Recently, the cold resistance becomes a common topic in scientific articles. If we focus on order Heteroptera, we can find a lot of studies dealing with the cold resistance or with the supercooling point (SCP) and also with the factors that influence them. According to the general rule, the acclimation at low temperatures increases the cold resistance. Therefore, the main goal of this thesis is to find out, whether the acclimation also increases the cold resistance of the water cricket Velia caprai Tamanini, 1947 (Veliidae), with the intention to measure SCP of the water crickets depending on the acclimation temperature and the length of exposure. Due to the high mortality (the 284 individuals remained alive of total 1300) and due to the technical difficulties in measuring of SCP (measured only 36 individuals) it was necessary to modify the original goal of the thesis. The new goal was to test the influence of acclimation (during one month vs. one week) and the influence of different temperatures (0°C, 5°C, 10°C) on SCP of V. caprai. The individuals used for this measurement were collected during the year 2010 and in March 2011. The results of this thesis did not confirm the hypothesis that the acclimation at low temperatures increases the cold resistance. The individuals who were acclimated at a higher temperature have the values of SCP demonstrably lower than the individuals who were acclimated at low temperatures. The individuals who overwinter for the first time have arguably higher cold resistance than the individuals who overwinter for the second time. Probable cause of these results is the fact that the water cricket V. caprai does not start with diapause in the fall but it overwinters in quiescence.
| Identifer | oai:union.ndltd.org:nusl.cz/oai:invenio.nusl.cz:111861 |
| Date | January 2012 |
| Creators | NOVOTNÁ, Iveta |
| Source Sets | Czech ETDs |
| Language | Czech |
| Detected Language | English |
| Type | info:eu-repo/semantics/masterThesis |
| Rights | info:eu-repo/semantics/restrictedAccess |
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