Report on economic zoology Volume 1

This historic book may have numerous typos and missing text. Purchasers can download a free scanned copy of the original book (without typos) from the publisher. Not indexed. Not illustrated. 1903 Excerpt: ...remedy I can take. (2) I herewith send two insects that I have found amongst my potatoes. They were looking well to about a week ago. Any information about them will be thankfully received. In both cases the caterpillars were found to be working in a similar way, namely, by tunnelling up the stalks of the potatoes, completely hollowing them out and so killing the haulm. Should this pest become very numerous it would be a serious matter, as remedies are quite out of the question save hand-picking the attacked haulm. These caterpillars are recorded as feeding in the stems of equisetums, docks, valerian, but probably attack a variety of other plants. The larva when mature varies from an inch and a quarter to an inch and a half in length. The back and sides are dull purplishbrown, paler on the first three segments and where the segments join, the sides and venter are of a dull flesh colour, the legs pale and the head yellowish-brown; on the second segment is a brown semicircular plate broadly margined in front with blackish-brown and a shiny yellowish-brown patch on the anal segment with a posterior border of small dark warts; on the segments are small dark-brown tubercular warts each with a fine terminal hair; the spiracles are deep brown and the prolegs pale with black extremities. Before pupation the larva becomes a paler dull smoky flesh colour all over, with a dusky median dorsal line. The full-fed stage is reached from the beginning to the end of July. During the whole of its life the larva burrows up the haulm and emits a great quantity of green frass; a round exit hole is made in the stem, the frass being G emitted through this. Buckler quotes a letter from the Hon. T. de Grey as follows:--" I first observed the larva by pulling up, on the 14th May...