. Bulletin of the Department of Agriculture. Agriculture. Phylloxera vitifoUae: Types of antennae of intermediates. Oreatly enlarged. eyes were absent, and in no case were ocelli discernible. In most in- dividuals there were two sensoria on the last antennal joint, and in one antenna there were two small basal sensoria and the usual apical sensorium, makin^: three in all. The basal sen- soria were not in any case as large as those of the winged migrant. The an- tennae and legs were about as long as those of the nymph, noticeably longer on the average than those of the individuals of group
. Bulletin of the Department of Agriculture. Agriculture. Phylloxera vitifoUae: Types of antennae of intermediates. Oreatly enlarged. eyes were absent, and in no case were ocelli discernible. In most in- dividuals there were two sensoria on the last antennal joint, and in one antenna there were two small basal sensoria and the usual apical sensorium, makin^: three in all. The basal sen- soria were not in any case as large as those of the winged migrant. The an- tennae and legs were about as long as those of the nymph, noticeably longer on the average than those of the individuals of group 2, which in turn were longer than those of the two indi- viduals of group 1.^" It would appear, therefore, that greater devel- opment of wing pads and comi^ound eyes is complemented with a lengthening of legs and antennae and a tendency to bear the extra sensorium of the winged forms. The femora exceed the tibia? in length. There is among the intermediates a tendency toward asymmetr3\ This was remarked in Italy and has also appeared in California. One eye may have more facets than the other; the lengths of antennae and legs may differ in individuals, those of one side being longer than their counter- parts, and one antenna may possess more sensoria than the other. In two instances the fourth stage of intermediates was observed in Califor- nia. In one case an individual of group ;^ molted from what appeared, under the lenses of the binocular microscope, to be a true nymph. In the other case an example of the same group molted from an insect which itself resem- bled a nymphical; in fact, after the molt the individual did not appear to have changed its structure at all. In both fourth and fifth instars the wing pads were large and " fleshy.'' From three individuals, all of group 3, eggs were obtained. These eggs could not be differentiated from eggs laid by wingless radici- coles. One nymphical deposited two eggs, which were lost. An- >" The insect depicted in f
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectagriculture, bookyear
