Ceratitis capitata, the Mediterranean fruit fly, or medfly for short, is a species of fruit fly capable of causing extensive damage to a wide range of fruit crops. It is native to sub-Saharan Africa, but has spread invasively to many parts of the world, including Australasia and North and South America.
Adult medflies lay their eggs under the skins of fruit, particularly where the skin is already broken. The eggs hatch within 3 days, and the larvae develop inside the fruit. Maggots may stay from 5 to 10 days (depending on temperature and food availability by fruit size). Once the larvae reach the next development stage, they dig their way out of the fruit, making a small hole and then falling to the ground where they start to dig and then pupate a few centimeters underground. Depending on temperature, adult emergence may occur in as short as 7 days. The adults have a limited ability to disperse, but the global fruit trade can transport infected fruit over thousands of miles.
Sex determination in C. capitata is by the familiar XY system. Unusually for a dipteran and for a frugivore, medflies do not have an opsin gene for blue light perception as shown from the whole-genome sequencing project completed in September 2016.
The Geographic Distribution Map of Ceratitis capitata (Updated December 2013).
This map provides information on the distribution of the Mediterranean fruit fly, C. capitata, throughout the world. The information is mainly based on available Mediterranean fruit fly national surveillance reports. Therefore, the map displays assessments of the presence of this pest at the national level and in some cases at subnational levels.
In the United States, C. capitata has invaded four states (Hawaii, California, Texas, and Florida), but has been eradicated from all but Hawaii. Reintroduced populations of the medfly have been spotted in California as recently as 2009, requiring additional eradication and quarantine efforts. It has also been eradicated from New Zealand and Chile.
California medfly crises
Much research has been dedicated to means of controlling the medfly. In particular, use of the sterile insect technique has allowed the species to be eradicated from several areas.
In 1981, California Governor Jerry Brown, who had established a reputation as a strong environmentalist, was confronted with a serious medfly infestation in the San Francisco Bay Area. He was advised by the state's agricultural industry and the US Department of Agriculture's Animal and Plant Health Inspection service (APHIS) to authorize airborne spraying of the region. Initially, in accordance with his environmental protection stance, he chose to authorize ground-level spraying only. Unfortunately, the infestation spread as the medfly reproductive cycle outpaced the spraying. After more than a month, millions of dollars of crops had been destroyed and billions of dollars more were threatened. Governor Brown then authorized a massive response to the infestation. Fleets of helicopters sprayed malathion at night, and the California National Guard set up highway checkpoints and collected many tons of local fruit. In the final stage of the campaign, entomologists released millions of sterile male medflies in an attempt to disrupt the insects' reproductive cycle.
Ultimately, the infestation was eradicated, but both the governor’s delay and the scale of the action has remained controversial ever since. Some people claimed that malathion was toxic to humans, as well as insects. In response to such concerns, Brown's chief of staff, B. T. Collins, staged a news conference during which he publicly drank a small glass of malathion. Many people complained that, while the malathion may not have been very toxic to humans, the aerosol spray containing it was corrosive to car paint.
During the week of September 9, 2007, adult flies and their larvae were found in Dixon, California. The California Department of Food and Agriculture and cooperating county and federal agricultural officials started eradication and quarantine efforts in the area. Eradication was declared on August 8, 2008, when no "wild" (i.e. non-sterile) medflies were detected for three generations.
On November 14, 2008, four adult flies were found in El Cajon, California. The San Diego County Agricultural Commission implemented a treatment plan, including distributing millions of sterile male flies, local produce quarantines, and ground spraying with organic pesticides.
- Atkinson, Peter W.; Benoit, Joshua B.; Cavanaugh, John P.; Gibbs, Richard A.; Giers, Sarah D.; Gomulski, Ludvik M.; Handler, Alfred M.; Hatzigeorgiou, Artemis G.; Hughes, Daniel S. T.; Jones, Jeffery W.; Lee, Sandra L.; Malacrida, Anna R.; Murali, Shwetha C.; Murphy, Terence D.; Muzny, Donna M.; Paraskevopoulou, Maria D.; Robertson, Hugh M.; Rosendale, Andrew J.; Rosselot, Andrew E.; Schetelig, Marc F.; Sim, Sheina B.; Vlachos, Ioannis S.; Werren, John H.; Wimmer, Ernst A.; Worley, Kim C.; Papanicolaou, Alexie; Arensburger, Peter; Bourtzis, Kostas; Castañera, Pedro; Chao, Hsu; Childers, Christopher; Curril, Ingrid; Dinh, Huyen; Doddapaneni, HarshaVardhan; Dolan, Amanda; Dugan, Shannon; Friedrich, Markus; Gasperi, Giuliano; Geib, Scott; Georgakilas, Georgios; González-Guzmán, Miguel; Guillem-Amat, Ana; Han, Yi; Hernández-Crespo, Pedro; Karagkouni, Dimitra; Koskinioti, Panagiota; Manni, Mosè; Mathiopoulos, Kostas; Meccariello, Angela; Oberhofer, Georg; Ortego, Félix; Poelchau, Monica; Qu, Jiaxin; Reczko, Martin; Saccone, Giuseppe; Salvemini, Marco; Savini, Grazia; Schreiner, Patrick; Scolari, Francesca; Siciliano, Paolo; Tsiamis, George; Ureña, Enric; Zacharopoulou, Antigone; Richards, Stephen (22 September 2016). "The whole genome sequence of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann), reveals insights into the biology and adaptive evolution of a highly invasive pest species". Genome Biology. 17 (192). doi:10.1186/s13059-016-1049-2. PMC 5034548. PMID 27659211. Retrieved 26 September 2016.
- "County planning quarantine after Medfly discovery in Escondido". September 16, 2009.
- Drake (2013). "Followup on targeted medfly eradication strategies in New Zealand". Journal of Ecology. 41 (6): 72–78.
- Susan Shroder (November 14, 2008). "Medfly treatment begins In El Cajon". San Diego Union-Tribune. Archived from the original on 2013-02-02.
- L. E. Carroll; I. M. White; A. Freidberg; A. L. Norrbom; M. J. Dallwitz; F. C. Thompson (July 15, 2005). "Pest Fruit Flies of the World".
- M. C. Thomas; J. B. Heppner; R. E. Woodruff; H. V. Weems; G. J. Steck; T. R. Fasulo. "Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Insecta: Diptera: Tephritidae)".
|Wikimedia Commons has media related to Ceratitis capitata.|
- University of Hawaii. "Crop Knowledge Master".
- "Global Invasive Species Database".
- The 1981 California Medfly Panic
- CISR Summary on Mediterranean Fruit Fly
- Species Profile - Mediterranean Fruit Fly (Ceratitis capitata), National Invasive Species Information Center, United States National Agricultural Library. Lists general information and resources for Mediterranean fruit fly.
- Tephritid Workers Database