354 ILLINOIS STATE HORTICULTURAL SOCIETY. 



claw, and are situated on the three front segments, immediately behind 

 the head. 2. Those having not only the six true legs, but also ten or 

 twelve thick, fleshy, short legs, situated on the middle and hind segments. 

 I presume it is well known to all of my hearers that larvae often possess 

 two kinds of legs : first, the true legs, of which, when any are present, 

 there are six, always situated on the first three segments behind the head, 

 and are jointed and terminate with a claw ; these are called "true," or 

 "thoracic" legs. The others are thick, fleshy, unjointed, and usually 

 very short legs, situated on some of the remaining segments ; these are 

 called "prolegs," or "abdominal legs." 



Borers which have any prolegs, generally, and so far as Illinois is 

 concerned we may say always, have ten of these, which, with the six true 

 legs, gives them sixteen. The prolegs are placed, one pair on each, the 

 sixth, seventh, eighth and ninth segments, and one pair on the last seg- 

 ment. These are true caterpillars, and all belong to the order Lepidop- 

 tera, and in the perfect state are moths. They belong to the two families, 

 or rather sub-families, Cassidce and jEgeriada;. 



These groups may be distinguished, so far as our insects are concerned, 

 by their operations, as well as by the characters of the larvae themselves. 

 The former, Cassidce, or, as Harris and some other entomologists name 

 the group, Hepialidce, are trunk-borers; the jEgeriadce operate in the 

 roots of trees, stems and canes of shrubs, or under the bark of the trunks 

 of trees, seldom penetrating into the wood. Our only troublesome species 

 belonging to Cassidce, the locust-borer {Xyleutes robinice), when fully grown 

 in the larval state is nearly three inches lojig. The larvae of this group, 

 or rather of this genus, which is limited to the carpenter-moths, are white, 

 or reddish white, soft and naked, or nearly so, with brown heads, and a 

 spot on the front part of the body alone, which is brown and hard ; they 

 are elongate and comparatively slender, cylindrical, and have the inden- 

 tations between the segments deep. 



The larvae of the jEgcriadce are whitish, soft, and slightly downy, 

 and small ; usually somewhat flattened beneath, and the segments not 

 usually so deeply divided. The peach-root borer {^geria exitiosa) is a 

 familiar example of this family. 



We see, therefore, that we need to look to but two families of moths 

 for our borers which have more than six legs. 



Those larvae which have but the six true legs may be divided into two 

 groups, thus : Those which have a horn or spine projecting from the tail, 

 and those which have not. 



The former of these two groups are cylindrical, fleshy grubs, of a 

 whitish color, with a small, rounded, horny head, and a pointed, horny 

 tail, with six small legs under the front part of the body. They generally 

 attack pines and firs; but the pigeon tremex {Tremex columba), which 

 is found in the West, attacks the elm, sycamore, and sometimes the pear. 

 These borers belong to the order Hymenoptera, which contains the bees, 

 ■wasps, etc., and to the family Uroceridm, or "horn-tails," which in the 

 perfect state are wasp-like insects, but are not constricted at the waist as 

 are the wasps. 



