Publicação
The Impact of Sub-lethal Temperatures on Spider Mite Reproduction
| Resumo: | Due to climate change, organisms are being increasingly exposed to longer and more intense periods of heat stress, which critically affect their life-history traits. Reproduction is generally more sensitive to high temperatures than survival, although most studies focus on the latter trait. This suggests that populations will be affected by climate change earlier than predicted by current knowledge. To test the influence of temperature on reproduction, we addressed how sub-lethal high temperatures affect reproductive traits in Tetranychus urticae, a haplodiploid agricultural pest of great economic importance. Although several studies have tackled the effect of temperature on this species, and their reproductive behavior, few have addressed the interaction temperature – reproductive behavior. First, we assessed fertility and survival of both sexes at high temperatures, to identify the temperature that critically impairs fertility but not survival. This is measured in females by decreased fecundity and in males by reduced ratio of female offspring. Results showed that 36ºC best fits this condition. Additionally, male fertility was more affected by temperature in pesticide resistant populations. Then, we measured how temperature affected offspring paternity share, as the pattern of first male sperm precedence seen in this species may change when the first male is sterile due to temperature. Results suggest this is the case. Moreover, females mated with sterilized males had higher remating eagerness, leading to restored offspring sex ratio levels after they remated with fertile males. We also tested if, and how fast, sterilized males regain fertility once placed at an optimal temperature. We show that there is no recovery across five consecutive matings or after two days at an optimal temperature. This project provides new insights regarding the effects of climate change on reproductive traits in an important crop pest, paving the way to future studies in sexual selection and adaptation to abiotic stresses. |
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| Autores principais: | Costa, Sofia Garcia da |
| Assunto: | Tetranychus urticae temperatura fertilidade precedência espermática comportamento de acasalamento Teses de mestrado - 2021 |
| Ano: | 2021 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade de Lisboa |
| Idioma: | inglês |
| Origem: | Repositório da Universidade de Lisboa |
| Resumo: | Due to climate change, organisms are being increasingly exposed to longer and more intense periods of heat stress, which critically affect their life-history traits. Reproduction is generally more sensitive to high temperatures than survival, although most studies focus on the latter trait. This suggests that populations will be affected by climate change earlier than predicted by current knowledge. To test the influence of temperature on reproduction, we addressed how sub-lethal high temperatures affect reproductive traits in Tetranychus urticae, a haplodiploid agricultural pest of great economic importance. Although several studies have tackled the effect of temperature on this species, and their reproductive behavior, few have addressed the interaction temperature – reproductive behavior. First, we assessed fertility and survival of both sexes at high temperatures, to identify the temperature that critically impairs fertility but not survival. This is measured in females by decreased fecundity and in males by reduced ratio of female offspring. Results showed that 36ºC best fits this condition. Additionally, male fertility was more affected by temperature in pesticide resistant populations. Then, we measured how temperature affected offspring paternity share, as the pattern of first male sperm precedence seen in this species may change when the first male is sterile due to temperature. Results suggest this is the case. Moreover, females mated with sterilized males had higher remating eagerness, leading to restored offspring sex ratio levels after they remated with fertile males. We also tested if, and how fast, sterilized males regain fertility once placed at an optimal temperature. We show that there is no recovery across five consecutive matings or after two days at an optimal temperature. This project provides new insights regarding the effects of climate change on reproductive traits in an important crop pest, paving the way to future studies in sexual selection and adaptation to abiotic stresses. |
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