Hemimetabolous Development

Exopterygotes usually molt a fixed number of times, but, with the exception of Ephemeroptera, which pass through a winged subimago stage, never as adults. In species where the female is much larger than the male, she may undergo an additional larval molt. The number of molts is typically 4or5, though in some Odonata and Ephemeroptera whose larval life may last 2 or 3 years a much greater and more variable number of molts occurs (e.g., 10-15 in species of Odonata, 15-30 in most Ephemeroptera).

In almost all exopterygotes the later juvenile instars broadly resemble the adult, except that their wings and external genitalia are not fully developed. Early instars show no trace of wings, but, later, external wing buds arise as sclerotized, non-articulated evaginations of the tergopleural area of the wing-bearing segments. Wings develop within the buds during the final larval stadium and are expanded after the last molt. Other, less obvious, changes that occur during the growth of exopterygotes include the addition of neurons, Malpighian tubules, ommatidia, and tarsal segments, plus the differentiation of additional sensilla in the integument. This mode of development is described as hemimetabolous and includes a partial (incomplete) metamorphosis from larva to adult.

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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