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Aculeate hymenoptera are those species whose ovipositors have been modified into stingers; there are 50,000 to 60,000 such species.
Hymenoptera metamorphosis is complete. Larvae have a well developed head with chewing mouthparts. Most are legless, but sawfly larvae have legs attached to the thorax as well as abdominal prolegs. In bees and a few wasps the larvae feed on nectar or pollen. Most wasps lay eggs in cavities, tunnels or burrows in the ground, or nests made of paper or mud. The female wasp provisions these nests with paralyzed insects on which the larvae, after hatching, feed. Sawflies usually lay their eggs in plant tissue, using the sawlike ovipositor that gives the family their common name. Sawfly larvae live inside stems or leaves and feed externally on foliage. This unhappy trait makes many sawfly species terrible agricultural pests. In braconids, ichneumons and some others, the larvae are parasites of many different insects and spiders. One such wasp, The Tarantula Hawk (Hemipepsis species), featured here, is famous for using paralyzed tarantula spiders as food for its larvae, and many species specialize in other prey such as cicadas and katydids. The honey bees, bumblebees, mason and orchard bees pollinate a variety of important agricultural crops in the U.S. including blueberry, apple, raspberry, cranberry, tomato, peppers, kiwi, pumpkin, and squash. Both wild and domesticated honeybee populations have been declining worldwide, due to widespread infestations of Varroa mites, an external parasite that attacks adults and brood (larvae). Honeybees are the preferred pollinator for most fruit crops because they have high populations. Thorough honeybee pollination requires warm, sunny weather. Some 90 different crops -- ranging from apples to zucchini and cantaloupes to cucumbers -- depend on honeybee pollination. To some extent, other insects will pollinate specific crops, however, no insect is as widely effective as the honeybee. The value added by honeybee pollination to American agriculture is estimated to range from $5 billion to $20 billion a year. Bumblebees are also effective pollinators because they fly from early light until almost dark, and they fly during poor weather. They have long ‘tongues’ and are able to gather nectar and pollen from deep flowers like tomato. Unfortunately, bumblebee populations are not nearly as high as honeybee populations and therefore are used primarily for vegetable pollination. Bumblebees are not good subjects for domestication, as their habit is to nest underground. The various bumblebee species have successfully resisted efforts to entice them into man-made beehives. [2] |
