Effects of Larval Population Density on Rates of Development and Interactions between Two Species of Chrysomya (Diptera: Calliphoridae) in Laboratory Culture

Abstract

Rearing of Chrysomya megacephala (F.) and Chrysomya rufifacies (Macquart) in pure cultures at seven different population densities (larvae per gram of liver) demonstrated an inverse relationship between density and the duration of the larval stage. In pure cultures, larval mortality rates decreased with increasing density until an optimum density was reached (8 larvae/g liver for C. megacephala and 10 larvae/g liver for C. rufifacies), then decreased directly with density. Puparial and adult weights varied inversely with density for both species in pure cultures. Internal feeding mass temperatures were above ambient temperatures for all cultures, with maximum temperatures recorded in cultures with 20 and 40 larvae/g liver for G. rufifacies and C. megacephala, respectively. In paired encounters, larvae of C. rufifacies were cannibalistic and predatory on C. megacephala larvae after the first instar. In mixed cultures of these two species, the larval mortality of C. rufifacies remained relatively stable, whereas the larval mortality of C. megacephala increased directly with population density.

Effect of temperature on development of the blowfly, Lucilia cuprina (Wiedemann) (Diptera: Calliphoridae)

“…Each feeding container was composed of 50g of catering-grade chicken liver in a 125-ml Styrofoam cup placed in a container with washed sand approximately 3.0-3.5 cm deep in which larvae could pupate and covered with mesh to confine larvae and exclude parasitoids. The stocking density (0.4 larvae/g) minimized the accumulation of maggot-generated heat [21] that might have stimulated growth [1][2][3][4] and avoided stunted growth associated with isolation of larvae [22]. Fifteen cups were prepared in this manner for each temperature.…”

The dynamics of intraguild predation in Chrysomya albiceps Wied. (Diptera: Calliphoridae): interactions between instars and species under different abundances of food

“…of their population sizes, and by excluding one of them (Goodbrod & Goff 1990, Ullyett 1950). For C. albiceps and C. rufi facies Fabricius, local competition can cause the competitor to become an active predator, and can lead to a contest-type process instead of the scramble competition that usually occurs in blowfl ies (Ullyett 1950, Nicholson 1954.…”

Larval dispersal and predation in experimental populations of Chrysomya albiceps and Cochliomyia macellaria (Diptera: Calliphoridae)

“…Chrysomya albiceps (Wiedemann) is a facultative predator of other dipteran larvae (Fuller 1934, Coe 1978, Gagné 1981, Erzinçlioglu & Whitcombe 1983 and this habit probably has important effects on such prey species, particularly in communities where reduction in population size of native species is evident (Hanski 1977, Goodbrod & Goff 1990, Wells & Greenberg 1992a. Recently, Faria et al (1999) and Faria and Godoy (2001) investigated facultative predation rates on third instar larvae of C. macellaria, C. putoria and C. megacephala by third instar larvae of C. albiceps in no-choice, two-choice and three-choice situations.…”