BULLETIN 1102, U. S. DEPARTMENT OF AGRICULTURE. 



was made to determine at what period the spots may appear during 

 the development of the pecan kerneh However, the biiirs are found 

 most abundantly on pecan nuts in September and October. 



The experiment required no further attention until the nuts were 

 harvested, except to replace with live bugs those that had died. The 

 Schley nuts were harvested on October 16 and the Curtis nuts on 

 November 19, and the result's are shown in Table 1. 



Tablk 1. — Result of experiment showing number of pecan nuts spotted lohen 

 caged icith and loithout bugs. 



Percent- 

 Virietv iNumoer witn age of 



' ^*^y ' nfnntc Triarnol- kemcls 



si^otted. 



Schley, without bugs (check) 



Schley, with bugs 



Curtis, withovit bugs (check). 

 Curtis, with bugs 





Number 



Number 



with 



of nuts. 



kernel- 





spot. 



36 







145 



140 



55 







16S 



166 





 93.6 

 



9S.8 



In no case did the protected nuts, or checks, show any evidence of 

 spotting, while a very large percentage of those confined with bugs 

 were badly affected with typical kernel spots. Many of these indi- 

 vidual nuts had 15 to 25 spots. In fact, some nuts were so badly 

 spotted that almost the entire kernel was discolored and partially 

 shriveled. 



An attempt was made to produce kernel-spot artificially by punc- 

 turing the nuts with sterile needles. Several punctures were made 

 in each of 12 nuts. This work was done during the first week in 

 September at the time when most of the bugs were placed in the 

 other cages. The shells of the nuts had hardened to such an extent 

 by this time that several needles were broken while attempting to 

 forcp them through to the kernels. It appears to be a remarkable 

 feat that the bugs are able to pierce through the hardening pecan 

 shells with their delicate mouth parts. These artificially punctured 

 nuts were examined at harvest time as to the effect the punctures had 

 upon the kernels. While these injuries were still evident as either 

 open holes or holes partially healed over, they in no manner resem- 

 bled the spots caused by the insect punctures. 



In addition to the caged nuts, an examination w^as made of un- 

 caged nuts growing upon the same trees. Of 375 Schley nuts thus 

 examined, 9 per cent were'spotted. Of 82 Curtis nuts examined, 8-J- 

 per cent had kernel spots.^ 



The result of the experiment recorded above demonstrates very con- 

 clusively that punctures by the southern stinkbug {Nezara viridula 



» A smaller number of uncaged Curtis nuts were examined than the writer wished, as 

 the crop that grew upon these trees was stolen soon after it was harvested. The nuts 

 examined were gathered under the trees as a last resort. 



