BOARD QF HORTICULTURE 119 



Life Historj' 



As with the majority of the stored food product insect pests, the Indian meal 

 moth may be found in all Staues of development throughout the year. Genei*ation 

 follows generation, the cycles becoming more or less confused, depending on 

 temperature, food supply, etc. 



Eggs are deposited inore or less promiscuously by the adult moths, either on 

 the food itself where exposed, on the carton or Container, or on the walls, floors 

 or similar situations adjacent to the product. One female moth may deposit 

 from 275 to 350 eggs. 



The eggs are a dull white in color with a slight lustre. the surface roughened. 

 They are very small, barely visible to the naked eye. The eggs hatch in about 

 four to eight days, and the young active larva seeks about for food. It will eat 

 through the softer stem end of a walnut hüll, discover cracks, tears or any pos- 

 sible openings in cartons or Containers and work its way to the interior. Where 

 once a package is infested the moth can breed indefinitely within the Container 

 until the food contents are reduced to a mass of web and frass. 



The average larval stage is about 60 days. It is as a worm that the i)est 

 attacks food products. In addition to the actual destruction of food, the worm 

 spins wel>s and promiscuously scatters excrement through the protluct. 



The mature worm transforms to a pupa within the food product where the 

 larva feeds. The pupa is reddish brown in color, slightly less than one-fourth 

 inch long. From ten to twenty days are passed as a pupa. The adult insect then 

 emerges from the pupa case. 



The adult moth measures about one-fourth inch in length. The Indian meal 

 moth is very conspicuously marked. The general ground color is a grayish brown. 

 Across the Shoulders is a conspicuous white band, the outer third of the wings 

 being brown with some lustre. The moths are normally night fliers. They fly 

 readily. moving with a zig-zag flight. After mating the females seek favorable 

 positions for egg laying, 



The Injury 



As intimated earlier, the general injury to cereals and household products 

 l)ecomes of secondary importance beside the serious injury and menace to our 

 commercial horticultural intei'ests in the attack of the pest on English walnuts, 

 dried and evaporated fruits including prunes, loganberries. raspberries, etc., and 

 evaporated vegetables. 



The initial infestation is a comparatively simple process, as the moths are 

 present and active at all times of the year. A Single sack of infested walnuts 

 may serve to contaminate an entire lot where held in storage for any length of 

 time. Dried or evaporated fruit left for a time in open bins, as is the general 

 practice, is subject to infestation. Then later in the packed cases the breeding and 

 uestructive work of the moth continues with increasing seriousness. Dried logan- 

 berries and prunes packed in the West apparentl.v free from infection, when 

 opened in the eastern market have been found a mass of worms, web and excre- 

 ment. Evaporated vegetables held for a time have been condemned as unfit for 

 human food because of the activities of this pest. Walnuts held in storage for 

 eight months have developed as high as 95 per cent infestation. Unfortunately 

 the presence of the moth Is not of rare occurrence. The insect is generally present 

 and active in situations where food products are prepared, stored or handled 

 in quantities. 



Combative Measures 



Clean Surroundings. A general cleanup at frequent intervals will do much to 

 keep down serious outbreaks. Frequently the insect breeds in waste material 

 in out of the way corners, basements, etc. 



Frequent Stirring. Substances that must be left exposed in open bins or in 

 sacks should be moved frequently. Shoveling from one bin to another or rear- 

 rauging the sacks occasionally is of value. 



