288 Forty-second Report on the State Museum. [146] 



fine and delicate texture. A careless observer would not suspect their 

 true character, but would pass them by as a simple sheen upon the 

 leaf. The separate threads are so fine that they are not to be seen 

 even by the aid of a magnifying glass, but are only visible when com- 

 bined in an extended web. The silk is secreted from a minute nipple 

 underneath the end of the abdomen. Beneath the web may often be 

 found a large colony of the mites, embracing both old and young, in 

 different stages of maturity, where, under this safe shelter, they are 

 actively engaged in feeding upon the leaf. After biting with the 

 mandibles with which they are provided, through the surface of 

 the leaf, they insert the sucking apparatus and imbibe the juices 

 Small as is each individual wound, the aggregation of the myriads 

 soon tells upon the leaf and plant, which discolors, droops, turns 

 yellow and perhaps dies under the attack. 



It is unfortunate that this insect is so general in its food, for 

 scarcely any tender garden plant is free from liability to its attack. 

 In addition to the Galla, Spircea, Thunbergia and violet, above-named, 

 it was also present upon the leaves of Mitella, Tropceolum, Adlumia, 

 and beans, sent with the inquiry. Their examination by Prof. Herbert 

 Osborn, to whom they were submitted, showed the presence upon 

 each of the same insect, in the egg, larval, and perfect stages. 



This little mite, under favoring conditions, may multiply to an 

 incredible extent, and become very injurious. A notable instance of 

 this has lately been brought to my notice. Leaves of a quince tree 

 infested by this species were sent to me for name, under date of 

 August eleventh, by Prof. Arthur of the New York Agricultural 

 Experiment Station, at Geneva. He reports the attack as occurring 

 in one of the largest quince orchards in the State, about four miles 

 from Geneva. The leaves upon many of the trees were like those 

 received by me, which were nearly destroyed. The attack was 

 rapidly spreading throughout the orchard, and the fruit upon the 

 most seriously infested trees would be an entire loss. 



Prof. Arthur was experimenting with the kerosene emulsion to 

 kill the insect, but with what success has not been learned. Properly 

 applied, it could not fail of accomplishing the purpose. A favorite 

 remedy, long used in green-houses, is syringing with a soap solution 

 in which sulphur is mixed. Quassia has also been thought service- 

 able when added to the mixture. It is quite important that the 

 liquid be so applied as to reach the under surface of the leaves where 

 the mites occur. It is worthy of note that in the above quince attack 

 most of the mites were observable upon the upper side of the 

 leaves. 



