Brood XI

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Brood XI ( Brood 11 ) is a presumably extinct population of the "Periodic Cicadas" ( Magicicada ) in the eastern United States . At the beginning of the 20th century, the entomologist Charles Lester Marlatt identified 30 different populations, of which around 15 could also be confirmed over the years. Brood XI was one of the smallest populations, which also consisted exclusively of cicadas of the Magicicada septendecim . It occurred only in the area of Connecticut , Massachusetts and Rhode Island and was thus on the northern edge of the range. Brood XI has not been observed since 1954 and is now considered extinct.

Old reports

The mass occurrence of the cicadas has historically been described in very dispersed areas in the northeastern United States. The records go back to the 18th century. An early example can be found in Sandwich, Massachusetts . EC Herrick saw her swarming in Tolland County's woods in 1835.

Sightings had already become rare by the end of the 19th century. Entomologist George Dimmock recorded large numbers of animals in Suffield, Connecticut in 1869 and caught one, but failed to find any animals when he looked for it seventeen years later. Similarly, it went Alpheus Spring Packard , in 1903 at three sites in Rhode Iceland, among others, at a location in Coventry , near the southwestern end of the Tiogue reservoir collected, animals, where they "the Busch-oak in the field a furlong" but not a single specimen was found in 1920. As early as the 1920s, the lack of observations suggested that the population was extinct.

Occurrence in 1937

To the great astonishment of the entomologists, Brood XI was rediscovered in 1937. Jerauld A. Manter of the University of Connecticut was notified on June 7, 1937 that Periodical Cicadas had been discovered near Willington . While visiting the area, he found a "thriving colony" in the pastureland of a Mr. John Blahusiak's farm. Manter also recorded reports of cicadas in the area from 1903 and 1920, and estimated the colony to be about 10 acres, with "many thousands clinging to the trees." ). However, he wrote that there were no further reports and that therefore the colony was likely the last remnant of Brood XI .

Appearance 1954

The last sighting of the population was recorded again by Manter, who revisited the area in 1954. Cicadas were observed from June 10th, but "their numbers never approached those of 1937" (at no time did their numbers approach those of 1937). A later inspection in the summer did not reveal any evidence of egg-laying or wilting branches as a result, which meant that the cicadas were expected to be dying out. In 1971 a search was carried out at the site, but it did not reveal any sightings and there have been no further sightings since then. Habitat loss and environmental influences, which hit the edge of the distribution area particularly hard, could have led to the extinction of the population.

Individual evidence

  1. ↑ Cooley, J. et al "At the limits: habitat suitability modeling of northern 17-year periodical cicada extinctions", Global Ecology and Biogeography 22 (2013), 410-421, 419
  2. ↑ a b Cooley et al 2013, 411
  3. ^ Herrick, "Uprising of the Seventeen-year Cicada," American Journal of Science , 33, 434
  4. ^ A b Dow, "Is Brood XI Extinct?", Bulletin of the New England Museum of Natural History , 1929, 28
  5. ^ Packard, AS "Appearance of the 17-year cicada in Rhode Island in 1903", Psyche , 10 (1903), 219
  6. ↑ a b Manter, YES "Magicicada septendecim Linn. Brood XI in Connecticut," psyche 62 (1955), 157-158
  7. ↑ The area was east of what is now Cowles Road , near the city limits of Willington (Cooley, 411)
  8. ↑ a b Manter, JA "The periodical cicada in Connecticut in 1937" in Britton (ed). Connecticut State Entomologist, Thirty-Seventh Report , 1938, 249
  9. ↑ Manter, JA "Brood XI of the periodical cicada seems doomed" in Beard (ed) 25th Anniversary Memoirs of the Connecticut Entomological Society , (1974), 99-100