. Bulletin. Insects; Insect pests; Entomology; Insects; Insect pests; Entomology. 32 Characters commoul}" used to separate the sexes in the family Cur- culionidje are not distinctive in this species. As a rule the antennse are inserted nearer the tip of the snout in the male than in the female. This character is variable among boll weevils; and though a large number of accurate measurements might show that a slight difference generally exists^, it is too inconspicuous a character to be of general use. With most species the top of the rostrum of the male is rougher tlian is that of the fem
. Bulletin. Insects; Insect pests; Entomology; Insects; Insect pests; Entomology. 32 Characters commoul}" used to separate the sexes in the family Cur- culionidje are not distinctive in this species. As a rule the antennse are inserted nearer the tip of the snout in the male than in the female. This character is variable among boll weevils; and though a large number of accurate measurements might show that a slight difference generally exists^, it is too inconspicuous a character to be of general use. With most species the top of the rostrum of the male is rougher tlian is that of the female. However it may Ji)e with other species, there is but little if anj^ difference in this respect between the young adults of the boll weevil. As the individuals become older the greater activity of the females serves to wear the roughness from the top of the rostrum, and thus gradually, as a result of different habits, this character becomes more distinctive. In less than half of the boll weevils, however, is tliis character sufficiently noticeable to separate the sexes. The terminal segment of the abdomen shows no external difference in either sex, although in many weevils important charac- ters are there found. PROPORTIONS OF THE SEXES. No reliable secondary sexual characters having as yet been discov- ered, the cei'tain determination of sex therefore rests solely upon the primary characters, thus requiring a certain amount of dissection in each case. Such determinations have been made upon large numbers of weevils taken in the field and upon many bred in the laboratory at various seasons of the year. The results are brieflj'^ summarized in Table VI. Table VI.—Proportions of the sexes. Number of fe- males. Season of 1902, both bred and from field Hibernated weevils, 19(J2-3 First generation, 1903 Bred weevils, 1903 Field weevils, midsummer, 190'> Total --- ---. From these 1,207 determinations it appears that males are somewhat more numerous than females, the i^ercenta
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