Female breeding-site preferences and larval feeding strategies of carrion-breeding Calliphoridae and Sarcophagidae (Diptera): a quantitative analysis

Abstract

Protection from the elements, predators and parasitoids, and access to food is critical for insect larvae. Therefore, adult female insects are strongly selected to deposit offspring in safe, nutritious locations. Additionally, larvae may move to new feeding sites as food becomes depleted at the natal site. Maggots of carrion-breeding flies exploit patchy resources and are at risk from predators, desiccation and competition. Natural orifices, body folds, fur and feathers are protective locations that provide ready access to food, but their suitability as ovi-or larviposition sites may vary according to the degree of decomposition and presence of other larvae. Accordingly, female preference for ovi-or larviposition sites, and maggot distribution at feeding sites may depend upon carcass condition. We conducted a field experiment to investigate the preferences of female carrion flies for ovi-or larviposition sites on piglet carcasses. We also recorded movement of maggots on carcasses over the first 48 hours after carcass exposure. Females initially preferred to deposit offspring in the mouth; however, this preference changed to the body folds by 24 hours after the carcass exposure. Maggot distribution also changed over time, and the pattern suggested that individuals moved from food-depleted sites to more favourable locations.Z O 0 2 0 6 7 C a r r i o n f l y o v i p o s i t i o n a n d m a g g o t f e e d i n g M . S . A r c h e r a n d M . A . E l g a r

The Influence of Wounds, Severe Trauma, and Clothing, on Carcass Decomposition and Arthropod Succession in South Africa

“…The natural history of blow flies is thought to include severe competition for larval (maggot) food resource (20). In fact, almost every aspect of their biology suggests intense competition for the rapid location and consumption of decomposing bodies (8,(20)(21)(22)(23). This makes blow flies one of the most important forensic indicators during the initial decomposition of a carcass (24).…”

Density of pheromone sources of the weaver antOecophylla longinodaaffects oviposition behaviour and damage by mango fruit flies (Diptera: Tephritidae)

“…This indicates that despite the fly oviposition requirement, the ant pheromone effect was predominant and hindered fruit fly oviposition and caused significant damage to fruits covered by ant pheromones. Research on other insect species reported that protection from predators and access to food is critical for insect larvae and therefore, adult female insects choose to deposit offspring in safe locations (Archer and Elgar 2003). Therefore, in an environment marked by ant pheromones, fruit flies will choose ant-free areas where they will not be inhibited for oviposity and can increase the survival rate of their off-spring.…”

Blow fly responses to semiochemicals produced by decaying carcasses

“…Interestingly, no differences were found between males and females in oriented flight responses towards carcasses. This at first appears to contradict several previous suggestions that female flies are more attracted by carcass odours than males (Stoffolano et al ., ; Wall et al ., ; Archer & Elgar, ; Aak et al ., 2010a). However, most of these studies used capture rates of male and female flies to assess attraction.…”

“…No such bias was observed in this study, indicating that males are equally dependent on locating carcasses in optimal condition. As long‐range volatile pheromones are unknown in C. vicina , it may be that carcass odours function as an aggregating signal increasing the probability of successful mating (Shorey et al ., ; Archer & Elgar, ). Although no difference in attraction was found, higher landing responses were observed in females on the most attractive resources (3‐, 6‐ and 9‐day‐old carcasses).…”

“…It has been documented that the physiological condition of blow flies influences their flight responses (Campan, 1977;Eisemann, 1988;Ashworth & Wall, 1995;Aak & Knudsen, 2012) and that the proportion of responders varies with the chemical composition of the signal (Morris et al, 1998;Urech et al, 2004;Morris, 2005;Cork & Hall, 2007;Aak et al, 2010a). Male saprophagous blow flies attend carrion to obtain food and mates, whereas females also depend on carrion to provide an oviposition site (Shorey et al, 1969;Rognes, 1991;Smith & Wall, 1997;Archer & Elgar, 2003). Such a differentiated use of a resource can lead to sex-specific responses to odours from carcasses.…”