274 STATE HORTICULTURAL SOCIETY, 



a white head, a white V shaped spot on 



the front of the thorax and a conspicuous 



white line on the outer half of the front 



margin of the anteriors wings. This 



has a sinus on the hind margin. Back 



of this is an irregular brownish area 



which is broadest and darkest at the 



outer end. Two very dark or brownish 



lines ruin parallel with the outer margin 



• of the wings. The posterior wings are dusky, while the throax is dark 



gray and the abdomen light gray. The moth expands three and one half 



cm. (1.4 inches.) 



As before stated this insect is usually quite rare, at least not 

 so common as to attract general attention. Owing doubtless to very 

 favorable circumstances, which enabled the insect to reproduce rapidly, we 

 this season were visited by the hoard of caterpillars which have awakened 

 such general alarm; very likely the two very mild winters of '89-'90, and 

 : 90-'91, were the favoring conditions. It is quite possible that in average 

 winters the pupae are destroyed, while in the past two winters, nearly all 

 have survived. Thus myriads of eggs were laid and a multitude of 

 caterpillars were the result. We need not expect, then, a long continuance of 

 this oak caterpillar raid. Possibly, though not probably, they may come in 

 equal abundance next year. That they will continue so numerous for three 

 or even two years is not at all likely. Again, any insect that defoliates the 

 trees so late in the season as September, does comparatively little damage. 

 The insect in this case anticipates frost or maturity but very slightly, and 

 the leaves have really done their work for the season. Thus I am sure that 

 we may suffer no anxiety because of these insects. It is more than likely 

 that we shall never see a like outbreak again. 



THE WHITE PINE SAW FLY. 



For many years this saw-fly (Fig 6), Lophyrus abbotii Leach, has been 

 no insignificant pest on the ornamental pines in the parks and door yards 

 of Michigan. We have received it from nearly every county of the state, 

 and have always recommended spraying the tree with the arsenites, 

 London purple or Paris green, which has in every case quickly destroyed 

 the destroyers. 



The Larva (Fig. 5) is very light yellow or straw color and has a black 

 head and four longitudal rows of black spots, which are nearly square in 



the side rows and elongated in the upper rows. 

 The larvae of the saw-flies are called slugs, for 

 often, as noted in the very common pear and 

 Fi g- 5 - cherry slug, they secrete a slime which always 



covers their bodies. These slugs do not secrete the slime. Slug, unlike 

 all other larvae, have eighteen, twenty, or twenty-two legs — the six jointed 

 legs just back of the head, and twelve, fourteen, or sixteen, non-jointed 

 pro-legs, as the abdominal legs are called. This white pine slug has the 

 full number, twenty-two. Many caterpillers have sixteen legs, which is the 

 maximum number in all other larvae except the slugs. The length of the 

 full grown slug is 22 mm. (.88 inches). The larvae feed on the pine leaves 

 from July to November, though the insect is single-brooded. When full 

 grown it passes to the earth and forms a thick, oval, watertight, light brown 



