Date of Award
Behaviour, Forensic entomology, Oviposition, Relative humidity, Temperature gradient
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Blow flies are usually the first insects to arrive at carrion, using it to oviposit or breed. The behaviour to search for and accept a carrion resource as suitable for oviposition is influenced by abiotic factors, particularly temperature and humidity, as well as by the presence of other insects. My thesis focuses on the influence of relative humidity (RH), combined with intraspecific interactions, on oviposition choices of three blow fly species Lucilia sericata (Meigen), Phormia regina (Meigen), and Calliphora vicina Robineau-Desvoidy (Diptera: Calliphoridae). Individual fly oviposition behaviour was measured on a temperature gradient (10-40°C) under high (75- 85%) and low (25-35%) RH conditions, and in the presence of intraspecific eggs at hotter or cooler non-preferred locations on the temperature gradient under each RH conditions. The choice to oviposit or not, timing of first oviposition event, clutch size, and temperature choice for oviposition location along the temperature gradient were recorded. The results indicated that RH affected whether females would oviposit or not on the gradient, but for those that oviposited, RH did not affect clutch size or timing of oviposition. When in the presence of intraspecific eggs, fewer L. sericata females oviposited, with no change in behaviours regardless of RH. In contrast, no P. regina females oviposited in low RH but more females oviposted in high RH, ovipositing larger clutches and closer to the non-preferred intraspecific egg location on the gradient.Neither RH, nor presence of conspecific eggs influenced the number of C. vicina females that chose to oviposit, however, they laid fewer eggs in the presence of conspecifics. This study demonstrated that behavioural generalizations across insect family, such as blow flies, fail to recognize the species-specific responses to thermal preferences, RH conditions and even to the presence of eggs of their own species. These differences are vital to understanding oviposition behaviours, as it relates to species co-existence and to use of these species in forensic entomology.
Tran, Theresa, "Variation in Oviposition Behaviour of Blow Flies (Diptera: Calliphoridae) due to Relative Humidity and Intraspecific Interactions" (2022). Electronic Theses and Dissertations. 8897.