. Elementary entomology . Fig. 174. The pear psylla. (Greatly enlarged, in different proportions) rt, adult; /'. full-grown nymph from above ; r, egg. (After -Slingerland) which covers the foliage and bark, on which grows a sooty black fungus which is a good indication of the presence of the pest. The plant-lice, or aphides (Aphididae), are the most abundant and possibly the most destructive family of all the Hemiptera. Florists commonly call them green-flies, which term may refer to several species. Usually they are not over a tenth of an inch long, and the wingless forms are more or less pea
. Elementary entomology . Fig. 174. The pear psylla. (Greatly enlarged, in different proportions) rt, adult; /'. full-grown nymph from above ; r, egg. (After -Slingerland) which covers the foliage and bark, on which grows a sooty black fungus which is a good indication of the presence of the pest. The plant-lice, or aphides (Aphididae), are the most abundant and possibly the most destructive family of all the Hemiptera. Florists commonly call them green-flies, which term may refer to several species. Usually they are not over a tenth of an inch long, and the wingless forms are more or less pear-shaped, with long legs and antennae, and the common forms have two tubes projecting from the abdomen, called honey-tubes. The vast amount of injur)^ done by them is chiefly due to their remarkably rapid power of reproduction. During the summer the females will give birth to from fifty to seventy-five young during a week or two, which will become full grown in from one to two weeks. All of these
Size: 2164px × 2309px
Photo credit: © The Bookworm Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., bookcentury1900, bookdecade1, booksubjectentomology, bookyear1912
