8 BULLETIN 783, U. S. DEPAETMEISTT OF AGRICULTURE. 



The question has been raised by importers and manufacturers as 

 to whether or not it is possible to retard the development of the rice 

 moth in order that control measures may be undertaken at desirable 

 times. ' While it was not possible to undertake any experiments 

 along this line, it is known from analogy that development could be 

 considerably retarded by cold storage. The egg period might be 

 extended from the normal length of time, 3 to 10 days, to about a 

 month ; the larval period to 6 months or more ; and the pupal period 

 from the normal of from 5 to 14 days to' 4 weeks or longer, making 

 a possible total of about 8 months. 



While complete life-history data of this species would be desirable, 

 what has been learned is sufficient to show that such life-history 

 studies would not differ essentially from those of related species, 

 such as the Mediterranean flour moth and the Indian-meal moth, 

 and it has been developed that there is a practical certainty of four 

 generations annually and a possibility of as many as six in high 

 temperatures. 



ASSOCIATED INSECTS. 



The fig moth {Ephestia cafufellaWRlk.), as previously stated, has 

 been associated with this species in infested rice and cocoa products. 

 In one rearing jar containing the rice moth breeding in cocoa, 

 received June 18, 1915, the larvse of the latter were full grown on 

 August 27. The jar was examined again on September 10 and appar- 

 ently contained only the fig moth with its larvae. This latter had evi- 

 dently " run out " the former, its larvae perhaps feeding on the larvae 

 and pupae of the rice moth, which in nature is not an unusual occur- 

 rence.^ Some, however, remained, and in a few days the rice moth 

 reappeared. In this particular rearing cage the fig moth must have 

 deposited her eggs through the mesh covering the jar, although this 

 was decidedly thick and closely woven. Fig-moth females have been 

 known to do this in previous instances. 



The Indian-meal moth {Plodia hvterpudnctella Hbn.) developed in 

 great numbers in a lot of chocolate in which the rice moth had been 

 reproducing abundantly, completely devouring the edible material 

 and then perishing. 



It may be noted that when closely confined with edible material 

 the three moths mentioned, in common with others which feed upon 

 stored products, frequently perish because of the compact webbing 

 which prevents escape and the lack of moisture which produces 

 excessive drying of their food supply, curtailing the longer repro- 

 duction period of the species. 



1 The larvae of the cabbage worm (Pontia rapae L.) have been noted feeding- on the 

 eggs of the cabbage looper {Autographa irassicae Riley). The corn earworm {Chloridea 

 oOsoleta Fab.) is also well known to be cannibalistic. 



