SUIS OF oeARASI LES OF THE COTTON 
BOLL WEEVIL. 
INTRODUCTION. 
Although the boll weevil (Anthonomus grandis Boh.) has shown 
adaptation to many diverse conditions, it is not free from parasites. 
From the work detailed in this bulletin it has become apparent that 
certain enemies attack it in arid regions and certain others in humid 
regions; that some species attack principally larve in dried or sun- ° 
exposed forms, while other species attack the weevil stages in moist, 
decaying forms; that some species work most readily in prairie 
country, while others prefer woodland. The weevil does not escape 
parasitism by dispersion, for the local parasites are capable of 
‘‘adaptation and attack the boll weevil in its first generation. 
Being a species with an all-season food plant, Anthonomus grandis 
has made a decisive gain over most of its near relatives, which are 
confined to more or less limited periods because of the shorter sea- 
sons of their host plants. The most active weevil parasites in 
the South have become adjusted to one host after another until in 
most localities they have a regular seasonal rotation of hosts. From 
this multiplicity of parasitic relations it is but natural to evolve a 
new tendency and to attack the most abundant species of the locality, 
namely, the boll weevil. 
As the native weevil hosts are more or less limited in distribution, 
it is found that the boll-weevil parasites are likewise geographically 
restricted. The combined activity of two or more species in certain 
favored districts has been the cause of forming three known centers 
of intensive parasitism in Texas, of which the most important is 
near Waco; the next around Goliad, Cuero, and Victoria, and the 
third in eastern Texas. The agencies forming these centers are in 
no case identical. Catolaccus incertus is the most active parasite at 
Brownsville, Tex., and Orange, La. Bracon mellitor (fig. 1), which is 
the predominant parasite for the entire infested area, is the most 
active in the entire western half of Texas. Cerambycobius cyaniceps 
is predominant in northeastern Texas. Hurytoma tylodermatis shows 
its greatest activity at Overton and Dallas. 
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