Life-history responses of larviparous Boettcherisca formosensis (Diptera: Sarcophagidae) to larval competition for food, including comparisons with oviparous Hemipyrellia ligurriens (Calliphoridae)

For Boettcherisca formosensis increases in rearing density resulted in lowered larval survivorship, shortened larval development time and production of smaller, shorter-lived adults with reduced fecundity. B. formosensis is larviparous. Average brood size was 17.5±1.0 (mean±SEM) larvae, much less than the average number of mature larvae inside gravid females. Females apparently produced a series of small broods, distributing their offspring over a number of carcasses. Compared with the oviparous Hemipyrellia ligurriens, B. formosensis adults were larger and longer-lived, with a longer larval development time but shorter larval feeding period, but females had a shorter pre-reproductive period, were less fecund, and had a lower life time reproductive investment. B. formosensis had lower relative performance than H. ligurriens over the larval rearing density range, and was more sensitive to increases in density. Although the sarcophagid may be a competitively inferior species, other features (eg larvipary, short larval feeding period and spreading of offspring from a single brood among carcasses) may be of significant adaptive value. -from Authorslink_to_subscribed_fulltex

Associação entre larvas de Chrysomya megacephala (Fabricius) e Chrysomya albiceps (Wiedemann), Chrysomya megacephala (Fabricius) e Cochliomyia macellaria (Fabricius) (Calliphoridae, Diptera) sob condições de laboratório Association between Chrysomya megacephala (Fabricius) and Chrysomya albiceps (Wiedemann), Chrysomya megacephala (Fabricius) and Cochliomyia macellaria (Fabricius) larvae (Calliphoridae, Diptera), under laboratory conditions

<abstract language="eng">This paper intends to recognize some aspects of interspecific relationships between Chrysomya megacephala (Fabricius) and C. albiceps (Wiedemann) and between C. megacephala and Cochliomyia macellaria (Fabricius) larvae in laboratory. A diet consisting of decomposing horse flesh was used, and the relation of 1 larva/g diet was established. The development of the two species was done in pure and associated cultures. The association with Chrysomya albiceps influenced the post-embrionary development period and the weight of mature larvae of the C. megacephala, reducing their. Such weight decrease, along with the predation of larvae of C. megacephala larvae, yelded a decrease in survival in all of the stages. Larvae of this species showed an increase in its weight when associated with Cochliomyia macellaria. The native species responded to the association by reducing its body weigth and its viability. This association doesnt influence the duration of post-embrionary development

Influence of weather conditions on fly abundance and its implications for transmission of Rabbit Haemorrhagic Disease Virus in the North Island of New Zealand

Blowflies (Diptera: Calliphoridae) and flesh flies (Diptera: Sarcophagidae) are potential vectors of rabbit haemorrhagic disease virus (RHDV) in New Zealand. The associations between habitat and weather factors on the abundance of these flies were investigated. Between October 1999 and June 2001, flies were trapped on open pasture and in dense vegetation patches on farmland in the Himatangi area of the North Island. Five calliphorid species were trapped commonly at scrub edges and the most abundant sarcophagid, Oxysarcodexia varia Walker, was trapped mainly on open pasture. An abundance peak of O. varia was probably associated with the occurrence of a rabbit haemorrhagic disease (RHD) outbreak in the study area. Overall abundance of flies varied according to habitat and species, and species numbers differed between seasons and years. The all-day minimum temperature 3 weeks before trapping was a significant variable in all models of fly abundance, whereas average rainfall did not affect fly abundance. The all-day temperature range was significant only for O. varia. The influence of other climatic factors varied between fly species. Climate dependent variations in fly abundance may contribute to the risk of transmission of RHD, which occurred intermittently on the site during the study period