Author: (Busck, 1916)
Oriental fruit moth
(Oriental peach moth, Peach tip moth)
Species Overview:
Adult: 11-14 mm wingspan; general colouration of forewing fuscous, diffusely strigulated with dark fuscous; distal area weakly irrorate (tips of scales) with white or greyish white; fasciate markings blackish brown. Hindwing fuscous, paler basally. Distinguished from Grapholita funebrana by its generally smaller size, the better defined fasciate markings and white discocellular spot of the forewing, and in the males by the patch of pale scales along the middle of the termen of the hindwing.
Egg: flattened, slightly oval in shape (average diameter 0.8 mm), translucent white, later becoming yellow with a red ring; deposited singly on the host plant.
Larva: mature larva: 12-14 mm long; head brown; prothorax pale yellow, prothoracic plate pale brown with darker brown mottling along posterior margin; thoracic legs pale yellow; abdomen dirty pink dorsally and yellowish ventrally; pinacula light brown, inconspicuous; peritreme of spiracles brown, inconspicuous; anal plate pale brown, marked with small blackish spots; anal comb with 4-7 prongs and 1-3 small additional prongs laterally [G. molesta larva ]. Young larvae are translucent white and have grey-black prothoracic and anal plates, spiracles, spinules and legs.
Pupa: pale brown; in a whitish silken cocoon on the twigs or fruit, under bark or in the earth.
Taxonomic Description:
Male:
G. molesta male
G. molesta adult 1
G. molesta adult 2
External characters: 11-14 mm wingspan. Forewing ground colour white, coarsely overlaid with fuscous and diffusely strigulated with dark fuscous, costa with thin, poorly defined interspaces between black-brown strigulae, those beyond middle producing plumbeous striae, an obscure, coarsely strigulated medio-dorsal blotch, distal area weakly irrorate (tips of scales) with white or greyish white; fasciate markings blackish brown, obsolescent but usually discernible dorsally; median fascia diffuse, its outer edge angulated above middle, enclosing a small, white, moderately conspicuous discocellular spot; ocellus narrow, consisting of a vertical series of five or six black dots or dashes, edged laterally with plumbeous striae, the dashes more or less continuous with an oblique, black postmedian line or series of dots from costa; cilia concolorous with wing basally, otherwise grey, with a black sub-basal line. Hindwing fuscous, paler basally, with a variable, usually elongate, patch of light grey or greyish white scales along middle of termen; cilia white, suffused with grey apically, with a fuscous sub-basal line (Bradley et al., 1979).
male genitalia G. molesta
Genitalia: Ventral margin of valva with deep notch; dorsal margin almost straight. Cucullus long, ovate. Aedeagus with several cornuti; apical part of aedeagus rather narrow.
Female:
External characters: Similar to male but lacking the patch of pale scales at middle of termen of hindwing.
female genitalia G. molesta
Genitalia: Sterigma very large and broad; posterior margin convex and posterior corners elongated into carinate appendages; ostium located in center of sterigma and far from its margin. Cingulum fairly long.
Variation:
Minor variation occurs in the forewing markings and general colouration.
Biology
The oriental fruit moth is a multivoltine species with the number of generations completed each season depending primarily upon temperature; the life cycle of the insect is generally synchronized with that of its host plant, in terms of availability of larval food sources. The eggs are flattened, slightly oval in shape (average diameter 0.8 mm) and are laid singly on the host plant. On the main stone-fruit hosts, the eggs are laid adjacent to young shoots, on the underside of leaves and sometimes on the smooth surface of newly developed twigs. As smooth surfaces are preferred to pubescent substrates, eggs are rarely found on peach fruits (and then usually on the pedicel). On apples and quince, the eggs are often laid on the upper surface of the leaves. After hatching, the neonate larvae feed on their egg shells and then "wander" for up to 2 hours, occasionally more, until an appropriate entry site to the host plant is found. This may be near the tip of a shoot, often through the petiole, or directly where two fruits touch each other or are in contact with a twig or leaf. The neonate larvae are usually unable to directly penetrate hard young fruits, partly because of the exudates of gum, and will then feed in the pedicel until they are able to enter the fruit at a later instar.
Shoot-boring larvae tunnel for a distance of up to 10 cm and will, if the plant terminal wilts and dies, vacate the shoot and enter another. Where the fruit are attacked directly, an individual larva will usually complete its feeding period within the same fruit. In hard young fruit, larval tunnelling remains superficial, but as the fruits mature, the larvae reach and feed around the central seed pit. On the basis of laboratory culture data and field sampling it appears that the larvae pass through four instars. Under certain conditions, including relatively high temperatures (25-30 °C), the larvae may pass through an additional fifth instar. On completion of feeding, the final instar larvae leave the shoots, stems or fruits, and after locating an appropriate site form a silken cocoon, which is of particularly robust construction for the overwintering diapausing generation. During the spring and early summer generations, up to 50% of the larvae form cocoons on the trees, but this falls to below 20% in later generations, when the larvae locate cocooning sites on the ground. On the trees, cocoons of the earlier generations are constructed in depressions on the fruit surface, in leaf axils or under bark, often high up in the trees, while those of the overwintering generation are found near the base of the tree under bark. On the ground, larvae form cocoons on or near the soil surface, litter, mummified fruits and other debris, generally within the radius of the tree from which they originate. The larvae pupate after a prepupal period, which is greatly extended during the diapausing overwintering generation. The developmental periods of individual stages in the life cycle vary greatly with temperature, and ranges of mean estimates in days (based on numerous authors) are: eggs, 4-8 days; larvae (feeding), 12-22 days; prepupae, 3-12 days (130-300 days overwintering generation); pupae, 10-16 days (no difference between male and female pupae); egg to adult (other than overwintering generation), 30-49 days (Rothschild and Vickers, 1991).
Host plants:
Prunus amygdalus (almond), Prunus armeniaca (apricot), Prunus cerasus (cherry), Prunus domestica (plum), Prunus ilicifolia (Catalonia cherry), Prunus japonica (Japanese plum), Prunus laurocerasus (cherry laurel), Prunus persica (peach), Prunus persica var. nectarina (nectarine), Pyrus communis (pear), Pyrus japonica (sand pear), Pyrus pyrifolia (Chinese pear), Rosa sp., Cotoneaster sp., Eugenia myrianthus, Crataegus sp., Cydonia vulgaris, Eriobotrya japonica, Malus sylvestris (apple), Mespilus germanica , Photinia arbutifolia (Christmas berry), Photinia sp.
Damage:
The larvae cause damage to their plant hosts by tunnelling and feeding in the shoots and/or fruits. The species has the capacity to cause economic damage at relatively low population densities. Most information on damage has been obtained from peach and nectarine crops and is generally confined to estimates of the percentages of fruit infested, but where such estimates are based on harvested fruit, they fail to take into account infested fruit that may have fallen from the trees earlier. The proportion of fallen fruits can be high, particularly where oriental fruit moth damage is associated with secondary brown rot (Sclerotinia fructicola) infestations. Such damage is most commonly found in mature fruit towards harvest time. There is some evidence to suggest that nitidulid beetles (Carpophilus spp.) act as vectors of the fungus when they secondarily invade fruit attacked by oriental fruit moth.
Damage figures for peach fruit obtained during the 1920s and 1930s, when synthetic organic pesticides were not available, were often very high. The advent of synthetic organic pesticides in the late 1940s was in general followed by a decline in the overall level of damage attributed to the oriental fruit moth. In North America, over a 14-year period (in the 1950s and 1960s), average yearly damage estimates ranged from 0.3 to 2.7% in early peach varieties and from 2.5 to 9% in late maturing cultivars; the highest local figures were 14 and 30% for early and late varieties, respectively. In areas of the USSR where the insect has been accidentally introduced in more recent times (mid- to late-1960s), infestations of late varieties in particular have exceeded 70%. High levels of infestation in newly invaded areas probably result from a combination of inadequately developed control strategies and the initial lack of natural enemies.
In contrast to fruit infestations, shoot damage is usually of direct significance only in nurseries, where infestations of young plants can cause compensatory "bunchy" growth and overall deformation. In older bearing trees, the level of fruit damage is frequently related to the relative proportion of young shoots and fruit. Actively growing shoots are favoured feeding sites, and the shift to fruits is usually a consequence of maturing and hardening of the shoots.
Damage to other crops such as apples, pears and quinces is usually of minor importance in economic terms and occurs where these fruits are grown adjacent to peaches (Rothschild and Vickers, 1991).
Distribution:
The oriental fruit moth is considered to have originated in North-Western China, but its main plant hosts in the genus Prunus and Pyrus are thought to have a wider native range in Central Asia, and this probably applies to the insect also. From central Asia, it has become widely distributed throughout the stone-fruit growing areas of the world, into other parts of Asia, Europe, South and North America, Northern Africa, the Middle East, New Zealand and Australia. The main agent for its spread has undoubtedly been man.
List of countries in Eurasia:
Austria, Bulgaria, Czech Republic, Germany, France, Greece, Hungary, Italy, Malta, Romania, Slovakia, Spain, Switzerland, Turkey, former Yugoslavia, former USSR, China, Japan, Korea, Taiwan.
Other regions:
Africa: Mauritius, Morocco, South Africa
North America: Canada, Mexico, USA
South America: Argentina, Brazil, Chile, Uruguay
Oceania: Australia, New Zealand
Pheromone:
Z 8-12Ac : 92
E 8-12Ac : 8
Z 8-12OH : 2
(Biwer et al., 1979)
(effluvia)
Z 8-12Ac : 100
E 8-12Ac : 7
Z 8-12OH : 30
12OH : 6
(Cardé et al., 1979)
Parasitoids:
Calliephialtes (Ephialtes) grapholithae (Cresson) (Ichneumonidae)
Coccygomimus annulipes (BruIIé) (= Coccygomimus inflatus (Townes)) (Ichneumonidae)
Coccygomimus turionellae (Linnaeus) (Ichneumonidae)
Diadegema molestae (Uchida) (Ichneumonidae)
Glabridorsum stokesii (Cameron) (Ichneumonidae)
Glypta rufiscutellaris Cresson (Ichneumonidae)
Itoplectis alternans (Gravenhorst) (Ichneumonidae)
Itoplectis conquisitor (Say) (Ichneumonidae)
Liotryphon laspeyresiae (Uchida) (Ichneumonidae)
Pristomerus euryptychiae Ashmead (Ichneumonidae)
Pristomerus orbilatis Holmgren (Ichneumonidae)
Pristomerus vulnerator (Panzer) (Ichneumonidae)
Scambus hispae (Harris) (Ichneumonidae)
Temelucha minor (Cushman) (Ichneumonidae)
Trathala flavoorbitatis (Cameron) (Ichneumonidae)
Agathirsia diversa Muesebeck (Braconidae)
Agathirsia festiva (Muesebeck) (Braconidae)
Apanteles anarsiae Faure and Alabouvette (Braconidae)
Apanteles molestae Muesebeck (Braconidae)
Apanteles taragmae Viereck (Braconidae)
Ascogaster quadridentata Wesmael (Braconidae)
Charmon extensor (Linnaeus) (Braconidae)
Macrocentrus ancylivorus Rohwer (Braconidae)
Macrocentrus delicatus Cresson (Braconidae)
Macrocentrus thoracicus (Nees) (Braconidae)
Phanerotoma grapholithae Muesebeck (Braconidae)
Phanerotoma molestae Muesebeck (Braconidae)
Trichogramma cacoeciae Marchal (Trichogrammatidae)
Trichogramma euproctidis (Girault) (Trichogrammatidae)
Trichogramma funiculatum Carver (Trichogrammatidae)
Trichogramma minutum Riley (Trichogrammatidae)
Perisierola angulata Muesebeck (Bethylidae)
Elodia flauipalpis Aldrich (Tachinidae)
Zenillia roseanae Brauer and Bergenstamm (Tachinidae)
Pseudoperichaeta nigrolineata (Walker) (Tachinidae)