Female reproductive patterns in the millipede Polydesmus angustus (Diplopoda: Polydesmidae) and their significance for cohort-splitting
First-stadium juveniles of Polydesmus angustus born each month from May to September were reared throughout their life cycle under controlled seasonal conditions. At maturity, the reproductive patterns of 62 females were studied individually. It was confirmed that females born from May to August hav...
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Institute of Entomology, Biology Centre, Czech Academy of Science
2009-05-01
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doaj-3d71ea8853064784bccd242dbd95d6452021-04-16T20:34:37ZengInstitute of Entomology, Biology Centre, Czech Academy of ScienceEuropean Journal of Entomology1210-57591802-88292009-05-01106221121610.14411/eje.2009.027eje-200902-0010Female reproductive patterns in the millipede Polydesmus angustus (Diplopoda: Polydesmidae) and their significance for cohort-splittingDAVID Jean-François0Centre d'Ecologie Fonctionnelle & Evolutive, CNRS, 1919 route de Mende, F-34293 Montpellier cedex 5, France;First-stadium juveniles of Polydesmus angustus born each month from May to September were reared throughout their life cycle under controlled seasonal conditions. At maturity, the reproductive patterns of 62 females were studied individually. It was confirmed that females born from May to August have a 1-year life cycle and those born from late August onwards a 2-year life cycle (cohort-splitting). A third type of life cycle - interseasonal iteroparity - was observed in a few females born late in the season. On average, annual females started to reproduce when 11.4 months old and produced 3.6 broods per female over 1.8 months; the later they were born from May to August, the later they reproduced the following year. Biennial females started to reproduce when 19.9 months old and produced 3.8 broods per female over 2.2 months; all reproduced early in the breeding season. These results indicate that only annual females can produce an appreciable proportion of biennial offspring from late August onwards, which rules out direct genetic determination of life-cycle duration. The reproductive characteristics of P. angustus suggest a non-genetic mechanism that can drive cohort-splitting. Because individual females reproduce for about 2 months on average, this automatically results in cyclic variation in life-cycle duration (annual/biennial/annual) in the long-term progeny of any female.https://www.eje.cz/artkey/eje-200902-0010_Female_reproductive_patterns_in_the_millipede_Polydesmus_angustus_Diplopoda_Polydesmidae_and_their_significa.phpdiplopodapolydesmus angustusreproductionlife cyclecohort-splittingparsivoltinism |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
DAVID Jean-François |
spellingShingle |
DAVID Jean-François Female reproductive patterns in the millipede Polydesmus angustus (Diplopoda: Polydesmidae) and their significance for cohort-splitting European Journal of Entomology diplopoda polydesmus angustus reproduction life cycle cohort-splitting parsivoltinism |
author_facet |
DAVID Jean-François |
author_sort |
DAVID Jean-François |
title |
Female reproductive patterns in the millipede Polydesmus angustus (Diplopoda: Polydesmidae) and their significance for cohort-splitting |
title_short |
Female reproductive patterns in the millipede Polydesmus angustus (Diplopoda: Polydesmidae) and their significance for cohort-splitting |
title_full |
Female reproductive patterns in the millipede Polydesmus angustus (Diplopoda: Polydesmidae) and their significance for cohort-splitting |
title_fullStr |
Female reproductive patterns in the millipede Polydesmus angustus (Diplopoda: Polydesmidae) and their significance for cohort-splitting |
title_full_unstemmed |
Female reproductive patterns in the millipede Polydesmus angustus (Diplopoda: Polydesmidae) and their significance for cohort-splitting |
title_sort |
female reproductive patterns in the millipede polydesmus angustus (diplopoda: polydesmidae) and their significance for cohort-splitting |
publisher |
Institute of Entomology, Biology Centre, Czech Academy of Science |
series |
European Journal of Entomology |
issn |
1210-5759 1802-8829 |
publishDate |
2009-05-01 |
description |
First-stadium juveniles of Polydesmus angustus born each month from May to September were reared throughout their life cycle under controlled seasonal conditions. At maturity, the reproductive patterns of 62 females were studied individually. It was confirmed that females born from May to August have a 1-year life cycle and those born from late August onwards a 2-year life cycle (cohort-splitting). A third type of life cycle - interseasonal iteroparity - was observed in a few females born late in the season. On average, annual females started to reproduce when 11.4 months old and produced 3.6 broods per female over 1.8 months; the later they were born from May to August, the later they reproduced the following year. Biennial females started to reproduce when 19.9 months old and produced 3.8 broods per female over 2.2 months; all reproduced early in the breeding season. These results indicate that only annual females can produce an appreciable proportion of biennial offspring from late August onwards, which rules out direct genetic determination of life-cycle duration. The reproductive characteristics of P. angustus suggest a non-genetic mechanism that can drive cohort-splitting. Because individual females reproduce for about 2 months on average, this automatically results in cyclic variation in life-cycle duration (annual/biennial/annual) in the long-term progeny of any female. |
topic |
diplopoda polydesmus angustus reproduction life cycle cohort-splitting parsivoltinism |
url |
https://www.eje.cz/artkey/eje-200902-0010_Female_reproductive_patterns_in_the_millipede_Polydesmus_angustus_Diplopoda_Polydesmidae_and_their_significa.php |
work_keys_str_mv |
AT davidjeanfrancois femalereproductivepatternsinthemillipedepolydesmusangustusdiplopodapolydesmidaeandtheirsignificanceforcohortsplitting |
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