Spider beetles

Cereals (wheat, barley, triticale, rye) Organic practices (lower fertility, no pesticides) No difference in epigeic collembolan composition No difference in species richness of butterflies, rove beetles, spiders, lower richness of carabids Alvarez et ai. (2001) Weibull et ai. (2003)... 

The total potassium concentration in the bodies of earth worms, edible snails and slugs varies between 4.4 and 8.3 g kg DM, and that of several beetles, spiders and grasshoppers between 6.5 and 12gkg DM (Table 1-3.6). In comparison to mollusks, the potassium concentrations accumulated by beetles are moderate, although the difference between both animal groups is not significant. 

The pads on the feet and/or legs of insects or animals such as beetles, spiders and geckoes have nanoscale hairs that enable them to attach and detach from different kinds of surfaces, allowing them to walk on them. These provide natural examples of reversible adhesion or smart adhesion. It has been suggested that the adhesion arises from a combination of van der Waals attractive forces and capillary forces (depending on the humidity) [103]. Synthetic surfaces comprising arrays of 400 X 600 nm nanopillars have been produced that mimic the gecko-foot effect with reversible adhesion for at least a few contact cycles [103]. 

One negative effect of pesticide use is how they stimulate suppressed species. For example, DDT and several other pesticides may accelerate the development of suppressed species (just as they did with the spider mites) and increase the frequency with which new generations are born. Sublethal doses of dieldrin and parathion do not decrease the Colorado beetle s egg production - they increase it by 33-65% in a way we do not yet understand [3]. Data from 1976 showed that using carbofurans increased the Colorado beetle population in several U.S. states [20]. Trichlorfon also stimulates the Colorado beetle s development at specific dose levels. 

In this discussion, we have restricted ourselves to the consideration of only a few examples of arthropod chemistry. From these alone, it is evident that insects synthesize defensive compounds by using all of the major biosynthetic pathways, producing acetogenins, simple aromatics and quinones, isoprenoids, and alkaloids. In addition, some of the millipedes, coccinellid beetles, and spiders we have studied utilize biosynthetic pathways that have yet to be characterized. 

Several predation tests especially with spiders and blister beetles [121,313, 314], show that spiders exhibit a wide range of sensitivities to meloid beetles as prey. In the racoon Procyon lotor it was shown that they quickly form an aversion to blister beetle prey, which is induced by cantharidin [314]. 

A woodchip or bark mulch will shelter beetles, centipedes, and the like, while thicker mulches of hay and straw may be frequented by frogs, toads, shrews, and spiders. In winter, try to leave some areas of mulch undisturbed for creatures to hibernate in. 

Kromp, B. and K.-H. Steinberger (1992). Grassy field margins and arthropod diversity a case study on ground beetles and spiders in eastern Austria (Coleoptera Carabidae Arachnida Aranei, Opiliones). Agriculture, Ecosystems and Environment AQ 71-93. 

Most acetylenic compounds in plants are derived from meta-bolically altered fatty acids. These often are active in plant-insect relationships. 8-cis-Dihydromatricaria acid is also found in the defensive secretion of the soldier beetle (Chaulioqnathus 1econtei) (125), and has subsequently been shown to have anti-feedant properties against Phidippus spp. (jumping spiders) (126). As previously mentioned matricaria ester has antifeedant properties to the pink bollworm, bollworm and tobacco budworm (115). 

Red spider adults Red spider eggs Colorado potato beetle eggs Mexican bean beetle eggs... 

Insecticides Vetch aphid (Megoura viciae) bollworm (Helicoverpa zea) army worm (Spodoptera littoralis) diamondback moth (Plutella xylostella) mustard beetle (Phaedon cochleariae) corn rootworm (Diabrotica undecimpunctata) whitefly Bemisia tabaci) red spider mite (Tetranychus urticae). 

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