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

Abstract

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 Authors