Crisomia megacefala

Acta Oecologica 27 (2005) 179–183 www.elsevier.com/locate/actoec

Original article

Life table of Chrysomya megacephala (Fabricius) (Diptera: Calliphoridae)
Refaat M. Gabre a, Fatma K. Adham a, Hsin Chi b,*
b

Department of Entomology, Faculty of Science, Cairo University, Giza, Egypt Laboratory of Theoretical Ecology, Department of Entomology, National Chung Hsing University, Taichung,Taiwan Received 25 February 2004; accepted 10 December 2004 Available online 21 January 2005

a

Abstract The life history of the oriental latrine fly, Chrysomya megacephala (Fabricius), was studied at 26 °C in the laboratory. The raw data were analyzed based on the age–stage, two-sex life table, in order to take both sexes and the variable developmental rate among individuals and between sexesinto consideration. The intrinsic rate of increase (r), the finite rate of increase (k), the net reproduction rate (R0) and the mean generation time (T) of C. megacephala were 0.2182, 1.2438 d–1, 91.7 offspring/individual and 20.7 days, respectively. The life expectancy of a newborn egg is 32 days. The maximum reproductive value of females is on the 19th day, which coincides with the totalpre-oviposition period counted from birth. The two-sex life table analysis gives a comprehensive description of the stage differentiation of C. megacephala. © 2005 Elsevier SAS. All rights reserved.
Keywords: Chrysomya megacephala (Fabricius); Life table; Reproduction

1. Introduction Blowflies are distributed worldwide and cause medical problems and losses to the animal industry (Zumpt, 1965;Greenberg, 1971, 1973; Kuhlhorn, 1983; Ghandour, 1988). Norris (1965) gave a comprehensive review on the bionomics of blowflies. Among blowflies, the oriental latrine fly Chrysomya megacephala (Fabricius) is one of the most common blowflies in Egypt (Gabre 1994) and its range is expanding (Greenberg, 1988; Wells, 1991; Tomberlin et al., 2001). Greenberg (1971, 1973) reported that this species is among the mostdangerous dipteran vectors of enteric pathogens. In Malaysia, C. megacephala is the dominant vector of helminth parasite eggs (Sulaiman et al., 1988, 1989). On the positive side, C. megacephala is an important pollinator of mango in Australia (Anderson et al., 1982), and in Taiwan, farmers increase C. megacephala population to increase pollination of mango (Hu et al., 1995). Under laboratoryconditions, C. megacephala was able to develop on a variety of living
* Corresponding author. P.O. Box 17-25, Taichung, 40098, Taiwan. Tel.: +886 4 22876080; fax: +886 4 22851921. E-mail addresses: hsinchi@dragon.nchu.edu.tw (H. Chi), liebchi@ms47.hinet.net (H. Chi). 1146-609X/$ - see front matter © 2005 Elsevier SAS. All rights reserved. doi:10.1016/j.actao.2004.12.002

animals including catfish,toads, frogs, lizards, and pigeons (Roy and Dasgupta, 1971). Esser (1990, 1991) and Gabre (1994) studied the factors influencing ovipositon, larval growth, mortality, longevity, and reproduction of C. megacephala, but no life table was developed. A life table describes the development, survival, and fecundity of a cohort and provides basic data on population growth parameters. A life table developedfrom field data may be used to estimate fitness of a population as influenced by various biotic and abiotic factors. Unfortunately, field life tables are often difficult to construct because tracing population survival and reproduction in the open field under variable environmental conditions is exceedingly difficult. On the other hand, life tables constructed using laboratory data collected undercontrolled conditions and are useful in revealing the maximal growth potential of a population. Traditional life tables, e.g., Lotka (1907, 1922) and Lewis–Leslie matrix (Lewis, 1942; Leslie, 1945), deal only with female populations and ignore the variable developmental rates among individuals. However, most economic species of Lepidoptera, Coleoptera, Orthoptera, and Diptera pests are bisexual...