The Hemipteroid Orders

FIGURE 8.7. Coccoidea. (A) The oystershell scale, Lepidosaphes ulmi (Diaspididae); (B) female L. ulmi; (C) female long-tailed mealybug, Pseudococcus longispinus (Pseudococcidae); and (D) male cottony-cushion scale, Icerya purchasi (Margarodidae). [A, B, from D. J. Borror, D. M. Delong, and C. A. Triplehorn, 1976, An Introduction to the Study of Insects, 4th ed. By permission of Holt, Rinehart and Winston, Inc. C, D, from P.-P. Grasse (ed.), 1951, Traité de Zoologie, Vol. X. By permission of Masson, Paris.]

while others recognize up to 11 families. Members of the superfamily are characterized by their complex life cycles, in which the species takes on a variety of forms and frequently alternates between two taxonomically distinct host plants. By far the largest of the four families of Aphidoidea, with some 4300 species, is the APHIDIDAE (aphids, plant lice, greenfly, and black fly). Most aphids are found on leaves, shoots, or buds, though a few species live in rather specialized situations, for example, in unfolded leaves or in earth shelters especially constructed for them by ants with which they are associated. Most species are polymorphic in different generations and reproduce in a variety of ways. They may also show host alternation. A typical life cycle, that of Dysaphis plantaginea, the rosy apple aphid, is shown in Figure 8.8. Usually aphids overwinter in the egg stage. In spring the eggs hatch and give rise to wingless, viviparous parthenogenetic females. A variable number of such generations occur, and these are followed by the production of winged individuals that migrate to the alternate host on which reproduction continues. Later in the season sexual males and females are produced, and the aphids return to the original host. They mate and females lay the overwintering eggs. Parthenogenesis provides the means by which aphids can increase their population extremely rapidly. Fortunately, the occurrence of a large number of predators and adverse weather conditions usually keep their numbers in check.

Aphids in sufficient numbers may have a direct effect on their hosts, causing wilting and stunted growth. They are, however, economically more important through their role

FIGURE 8.8. Life cycle of the rosy apple aphid, Dysaphis plantaginea. [After D. J. Borror, D. M. Delong, and C. A. Triplehorn, 1976, An Introduction to the Study of Insects, 4th ed. By permission of Holt, Rinehart and Winston, Inc.]

as vectors of disease-producing viruses. Migratory species that are not particularly host-specific are especially important, since these can transmit diseases among a wide variety of plants. Myzus persicae, the green peach aphid (Figure 8.9A), is the classic example, being known as a vector for more than 100 virus diseases.

PEMPHIGIDAE (ERIOSOMATIDAE) are closely related to the Aphididae. The family is small (275 species), widely distributed (often by commerce), and includes both above- and below-ground feeders and many gall-making species. Many of the woolly aphids, so-called

FIGURE 8.9. Aphidoidea. (A) The green peach aphid, Myzus persicae (Aphididae); (B) winged female of the grape phylloxera, Phylloxera vitifoliae (Phylloxeridae); and (C) section through galls on grape leaf showing wingless female and eggs. [A, reproduced by permission of the Smithsonian Institution Press from Smithsonian Scientific Series, Volume V (Insects: Their Ways and Means of Living) by Robert Evans Snodgrass: Fig. 101B, page 171. Copyright © 1930, Smithsonian Institution, New York. B, C, from P.-P. Grassé (éd.), 1951, Traité de Zoologie, Vol. X. By permission of Masson, Paris.1

Beekeeping for Beginners

Beekeeping for Beginners

The information in this book is useful to anyone wanting to start beekeeping as a hobby or a business. It was written for beginners. Those who have never looked into beekeeping, may not understand the meaning of the terminology used by people in the industry. We have tried to overcome the problem by giving explanations. We want you to be able to use this book as a guide in to beekeeping.

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