Sex ratio in two species of Pegoscapus wasps (Hymenoptera: Agaonidae) that develop in figs: can wasps do mathematics, or play sex ratio games?
The fig pollinating wasps (Hymenoptera: Agaonidae) have obligate arrhenotoky and a breeding structure that fits local mate competition (LMC). It has been traditionally assumed that LMC organisms adjust the sex ratio by laying a greater proportion of male eggs when there is superparasitism (several f...
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Vicerractoría Investigación
2009-09-01
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doaj-7acbf0ebbfeb4e5ebb345157f123a7772020-11-24T23:46:17ZengVicerractoría InvestigaciónRevista de Biología Tropical0034-77442009-09-01573605621S0034-77442009000300012Sex ratio in two species of Pegoscapus wasps (Hymenoptera: Agaonidae) that develop in figs: can wasps do mathematics, or play sex ratio games?William Ramírez-Benavides0Julián Monge-Nájera1Juan B Chavarría2Universidad de Costa RicaUniversidad de Costa RicaUniversidad de Costa RicaThe fig pollinating wasps (Hymenoptera: Agaonidae) have obligate arrhenotoky and a breeding structure that fits local mate competition (LMC). It has been traditionally assumed that LMC organisms adjust the sex ratio by laying a greater proportion of male eggs when there is superparasitism (several foundresses in a host). We tested the assumption with two wasp species, Pegoscapus silvestrii, pollinator of Ficus pertusa and Pegoscapus tonduzi, pollinator of Ficus eximia (= F. citrifolia), in the Central Valley of Costa Rica. Total number of wasps and seeds were recorded in individual isolated naturally colonized syconia. There was a constant additive effect between the number of foundresses and the number of males produced in the brood of a syconium, while the number of females decreased. Both wasp species seem to have precise sex ratios and probably lay the male eggs first in the sequence, independently of superparasitism and clutch size: consequently, they have a non-random sex allocation. Each syconium of Ficus pertusa and of F. eximia colonized by one foundress had similar mean numbers of females, males, and seeds. The two species of wasps studied do not seem to adjust the sex ratio when there is superparasitism. Pollinating fig wasp behavior is better explained by those models not assuming that females do mathematical calculations according to other females’ sex ratios, size, number of foundresses, genetic constitution, clutch size or environmental conditions inside the syconium. Our results are in agreement with the constant male number hypothesis, not with sex ratio games. Rev. Biol. Trop. 57 (3): 605-621. Epub 2009 September 30.http://www.scielo.sa.cr/scielo.php?script=sci_arttext&pid=S0034-77442009000300012&lng=en&tlng=enajuste de la proporción sexualcompetencia por apareamiento a nivel localpolinizadores de los higosPegoscapusCosta Rica |
collection |
DOAJ |
language |
English |
format |
Article |
sources |
DOAJ |
author |
William Ramírez-Benavides Julián Monge-Nájera Juan B Chavarría |
spellingShingle |
William Ramírez-Benavides Julián Monge-Nájera Juan B Chavarría Sex ratio in two species of Pegoscapus wasps (Hymenoptera: Agaonidae) that develop in figs: can wasps do mathematics, or play sex ratio games? Revista de Biología Tropical ajuste de la proporción sexual competencia por apareamiento a nivel local polinizadores de los higos Pegoscapus Costa Rica |
author_facet |
William Ramírez-Benavides Julián Monge-Nájera Juan B Chavarría |
author_sort |
William Ramírez-Benavides |
title |
Sex ratio in two species of Pegoscapus wasps (Hymenoptera: Agaonidae) that develop in figs: can wasps do mathematics, or play sex ratio games? |
title_short |
Sex ratio in two species of Pegoscapus wasps (Hymenoptera: Agaonidae) that develop in figs: can wasps do mathematics, or play sex ratio games? |
title_full |
Sex ratio in two species of Pegoscapus wasps (Hymenoptera: Agaonidae) that develop in figs: can wasps do mathematics, or play sex ratio games? |
title_fullStr |
Sex ratio in two species of Pegoscapus wasps (Hymenoptera: Agaonidae) that develop in figs: can wasps do mathematics, or play sex ratio games? |
title_full_unstemmed |
Sex ratio in two species of Pegoscapus wasps (Hymenoptera: Agaonidae) that develop in figs: can wasps do mathematics, or play sex ratio games? |
title_sort |
sex ratio in two species of pegoscapus wasps (hymenoptera: agaonidae) that develop in figs: can wasps do mathematics, or play sex ratio games? |
publisher |
Vicerractoría Investigación |
series |
Revista de Biología Tropical |
issn |
0034-7744 |
publishDate |
2009-09-01 |
description |
The fig pollinating wasps (Hymenoptera: Agaonidae) have obligate arrhenotoky and a breeding structure that fits local mate competition (LMC). It has been traditionally assumed that LMC organisms adjust the sex ratio by laying a greater proportion of male eggs when there is superparasitism (several foundresses in a host). We tested the assumption with two wasp species, Pegoscapus silvestrii, pollinator of Ficus pertusa and Pegoscapus tonduzi, pollinator of Ficus eximia (= F. citrifolia), in the Central Valley of Costa Rica. Total number of wasps and seeds were recorded in individual isolated naturally colonized syconia. There was a constant additive effect between the number of foundresses and the number of males produced in the brood of a syconium, while the number of females decreased. Both wasp species seem to have precise sex ratios and probably lay the male eggs first in the sequence, independently of superparasitism and clutch size: consequently, they have a non-random sex allocation. Each syconium of Ficus pertusa and of F. eximia colonized by one foundress had similar mean numbers of females, males, and seeds. The two species of wasps studied do not seem to adjust the sex ratio when there is superparasitism. Pollinating fig wasp behavior is better explained by those models not assuming that females do mathematical calculations according to other females’ sex ratios, size, number of foundresses, genetic constitution, clutch size or environmental conditions inside the syconium. Our results are in agreement with the constant male number hypothesis, not with sex ratio games. Rev. Biol. Trop. 57 (3): 605-621. Epub 2009 September 30. |
topic |
ajuste de la proporción sexual competencia por apareamiento a nivel local polinizadores de los higos Pegoscapus Costa Rica |
url |
http://www.scielo.sa.cr/scielo.php?script=sci_arttext&pid=S0034-77442009000300012&lng=en&tlng=en |
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