Reflex bleeding is one of the many anti-predation behavioural tactics used by insects. This behaviour is recorded widely in several insect taxa and provides scientists with an interesting opportunity for easily obtaining samples of haemolymph for physiological experiments. However, there is no good evidence that haemolymph and reflex blood have the same characteristics. In this study, we compared three basic characteristics of reflex blood and haemolymph collected from the body cavity, of three species of ladybirds: Harmonia axyridis, Coccinella septempunctata and Ceratomegilla undecimnotata. In the reflex blood we recorded the same concentration of haemocytes and total protein, and level of antimicrobial activity against Escherichia coli as in samples of haemolymph collected from within the body cavity. Therefore, reflex blood is a promising source of haemolymph for use in many physiological and immunological studies. It is the best way of collecting haemolymph if one wants to avoid challenging the immune system and concurrently also enables one to repeatedly collect haemolymph from one individual without injuring it, which would initiate repair mechanisms. The interspecific comparison indicates significant differences among the species studied in three characteristics measured. Interestingly, the native species Ceratomegilla undecimnotata has nearly as effective immune system as the invasive Harmonia axyridis based on the level of antibacterial activity against Escherichia coli.
Pitfall trapping is the most frequently used sampling technique for epigeal arthropods. Trap design could significantly affect the catch so the results of studies using different trap designs may be difficult to compare. Although species composition is frequently investigated in ecological studies, however when pitfall trapping is employed, the effect of trap design on the recorded species composition is rarely considered. In the present study, we investigated the effect of trap construction (funnel or cup trap) and the preservative used (formaldehyde or propylene glycol) on total catch, catch of particular species, species richness and species composition of the ground beetle assemblage sampled. We were interested in the extent to which trap design could bias these characteristics. Total catch was significantly affected by trap construction and preservative used, with the effect of the latter being the stronger. Species richness was only slightly affected by trap design when assemblages caught by traps of a particular type were corrected for unequal sample size. Moreover, we show that the traps of different designs differ in their efficiency for catching particular species of carabid and thus the composition of assemblages recorded using pitfall traps is affected by trap construction and the preservative used. We conclude that to assess the full significance of the effect of pitfall trap design on the results of ecological studies on epigeal arthropods it is necessary to simultaneously use traps of various designs., Michal Knopp, Jan Růžička., and Obsahuje seznam literatury