12 THE EICE WATEE-WEEVIL. 



As indicated by the preceding table, several thousand weevils may- 

 hibernate in the moss on a single tree. The appearance of large 

 numbers of weevils in rice fields when they are first flooded has led 

 to the opinion that the pest completes one generation on host plants 

 other than rice before this time. But as already pointed out, no 

 evidence has been secured that will sustain this view. Abundance of 

 the weevils is probably due to their successful survival through the 

 winter and emergence from hibernation. 



One reference in literature mentions the occurrence of adults " in 

 wintertime under old leaves and other shelter in drier places near the 

 swamps." The finding of one adult in litter beneath rich stubble is 

 recorded by Mr. D. L. Van Dine as the result of searching for half 

 of a day at Stewart, Tex., on October 28, 1909. Entrance into hiber- 

 nation is probably not begun much before the time when the nights 

 are cold enough for frost. Not a single weevil could be found by 

 the writer in a collection of Spanish moss obtained on September 29, 

 at Crowley, La., and in the preceding spring after the first weevils 

 appeared Mr. Hood was unable to find any specimens remaining in 

 the moss. 



NATURAL ENEMIES. 



Besides birds no enemy is known to feed on the mature w r eevils, 

 although the snakes and frogs which frequent the fields probably 

 do so. Bird droppings found by Mr. Hood in a rice field at Stutt- 

 gart, Ark., on September 12 consisted largely of insect remains., those 

 of the rice water-weevil being the most abundant. However, two 

 perfect specimens of the weevil were removed from the droppings 

 and one was found to be alive. According to records in the Biological 

 Survey, this weevil is eaten by the long-billed marsh wren (Telma- 

 todytes pdlustris) and the mallard duck (Anas platyrhynchos) . 



Owing to their concealment in mud the larva and pupa are secure 

 from enemies. When infested roots are pulled for examination and 

 larvae are washed out any minnows that happen to be present in the 

 water will greedily snap the floating bodies. Predaceous larvae of 

 water beetles, which also abound in flooded fields, struggle with one 

 another for possession of a weevil larva. If these predators and the 

 several kinds of rapacious water bugs were adapted for burrowing in 

 the mud and reaching the rice roots, they would be very efficient 

 destroyers of both weevil larva 1 and pupae. But their habit of hunt- 

 ing in the open spaces of water renders them of little or no service 

 against the weevil. 



METHODS OF CONTROL. 

 DRAINING OF THE FIELDS. 



As pointed out in the study of the life history, the existence of the 

 larvae and likewise the pupae depends upon a saturation of the soil. 



