Apple maggot Rhagoletis pomonella Walsh Diptera:Tephritidae

Transcription

1 Islamic Republic Of Iran Ministry of Jihad-e-Agriculture Plant Protection Organization A Guide for Diagnosis & Detection Of Quarantine Pests Apple maggot Rhagoletis pomonella Walsh Diptera:Tephritidae Edited by: Ahmad cheraghian Bureau of Plant Pest Surveillance and Pest Risk Analysis 2014

2 Rhagoletis pomonella Walsh Diptera : Tephritidae Common name: Apple maggot, railroad worm, maggot, apple Synonyms: Rhagoletis symphoricarpi, Trypeta pomonella Spilographa pomonella (Walsh), Zonosema pomonella (Walsh) Economic impact: R. pomonella, which primarily attacks apples, is the most serious fruitfly pest in North America, except for introductions of Ceratitis capitata (EPPO/CABI, 1996). The apple maggot, Rhagoletis pomonella (Walsh) (also known as the "railroad worm") is an insect native to North America. Originally it fed in the fruit of wild hawthorn (Crataegus spp.), but then it became a primary pest of cultivated apples, especially in the northeastern United States and southeastern Canada. Summer- and early fallmaturing varieties are particularly vulnerable, but hard winter apples are sometimes infested. Thin skinned sweet and subacid varieties are most susceptible, but acid varieties may be attacked. Plum, pear, and cherries also serve as hosts, but usually the apple maggot is not a serious pest of these fruits. Crab apples are invariably infested by this pest. A closely related species, the blueberry maggot fly (Rhagoletis mendax Curran), is important as a pest of cultivated blueberries. Hosts: Major hosts:malus domestica (apple) Minor hosts : Malus (ornamental species apple), Malus baccata (siberian crab apple), Prunus americana (apricot), Prunus angustifolia (Mountain cherry tree), Prunus armeniaca (apricot), Prunus avium (sweet cherry), Prunus cerasus (sour cherry), Prunus mahaleb (mahaleb cherry), Prunus persica (peach), Prunus virginiana (common chokecherrytree), Pyracantha coccinea (Scarlet firethorn), Rosa rugosa (Rugosa rose), Rosa virginiana (Virginia rose) Wild hosts Amelanchier (serviceberries), Aronia (chockeberry), Cotoneaster, Crataegus (hawthorns), Crataegus crus-galli (Cockspur hawthorn), Crataegus douglasii (black hawthorn), Crataegus laevigata, Crataegus monogyna (hawthorn), Prunus (stone fruit), Rosa (roses) Geographic distribution: North America: USA, Canada, Mexico World distribution map of Rhagoletis pomonella

3 Morphology: Egg The eggs are elliptical, semi-opaque and creamy white, with both ends slightly yellow and more opaque, about 0.9 mm long and 0.23 mm wide. Larvae The legless larva when fully grown are usually mm long and mm wide at the widest point. The cream coloured body consists of 11 apparent segments. Pupae The oval, yellow-brown pupae are approximately 5 mm long and 2.3 mm wide. Adults The adult is about 2-4 mm long, a little smaller than the housefly, easily recognizable by four irregular or zig-zag black bands on the wings. The body is generally black with a yellowish head and legs, and greenish eyes. The male has three white bands on the abdomen and the female has four similar white bands and is considerably larger.. Head. Number of frontal bristles three pairs. Number of orbital bristles two pairs. Anterior orbital bristle of male normal, unmodified. Posterior orbital bristles reclinate; acuminate. Ocellar bristles long, about as long as frontal bristles. Postocellar bristles present. With both inner and outer vertical bristles. Outer vertical, postvertical and postocellar bristles all acuminate. Postocular bristles acuminate; normal. Genal bristle present. Head higher than long (height x length). Male and female head width the same. Frontofacial angle much greater than a right angle and rounded. Face concave (slightly), or flat; without transverse sulcus, antennal grooves, or carina; shorter than frons; vertical; without dark marks. Parafacial spot absent. Frons and parafacial without small silvery markings. Fronto-orbital plate setulose. Frontal stripe setulose. Eye elongate, considerably higher than long. Antenna considerably shorter than face. Scape, pedicel, and first flagellomere all relatively short. First flagellomere shorter than face; pointed dorsoapically. Arista longer than first flagellomere; pubescent, with hairs about as long as greatest aristal width; hairs both dorsal and ventral. Proboscis short, capitate. Thorax. Inner scapular bristle present and distinguishable from surrounding vestiture; pale. Outer scapular bristle present and distinguishable from surrounding vestiture; pale. Postpronotal bristle present. Presutural dorsocentral bristle absent. Presutural supra-alar bristle present. Postsutural supra-alar bristle present. Acrostichal bristle present. Postsutural dorsocentral bristle present; bristles aligned with postsutural supra-alar bristles or slightly behind. Intra-alar bristle present, well developed, similar to postalar bristle. Intrapostalar bristles absent. Number of scutellar bristles two pairs. Apical scutellar bristles as long as basals or longer. Anterior notopleural bristle present. Posterior notopleural bristle(s) acuminate. Number of outstanding anepisternal bristles two. Katepisternal bristles present. Anepisternal bristles dark, brown to black. Long, erect setulae on laterotergite absent. Scutal setulae acuminate, mixed dark and pale. Scutellum non-setulose, or sparsely setulose. Setulae on scutellum short, decumbent; unicolorous, acuminate. Transverse suture with the lateral branches wide apart. Complete sclerotized postcoxal metathoracic bridge absent or semimembranous. Scutum black; without a large dark central stripe which broadens basally. Postpronotal lobe entirely pale whitish or yellowish. Posterior half of notopleuron same as ground color. Scutum dorsad of notopleuron of the ground color, not whitish or yellowish. Dark lyre-like pattern on scutum absent. Discrete shiny black spots on scutum absent. Median longitudinal black stripe on scutum absent. Number of pale whitish to yellow postsutural stripes zero. Scutum without blackish dorsocentral stripe. Area bordering scutoscutellar suture medially without

4 dark brown spot, brown. Discrete pale horizontal stripe along upper anepisternum present and distinct, extending from postpronotal lobe to wing base. Distinct pale vertical anepisternal stripe absent. Katepisternite with pale yellowish or whitish spot absent or indistinct. Transverse suture without distinct stripe or spot. Katatergite with pale yellowish or whitish spot absent or indistinct. Anatergite with pale yellowish or whitish spot absent or indistinct. Subscutellum uniformly black. Mediotergite uniformly brown. Scutum microtrichia in discrete pattern due to density differences. Dorsum of scutellum flat or slightly convex, not swollen. Scutellum normal; with a dark and pale pattern; with no isolated dark spots; with lateral black marks extending apically, leaving apical area pale; without mark. Legs. Femora slender. Fore femur with regular bristles; without ventral spines; with 1 to 3 posterodorsal and 1 posteroventral rows of bristles only. Mid femur and hind femur without spine-like bristles. Middle leg of male without feathering. Femora all entirely of one color, or at least one femur markedly paler in apical part than in middle or basal part; dark mark on fore femur 0 50% of length of femur (posterior surface darker); dark mark on middle femur % of length of femur; dark mark on hind femur % of length of femur. Wings. Wing with microtrichia covering entire wing. Cell bc microtrichia covering whole cell. Cell c microtrichia covering whole cell. Cell dm entirely microtrichose. Dense microtrichia at end of vein A1+CuA2 in male absent. Dominant wing pattern cross-banded. Crossbanded wing patterns Rhagoletis-like. Wing pattern mostly brownish. Dark longitudinal streaks through basal cells absent. Crossvein r-m covered by a major crossband. Crossvein dm-cu covered by a major crossband which reaches posterior margin of wing. Cell r2+3 apical to r-m with large hyaline area. Anal band absent, or not reaching nearly to wing margin. Cell r1 and r2+3 without darker spots within the pattern. Intercalary band absent. Subbasal crossband present. Subbasal and discal crossbands joined. Marginal hyaline area in cell r1 absent or indistinct. Ratio of width of apical band in cell r4+5 to length of r-m Anterior apical crossband partly to entirely separated from costa by marginal hyaline band or spots. Anterior apical band or costal band extended to vein M. Posterior apical crossband absent. Discal band transverse, or oblique in anterobasal-posteroapical direction, or absent. Discal and apical crossbands directly joined. Discal and subapical crossbands joined along anterior wing margin or along vein R4+5. Discal and subapical bands connected along vein R4+5. Subapical and anterior apical crossbands not joined, subapical crossband not reaching costa. Outstanding costal spine(s) at subcostal break present. Ratio of length of costal section 3 to costal section Ratio of pterostigmal length to width 2.5. Vein R1 dorsal setation without bare section opposite end of vein Sc. Vein Rs dorsal setation non-setulose. Vein R2+3 generally straight. Anteriorly-directed accessory vein emerging from R2+3 absent. Vein R4+5 dorsal setation absent; ventral setation absent or only present on node or close thereafter. Distance between crossvein r-m and costa longer than r-m. R-m crossvein on cell dm at or near middle of cell dm. Cell bm narrow, triangular; ratio of length to width 3; ratio of width to cell cup width 1. Vein M distally straight. Cell dm widens apically gradually from base. Posterodistal corner of cell dm distinctly acute. Cell cup extension or lobe present, vein CuA2 abruptly bent; shorter than vein A1+CuA2; with parallel margins. Abdomen. Abdomen ovate or parallel sided. Abdominal tergites separate. Abdomen in lateral view flatter, more flexible. Abdominal tergite 1 broader at apex than at base; without a prominent hump laterally. Pecten of dark bristles on tergite 3 of male absent. Tergal glands on tergite 5 absent. Abdominal tergite 5 normal. 6th tergite of

5 female exposed; shorter than 5th. Abdominal setulae mixed dark and pale acuminate (pale setulae on margin of T1+2; dark setulae elsewhere). Abdominal microtomentum in bands. Abdominal sternite 5 of male less than 2x wider than long, not longer than wide. Posterior margin of sternite 5 of male with shallow posterior concavity. Abdominal tergites 3 5 predominantly black. Abdominal tergites without medial dark stripe; not brown with medial T-shaped yellow mark; without isolated dark areas on lateral margins of T3-T5; with dark brown transverse bands which may be interrupted medially. Male terminalia. Epandrium in posterior view with long outer surstyli, which are more than half as long as epandrium; lateral view with outer surstyli distinctly narrower than epandrium, clearly differentiated. Distiphallus present; without basolateral membranous lobe; with extensive medial sclerotization; without stout, curved, basal spine; without basal setulose rod. Sclerite of vesica of distiphallus absent. Female terminalia. Syntergosternite 7 straight; shorter than preabdomen; base without a laterally projecting flap; conical, or flattened. Ratio of syntergosternite 7 to abdominal tergite Dorsobasal scales of eversible membrane about as large as other scales. Aculeus length mm (Florida (Prunus), (Crataegus) and Texas (Cotoneaster) populations ranged , , and mm). Aculeus tip gradually tapering, needle-like, with flat cross-section; fused to main part of aculeus, not movable; 0% serrated; not serrate. Three sclerotized spermathecae. Spermathecae elongate. Adult of Rhagoletis pomonella

6 Adult and larvae of Rhagoletis pomonella

7 Biology and ecology: R. pomonella has only one generation a year. Females lay their eggs singly beneath the skin of the fruit. The larvae hatch 3-7 days later and tunnel into the fruit pulp. They complete their development within the fruit, taking anywhere from 2 weeks to several months to mature. Very rarely will larvae exit from hanging fruit. The infested fruit usually drops to the ground. larvae remain in the dropped fruit until reaching maturity when they make an exit hole in the skin of the fruit and wriggle to the ground. Larvae emergence from fruit may continue into early December. Larvae then enter the soil where pupation occurs. They enter the soil to a dpeth of 2-5 cm, usually beneath the host plant. Pupae stay dormant over winter, and they may persist in the soil for several years. Adult emergence in late June or July and may feed on insect honeydew and bird dung, reaching sexual maturity 7-10 days after emergence. As the flies mature and mate they respond more to oviposition-site stimuli, i.e., fruit shape and fruit odour. After mating, a single female fly is capable of laying more than 200 eggs in her lifetime. Adults usually die after 3-4 weeks but may live up to 40 days under field conditions.. Lay eggs singly beneath the skin of the fruit by Rhagoletis pomonella

8 Symptoms: R. pomonella burrow in all directions through the flesh of apples feeding on the pulp and leaving brown channels. When a single fruit is infested with several larvae, the pulp will be honeycombed with their burrows until it finally breaks down. Infested fruit are usually misshapen. Attacked fruit are pitted by oviposition punctures, around which some discoloration usually occurs. Injury to fruit is caused by the legless maggots.these maggots bore throughout the fruit, forming irregular, winding tunnels which turn brown, often causing premature dropping of fruit. When the fruit is slightly infested, there may be no external indication of the presence of the maggots, but when the fruit ripens, the burrows show as dark, winding trails beneath the skin. Minute egg punctures and distorted, pitted areas may show on the surface. Heavily infested early varieties of fruit will be reduced to a brown rotten mass filled with the fly larvae. Symptoms by affected plant part Fruits/pods: internal feeding. Damage of on fruit by Rhagoletis pomonella

9 Means of movement and dispersal: Plant parts liable to carry the pest in trade/transport - Fruits (inc. Pods): Eggs, Larvae; borne internally; visible to naked eye. - Growing Medium Accompanying Plants: Pupae; borne internally; visible to naked eye. Plant parts not known to carry the pest in trade/transport - Bark - Bulbs/Tubers/Corms/Rhizomes - Flowers/Inflorescences/Cones/Calyx - Leaves - Seedlings/Micropropagated Plants - Roots - Stems (above Ground)/Shoots/Trunks/Branches - True Seeds (inc. Grain) - Wood. Transport pathways for long distance movement - Conveyances (transport Vehicles): Aeroplanes And Boats, With Fruit Cargo. - Mail: Fruit In Post. - Containers And Packing: Of Fruit Cargo. - Soil, Gravel, Water, Etc.: Risk Of Puparia In Soil. - Travellers And Baggage: Fruit In Case Or Handbag. Phytosanitary significance: R. pomonella has already shown its capacity to spread from its original range in eastern North America, to western states of the USA since 1979 (Foote et al., 1993) and it represents the most serious potential new tephritid pest for many apple producing temperate areas. Canada considers it as an internal quarantine pest (absent from the fruit-producing areas of British Columbia). R. pomonella is of quarantine significance for COSAVE, EPPO, OIRSA and our country Iran. Consignments of apples from countries where R. pomonella occurs should be inspected for symptoms of infestation and those suspected should be cut open in order to look for larvae. For example, EPPO recommends that such fruits should come from an area where R. pomonella does not occur, or from a place of production found free from the pest by regular inspection for 3 months before harvest. Fruits may also be treated, but specific treatment schedules have mostly not been developed for Rhagoletis spp., since there is no need for them in North America. Schedules developed for other fruit flies on apples will probably be adequate, for example treatment in transit by cold treatment (13, 15 or 17 days at 0.5, 1 or 1.5 C, respectively) (USDA, 1994). Ethylene dibromide was previously widely used as a fumigant but is now generally withdrawn because of its carcinogenicity; methyl bromide is less satisfactory, damaging many fruits and reducing their shelf life, but treatment schedules are available for apple (for example, 32 g/m³ for 2 h at C; USDA, 1994). Plants of host species transported with roots from countries where R. pomonella occurs should be free from soil, or the soil should be treated against puparia, and should not carry fruits. Such plants may be prohibited importation.

10 Detection and inspection: Traps that capture both sexes are based on visual attraction, or visual plus odour attraction. They are coated in sticky material and are usually either flat-surfaced and coloured fluorescent yellow to elicit a supernormal foliage response, or spherical and dark-coloured to represent a fruit; traps which combine both foliage and fruit attraction can also be used. The odour comes from protein hydrolysate or other substances emitting ammonia, such as ammonium acetate; for R. pomonella synthetic apple volatiles are also very effective attractants (Reissig et al., 1985). See Boller and Prokopy (1976) and Economopoulos (1989) for a discussion of these traps. Field Monitoring Monitoring is largely carried out by traps (see Early Warning Systems) set in areas of infestation. However, there is evidence that some fruit flies have different host preferences in different parts of their range and host fruit surveys should also be considered as part of the monitoring process. Monitoring Use canary-yellow, sticky baited traps and red spheres coated with bird Tanglefoot to detect adult emergence. Growers can enhance the attractiveness of traps by sprinkling one or two teaspoons of fresh ammonium acetate over each trap when it is hung. Place four yellow traps per orchard at about eye level in the foliage on the south side of trees one to two rows in from the edge of the orchard. Change the traps every three weeks until the end of July. Then replace the yellow traps with red spheres (with volatiles available) to detect female egg-laying activity. Clean and renew the Tanglefoot every two weeks. Use of trap for Detection Rhagoletis pomonella.

11 References: Abai, M. (1984).List of forest trees and shrubs of Iran. Plant pests and Diseases Rech. Inst.,Tehran, 147p. Barouti,S.,A.alavi,2004,Plant Nematology,Principles, Parasitic and Quarantine Nematode in Iran., p. Behdad,E.,1984.Pests of Fruit Crops in Iran,Sepehr pub,tehran,822p. Esmaile,M.1983, Pests of Fruit Crops in Iran, Sepehr pub,tehran,366p. CAB International Crop Protection Compendium Edition. CAB International. Wallingford, Oxon, UK. Modarres Awal, M.2012.List of Agricultural pests and Their Natural Enemies in Iran. Revised Edition, Ferdowsi university Prss,778p. Salavatean, Mer.1996, Plant quarantine in Iran, Research Institute,Ministey of Agriculture pub,279p