40 



THE MONTHLY BULLETIN. 



THE CHERRY AND PEAR SLUG. 



This, like most of our dreaded pests, is of European origin and is 

 widely distributed. Wherever the cherry and pear are cultivated the 

 slug is found. It has dainty habits, as it only takes the parenchyma — 

 green portion — of the leaf. It is no slug, as the true slug is a mollusk, 

 but it carries a slimy secretion like the slug and so carries the name. 



Family Tenthredinidae. 



The family of this insect is well defined. Like all of the order of 

 Hynienoptera it has four membranous wings, biting mouth-parts and 

 complete transformations. This is the sawfly family. The adult, or 

 imago, has a saw at the tip of the abdomen, which is wondrous in its 

 finish and polish. With this it saws a groove in which to deposit its 

 eggs in stem or leaf. This saw may be single or double. These saw- 

 tlies often pupate in the earth in a coarse paper-like cocoon. The larvge 

 have from eighteen to twenty-two legs, more than any other insect 

 larvffi, though most caterpillars approximate this number, having six- 

 teen. 



Fig. 5. — The pear or cherry 

 slug (Caliroa cernsi) and its 

 work upon the leaf. (After 

 Ewing. ) 



Life History. 



The shining black flies lay their eggs in late spring and early summer. 

 The unctuous greenish-brown large-headed larvse feed in summer on the 

 green part of the leaves, making them apper;r gray and sear. There is 

 but one brood in the season. They pass the winter as pupje in their 

 cocoons. The scientific name is Caliroa (Selandria) ccrasi. The spe- 

 cific name cerasi comes from cherry, one of its two principal food plants. 

 While it attacks other plants, its chief mischief comes from its injury to 

 the pear and the cherry. 



Control. 



The arsenious poisons are quick death to these pests, but owing to the 

 viscid secretion, lime or even the earth dust thrown on them is effective 

 in their destruction. These last irritate, and the slugs fall to the ground 

 and soon die. That these slugs do not do more harm is doubtless owing 

 to natural enemies. — A. J. Cook. 



