Chilean false red mite Brevipalpus chilensis Baker,1949 Acari:Tenuipalpidae

Transcription

1 Islamic Republic Of Iran Ministry of Jihad-e-Agriculture Plant Protection Organization A Guide for Diagnosis & Detection Of Quarantine Pests Chilean false red mite Brevipalpus chilensis Baker,1949 Acari:Tenuipalpidae Edited by: Ahmad Cheraghian Bureau of Plant Pest Surveillance and Pest Risk Analysis 2013

2 Brevipalpus chilensis Baker, 1949 Acari: Tenuipalpidae Common name: Chilean false red mite, grape flat mite, Chilean grape flat mite Economic impact: Among fruit trees, the vines are the most economically affected crops, particularly red grape wine cultivars, which must be treated with chemical acaricides to deplete populations. Due to its small size it is common for mobile forms and eggs to be overlooked on the lower part of the foliage; overwintering populations that move to the young shoots and leaflets as soon as they begin to emerge produce the main economic damage. On table grapes, with few exceptions (e.g. the black cultivar Ribier), economic damage has never been observed. However, as an overall problem, quarantine implications, even due to very small mite populations, are often responsible for either mandatory methyl bromide fumigation to the USA fresh fruit market or to unnecessary pest control management decisions. USA quarantine fumigation measures have been extended to citrus and kiwifruits (Actinidia deliciosa), whereas cherimoyas (Annona cherimola) and other citrus fruits must be treated with wax Gonzalez, 1958, 1989).. Hosts: Major hosts: Actinidia deliciosa (kiwifruit), Annona cherimola (cherimoya), Ficus benghalensis (banyan), Ligustrum sinense (chinese privet), Vitis vinifera (grapevine) Minor hosts: Antirrhinum (snapdragon), Chrysanthemum (daisy), Citrus aurantium (sour orange), Citrus limon (lemon), Citrus sinensis (navel orange), Diospyros kaki (persimmon), Geranium (cranesbill),convolvulus arvensis (bindweed) Geographic distribution: South America: Chile World distribution map of Brevipalpus chilensis

3 Morphology: Female Body oval, µm, body setae very short, dorsal setae 14 to 16 µm. Six pairs of short dorsolateral setae, of which five pairs are strictly hysterosomal and the sixth pair is humeral (Jeppson et al., 1975). The distal segment of the palpus has three setae and tarsus II has a single distal solenidion rod. The main distinguishing character is the propodosoma, which is evenly reticulate. The latter character separates B. chilensis from Brevipalpus obovatus; this feature can be better seen under a phase contrast microscope. Male The male is very similar to the female with respect to the above morphological features. Protonymph From laboratory pure cultures, it is confirmed that the main characters used in separation are the shapes of the first and second propodosomal setae and the final three hysterosomal pairs, which are oblong in shape, whereas all other dorsal setae are much shorter and setiform. Deutonymph The dorsocentral setae are short and setiform; all others are oblong of denticulated margin.. Deutonymph Female

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5 Biology and ecology: In grapes (Vitis vinifera), the mites overwinter at the fertilized stage hidden under bark crevices. In late winter, as soon as the new shoots start swelling, the females move to the bases of opening buds and the underside of the new foliage. Often the real injury occurs at this phenological stage of the crop, represented by the cracking of bark and wilting of new leaves. The oviposition period of the first generation may extend for 3 weeks and the total length of this generation, which occurs in mid-spring, may take up to 2 months. Four to five generations are known annually on wine grapes.

6 Symptoms: The symptomatology and economic damage differ according to the host life cycle and cultivars within a species. The mites are active throughout the year on citrus, but inactive in winter on grapes (Vitis vinifera), kiwifruit (Actinidia deliciosa) and other deciduous crops. Among grapes the most seriously damaged are the red wine varieties, whereas the white cultivars are unable to harbour high mite populations on the foliage and bunches. Table grape cultivars, with the exception of a couple of old red varieties, are practically not attacked by the mite and bunches can be harvested without mobile stages on the berries. However, they are subject to post-harvest mandatory fumigation treatments to importing markets such as Mexico and the USA. The most commonly infested plant in central Chile is the privet Ligustrum sp., an ornamental plant used as a hedge in home gardens. All stages of B. chilensis develop on the underside of the leaves, particularly along the midrib vein of mature leaves. A yellow discoloration occurs on the infested tissues accompanied by a reduction in size of the newer foliage. No twisting or distortion occurs. Red wine cultivars suffer the most due to false mite feeding through the spring and summer. A reduction in size and losses of the new growth are observed from October onwards due to feeding by the adult females moving from their wintering sites in the trunk. The forthcoming invasion of the leaves in early summer may produce leaf rolling and discoloration of the leaves; grape bunches are also damaged by feeding. The species of citrus affected by the mite, including lemons (Citrus limon), oranges (Citrus spp.), clementines (Citrus reticulata) and, more frequently, mandarins, with peak populations occurring during the warmest month, are not economically damaged whatsoever. Mite populations are very low on the leaves and fruits. However, they are subject to pre- and/or post-harvest treatments due to quarantine regulations. Kiwifruits, notwithstanding their late arrival in Chile, were immediately subject to mite colonization, thus posing another quarantine problem to some importing countries, namely the USA. The mites overwinter as adult females, and shortly after bud growth in the very early spring, the females start crawling to shoots and leaf petioles. These organs may be scarred by feeding and call for a very early acaricide treatment because female movement to the growing foliage may be slow; usually two spray applications are needed. Symptoms by affected plant part Fruits/pods: lesions; external feeding. Growing points: external feeding; abnormal forms; discoloration. Leaves: external feeding; abnormal colours; abnormal forms. Whole plant: external feeding; distortion; rosetting; discoloration...

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8 Means of movement and dispersal: Due to their small size, B. chilensis can be easily transported in any live or dead plant material. Under field conditions, it is surprising to discover how soon the mites move to newly established kiwifruit (Actinidia deliciosa) orchards (a fairly recently introduced crop from New Zealand into Chile) from adjacent infested vineyards. Plant parts liable to carry the pest in trade/transport - Fruits (inc. Pods): Eggs, Nymphs, Adults; borne externally; visible under light microscope. - Leaves: Eggs, Nymphs, Adults; borne externally; visible under light microscope. - Stems (above Ground)/Shoots/Trunks/Branches: Eggs, Nymphs, Adults; borne externally; visible under light microscope. Plant parts not known to carry the pest in trade/transport, - Bark, - Bulbs/Tubers/Corms/Rhizomes, - Growing Medium Accompanying Plants, - Flowers/Inflorescences/Cones/Calyx, - Seedlings/Micropropagated Plants, - Roots, - True Seeds (inc. Grain), - Wood.. Phytosanitary significance: This species was first identified as new on a shipment of lemons from Chile, intercepted in the USA (Baker, 1949). Shortly after, the false mite was found to occur throughout the major wine grape areas in central Chile. With the export fruit boom, the planting of grapes (Vitis vinifera), citrus (Citrus spp.) and later of kiwifruit (Actinidia deliciosa), extended the dispersion of this mite to the north, where it cohabits with Brevipalpus obovatus and Brevipalpus californicus. The host plant list in this datasheet is incomplete; however, the current distribution of B. chilensis on fruits and ornamental plants subject to trading is fairly well known. Introduced forest trees in the genera Catalpa proved to be efficient host plants for the species. Its dispersion into new areas could be possible via cuttings and rooted host plants such as grapes, kiwifruits, privets, citrus and persimmon (Diospyros kaki). The quarantine concern through fruit exports is limited by the cold storage treatments to which citrus fruits and grapes are subjected, provided that storage at 3-4 C extends beyond 3 to 4 weeks (R Gonzalez, Universidad de Chile, Santiago Chile, personal communication, 2004). B. chilensis is quarantine pest for Iran and some of other countries.

9 Detection and inspection: Under field conditions, all Brevipalpus mites look very similar in colour, shape and size. They can be easily found in preferred host plants with the aid of a x15 magnification hand lens. Overwintering adult females should be searched for on the underside of leaves, the pedicel disk area of citrus (Citrus spp.) and kiwifruit (Actinidia deliciosa), grape (Vitis vinifera) bunches near the pedicel, and under the bark or petiole cavities in deciduous plants. For quarantine inspection purposes, the grape bunches can be washed with detergents within a funnel system to convey the water down and inspect specimens in a collecting pan. Inspection Fruit and Host plant for B. chilensis

10 References: 1.Abai, M. (1984).List of forest trees and shrubs of Iran. Plant pests and Diseases Rech. Inst.,Tehran, 147p. 2.Barouti,S.,A.alavi,2004,Plant Nematology,Principles, Parasitic and Quarantine Nematode in Iran., p. 3.Behdad,E.,1984.Pests of Fruit Crops in Iran,Sepehr pub,tehran,822p. 4.Esmaile,M.1983, Pests of Fruit Crops in Iran, Sepehr pub,tehran,366p. 5.CAB International Crop Protection Compendium Edition. CAB International. Wallingford, Oxon, UK. 6.Modarres Awal, M.2012.List of Agricultural pests and Their Natural Enemies in Iran. Revised Edition, Ferdowsi university Prss,759p. 7. pliar.tpl&pos= :la-aranita-roja-un-enemigo-autoctono-de-los-vinateros-del- 10.secano&catid=63:rural&Itemid= ages/0298.jpg