Overige insecten

Es kann keinen Zweifel mehr geben, dass das „Insektensterben“ von großer Tragweite ist, für die Landwirtschaft, für die Ökosysteme und die Biodiversität im Land, und nicht zuletzt für alle, die sich einen Frühling ohne Schmetterlinge nicht vorstellen können. Fakt ist ein Rückgang von Insekten und insektenfressenden Wirbeltieren in Deutschland. Als Hauptgrund für dieses „Verschwinden“ wird jeweils der Einsatz von systemischen Insektiziden vermutet. Diese Stoffe wirken auf das Nervensystem und somit auf den Orientierungssinn und das Verhalten von Insekten und anderen Gliedertieren.

Historically, the American burying beetle (Nicrophorus americanus) was found in 35 states, including Missouri, according to Bob Merz, zoological manager for invertebrates at the St. Louis Zoo and director of the Center for Conservation of the American Burying Beetle at the zoo’s Wildcare Institute. It is a partner with the U.S. Fish and Wildlife Service, the Missouri Department of Conservation and the Nature Conservancy in beetle restoration. The last orange-and-black American burying beetle found in Missouri was collected in 1972 in Newton County.

In a new study, biologists at Bielefeld University show the effects of pesticides and how even slight traces lead to long-term damage to beetles. One finding is that leaf beetles lay roughly 35 per cent fewer eggs after coming into contact with traces of a frequently used pesticide: a pyrethroid. The researchers also showed that female offspring develop malformations through the poison. The biologists have published their study in the journal Environmental Pollution.

In this study, effects of two neonicotinoid insecticides, imidacloprid and dinotefuran, on aquatic insect assemblages were evaluated in experimental rice mesocosms. During the 5-month period of the rice-growing season, residual concentrations of imidacloprid were 5–10 times higher than those of dinotefuran in both soil and water. Imidacloprid treatment (10 kg/ha) reduced significantly the populations of, Crocothemis servilia mariannae and Lyriothemis pachygastra nymphs, whereas those of Orthetrum albistylum speciosum increased slightly throughout the experimental period.

Dass die Insekten auf dem Rückzug sind, ist vielen Menschen nicht bewusst. Eine Ausnahme bilden die Bienen. Ihr Niedergang ist bereits länger bekannt, was unter anderem daran liegt, dass sie als fleissige und nützliche Tiere gelten. Der Rest ist meistens nur lästig. Erst langsam spricht sich herum, dass auch Falter, Fliegen und Wespen bedroht sind.

The horned lizard (Phrynosoma cornutum) - more commonly known among Texans as the horny toad - was as common as ants and grasshoppers over most of Texas just decades ago. "Historically, they were all the way into East Texas, and abundant in Central Texas, but they have basically receded back to 50 miles west of the I-35 corridor. They are still common in the Panhandle and West Texas, and there are some in South Texas, but they are down to 50 percent or less of their historic range," said Nathan Rains, a wildlife diversity biologist with Texas Parks and Wildlife Department.

Individually, insects are not incredibly interesting, unless you get down on the ground or view them under a microscope to look at their complexity. But they are the invisible force working throughout the world to keep it running. There are 1.4 billion insects for each one of us. Insects are “the lever pullers of the world,” says David MacNeal, author of Bugged. They do everything from feeding us to cleaning up waste to generating $57 billion for the U.S. economy alone. Almonds in California or watermelons in Florida wouldn’t be available if it were not for bees.