IM 



STATE BOARD OF xVGRICULTURE. 



I'M"-. 7. Forest Tent-Caterpillar, ClisiorKinpa dissfria. After Riley, l{ei>ort on Insects of Missouri. 



(Third.) 



Description of Larva. — Tlie full-^rown calcipillar (Fi^'. 7) is about iVa inches long 

 with a ground color of pale blue, sprinklod with l)lack points and dots. Along the 

 middle of the back is a row of about ten lozenge shaped white spots and behind each 

 of these spots is a smaller dot of the same color. The entire caterpillar is sparsely 

 covered with soft hairs. 



After finding a suitable place, the caterpillar spins up in a loose but strong cocoon, 

 with the silk of which is usually mixed a good leal of yellow powder. The specimens 

 sent to us emerged on July 14 as winged moths (Fig. 7 b); they are dull yellowish 

 or reddish brown in color and when the wings are spread out the female measures 

 about one and three-fourths inches across, the male being a little smaller. Across 

 the front wings extend two oblique dark stripes. After pairing, the eggs are laid 

 and remain for about nine months before hatching. The number of trees attacked by 

 this insect is very large, the list including the oak, walnut, ash, bass-wood, rose, 

 hickory, apple, peach, willow, maple, poplar, plum, cherry, thornapple, beech, and 

 several others. With so large a list of available food-plants, the caterpillars cannot 

 easily be starved out. Luckily they are seldom numerous two years in succession, as 

 their parasites usually keep them in subjection. 



REMEDIES. 



Of course in the forest spraying would seldom be resorted to. both because of the 

 difficulty of reaching tlie tree tops and because of the expense. It often happens, how- 

 ever, that the caterpillars work in shade trees, and here they can readilj'' be killed 

 by a spray of Paris green, using one pound of the poison to about 150 gallons of 

 water, and adding one pound of fresh quick-lime to the mixture. Do not spray without 

 the lime, for the mixture recommended would do serious injury to many trees if the 

 lime were omitted. 



7. THE SADDLE-BACK CATERPILLAR. 



(Empretia stimulea Clem.) 



From time to time insects are carried far from their natural home and colonies are 

 started which may or may not survive the change, depending on the amount of climatic 

 differences between the two places and on the hardiness of the insects. Two species 

 of insects, transported in this way, have been found in Michigan during the past 

 season, one of which, so far as is known to the writer, has not been reported hereto- 

 fore. One is the saddle-back caterpillar, Empretia stimulea, Clem., and the other the 

 American Locust, Schistocerca americana. Both are very destructive insects in their 

 native states. Whether they will remain with us and become serious pests, or die 

 out owing to our more severe winters, or stay with us, but not become numerous enough 

 to be injurious, are questions that it is impossible to answer at present. It would 

 seem, however, that as they are both natives of America, they would have been here 

 before if the climatic conditions were at all favorable to them, the more so as they 

 are found directlv south of us in Southern Indiana and Ohio. 



