16 FARMERS' BULLETIN 843. 



gence they are to be found laying eggs in nuts that are approaching 

 maturity. Adults may be found in the ground as late as November, 

 as one specimen, apparently fully developed, was taken on November 

 23, 1915, about 8 inches below the surface of the soil. The main egg 

 deposition takes place during the first half of September, but appar- 

 ently eggs are laid over a much longer period, as is evidenced by the 

 time during which larvae leave the nuts. It has been found that the 

 egg stage lasts about 9 days, and as many as 7 eggs may be deposited 

 in a single nut, although the usual number, perhaps, is 3. According 

 to the writer's records, the larvae are gnawing their way out of the 

 nuts from September 28 to November 25, although certain observers 

 have reported that the larvae may leave the nuts as late as January. 

 Immediately upon leaving the nuts they enter the soil to a depth of 

 6 inches or more for the purpose of hibernation. 



CONTROL MEASURES. 



The fumigation of chestnuts with disulphid of carbon has been 

 used for a long time as a remedy against the chestnut weevil, and no 

 doubt this treatment will prove effective against the pecan weevil. 

 The nuts to be fumigated should be placed in a tight box or barrel or 

 other receptacle provided with a tight-fitting lid. The disulphid of 

 carbon should be used at the rate of 1 ounce to each bushel of nuts, 

 and fumigation should last for from 24 to 48 hours. The chemical 

 should be placed in a shallow dish or pan on the top of nuts, and im- 

 mediately after the liquid is poured into the dish the lid should be 

 put in place, care being taken to have it fit tightly. After the nuts 

 have been exposed to the fumes of this gas for from 1 to 2 days, all 

 larvae will have been killed and the lid should be removed to expose 

 the nuts to the air. Since the vapor of disulphid of carbon is very 

 inflammable when mixed with air, fire should be kept away from it. 



The extensive cultivation of the soil in pecan orchards should result 

 in the destructuon of many of the larvae and pupae by their exposure 

 to the air and to natural enemies, and where the weevil is prevalent 

 this practice is recommended. After the harvesting of the crop in 

 the fall, hogs should be pastured in the orchard, as they will find the 

 nuts that have been overlooked, and by their rooting into the soil 

 should destroy many of the hibernating larvae. 



INSECTS INJURING THE FOLIAGE AND SHOOTS. 



THE PECAN LEAF CASE-BEARER.i 



The pecan leaf case-bearer is one of the worst pests affecting the 

 culture of pecans, and it occurs in very injurious numbers in orchards 

 in the southern portion of the pecan-growing area, extending from 

 Florida to Texas. Although this insect has been reported definitely 



1 Acrdbasis ncbuldla Riloy. 



