Stone Fruit Commodity-Based Pest Survey

European Cherry Fruit Fly Rhagoletis cerasi

Introduction While the European cherry fruit fly has not yet been found in the United States, elsewhere in the world it has become an economically damaging pest to cherry crops. The pest has evolved genetically and it can be found in two different “races,” demonstrating its unique ability to adapt. The most significant threat for the United States is its presence in mainland Europe, including Austria, Italy, Portugal, southern France, southern Germany, Spain, and Switzerland.

Biology European cherry fruit fly adults (Figure 1) are active from late May to early July during hot, dry conditions. Adults must feed to mature sexually and can be found feeding on honeydew as well as sugary excretions from aphids. Males establish territories on fruit and defend them while awaiting the arrival of females for mating. Females begin laying eggs in mid-June and insert them individually beneath the skin of ripening fruit. After 1 to 2 weeks, eggs hatch, and then larvae feed on developing fruits for approximately 4 weeks. Larvae then move to the soil where they pupate beneath the surface. Pupae can remain in this stage from 1 to 3 winters. This pest produces one generation each year.

Symptoms FIGURE 1. Female European cherry fruit fly (Rhagoletis cerasi) on a cherry. The fruit tissue around the scars where European cherry Photo courtesy of R. Coutin, Office Pour les Insectes et Leur Environnement (OPIE). fruit flies lay their eggs can become soft and brownish (Figure 2). Fruit damaged by larvae often rots. Heavy infestations can reduce marketable yields significantly. Fruit processors may reject consignments of infested harvested cherries.

Hosts The cherry is a major host of the European cherry fruit fly, but the pest will attack other host plants. Other hosts include bloodtwig dogwood (Cornus sanguinea), coralberry (S. orbiculatus), garden snowberry (S. rivularis), holly-leaved barberry (Mahonia aquifolium), several types of honeysuckle (Lonicera spp.), matrimony vine (Lycium barbarum), snowberry (Symphoricarpos albus), and whortleberry (Vaccinium myrtillus).

Cherry hosts include all saints cherry (P. cerasus var. semperflorens), almond cherry (P. glandulosa), black cherry (P. serotina), bunge cherry (P. humilis), European bird cherry (P. padus), European dwarf cherry (P. fruticosa), mahaleb cherry (P. mahaleb), sour cherry (P. cerasus), and sweet cherry (Prunus avium).

Distribution The European cherry fruit fly has been detected in: Austria, Belgium, Bulgaria, Croatia, Czech Republic, Denmark, Estonia, France, Germany, Greece, Hungary, Iran, Italy, Kazakhstan, Kyrgyzstan, Latvia, Lithuania, Moldova, Netherlands, Norway, Poland, Portugal, Republic of Georgia, Romania, Russia, Serbia, Spain, Sweden, Switzerland, Tajikistan, Turkey, Turkmenistan, Ukraine, and Uzbekistan.

Identification This species can be identified by examining its form and structure (morphological characteristics). It can be distinguished from many of the Rhagoletis species present in North America, including black cherry fruit fly (R. fausta), cherry fruit fly(R. cingulata), and western cherry fruit fly (R. indifferens), by its wing pattern.

Survey A trap and lure combination is the common method used to survey for this pest. Details on trap type and lure compounds can be found at http://pest.ceris.purdue.edu/ services/napisquery/query.php?code=cam2012

Contact your regional Plant Protection and Quarantine fruit fly program manager for further information on fruit fly FIGURE 2. Cherry damage caused by larvae exit holes of European cherry fruit fly. Photo courtesy of R. Coutin, Office Pour les Insectes et Leur surveys. For a list of program managers, please visit http:// Environnement (OPIE). www.aphis.usda.gov/plant_health/plant_pest_info/fruit_flies/ index.shtml.

What Can We Do? If you find an insect that you suspect is the European cherry fruit fly, please contact your local extension office or State plant regulatory official to have the specimen properly identified. For contact information, visit www.aphis.usda.gov/StateOffices, www.nationalplantboard.org/member/index.html, or www.nifa.usda.gov/Extension/index.html.

References for the above information can be found on the Cooperative Agricultural Pest Survey (CAPS) Web site at http://caps.ceris.purdue.edu/stonefruit/references.

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United States Department of Agriculture Animal and Plant Health Inspection Service