THE LEPIDOPTERA 



247 



Fig. 242. — Angoumois Grain Moth 

 (Sitotroga cerealella Oliv.) : a, adult 

 moth, Ubout twice natural size; b, larva 

 in a grain of wheat; c, pupa in another 

 grain, b and c about three times 

 natural size. (Modified from Sander.) 



Family Gelechiidae. — Some of the small insects which compose this 

 group are leaf-miners; others feed on buds and others skeletonize leaves 

 or attack plants in various ways. Many are injurious at times, the 

 amount of injury done dei)ending on their abundance which varies frcrm 

 year to year. 



The Angoumois Grain Moth (Sitotroga cerealella Oliv .) . — Tliis little 

 insect, a native of Europe where it was extremely injurious in the French 

 province of Angoumois, whence its name, has been known in the United 

 'States since about 1730 and is widely distributed but is not often im- 

 portant in the more northerly states. The larva attacks wheat, barley, 

 oats and corn, both in the fields and 

 in storage, often destroying a large 

 part of the grain. 



The adult moth (Fig. 242a) is 

 small, spreading about half an inch, 

 yellowish in color, slightly speckled 

 with black. Winter is spent as the 

 caterpillar in the grain wherever it 

 may be stored, and pupation occurs in 

 the spring, also in the grain, followed 

 by the emergence of the adult which 

 flies to the fields and lays its eggs, 

 about a hundred in all, in the young 



grain heads. The eggs hatch in about a week and each tiny caterpillar 

 attacks a kernel, gnawing into it (Fig. 2426) and consuming its contents. 

 After about 3 weeks the larva becomes full-grown and pupates in the 

 kernel (Fig. 242c) where it fed, escaping a little later as the adult moth. 

 Eggs are now laid on grain ready to harvest and either in the harvested 

 grain or in corn after it has been husked and is therefore accessible to 

 the insects, there now foll^ow later generations, until cold stops their 

 further development which is resumed the following spring. 



Small grains and corn thus attacked are badly injured, not only by con- 

 sumption of the contents of the kernels but also because of the presence 

 of the bodies of the insects themselves and of their excrement which 

 -gives a disagreeable taste to the flour, which lacks adhesiveness and 

 breaks up when stirred in water. 



Control. — When this insect is present, destroy or feed all waste grain 

 and screenings and clean up all grain and refuse from places where grain 

 has been stored, in early spring. Good grain should be fumigated at this 

 time also, if the caterpillars are present. The purpose of this is to destroy 

 the insects before they pass to the growing food plants out of doors. 

 Threshing the grain soon after harvest, not keeping it in the mow long, 

 is also important. Fumigation of the threshed grain for 24 hr., with 

 Carbon disulfid, using 1 lb. for each 100 bu., if it is infested or heats, 



