. Y perjudiciales insectos útiles; una introducción al estudio de la entomología económica. Los insectos; los insectos beneficiosos, las plagas de insectos. alas son muy similares en los dos primeros, pero el verde veteado especie tiene venas verdoso en el lado inferior de las alas posteriores. Las larvas se pueden distinguir sin mucha dificultad. Que de las grandes especies es amarillo, manchados de negro; el del pequeño repollo blanco es verde, salpicada de negro y amarillo; mientras que la larva de la especie verde veteado es verde en todo, excepto en el caso de los espiráculos de color rojizo, y un borde amarillo que rodea cada uno de ellos. Los huevos de la

• Colaborador/a: The Book Worm / Alamy Foto de stock
• ID de la imagen: RDHJ1A
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• Dimensiones: 2071 x 1206 px | 35,1 x 20,4 cm | 13,8 x 8 inches | 150dpi

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. Injurious and useful insects; an introduction to the study of economic entomology. Insects; Beneficial insects; Insect pests. wings are very similar in the first two, but the green-veined species has greenish veins on the under side of the hind wings. The larvae can be distinguished without much difficulty. That of the large species is yellow, spotted with black; that of the small cabbage white is green, spotted with black and yellow; while the larva of the green-veined species is green all over, except for the reddish spiracles, and a yellow border which surrounds each one. The eggs of the first species are laid in clusters on the under side of a leaf, while those of the other two are laid singly. Wintering as pupse, the insects emerge in spring as butteriiies, and com- monly produce two broods in the course of the sum- mer. There is, therefore, no time between April and October when we may not see the butterflies flitting over the fields, while the larvse often feed till near Christmas. When full-fed they quit the food-plant, and betake themselves to the nearest dry and shel- tered refuge that they can find. There they proceed to hang themselves up and pupate. The larva creeps up a paling or wall, chooses a convenient spot, and covers it with a little hillock of silk, to which the tail-end of the body, which bears hooks, is soon attached. But since the pupae of the cabbage whites do not hang downwards, like many other Lepidopterous pupae, but rest upright, a second attachment is provided. This takes the form of a girdle. Silken threads, issuing from the mouth of the larva, are passed backwards and forwards from one point of the supporting surface to another, and attached at both ends. When enough threads have been spun to give due strength to the girdle, the larval skin. Fig. 45.—Small cabbage white. The upper figure represents the female.. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readabilit