28 Tue BLOWFLIES or NortH AMERICA 
cophaga species are commonly attracted to baits which are very 
old and strong. Even in the Luciliini there is a strongly marked 
difference in preference for baits of different ages, Phaenicia 
sericata and pallescens preferring baits slightly older than 
Lucilia illustris and Bufolucila silvarum. 
Fig. I. Standard conical type blowfly trap. Designed by Bishopp and 
Laake, this trap has been found to be the most effective type for making 
collections of blowflies. Menard, Tex., August 23, 1929. 
Rearing. Few dipterous insects are more easily reared in 
numbers than many species of calliphorid flies. Most of the 
carrion-breeding forms can be reared continuously with a 
minimum of effort in either artificial or natural light, and they 
may be inbred for years without apparent weakening of the 
strain. Miller (1940) has inbred Phormia regina and Phaenicia 
