Leafminers in vegetables,ornamental plants and weeds in Indonesia: Surveys of host crops,species composition and parasitoids

Extensive surveys of vegetable, ornamental and weedy plant species were conducted in highland and lowland vegetable production areas in Indonesia with the aim of recording leafminer species present and their associated natural enemies. The most common dipterous species reared from samples was the pea leafminer, Liriomyza huidobrensis (Blanchard) (Diptera: Agromyzidae). This introduced pest was particularly serious in highland vegetables in Java, Sumatra and South Sulawesi, causing yield losses as high as 60-70%. Another alien species, the vegetable leafminer, Liriomyza sativae Blanchard, contributed to problems in lowland areas on the north coast of West Java, where cucumbers were heavily damaged. An Asian leafminer species, Chromatomyia horticola Goureau, was more common in snow peas (Pisum sp.). Intensive sampling of leafminer-infested leaves from surveyed host plants yielded 11 species of hymenopteran parasitoids: 10 eulophids (Asecodes sp., Chrysocharis sp., Cirrospilus ambiguus (Hansson and LaSalle), Closterocerus sp., Hemiptarsenus varicornis (Girault), Neochrysocharis formosa (Westwood), Neochrysocharis sp., Pnigalio sp., Quadrastichus sp., Zagrammosoma sp.) and 1 eucoilid (Gronotoma sp.). The most abundant parasitoid species was H. varicornis. Levels of parasitism varied among crops and growing seasons, but were usually low, especially on potato (< 3%). Surveys revealed that most farmers (63%) attempted to control leafminers by applying insecticides twice weekly although these applications were neither effective nor economical according to responses of about 72% of the farmers. An integrated pest management approach is suggested that emphasizes IPM training for vegetable farmers and includes reductionor elimination of broad spectrum chemicals that would adversely affect parasitoids that may already be present as well as those that may be introduced. The initiation of a classical biological control programme is recommended to enhance the limited parasitoid complex present in Indonesia and increase levels of biological control.     

Induced resistance against leafminer eggs by extrusion in young potato plants

Abstract

Egg extrusion patterns were investigated as an inducible defensive mechanism in potato plants against the leafminer Liriomyza huidobrensis (Blanchard) (Diptera: Agromyzidae). Increased multiplication rates in leaf cells surrounding an egg of L. huidobrensis leads to its exposure through the leaf cuticle, which might increase the risk of mortality. Extrusion rates were evaluated in laboratory tests, in relation to plant and leaf age in Solanum tuberosum L. var. Spunta. Stratified field sampling was also carried out in order to assess leafminer distribution on new and old leaves. Extrusion was higher in young plants, being restricted in older ones to new, still expanding leaves. Plant reaction was independent of egg density. In the field, damage was concentrated in older foliage, in line with the extrusion results. The relevance of egg extrusion for pest management is discussed.     

Note: Systemic effects of a spinosad insecticide onLiriomyza huidobrensis Larvae

In an effort to expand the spectrum of larvicides effective againstLiriomyza huidobrensis (Blanchard), the effect of spinosad was studied on the mortality of the leafminer under laboratory conditions. Bean plants infested with various leafminer stages (egg through third instar) were treated by dipping leaves in a liter of water containing 24, 48 or 96 mg a.i. spinosad or by drenching the soil of plants with 200 ml of water containing 12 mg, 24 mg or 48 mg a.i. spinosad. In general, leaf dipping was more efficacious and adverse effects were observed sooner than with soil drench. All concentrations of spinosad significantly reduced the number of adults that emerged except leaf dip of third instar; only the highest concentration caused significant reduction of pupae and adults. Spinosad would likely be a valuable insecticide for control of the pea leafminer,L. huidobrensis. http://www.phytoparasitica.org posting Nov. 4, 2005.     

First record of Phytomyza gymnostoma Loew (Diptera: Agromyzidae) a leaf mining pest of leeks in Greece

In autumn 2007, an allium leafminer, Phytomyza gymnostoma Loew (Diptera: Agromyzidae), was recorded for the first time in non‐commercial leek crops in the areas of Elassona and Katerini in Central Greece. Leek plants were severely damaged by the leafminer larvae infestation. Typical feeding symptoms were observed, caused by the mining behaviour of larvae within inner and outer leaves of leek plants, resulting in the formation of descending galleries. Pest control was performed locally using commercial insecticides with unknown efficacy mainly due to ignorance of the species biology.     

Systemic applications of neem in the control ofCameraria ohridella, a pest of horse chestnut (Aesculus hippocastanum)

Systemic injection of neem (azadirachtin) was tested in the control of horse chestnut leafminer,Cameraria ohridella Deschka & Dimic (Lepidoptera: Gracillariidae), a pest of horse chestnut trees (Aesculus hippocastanum L.: Hippocastanaceae). Three concentrations, 0.08, 0.15 and 0.25 g of active ingredient (a.i.) per cm of diameter at breast height (dbh), provided long-lasting insecticidal activity. The 0.15 and 0.25 g a.i. concentrations resulted in 100% pupae reduction in all generations; the 0.08 g a.i. concentration was effective against the horse chestnut leafminer for at least 23 weeks and led to 70–80% pupae reduction. Treated trees did not lose their leaves before winter. Neem applicationvia injection is cheap, with no environmental hazards, and thus this treatment is recommended for the control ofC. ohridella in horse chestnut trees. http://www.phytoparasitica.org posting Dec. 19, 2004.     

Aesculus pavia foliar saponins: defensive role against the leafminer Cameraria ohridella

BACKGROUND: Recently, the leafminer Cameraria ohridella Deschka & Dimic has caused heavy damage to the white‐flowering horse chestnut in Europe. Among the Aesculus genus, A. pavia L. HBT genotype, characterised by red flowers, showed an atypical resistance towards this pest. Its leaves, shaken in water, originated a dense foam, indicating the presence of saponins, unlike the common horse chestnut tree. The aim was to isolate and identify these leaf saponins and test their possible defensive role against C. ohridella. RESULTS: Spectroscopic analyses showed that A. pavia HBT genotype leaves contained a mixture of saponins, four of which were based on the same structure as commercial escin saponins, the typical saponin mixture produced by A. hippocastanum and accumulated only within bark and fruit tissues. The mixture showed a repellent effect on C. ohridella moth. The number of mines detected on the leaves of A. hippocastanum plants treated with A. pavia HBT saponins through watering and stem brushing was significantly lower than the control, and in many cases no mines were ever observed. CONCLUSION: The results showed that the exogenous saponins were translocated from roots/stem to the leaf tissues, and their accumulation seemed to ensure an appreciable degree of protection against the leafminer. Copyright © 2010 Society of Chemical Industry     

The newest leafminer pest in Israel,Liriomyza huidobrensis

The pea leafminer,Liriomyza huidobrensis (Blanchard), recently introduced into Israel, has proven to be extremely proliferous and difficult to control. It is a much more serious pest of vegetable and flower crops than the previously introducedLiriomyza trifolii (Burgess). Photosynthesis is reduced and cosmetic damage is incurred when adult flies stipple plant leaves with feeding punctures and larvae mine the leaves. This paper will review briefly the history, biology and potential control measures of the pea leafminer.     

Checklist of agromyzidae (Diptera) of Turkey,with a new record

The first checklist of Turkish leafminers of the family Agromyzidae (Diptera), comprising 78 species, is presented.Melanagromyza cunctans (Meigen, 1830) is recorded as new for the Turkish leafminer fauna. http://www.phytoparasitica.org posting Feb. 2, 2002.     

Establishment and dispersal of the parasitoids Ageniaspis citricola Logvinovskaya (Hymenoptera: Encyrtidae) and Semielacher petiolatus Girault (Hymenoptera: Eulophidae), introduced into Tunisia for the biological control of Phyllocnistis citrella (Lepidoptera: Gracillariidae)

Abstract

A programme for the biological control of the citrus leafminer Phyllocnistis citrella Stainton (Lepidoptera, Gracillariidae) was carried out in Tunisia between 1996 and 1998. Two exotic parasitoids, Ageniaspis citricola (Logvinovskaya) (Hymenoptera, Encyrtidae) and Semielacher petiolatus Girault (Hymenoptera, Eulophidae), were introduced from Australia, mass-reared in a greenhouse on Citrus aurantium L. seedlings infested with P. citrella, and released in different orchards located in the major citrus-growing area of Tunisia. In 1996, A. citricola was recovered in 39.13% of release sites, reaching a maximum percentage of parasitism of 28%. In 1997, the parasitoid was recovered in a third of all release points, with an average percentage of parasitism of 5%. However, the wasp was unable to survive the winter 1998, and has become extinct. The non-establishment of A. citricola may have been due to the more arid climatic conditions present during the rainless summer and most of the autumn in Tunisia. By contrast, the establishment, dispersal, and reduction in citrus leafminer population observed with S. petiolatus between 1997 and 1998 shows this species to be well-adapted to the Tunisian climate. The average percentage parasitism of P. citrella by S. petiolatus increased from 6.6% in 1997 to 15% in 1998. Moreover, S. petiolatus was established in 76% of release points in 1997 and in 82% in 1998. It spread as much as 30 km from some release points, with no apparent decline in parasitism levels with distance. Semielacher petiolatus is considered to be an effective biological control of the leafminer in Tunisia. Its biological control action would supplement the action of the native parasitoids Pnigalio sp. and Cirrospilus pictus Nees (Hymenoptera, Eulophidae).     

Residual activity of abamectin and spinosad against the predatory bugOrius laevigatus

The residual effect of two biopesticides, abamectin and spinosad, on the predatory bugOrius laevigatus (Fieber) (Hemiptera: Anthocoridae) was tested using a laboratory and an extended laboratory method. Experiments were conducted in the spring and summer 2000. The LD₅₀s on the 2nd and 5th nymphal instar and the adult stage, were lower for abamectin than for spinosad. The toxicity of each product on the 2nd instar and adults was significantly greater than on the 5th nymphal instar. Abamectin was much more persistent in spring than in summer. Spray deposits (at the recommended rate of 10 ppm a.i. for leafminer control) were toxic for 1 month in spring, whereas in summer they were no longer toxic after 2 weeks. Spinosad summer spray deposits (recommended rate of 250 ppm a.i. for leafminer and caterpillar control) were not toxic after 5 residual days. http://www.phytoparasitica.org posting Aug. 26, 2002.     

Possible symbiont-induced thelytoky inGaleopsomyia fausta, a parasitoid of the citrus leafminerPhyllocnistis citrella

Galeopsomyia fausta (Hymenoptera: Eulophidae) is a thelytokous parasitic wasp attacking the citrus leafminer,Phyllocnistis citrella Stainton (Lepidoptera: Gracillariidae). To improve the performance of that wasp as a natural enemy, the nature of its uniparental reproduction was studied. It was found that the production of males can be induced by antibiotic treatments, but attempts to establish a biparentalG. fausta line have failed. The reproductive barrier between antibiotic-induced males and conspecific females appears to be the non-receptivity of females. The results imply involvement of microorganisms in the thelytokous reproduction ofG. fausta, but noWolbachia was detected in polymerase chain reaction.     

Occurrence and host plants of Frankliniella occidentalis and Liriomyza huidobrensis in Belgium1

Increasing international trade in plants has resulted in repeated import of foreign pests into Belgium; Opogona sacchari and Coccotrypes dactyliperda are well known examples. Recently two new pests have been introduced into Belgium, Frankliniella occidentalis and Liriomyza huidobrensis. The thrips F. occidentalis appeared in the summer of 1987, and was first found in chrysanthemums. At present, this insect can be observed in floriculture, as well as in vegetable growing, where it occurs on a wide range of host plants. F. occidentalis is now considered definitely established in glasshouses in Belgium. At the end of 1989, the leafminer L. huidobrensis was found for the first time in Belgium. The damage was observed on chrysanthemums and lettuce. In 1990, this leafminer also attacked other crops, especially tomatoes and celery. Its distribution is still limited, as is the damage it causes.     

Evaluation of effectiveness of Insegar (fenoxycarb 250 g/kg) WP against Phyllocnistis citrella Stainton (Lep., Gracillariidae) and its effect on Cales noacki How. (Hym., Aphelinidae)

Aiming to control the citrus leafminer Phyllocnistis citrella St. while at the same time protecting the biological equilibrium and mainly the beneficial insect Cales noacki, experiments have taken place in the regions of Argolis and Fthiotis, Greece in 1996 and 1997. Insegar (fenoxycarb) 2 5 WP was applied on young citrus trees. During 1996, the compound, applied every 10 days at a rate of 30 g/hI (with or without adjuvant), gave satisfactory protection from P. citrella without substantially harming C. noacki populations. No phytotoxicity symptoms were observed during the experiments.     

Evaluation of effectiveness of Insegar (fenoxycarb 250 g/kg) WP against Phyllocnistis citrella Stainton (Lep., Gracillariidae) and its effect on Cales noacki How. (Hym., Aphelinidae)

Aiming to control the citrus leafminer Phyllocnistis citrella St. while at the same time protecting the biological equilibrium and mainly the beneficial insect Cales noacki, experiments have taken place in the regions of Argolis and Fthiotis, Greece in 1996 and 1997. Insegar (fenoxycarb) 2 5 WP was applied on young citrus trees. During 1996, the compound, applied every 10 days at a rate of 30 g/hI (with or without adjuvant), gave satisfactory protection from P. citrella without substantially harming C. noacki populations. No phytotoxicity symptoms were observed during the experiments.     

Impact of glucosinolate in relation to leafminer,Liriomyza brassicae Riley (Diptera: Agromyzidae) infestation in crucifers

Eight species belonging to the Family Cruciferae were classified to lafminer resistant, tolerant and susceptible on the basis of leafminer infestation. They were analyzed for the glucosinolate content and correlated with leafminer infestation. Total glucosinolate content in general and sinigrin content in particular appeared to have the ability to repel the attack ofLiriomyza brassicae, while gluconapin appeared to attract them. The percentage of infestation, the number of mines and the number of living larvae were estimated for evaluating the glucosinolate efficacy againstL. brassicae on cabbage.     

Impact of glucosinolate in relation to leafminer,Liriomyza brassicae Riley (Diptera: Agromyzidae) infestation in crucifers

Eight species belonging to the Family Cruciferae were classified to lafminer resistant, tolerant and susceptible on the basis of leafminer infestation. They were analyzed for the glucosinolate content and correlated with leafminer infestation. Total glucosinolate content in general and sinigrin content in particular appeared to have the ability to repel the attack ofLiriomyza brassicae, while gluconapin appeared to attract them. The percentage of infestation, the number of mines and the number of living larvae were estimated for evaluating the glucosinolate efficacy againstL. brassicae on cabbage.     

南美斑潜蝇成虫活动规律的观察

应用黄板法对南美斑潜蝇活动特性进行观测。结果表明,南美斑潜蝇在作物顶端层飞翔种群数较高,在此层面黄板诱集成虫数量最大。在干热季南美斑潜蝇的日活动高峰在８∶００～１０∶００和１８∶００～２０∶００,成虫量与日气温呈负相关。     

The tomato leafminer Tuta absoluta (Meyrick) in Tunisia: current status and management strategies

The tomato leafminer Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae) was first identified in the region of Akkouda in October 2008 before it spread to all tomato‐producing areas in Tunisia. The introduction of this pest disturbed existing pest control programmes in greenhouses and open fields, forcing Tunisian growers to use more chemicals to reduce its impact on their crops. A national programme was adopted to control T. absoluta, including cultural practices, the use of pheromones, the installation of insect‐proof screens in greenhouses, and the use of organic insecticides including Bacillus thuringiensis Kurstaki (Bt) and plant extract‐based products. In addition, a few experiments in biological control, using the predatory Mirid Nesidiocoris tenuis Reuter (Heteroptera: Miridae) and the parasitoid wasp Trichogramma cacoeciae Marchal (Hymenoptera: Trichogrammatidae), were conducted in greenhouses and open‐field crops (producing tomatoes for fresh consumption as well as for processing). This paper describes the status of T. absoluta in Tunisia, including data collected from sex pheromone traps installed in six tomato‐producing areas (Takelssa, Korba, Teboulba, Bekalta, Sousse and Kairouan) between 2009 and 2011, and control strategies in greenhouses and open fields.     

Acute spread in France of an invasive pest, the horse chestnut leafminer Cameraria ohridellaDeschka & Dimic (Lep., Gracillariidae)

The horse chestnut leafminer, Cameraria ohridella Deschka & Dimic (Lepidoptera, Gracillariidae) spread over the last 10 years from central Europe to western Europe and was observed for the first time in 2000 in the east of France and near Paris. This study presents the results of surveys carried out in France in 2001 to investigate the distribution and infestation level of the leafminer. One year after its first discovery, the moth was present in a large part of the country and for the first time has been observed in Paris. The spread of the moth is due mainly to natural dispersal and to passive dispersal by human activities.     

Acute spread in France of an invasive pest, the horse chestnut leafminer Cameraria ohridellaDeschka & Dimic (Lep., Gracillariidae)

The horse chestnut leafminer, Cameraria ohridella Deschka & Dimic (Lepidoptera, Gracillariidae) spread over the last 10 years from central Europe to western Europe and was observed for the first time in 2000 in the east of France and near Paris. This study presents the results of surveys carried out in France in 2001 to investigate the distribution and infestation level of the leafminer. One year after its first discovery, the moth was present in a large part of the country and for the first time has been observed in Paris. The spread of the moth is due mainly to natural dispersal and to passive dispersal by human activities.