Primer design for identifying economically important Liriomyza species (Diptera: Agromyzidae) by multiplex PCR

Leafminer flies, especially, Liriomyza huidobrensis, Liriomyza sativae and Liriomyza trifolii, are quarantine species in many countries. Their morphological similarity makes identification difficult. To develop a rapid, reliable, sensitive and simple molecular identification method using multiplex PCR, we newly sequenced the mitochondrial cytochrome oxidase I (COI) genes of Liriomyza bryoniae, Liriomyza chinensis, L. huidobrensis, L. sativae, L. trifolii, Chromatomyia horticola and four parasitoid species. We aligned them with all the COI sequences of the leafminer flies found in the international DNA nucleotide sequence databases (DDBJ/EMBL/GenBank). We then designed species‐specific primers to allow us to differentiate between L. bryoniae, L. chinensis, L. huidobrensis, L. sativae, and L. trifolii.     

Egg-collection equipment for Liriomyza leafminers (Diptera: Agromyzidae)

Egg-collection equipment for Liriomyza leafminers was designed using a small glass tube with a glucose solution supported between two thin films. Adult female Liriomyza trifolii (Burgess), which were previously reared on kidney bean for 2–4 days, laid abundant eggs in 5 or 10% glucose solutions. Hatchability of the eggs in the solutions was greater than 80%. The equipment was used successfully to collect eggs from another leafminer species, Liriomyza sativae Blanchard.     

Allozymatic diagnosis of four economically important Liriomyza species (Diptera, Agromyzidae)

Liriomyza bryoniae, L. huidobrensis, L. sativae and L. trifolii are leafminers of great economic importance; morphologically they are difficult to separate, many being inseparable at the pre-adult stages. Horizontal starch gel electrophoresis of larvae, pupae and adults was carried out in order to search for diagnostic allozymic characters. Analysis of the variation patterns at 15 genetic loci reveals that each species can be identified at all three stages of the life cycle. A biochemical key is presented.     

Volatiles released from bean plants in response to agromyzid flies

Liriomyza sativae Blanchard and Liriomyza huidobrensis (Blanchard) (Diptera: Agromyzidae) are two invasive flies in China that have caused economical damage on vegetables and ornamental plants. In this article, we report the profiles of emitted volatiles from healthy, mechanically damaged, and leafminer-damaged bean, Phaseolus vulgaris L., plants. Among 25 emitted volatiles identified, (E)-2-hexen-1-al, (3E)-4,8-dimethyl-1,3,7-nonatriene (DMNT), (Z)-3-hexenyl acetate, (Z)-3-hexen-1-ol, (syn)- and (anti)-2-methylpropanal oxime, (syn)-2-methylbutanal oxime, linalool, and (E,E)-α-farnesene were consistently released from damaged bean plants. Combined amounts of these nine compounds made up more than 70% of the total volatiles emitted from each treatment. No qualitative differences in volatile emission were found between bean plants damaged by the two fly species; however, amounts of several major compounds induced by L. huidobrensis damage were significantly higher than those from plants damaged by L. sativae. The mechanically damaged plants released a higher proportion of green leaf volatiles than plants in the other treatments, whereas leafminer-damaged plants produced more terpenoids and oximes. Furthermore, the volatile profiles emitted from plants, damaged by adult leafminers, by second instar larvae, and even the plants with empty mines left by leafminer larvae (the pupal stage) were significantly different. The identification of volatile oximes released from damaged plants was confirmed and is discussed in a behavioral and biological control context.Electronic Supplementary Material Supplementary material is available for this article at and is accessible for authorized users.     

Effects of cyromazine and abamectin on the leafminer, Liriomyza huidobrensis and its parasitoid, Diglyphus isaea in celery

Field trials were conducted for 2 yr on celery (Apium graveolens L.) to determine the effects of two translaminar insecticides (abamectin and cyromazine) on the agromyzid leafminer, Liriomyza huidobrensis (Blanchard), and the eulophid parasitoid, Diglyphus isaea Walker. Abamectin and cyromazine were applied once early in the growing season by spray or drip application. Yellow sticky traps and leaf samples were used to monitor population levels; a gas chromatograph-mass spectrometer was used to monitor cyromazine residues within the celery plants during 1 yr. Spray applications of abamectin and cyromazine significantly reduced larval leafminers and D. isaea. Contrary to grower practices, application of cyromazine by drip irrigation systems had minor effects on larval leafminer and D. isaea as compared to spray application. Cyromazine residues in the plants treated by spray application declined sharply after 1 wk, and no residues were detected 2 wk after application; less than 0.05 ppm cyromazine residues were detected in plants treated by drip application. Implications of these results on management practices are discussed.     

Invasion of Japan by exotic leafminers <Emphasis Type="Italic">Liriomyza</Emphasis> spp. (Diptera: Agromyzidae) and its consequences

Identifying patterns and causes of species displacement is important from the viewpoints of ecology and evolutionary biology as this phenomenon affects community structure. Here I review the species displacement between Liriomyza trifolii (Burgess) and Liriomyza sativae Blanchard (Diptera: Agromyzidae) in Japan. These two species and Liriomyza huidobrensis (Blanchard) originated from the New World and are considered to have invaded Japan from around 1990 to the early 2000s. During this period, L. trifolii was apparently displaced by L. sativae, but the direction of displacement in Japan has been contrary to that observed between the same two species in the USA and China. While the displacement of L. sativae by L. trifolii in these two countries can be attributed to the lower insecticide susceptibility of L. trifolii there, species displacement in the opposite direction in Japan is probably due to the relatively high fecundity of L. sativae and differential effects of the introduced parasitoid Dacnusa sibirica Telenga (Hymenoptera: Braconidae) on both Liriomyza species, except in the south of the country.     

Effects of host instar and size on parasitization efficiency and life history parameters ofOpius dissitus

The braconid parasitoidOpius dissitus Muesebeck (Hymenoptera, Braconidae) produced 1.7 to 3 times more offspring when provided second and third instar leafminers (Liriomyza sativae Blanchard) as compared to first instars. Females arising from parasitization of different instars did not differ significantly in numbers of chorionated eggs in their ovaries at adult eclosion. Development time was prolonged by about two days when parasitoid oviposition occurred in first, as compared to third instar hosts. Parasitoid length was positively correlated with host weight (r²=0.75). Because only 7% of variation in host weight could be explained by host density, parasitoid length varied considerably among hosts reared at the same density. Longevity and lifetime fecundity of parasitoids were inversely related to the weight of their hosts.     

Host range and genetic strains of leafminer flies (Diptera: Agromyzidae) in eastern Brazil reveal a new divergent clade of Liriomyza sativae

相似文献   

A genome-wide phylogeny and the diversification of genus Liriomyza (Diptera: Agromyzidae) inferred from anchored phylogenomics

The genus Liriomyza Mik (Diptera: Agromyzidae) is a diverse and globally distributed group of acalyptrate flies. Phylogenetic relationships among Liriomyza species have remained incompletely investigated and have never been fully addressed using molecular data. Here, we reconstruct the phylogeny of the genus Liriomyza using various phylogenetic methods (maximum likelihood, Bayesian inference, and gene tree coalescence) on target-capture-based phylogenomic datasets (nucleotides and amino acids) obtained from anchored hybrid enrichment (AHE). We have recovered tree topologies that are nearly congruent across all data types and methods, and individual clade support is strong across all phylogenetic analyses. Moreover, defined morphological species groups and clades are well-supported in our best estimates of the molecular phylogeny. Liriomyza violivora (Spencer) is a sister group to all remaining sampled Liriomyza species, and the well-known polyphagous vegetable pests [L. huidobrensis (Blanchard), L. langei Frick, L. bryoniae. (Kaltenbach), L. trifolii (Burgess), L. sativae Blanchard, and L. brassicae (Riley)]. belong to multiple clades that are not particularly closely related on the trees. Often, closely related Liriomyza species feed on distantly related host plants. We reject the hypothesis that cophylogenetic processes between Liriomyza species and their host plants drive diversification in this genus. Instead, Liriomyza exhibits a widespread pattern of major host shifts across plant taxa. Our new phylogenetic estimate for Liriomyza species provides considerable new information on the evolution of host-use patterns in this genus. In addition, it provides a framework for further study of the morphology, ecology, and diversification of these important flies.     

Interspecific and intraspecific differences in two Liriomyzaleafminer species in California

In recent years, the pest status of Liriomyza trifolii (Burgess) and L. huidobrensis (Blanchard) (Diptera: Agromyzidae) has changed in California, as well as other areas of the world. In California, L. huidobrensis has become the predominant Liriomyza species in valleys along the central coast, while L. trifolii remains the predominant species in southern California. To investigate possible reasons for this change in status, differences in host plant use and reproductive success of intraspecific populations were examined for Liriomyza trifolii and L. huidobrensis from both central and southern California. The southern L. trifolii fed, oviposited and reproduced successfully on all five hosts tested, but the central population fed significantly less on all hosts and was restricted to reproducing on pepper only. With the exception of pepper, southern L. trifolii had significantly greater larval survival on all hosts than central L. trifolii. In contrast, the central L. huidobrensis population had greater reproductive success than the southern population of that species on all hosts plants tested. However, pepper was not a suitable host for either L. huidobrensis population. Both species showed positive assortative mating, with homotypic mating occurring more frequently than heterotypic mating; however, the difference between L. trifolii populations was much more pronounced than between L. huidobrensis populations. These data indicate that central and southern California populations of each species are distinct biotypes. Furthermore when coupled with previous genetic data, our results suggest the possible existence of cryptic species within L. trifolii.     

Adult experience modifies attraction of the leafminer parasitoidOpius dissitus (Hymenoptera: Braconidae) to volatile semiochemicals

Oviposition-experienced females of Opius dissitus Muesebeck, a braconid parasitoid of Liriomyza sativaeBlanchard, preferentially landed on leafminer-infested rather than uninfested lima bean (Phaseolus lunatus L.) plants in a flight tunnel assay. Both naive and oviposition-experiencedparasitoids responded strongly to odors of infested lima bean plants in a four-arm olfactometer in comparison with odors of uninfested plants, suggesting that volatile semiochemicals are used in host location. Parasitoids with an oviposition experience on lima bean (lima-experienced) spent significantly more time in the infested odor than naive individuals, however, eggplant-experienced wasps did not spend significantly more time in the infested odor field than naive wasps. When parasitoids reared on leafminers in lima bean were provided a choice between the odor of infested lima bean and the odor of infested eggplant or cotton, naive and lima-experienced wasps preferred infested lima odor. An oviposition experience on the other plant species resulted in a dramatic shift in preference. It was concluded that the experience effect was due, at least in part, to associative learning, as has been reported for other parasitoids. The parasitoids may perceive unconditioned stimuli during host contact and oviposition on an infested leaf and may associate those stimuli with volatile semiochemicals emanating from the leaf or host. Subsequently, the volatiles associated with the presence of hosts are used in directing the search for hosts.     

Morphological and genetic characteristics of Liriomyza huidobrensis (Blanchard) (Diptera: Agromyzidae) infesting potato crops in Korea

The pea leafminer fly, Liriomyza huidobrensis (Blanchard), was found infesting and damaging Korean potato crops during a 2012 field survey. Localized outbreaks of L. huidobrensis were observed in Miryang and Goryeong counties in the south of the Korean Peninsula. This paper describes the morphological and genetic characteristics of the Korean population of L. huidobrensis. The dorsal color pattern on the abdomen, and an array of microsetae on the thorax, were the main diagnostic characteristics of this species. On the basis of an analysis of a partial mitochondrial cytochrome c oxidase subunit 1 (COI) DNA sequence, we found that intraspecific variation in L. huidobrensis was negligible, and that the distance between L. huidobrensis and a closely related species, L. trifolii, was estimated to be 7.4–7.6 K2P. This is the first report of the infestation of field crops by the invasive leafminer L. huidobrensis in Korea.     

The occurrence of leafminers and their parasitoids on vegetables and weeds in Hangzhou area, Southeast China

Leafminers are the mostimportant insect pests of vegetables inHangzhou area, Zhejiang province, SoutheastChina as well as in the rest of China, but havenever been investigated for speciescomposition, relative abundance and theirassociated parasitoids. A survey was conductedin four localities of Hangzhou area during 1998–2000to determine the distribution ofleafminers and their parasitoids on vegetablecrops and weeds in the field. Over 20,000leafminers were collected and reared. Theleafminer species found were Liriomyzasativae, L. chinensis and Chromatomyia horticola, with C.horticola and L. sativae the mostabundant in spring and autumn, respectively.About 11,000 parasitoid adults were reared fromthe leafminers collected. In total 14hymenopteran species of four families (onebraconid, 10 eulophids, one megaspilid and onepteromalid) were found. Eleven species werereared from C. horticola, nine from L. sativae and seven from L. chinensis.Opius caricivorae and Chrysocharispentheus were the dominant species. Sevenspecies were recorded from L. chinensisfor the first time. Eleven parasitoid specieswere reared from leafminers on two weeds (Veronica undulata and Sonchusoleraceus). Parasitoids caused 48.5–68.8%parasitism on leafminers on crops and 83.7%parasitism on leafminers on weeds in the latergrowing season of vegetable crops. The resultssuggest that leafminer populations areregulated to a certain extent by their naturalenemies in the field.     

Displacement in two invasive species of leafminer fly in different localities

Liriomyza sativae was displaced by L. trifolii in the USA probably due to the lower insecticide susceptibility of L. trifolii, but L. trifolii was displaced by L. sativae in Japan. To know the possible causes of the species displacement observed in Japan, differences in the insecticide susceptibility, fecundity, effects of natural enemies, and reproductive interference between L. trifolii and L. sativae were evaluated. As a result, the higher fecundity of L. sativae and differential effects of parasitoids on the two Liriomyza species are considered to be contributing factors.     

Analysis of three leafminers' complete mitochondrial genomes

Liriomyza trifolii (Burgess), Liriomyza huidobrensis (Blanchard), and Liriomyza bryoniae (Kaltenbach), are three closely related and economically important leafminer pests in the world. This study examined the complete mitochondrial genomes of L. trifolii, L. huidobrensis and L. bryoniae, which were 16141 bp, 16236 bp and 16183 bp in length, respectively. All of them displayed 37 typical animal mitochondrial genes and an A + T-rich region. The genomes were highly compact with only 60–68 bp of non-coding intergenic spacer. However, considerable differences in the A + T-rich region were detected among the three species. Results of this study also showed the two ribosomal RNA genes of the three species had very limited variable sites and thus should not provide much information in the study of population genetics of these species. Data generated from three leafminers' complete mitochondrial genomes should provide valuable information in studying phylogeny of Diptera, and developing genetic markers for species identification in leafminers.     

Mass production of Diglyphus isaea (Hymenoptera: Eulophidae), a biological control agent of a Korean population of potato leaf miner Liriomyza huidobrensis (Blanchard) (Diptera: Agromyzidae)

The potato leaf miner, Liriomyza huidobrensis (Blanchard), is an important pest of potato throughout the world, including Korea. A method was developed for mass rearing the parasitoid Diglyphus isaea (Walker) using faba bean, Vicia faba L. (Fabaceae), as the host‐plant and L. huidobrensis as the insect host. Faba bean plants were planted in pots and maintained in a greenhouse for about 15 d. Pots were then exposed to adult leaf miners in oviposition cages for 4 h. Plants containing late second to early third instar larvae were exposed to adult D. isaea in parasitoid cages for 24 h. The leaf area per pot after 15 d was 597.9 cm², which produced 103.33 larvae per pot. The number of adult parasitoids emerging per pot was 72.5; about 41% of these were female. The daily cost of parasitoid production was USD20.95 per 1000 individual parasitoids. The methodology developed for D. isaea could be used to rear other ectoparasitoids such as Hemiptarsenus spp. and Pnigalio sp. with different insect hosts like L. trifolii. This is why this mass‐rearing information is important for securing test insect materials for ecological and biological study of Liriomyza species, and also for developing a biological control for Liriomyza species other than L. huidobrensis by mass production of associated natural enemies. We are facing rapid agro‐ecosystem changes including pest systems. Continuous monitoring of Liriomyza in solanaceous crops is needed.     

Parasitoid associated with Liriomyza huidobrensis (Diptera: Agromyzidae) outbreaks in tomato fields in Brazil

1. The knowledge of natural factors that affect pest populations is essential in predicting the occurrence of pest outbreaks and in developing integrated pest management programmes. Natural enemies, climatic elements and host plants are among the most important factors affecting pest dynamics.
2. Tomato (Solanum lycopersicum) is the second most consumed vegetable worldwide. The pea leaf miner Liriomyza huidobrensis (Diptera: Agromyzidae) is a major pest to the tomato in Brazil.
3. This study aimed to determine the main natural factors that regulate L. huidobrensis populations in tomato fields in Brazil.
4. Liriomyza huidobrensis densities were evaluated by directly counting the number of active mines on the basal leaf of the middle section of the plant canopy, and predators and parasitoids were assessed using the leaf‐beating‐against‐a‐tray technique. Eight commercial tomato fields were assessed over two years. The phenological growth stages of the tomato plants (vegetative and reproductive) were noted during the assessments.
5. Liriomyza huidobrensis populations peaked between the middle and end of the planting season.
6. Opius sp. (Hymenoptera: Braconidae) was the main natural enemy of L. huidobrensis.
7. Our results suggest that phenological growth stage and Opius sp. are associated with population dynamics of L. huidobrensis in tomato fields.
8. Therefore, integrated pest management programmes should aim to preserve populations of the parasitoid Opius sp.

     

A tritrophic analysis of host preference and performance in a polyphagous leafminer

The optimal oviposition theory predicts that oviposition preferences of phytophagous insects should correlate with host suitability for their offspring. As plant host suitability depends not only on its quality as food, but also on its provision of enemy‐free space, we examined the relationship between adult host preference and offspring performance for the leafminer Liriomyza huidobrensis (Blanchard) (Diptera: Agromyzidae) on various host plants, considering also the interaction with natural enemies. Preference and offspring performance were assessed through observational field data and laboratory experiments in central Argentina. Field data suggested a positive host preference – performance linkage, as the leafminer attained larger body size on the crops where it was more abundant. Laboratory trials supported these results: Vicia faba L. (Fabaceae) was the preferred host in the laboratory as well as in the field, performance of L. huidobrensis being also best on this host, with highest survival rates and shortest development time. The actively feeding larval stage showed the largest plant‐related effects. Higher overall parasitism rates were found on plants from which smaller leafminers were reared, reinforcing the preference–performance linkage. On the other hand, the main parasitoid Phaedrotoma scabriventris Nixon (Hymenoptera: Braconidae) reached larger body size, and caused higher mortality rates on crops where the leafminer was larger. Changes in abundance of particular parasitoid species could thus modify overall parasitism trends.     

Effects of Melia azedarach, (Meliaceae) fruit extracts on the leafminer Liriomyza huidobrensis, (Diptera, Agromyzidae): Assessment in laboratory and field experiments

Control of the widely distributed pest Liriomyza huidobrensis, is complicated due to the protected habit of the leafmining larvae, and their resistance to insecticides. The effects of Melia azedarach, (Meliaceae) fruit extracts against adults and larvae of L. huidobrensis, were investigated. In the laboratory, leaves of Cucurbita, sp. infested with first and third instar larvae were treated with different extract solutions. Larval and pupal survival, as well as wing‐spread of adults, were ssessed. Female adult behaviour towards the extract was also analysed in terms of number of feeding punctures and number of offspring left on treated/untreated leaves. In the field, an infested Vicia faba, crop was sprayed four times at weekly intervals with plant extract, water, and a blank solution. The number of adult leafminers and parasitoids emerging from sampled leaves from each treatment were compared. The laboratory tests showed translaminar action of the extracts, which negatively affected leafminer pupal survival, while body size was not affected. The extracts also deterred feeding by adult females and may also have caused reduction in oviposition rates. All solutions and concentrations tested had similar effects. In the field, extract effects were consistent with those from laboratory trials, number of pupae and pupal survival being lower on treated plants. Percentage parasitism was not affected by plant extract treatment, suggesting a selective activity.     

The compatibility of the entomopathogenic nematode,Steinernema feltiae, and chemical insecticidesfor the control of the South American leafminer, Liriomyza huidobrensis

The compatibility of infectivejuveniles (IJs) of entomopathogenic nematodes, Steinernema feltiae, and chemical insecticides tocontrol larval stages of the South American leafminer,Liriomyza huidobrensis, was investigated.Initially the effect of direct IJ exposure to 5insecticides (abamectin, deltamethrin, dimethoate,heptenophos and trichlorfon) for 24 hours was testedagainst Galleria mellonella in a standard sandtube bioassay. Trichlorfon and dimethoate did notreduce the nematodes ability to locate and infect G. mellonella larvae to an unacceptable level. However,nematode infectivity was significantly reducedfollowing exposure to abamectin, deltamethrin andheptenophos. Secondly, IJ infectivity for L.huidobrensis in the presence of dry pesticideresidues on foliage was tested. No significantdetrimental effects on the level of control of L. huidobrensis was recorded when compared with theeffect of nematodes applied to residue free foliage.The integration of these agents into a pest managementprogramme is discussed.