INFLUENCE OF PERIOD OF INFESTATION, 



51 



of locations which will IxMiclIl inosl larixclv l)\ I he a\'ci-a^(M'(]"ccl i\ ciicss 

 of those factors of natural contiol. 



INFLUENCE OF PERIOD OF INFESTATION UPON NATURAL 



CONTROL. 



A rcarranij:cnicnt of the data u:iven in Tahles HI and V may he used 

 to jjive a conij)arison of tlu* i'(*sults according to the classes of foiiiis 

 exaniiiUHl for Louisiana and for Tcwas. The s(>|)aration of (he (hila 

 for tlu^ two Stat(\s is made to eiiahle a com|)arison as to mortality in 

 a nuHMitly infest(Hl ar(ni, as in Louisiana, with an area which has heen 

 iniVsted for a considiM'ahle tim(\ as is the case with neai'ly all the 

 localiti(>s e.xamiiUMl in Tc^xas. 



Tahi.k X. — Si(ininiirii <>/ rrsulls shoiriiKj moiialilij m Louisiana and Texas rcsnUnuj 

 from licdl or drying, ants, and parasites. 





Total Total 



number nunil)er 



of ' of 



Total 

 number 



of 

 weevil 

 stages 

 dead. 







Weevil stages kiUed. 





State anil class of 



Total 

 mor- 

 tality 



threc 

 causes. 



^'"'^ng.'*'^"' ^^"t«- 



Parasites. 



fniit. 



fonns 

 exam- 

 ined. 



weevil 

 stages 

 found. 



Num- 

 ber. 



Per 



cent 



of total 



stages. 



Num- 

 ber. 



Per 



cent 



of total 



stages. 



Num- 

 ber. 



Per 



cent 



of total 



stages. 



Louisiana: 



Hanging bolls 



Hanging squares. . 

 Fallen bolls 



2.955 

 1.208 



2 Am 



4.170 



1.163 

 847 

 599 



2,508 



458 



519 



200 



1,031 



Per cl. 

 39.4 

 61.3 

 33.4 

 41.1 



137 

 175 

 54 

 160 



11.8 



20.7 



9.0 



6.4 



252 

 274 

 141 

 859 



21.7 

 32.3 

 23.5 

 35.7 



69 

 70 

 5 

 12 



6.0 

 8.3 

 0.8 



Fallen squan-s 



0.7 



Total. Louisiana. 



10,999 



5.117 



2,208 i 43.2 



526 



10 3 



1,526 



29.8 



156 



3.0 



Texas: 



Hanging l)olls 



Hanging squares. . 



P^alion boils 



Fallen squares 



14.404 



5. 736 



20,079 



35.738 



4.270 



3, 383 



4.019 



22.202 



1,192 27.0 



1,708 50 5 



1,323 32 9 



13.854 62.7 



289 



629 



473 



6,141 



6.8 

 18.6 

 11.8 

 27.8 



650 



(J09 



810 



6,947 



15.2 

 18.2 

 20.2 

 31.3 



253 



470 



40 



770 



6.0 



13.9 



1.0 



3.5 



Total. Texas 



75,957 



33.874 



18.077 1 53.5 



7,532 



22.3 



9,016 



26.7 



1,533 



4.6 



Total, Louisiana 

 and Texas 



86,956 



38,991 



20,285 52.0 



8,058 



• 



20.7 



10,542 



27.1 



1,689 



4.3 



Naturally the examinations in Texas cover a much larger number 

 of forms than do those in Louisiana, amounting to 87.4 per cent of 

 the total for the tw^o States. The Louisiana forms show a shghtly 

 greater proportion of weevil stages to forms examined than do those 

 from Texas, in the former case the proportion being one weevil stage 

 to each 2.15 forms, in the latter State one weevil stage per 2.25 forms. 

 Thi.^ (hfh'reiice is, of course, but slight. 



In comparing the mortality results for the two States it appears 

 that in Texas the total mortality averaged fully 10 per cent higher 

 than it i\'n\ in Louisiana. The smaller mortality found in Louisiana, 

 being inevitably connected with a higher proporticm of we(^vil develop- 

 ment, doubtless explains sufficiently the slightly higher proportion 

 of weevil stages to forms examined which was found in that State. 

 A comparison of the mortality from each of the three factors shows 

 that in Texas the mortality from heat or drying and from parasites 

 exceeds thai from these causes in Louisiana, while in the latter State 

 the proportion of mortality due to the work of ants is slightly greater 



