Sex ratios in juveniles and adults of Dichroplus maculipennis (Blanchard) and Borellia bruneri (Rehn) (Orthoptera: Acrididae)
Dichroplus maculipennis and Borellia bruneri are two of the 18 grasshopper species of actual or potential economic relevance as pests in Argentina. The objective of this study was to estimate the sex ratios for adults and older nymphs of D. maculipennis and B. bruneri in the field, and analyze possi...
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| Format: | Article |
| Language: | English |
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Sociedade Brasileira de Entomologia
2015-04-01
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| Series: | Revista Brasileira de Entomologia |
| Online Access: | http://www.sciencedirect.com/science/article/pii/S0085562615000321 |
| _version_ | 1830448076407439360 |
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| author | Yanina Mariottini Martina E. Pocco María L. de Wysiecki Carlos E. Lange |
| author_facet | Yanina Mariottini Martina E. Pocco María L. de Wysiecki Carlos E. Lange |
| author_sort | Yanina Mariottini |
| collection | DOAJ |
| description | Dichroplus maculipennis and Borellia bruneri are two of the 18 grasshopper species of actual or potential economic relevance as pests in Argentina. The objective of this study was to estimate the sex ratios for adults and older nymphs of D. maculipennis and B. bruneri in the field, and analyze possible temporal variations. The study was conducted during seven seasons (2005–06 to 2011–12) in representative plant communities of the southern Pampas region. A total of 4536 individuals of D. maculipennis, and 6038 individuals of B. bruneri were collected. The sex ratio registered in older nymphs for D. maculipennis and B. bruneri did not deviate from a 1:1 ratio (p > 0.05), suggesting that these species have such a primary sex ratio. However, a significant bias in sex composition in adults of both species was observed (p < 0.05). The sex ratio in adults of D. maculipennis was different in five of the 18 sampling dates carried out. In three sampling dates it was biased toward males, while in the other two it was biased toward females. Taking into account the sex ratio by sampling season, significant differences were recorded in two seasons. In 2007–08 the sex ratio was biased toward males (1 F:2.26 M), while in 2008–09 it was biased toward females (1.35 F:1 M). The sex ratio in adults of B. bruneri was always biased toward males (p < 0.05). We conclude that results obtained in this study indicate that various factors like differential survival, dispersion, predation, among others, could have modified the primary sex ratio in these species. Keywords: Acrididae, Adults, Nymphs, Pampas region, Sex ratio |
| first_indexed | 2024-12-21T07:32:48Z |
| format | Article |
| id | doaj.art-bb5af1782eb047d9bcec082770ec6671 |
| institution | Directory Open Access Journal |
| issn | 0085-5626 |
| language | English |
| last_indexed | 2024-12-21T07:32:48Z |
| publishDate | 2015-04-01 |
| publisher | Sociedade Brasileira de Entomologia |
| record_format | Article |
| series | Revista Brasileira de Entomologia |
| spelling | doaj.art-bb5af1782eb047d9bcec082770ec66712022-12-21T19:11:31ZengSociedade Brasileira de EntomologiaRevista Brasileira de Entomologia0085-56262015-04-015929699Sex ratios in juveniles and adults of Dichroplus maculipennis (Blanchard) and Borellia bruneri (Rehn) (Orthoptera: Acrididae)Yanina Mariottini0Martina E. Pocco1María L. de Wysiecki2Carlos E. Lange3Centro de Estudios Parasitológicos y de Vectores (CONICET), Buenos Aires, Argentina; Corresponding author.Centro de Estudios Parasitológicos y de Vectores (CONICET), Buenos Aires, Argentina; División Entomología, Museo de La Plata, Universidad Nacional de La Plata, Buenos Aires, ArgentinaCentro de Estudios Parasitológicos y de Vectores (CONICET), Buenos Aires, ArgentinaCentro de Estudios Parasitológicos y de Vectores (CONICET), Buenos Aires, Argentina; Comisión de Investigaciones Científicas de la Provincia de Buenos Aires, Buenos Aires, ArgentinaDichroplus maculipennis and Borellia bruneri are two of the 18 grasshopper species of actual or potential economic relevance as pests in Argentina. The objective of this study was to estimate the sex ratios for adults and older nymphs of D. maculipennis and B. bruneri in the field, and analyze possible temporal variations. The study was conducted during seven seasons (2005–06 to 2011–12) in representative plant communities of the southern Pampas region. A total of 4536 individuals of D. maculipennis, and 6038 individuals of B. bruneri were collected. The sex ratio registered in older nymphs for D. maculipennis and B. bruneri did not deviate from a 1:1 ratio (p > 0.05), suggesting that these species have such a primary sex ratio. However, a significant bias in sex composition in adults of both species was observed (p < 0.05). The sex ratio in adults of D. maculipennis was different in five of the 18 sampling dates carried out. In three sampling dates it was biased toward males, while in the other two it was biased toward females. Taking into account the sex ratio by sampling season, significant differences were recorded in two seasons. In 2007–08 the sex ratio was biased toward males (1 F:2.26 M), while in 2008–09 it was biased toward females (1.35 F:1 M). The sex ratio in adults of B. bruneri was always biased toward males (p < 0.05). We conclude that results obtained in this study indicate that various factors like differential survival, dispersion, predation, among others, could have modified the primary sex ratio in these species. Keywords: Acrididae, Adults, Nymphs, Pampas region, Sex ratiohttp://www.sciencedirect.com/science/article/pii/S0085562615000321 |
| spellingShingle | Yanina Mariottini Martina E. Pocco María L. de Wysiecki Carlos E. Lange Sex ratios in juveniles and adults of Dichroplus maculipennis (Blanchard) and Borellia bruneri (Rehn) (Orthoptera: Acrididae) Revista Brasileira de Entomologia |
| title | Sex ratios in juveniles and adults of Dichroplus maculipennis (Blanchard) and Borellia bruneri (Rehn) (Orthoptera: Acrididae) |
| title_full | Sex ratios in juveniles and adults of Dichroplus maculipennis (Blanchard) and Borellia bruneri (Rehn) (Orthoptera: Acrididae) |
| title_fullStr | Sex ratios in juveniles and adults of Dichroplus maculipennis (Blanchard) and Borellia bruneri (Rehn) (Orthoptera: Acrididae) |
| title_full_unstemmed | Sex ratios in juveniles and adults of Dichroplus maculipennis (Blanchard) and Borellia bruneri (Rehn) (Orthoptera: Acrididae) |
| title_short | Sex ratios in juveniles and adults of Dichroplus maculipennis (Blanchard) and Borellia bruneri (Rehn) (Orthoptera: Acrididae) |
| title_sort | sex ratios in juveniles and adults of dichroplus maculipennis blanchard and borellia bruneri rehn orthoptera acrididae |
| url | http://www.sciencedirect.com/science/article/pii/S0085562615000321 |
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