220 FIRST ANNUAL REPORT OF THE STATE ENTOMOLOGIST. 



often to occur under apparently quite different conditions. The larvae 

 of the European D. cellaris occur in fermented liquids in cellars, as 

 wine, cider, vinegar and beer, and also in decayed potatoes. DrosophUa 

 aceti Kol., infests decayed fruits. Its larvte occupy about eight weeks 

 in attaining their growth, and their pupal state lasts for ten or twelve 

 days ; the flies appear in May and June. DrosophUa fnnebris has been 

 reared from pupae taken from mushrooms; it is sometimes known as 

 the vinegar fly. Another European species, the D. flava, is stated by 

 Curtis, to mine the leaves of turnips, raising blister-like elevations on 

 their upper surface. 



Flour-paste DrosophUa. 



A species of DrosophUa seems to occur occasionally in flour-paste. A 

 gentleman wrote me as follows: " I send a package containing larvae 

 of a fly very troublesome around my cellar and pantry. These I found 

 in a little paste that I had set aside for a short time. I could not ob- 

 tain the flies, but presume that they will be produced from the larvae. 

 They are very partial to any thing in a state of fermentation, and if my 

 pickled fruit or jam begins to sour, they find it before I do, and fre- 

 quently the entire top of the fruit seems alive with the larvae, although 

 they never go deep in the jar." 



The paste larvae formed puparia one-tenth of an inch long, which in 

 a short time gave out flies having a spread of wings of one-eighth of 

 an inch. The large thorax and small abdomen are dull yellowish in 

 color, and under a lens show a number of long, stout hairs ; the wings 

 are brilliantly iridescent. These flies are probably an undescribed 

 species of DrosophUa, and may be presumed to be different from those 

 above mentioned as infesting the pickled fruit and jam: it is not im- 

 probable that the latter were D. ampelophUa. 



Mode of Attack upou Pickled Fruits. 



As our pickled fruits are usually preserved in large earthen or glass 

 vessels which are opened from time to time for the removal of a por- 

 tion of the contents, the escaping acetic odor which they give forth, 

 readily attracts the Drosophila flies which are to be found in our 

 houses during the early autumn. The minute fly effects an entrance 

 into the jar beneath a loosely-fitting lid, and deposits its eggs upon the 

 fruit, if accessible, or upon the side of the jar, whence the young larvte 

 instinctively, when hatched, make their way to the frnit, or find their 

 needed sustenance in the liquid in which they are sometimes seen to 

 swarm. Or, with a more closely-fitting lid, the eggs may be deposited 

 upon the outer edge, beneath which the newly-hatched diminutive 

 larvaj insinuate themselves without material difficultv. 



