. Annual report of the Agricultural Experiment Station. Cornell University. Agricultural Experiment Station; Agriculture -- New York (State). Fig. 4—Section of leaf showing structure of ?ail in autumn; g, gall; n, uninjured part of leaf; o, opening of gall. abnormal growths — the galls — which form their homes, are what are popularly known as mites. They are exceedingly small, being practi- cally invisible to the unaided eye; and even with a good lens they a])pear as minute whitish specks. In fact, the best of microscopes is necessary in order to study their structure satisfactorily. So small
. Annual report of the Agricultural Experiment Station. Cornell University. Agricultural Experiment Station; Agriculture -- New York (State). Fig. 4—Section of leaf showing structure of ?ail in autumn; g, gall; n, uninjured part of leaf; o, opening of gall. abnormal growths — the galls — which form their homes, are what are popularly known as mites. They are exceedingly small, being practi- cally invisible to the unaided eye; and even with a good lens they a])pear as minute whitish specks. In fact, the best of microscopes is necessary in order to study their structure satisfactorily. So small are they that it woidd take 150 of them placed end to end and 600 placed side by side to measui-e an inch. They are usually whitish in color, sometimes with a slight red or brown tinge. The body is cylindrical in form, tapering slightly towards each end (Fig. 5). It is ringed throughout the greater part of its length with about 100 very fine rings. Its four legs are placed near the head end of its body, so that when the mite walks it drags its body after it. The head is in the form of a conical snout, within which ai"e two sword like jaws. The body and legs are furnished with a few hairs which are constant in number and position. Classijicatioji of the Pest.— The cause of this Pear Leaf Blister is not a true insect, but a mite. (The mites are more closely allied to. ..^.,mjl0^f?9!X':^ *. ( Fio. 5.— The adult noite, greatly magnified. the Spiders and Scorpions than to the true insects.) The southern Cattle-tick, the Itch-mite and the Red Spider are well-known members of the same order {Acarina) of animals to which this pear pest belongs. As a rule, newly-hatched mites have three pairs of logs and a fourth pair is added during growth. The members of the genus. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the ori
Size: 1701px × 1468px
Photo credit: © Library Book Collection / Alamy / Afripics
License: Licensed
Model Released: No
Keywords: ., book, bookcentury1800, bookcollectionbiodiversity, bookdecade1880
