194 MAINE AGRICULTURAL EXPERIMENT STATION. 1916. 



Larva . PAGE 



The eggs hatch into slender, headless, footless, blind maggots of 

 remarkably varied appearance, but all with the posterior spir- 

 acles borne on the end of a short, or very long, double, but 



never forked, tube 202 



There appear to be twelve larval somites usually marked by a 



transverse row of twelve segmental bristles 203 



Other characteristics 203 



Pupa. 



When the larva is full grown its skin inflates and hardens, and in- 

 side of the puparium, so formed, the transformation from 

 maggot to winged fly takes place 204 



Characteristics 204 



Adult. 

 When this change is complete the fly pushes off the front of the 



puparium, crawls out of the skin, and is soon able to fly away 205 



It feeds on nectar and pollen 205 



Mating 205 



Oviposition for the next generation 206 



HABITS OF THE LARVAE 206 



The great variety of larval habits, with the species known to fol- 

 low each, is summarized in Figure 28 207 



STRUCTURE OF THE LARVAE . .1-08 



Careful study of the larvae following different habits shows a num- 

 ber of different structural types of larvae, the species of each 

 type for the most part following the same habit 208 



(1) The aphidophagous type, which is of prime importance since 

 it includes the valuable predaceous species, and also one crop- 

 pest, is characterized 208 



(2) The boring type of larva, including several serious pests of 

 bulbous crops likely to be spread in the State, is characterized 209 



(3) The short-tailed, filth-inhabitating type of larva, which em- 

 braces two species not hitherto described as breeding in human 

 excrement, is characterized 210 



(4) The long-tailed (or rat-tailed) filth-inhabiting type of larva, 

 which includes a number of species with a very remarkable 

 adaptation for breathing while feeding below the surface of 



water, is characterized 210 



(5) The Microdon type of larva, which includes species of that 

 genus that live in the nests of ants; and are so anomalous in 

 appearance that they were several times described as new 

 species of Molluscs and Coccidae, before their true nature as 



the young of flower-flies was recognized, is characterized 211 



