa (Germar), in an area that includes temperate and tropical lowlands, and semiarid to humid highlands. Three Diabrotica species were found to host the parasitoid, D. speciosa (Germar), Hystiopsis sp., and Diabrotica viridula (F.), with a total parasitism of 2.60, 5.55, and <0.02%, respectively. Laboratory experiments with field beetles and puparia, reared in the laboratory, indicate that C. bosqi overwinters obligatorily in overwintering adult host beetles, remaining quiescent in its live host below developmental temperatures. Based on the known climatic range of C. bosqi, and its requirement of adult overwintering hosts, a potential distribution in North America is projected.     

Tebufenpyrad: compatibility with integrated mite control on apples

Successful integrated mite control (IMC) depends on the availability of acaricides which act selectively on pest mites with minimal effects on predators. Laboratory bioassays of tebufenpyrad against adult female Panonychus ulmi (Koch) provided baseline toxicity data and showed it to be highly active. Bioassays also showed tebufenpyrad was toxic to the predatory mite Typhlodromus pyri Scheuten but it was approximately 70 times less toxic to the predators than to P. ulmi at the lc ₅₀. Field trials using four concentrations of tebufenpyrad (10, 7.5, 5 and 2.5 g a.i./100 l) confirmed it was selectively more toxic to the pest mites than to predators and showed that it is compatible with IMC. It is suggested that a concentration of 5 g a.i./100 l would be suitable for IMC. A resistance management strategy for tebufenpyrad is proposed.     

Feeding Life Style of Redlegged Earth Mite, Halotydeus Destructor (Acari: Penthaleidae), in pastures and the role of broad-leafed weeds

Redlegged earth mite, Halotydeus destructor, is a major pest of pastures and crops in Australia, and also feeds on lower plants on the soil surface. Feeding behaviour is reviewed, and the role of Arctotheca calendula, capeweed, in determining occurrence and abundance in pastures is investigated. Mites fed more and produced more progeny on Trifolium subterraneum (subclover) than on capeweed in non-choice experiments. In pastures with mixed species three times more mites were feeding on subclover than on capeweed foliage. However, twice as many mites were found on the soil surface under pasture patches consisting mainly of capeweed than of subclover. Patches were selected on the basis of pasture height, irrespective of plant composition. Twice as many mites were found in populations under patches of tall than short pasture. The daytime relative humidity was higher in tall than short patches, and the temperature slightly lower, making tall patches a more favourable niche for these mites. Ninety per cent of H. destructor were on the soil surface, while 10% were feeding on the upper canopy of pasture. The proportion of each population that was feeding was greater on subclover than capeweed, and subclover was a more suitable food. In Australia H. destructor occurs in regions with mixed pasture species, grown in rotation with grain crops. The ability of H. destructor to utilize foliage of a range of plant species of differing suitability for food, while living mostly on the soil surface in niches favourable for survival, has enabled it to become very abundant.     

Effect of a turnip rape <Emphasis Type="Italic">(Brassica rapa)</Emphasis> trap crop on stem-mining pests and their parasitoids in winter oilseed rape <Emphasis Type="Italic">(Brassica napus)</Emphasis>

Concerns about the negative effects of chemical control of oilseed rape (Brassica napus L.) pests on non-target species, human safety, and development of insecticide resistance, require alternative control strategies such as the use of trap crops and biocontrol to be developed. Psylliodes chrysocephala(L.) (Coleoptera: Chrysomelidae) (cabbage stem flea beetle) and Ceutorhynchus pallidactylus (Marsh.) (Coleoptera: Curculionidae) (cabbage stem weevil) are two major stem-mining pests of oilseed rape. This study investigated the phenology of these pests and their main parasitoids in the UK, the potential use of turnip rape (Brassica rapa L.) as a trap crop to reduce oilseed rape infestation, and the effects of insecticide treatment on pest incidence and larval parasitism. Water trap samples, plant dissections and pest larval dissections were done to determine: the incidence of adult pests and their parasitoids, the level of plant infestation by the pests and percentage larval parasitism, respectively. The turnip rape trap crop borders reduced P. chrysocephalabut not C. pallidactylus infestation of oilseed rape plots. Treatment of the trap crop with insecticide had little effect on either pest or parasitoid incidence in the oilseed rape. TersilochusmicrogasterSzép. andT. obscurator Aub. (Hymenoptera: Ichneumonidae) were the main larval parasitoids of P. chrysocephalaand C. pallidactylus, respectively. Tersilochus microgasteris reported for the first time in the UK. The implications for integrated pest management are discussed.     

Spider-Mite Problems and Control in Taiwan

Problems with spider mites first appeared in Taiwan in 1958, eight years after the importation of synthetic pesticides, and the mites evolved into major pests on many crops during the 1980s. Of the 74 spider mite species recorded from Taiwan 10 are major pests, with Tetranychus kanzawai most important, followed by T. urticae, Panonychus citri, T. cinnabarinus, T. truncatus and Oligonychus litchii. Most crops suffer from more than one species. Spider mites reproduce year-round in Taiwan. Diapause occurs only in high-elevation areas. Precipitation is the most important abiotic factor restricting spider-mite populations. Control is usually accomplished by applying chemicals. Fifty acaricides are currently registered for the control of spider mites. Acaricide resistance is a serious problem, with regional variation in resistance levels. Several phytoseiid mites and a chrysopid predator have been studied for control of spider mites with good effect. Efforts to market these predators should be intensified so that biological control can be a real choice for farmers.     

Effects of agroforestry on phytoseiid mite communities (Acari: Phytoseiidae) in vineyards in the South of France

The abundance and diversity of phytoseiid mites were surveyed from April to September 2003 to 2005 in vineyards (Grenache and Syrah cultivars) co-planted with rows of Sorbus domestica or Pinus pinea and in monoculture plots of grapes in the South of France. Densities of phytoseiid mites were different on the two tree species, with P. pinea a more suitable host than S. domestica. Typhlodromus (Typhlodromus) exhilaratus was the dominant species occurring on grapes and on co-planted rows of S. domestica and P. pinea, whereas T. (T.) phialatus was the most abundant species in monoculture plots of both S. domestica and P. pinea. Factors determining the dominance of T. (T.) phialatus over T. (T.) exhilaratus in monoculture trees are discussed. In this study, agroforestry management did not affect phytoseiid diversity in vineyards, but did affect phytoseiid density, especially in 2005. The results obtained in 2003 and 2004 are not easy to discuss in this regard because of the low densities of mites observed during these 2 years (very dry climatic conditions and pesticide applications).     

Rearing, release and establishment of imported predatory mites to control citrus rust mite in Israel

Citrus rust mite, Phyllocoptruta oleivora (Ashmead), is a major pest of citrus in Israel. Five species of predatory mites: Amblyseius herbicolus Chant, Euseius victoriensis (Womersley), Euseius elinae (Schicha), Typhlodromus rickeri Chant and Euseius stipulatus (Athias-Henriot), were imported to improve the biological control of the pest. Mite rearing and sampling methods were developed and improved, and the predators were released. Recovery in some citrus orchards was recorded, but only E. victoriensis became established in the north of Israel.     

华北平原地区景观格局对麦田害螨种群数量的影响

农业生产的集约化经营导致农田景观格局日趋单一,而农田景观格局的变化势必对害虫种群产生深刻的影响,阐明景观因子对害虫种群的作用是通过生境管理进行害虫控制的基础。以华北平原地区的山东省为研究区域,24个县级单元为样点,通过对卫星遥感影像和土地覆盖分类数据的分析,获取了样点单元的景观格局指数,同时定点调查了样点单元的麦田害螨种群数量。利用相关性分析明确了影响麦田中两种害螨—麦岩螨(Petrobia latens(Müller))和麦圆叶爪螨(Penthaleus major(Duges))种群发生的主要景观因子。研究结果表明景观因子对麦田中两种害螨种群均有显著影响,而两种害螨对景观因子的响应并不一致。麦岩螨的发生量与森林的最大斑块面积指数和平均斑块面积均呈显著正相关,而与森林类的形状和水体的景观形状指数均存在显著负相关;麦圆叶爪螨的发生量同水体的总面积、斑块面积比例、最大斑块面积指数以及县域范围的平均斑块面积均呈显著负相关,而与水体类的形状呈显著正相关。因此在麦田害螨发生较重的地区,在区域性景观规划时,可以通过优化农田周围的森林和水体管理,不利于其种群发生,从而达到对麦田害螨种群生态调控的目的。     

The pest termites of South America: taxonomy, distribution and status

Abstract: A total of 77 species of termites have been reported as structural or agricultural pests in South America. These records are reviewed, with indication of the damage they cause, their pest status, distribution and sources of information. Among these, 40 species are reported as structural pests, 53 species as agricultural pests and 15 species as both. However, only 18 species are considered major pests and the status of most of the others is uncertain. Uncertainty about status is much higher among agricultural pests. Specific taxonomic problems are discussed and distribution maps of the main pest genera and species are presented. The most important structural pests are the introduced Coptotermes havilandi and Cryptotermes brevis and the native Nasutitermes corniger. Reticulitermes was introduced into Uruguay and Chile, where it is the only serious pest. The main agricultural pests are Heterotermes spp., Nasutitermes spp., Cornitermes spp., Procornitermes spp. and Syntermes spp., and the most affected crops are sugarcane, upland rice and eucalyptus.     

Candidate natural enemies for control of Rhizoglyphus robini Claparède (Acari: Astigmata) in lily bulbs: exploration in the field and pre-selection in the laboratory

To find suitable candidates for biological control of the bulb mite, Rhizoglyphus robini Claparède (Acari: Astigmata) on lilies, exploration was undertaken in areas where the bulb mite is an established pest (The Netherlands, Taiwan and Japan). Among the predators, found in association with R. robini in the field and under storage conditions, mesostigmatic mites predominate. The most abundant species were Hypoaspis aculeifer (Canestrini), Lasioseius bispinosus Evans and Parasitus fimetorum (Berlese). These predators appeared to feed and reproduce on a diet of exclusively R. robini and they were able to control the bulb mite in small-scale population experiments initiated with a 1:20 predator-prey ratio. Under laboratory conditions corresponding to lily bulb propagation (lily scales mixed with vermiculite and stored at 23°C and >90% RH) the laelapid mite, H. aculeifer, was the most effective predator; the ascid predator, L. bispinosus, was much less effective, but being relatively small and being successful in attacking the juvenile stages of the bulb mite it may be better able to search for bulb mites hidden inside the lily bulb. The parasitid predator, P. fimetorum, failed to control the bulb mite when vermiculite was used as a medium, but turned out to suppress this prey when peat was used instead. Various strains of H. aculeifer or closely related species were compared with respect to their impact and performance on bulb mites as prey: two Dutch strains, one obtained from Breezand and the other from 'tZand, a Taiwanese strain, a German strain that in contrast to the previously mentioned strains was not collected from lily bulbs, but from agricultural areas near Bremen and, in addition, a Canadian strain of a related species (Hypoaspis miles Berlese), known to control sciarid fly larvae. These comparative experiments showed that H. miles died out without noticeable impact on the bulb mite population whereas all strains of H. aculeifer were able to suppress the bulb mites to very low numbers. However, the numerical responses of the H. aculeifer strains differed in that those collected in association with the pest (Breezand > Taiwan > 'tZand) were superior to the strain from Bremen. These results do not provide support to the Hokkanen and Pimentel hypothesis, which states that predators forming an evolutionary new association with the pest are often more effective in biological control.     

Biological control of thrips and whiteflies by a shared predator: Two pests are better than one

We studied the capacity of one species of predator to control two major pests of greenhouse crops, Western flower thrips (Frankliniella occidentalis (Pergande)) and the greenhouse whitefly (Trialeurodes vaporariorum (Westwood)). In such a one-predator–two-prey system, indirect interactions can occur between the two pest species, such as apparent competition and apparent mutualism. Whereas apparent competition is desired because it brings pest levels down, apparent mutualism is not, because it does the opposite. Because apparent competition and apparent mutualism occurs at different time scales, it is important to investigate the effects of a shared natural enemy on biological control on a time scale relevant for crop growth. We evaluated the control efficacy of the predatory mites Amblyseius swirskii (Athias-Henriot) and Euseius ovalis (Evans) in cucumber crops in greenhouse compartments with only thrips, only whiteflies or both herbivorous insects together. Each of the two predators controlled thrips, but A. swirskii reduced thrips densities the most. There was no effect of the presence of whiteflies on thrips densities. Whitefly control by each of the two predators in absence of thrips was not sufficient, yet better with E. ovalis. However, whitefly densities in presence of thrips were reduced dramatically, especially by A. swirskii. The densities of predators were up to 15 times higher in presence of both pests than in the single-pest treatments. Laboratory experiments with A. swirskii suggest that this is due to a higher juvenile survival and developmental rate on a mixed diet. Hence, better control may be achieved not only because of apparent competition, but also through a positive effect of mixed diets on predator population growth. This latter phenomenon deserves more attention in experimental and theoretical work on biological control and apparent competition.     

Tritrophic Choice Experiments with Bt Plants,the Diamondback Moth (Plutella xylostella) and the parasitoid Cotesia plutellae

Parasitoids are important natural enemies of many pest species and are used extensively in biological and integrated control programmes. Crop plants transformed to express toxin genes derived from Bacillus thuringiensis (Bt) provide high levels of resistance to certain pest species, which is likely to have consequent effects on parasitoids specialising on such pests. A better understanding of the interaction between transgenic plants, pests and parasitoids is important to limit disruption of biological control and to provide background knowledge essential for implementing measures for the conservation of parasitoid populations. It is also essential for investigations into the potential role of parasitoids in delaying the build-up of Bt-resistant pest populations. The diamondback moth (Plutella xylostella), a major pest of brassica crops, is normally highly susceptible to a range of Bt toxins. However, extensive use of microbial Bt sprays has led to the selection of resistance to Bt toxins in P. xylostella. Cotesia plutellae is an important endoparasitoid of P. xylostella larvae. Although unable to survive in Bt-susceptible P. xylostella larvae on highly resistant Bt oilseed rape plants due to premature host mortality, C. plutellae is able to complete its larval development in Bt-resistant P. xylostella larvae. Experiments of parasitoid flight and foraging behaviour presented in this paper showed that adult C. plutellae females do not distinguish between Bt and wildtype oilseed rape plants, and are more attracted to Bt plants damaged by Bt-resistant hosts than by susceptible hosts. This stronger attraction to Bt plants damaged by resistant hosts was due to more extensive feeding damage. Population scale experiments with mixtures of Bt and wildtype plants demonstrated that the parasitoid is as effective in controlling Bt-resistant P. xylostella larvae on Bt plants as on wildtype plants. In these experiments equal or higher numbers of parasitoid adults emerged per transgenic as per wildtype plant. The implications for integrated pest management and the evolution of resistance to Bt in P. xylostella are discussed.     

Papaya transformed with the Galanthus nivalis GNA gene produces a biologically active lectin with spider mite control activity

Snowdrop (Galanthus nivalis) lectin has previously been shown to have anti-feedant and insecticidal activity towards sap-sucking insects. However, its effectiveness against plant-parasitic mites has not been demonstrated. In this study, the commercial papaya (Carica papaya L.) cultivar Kapoho, which is highly susceptible to mites, was transformed with the snowdrop lectin (G. nivalis agglutin [GNA]) gene. Polymerase chain reaction confirmed the presence of the transgene and six independent transformed lines were selected for expression analysis. Western blot analysis showed that the lines expressed a recombinant protein with a molecular weight similar to that of the native snowdrop lectin. Leaf extracts containing the recombinant GNA protein agglutinated trypsinized rabbit erythrocytes thus, showing the GNA protein to be biologically active. ELISA and indirect measurement from the agglutination assay showed there to be variation in GNA expression among the lines produced. A laboratory bioassay using carmine spider mites (Tetranychus cinnabarinus) suggested improved pest resistance in the transgenic papaya plants. This is the first report that a transgenic plant expressing the GNA gene possesses enhanced resistance to a plant-parasitic mite.     

Survival and reproduction of the pest mites <Emphasis Type="Italic">Balaustium medicagoense</Emphasis> and <Emphasis Type="Italic">Bryobia</Emphasis> spp. on winter grain crops

Balaustium medicagoense and Bryobia spp. have recently been identified as emerging pests of winter crops and pastures in Australia. These mites have a high natural tolerance to currently registered pesticides, highlighting the need to develop alternative control strategies such as cultural controls which require an understanding of plant associations. In shade-house experiments, Bryobia spp. survived and reproduced successfully on pasture, lupins and oats, but progeny failed to reach the adult stage on canola and wheat. Balaustium medicagoense progeny failed to produce a generation on any crop but parental adults survived a few months on all crops, particularly wheat. Bryobia spp. damaged canola, pasture and lupins, but caused minimal damage to oats and wheat, whereas Ba. medicagoense caused considerable damage to wheat and lupins, but only moderate damage to canola, oats and pasture. Field survey data, taken from approximately 450 sites across southern Australia, combined with analysis of historical pest reports, suggest broadleaf crops such as canola, lucerne, lupins and weeds appear particularly susceptible to attack by Bryobia species. Balaustium medicagoense was more commonly found on cereals and grasses, although they also attacked broadleaf crops, particularly canola, lucerne and lupins. These findings show that the mites have the potential to be an important pest on several winter grain crops and pasture, but there are important differences that can assist in management strategies such as targeted crop rotations.