The Mexican cotton-boll weevil (Anthonomus grandis Boh.) . ares the weevils havebecome more numerous, and those which have developed from the gen-eration on volunteer cotton attack the planted cotton, and throughtheir punctures, either for feeding or egg-laying, cause a wholesaleshedding of the young squares. It seems to be an almost invariablerule that a square in which a weevil has laid an egg drops to the groundas a result of the work of the larva; in the square on the ground thelarva reaches full growth, transforms to pupa, and issues eventually asa beetle, the time occupied in this round
The Mexican cotton-boll weevil (Anthonomus grandis Boh.) . ares the weevils havebecome more numerous, and those which have developed from the gen-eration on volunteer cotton attack the planted cotton, and throughtheir punctures, either for feeding or egg-laying, cause a wholesaleshedding of the young squares. It seems to be an almost invariablerule that a square in which a weevil has laid an egg drops to the groundas a result of the work of the larva; in the square on the ground thelarva reaches full growth, transforms to pupa, and issues eventually asa beetle, the time occupied in this round approximating four , as the bolls form, the weevils attack them also, and lay theireggs in them, and the larvae develop in the interior just as with thesquares. The bolls, however, do not drop. Fig. 3, a and fr, show thelarvae in the squares, and c, a young boll cut open and the pupa in itscustomary position. There is a constant succession of generations from early spring untilfrost, the weevils becoming constantly more numerous and the larvae. shift- y;W* Yjg. 4.—Mature boll cut open at left, showing full-grown larva; the one at the right not cut, andshowing feeding punctures and oviposition marks. and pupae as well. A single female will occupy herself with egg-layingfor a considerable number of days, so that there arises by July an inex-tricable confusion of generations, and the insect may be found in thefield in all stages at the same time. The bolls, as we have just stated,do not drop as do the squares, but gradually become discolored, usuallyon one side only, and by the time the larva becomes full grown generallycrack open at the tip. While in a square one usually finds but a singlelarva, in a full-grown boll as many as twelve have been found. In anycase, however, the hatching of a single larva in a boll results in thedestruction of the boll to such an extent that its fiber is useless. Whereno serious frost occurs in December, the insects all, or nearly all, r
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Keywords: ., bookcentury1800, bookdecade1890, bookidme, booksubjectinsectpests
