Notable instances of avoidance behavior in Odonata

It is not uncommon to observe dead dragonflies in spider webs (A. KUMAR & M. PRASAD, 1977, Odonaiologica 6: 19-20; R. RAM & M. PRASAD, 1978, Notul. odonatol. I: 25-26; A. LAROCHELLE, 1978, Cordulia 4: 29-34, with references). Although teneral zygopterans are the usual victims, I observed in 1978 two examples of mature, robust anisopterans, Tanypteryx hageni (Sel.) and Gomphus intricatus Hag., which had died in spider webs. The circumstances of such demises are not known; however, I observed and will describe an unmistakable example of an anisopteran deliberately avoiding a spider web. Libellula saturata Uhler is a common and conspicuous dragonfly in central California. On 18 September 1977 I observed a male perched by a narrow cattail-lined pool near Putah Creek, Yolo County (38° 3179; 122° 05TV: elev. 55 m). As I approached it flew the length of the pool directly toward a large spider web spanning open water between cattails on each side. It stopped abruptly in front of the web, hovered in an almost vertical position, dropped down about 0.5 m, and flew under the web and away from the pool. There is no question that it had avoided the spider web.