The time is coming when that fearful enemy to the Arborvitae especially will make its appearance. Though we have kept a continual warning against suffering it to eat on, without molestation, it will do good service by again referring to it. The following good sketch is from the pen of Prof. Rathvon in the Lancaster Farmer. Hand-picking is the cheapest remedy :

"The spindle-shape cocoons you sent us some weeks ago - evidently taken from an Arborvitae tree - are the habitacula of a Lepidopterous insect known under the names of ' Sack-worm,' ' Basket-carrier,' ' Drop-worm,' ' Sack-trager,' and other names, but in scientific language it is called Thry-ridoptery xephemceriformis, a name almost 'as long as the moral law.' Perhaps if it knew the space its name occupies in natural history, it would be better mannered than it is. It is notorious as a tree defoliator, especially cone-bearing trees, and most especially, perhaps, the Arborvitae. It may have a choice, but it is by no means restricted by that choice, and will attack almost any kind of a tree. We have known it to be abundant on linden, maple, elm, apricot, plum, locust, apple, pear, various species of pine, quince, oaks - in short on nearly all kinds except the peach, and we have heard that it has been known in a 'strait' to attack the peach. Many of the follicles now found on trees are the deserted habitacula of the males of last season, but a goodly number are those of the female pupa filled with eggs, and now before the trees have put forth their leaves, is the time to collect and destroy them.

If the season is favorable, between the 1st and 15th of May, the young will be hatched from the eggs that have remained in the sacks or baskets of last summer. If they are left undisturbed until the last of May or the beginning of June, the trees will be in full foliage, and for a month or two the foliage will be too dense to see them. Each female deposits one hundred or more eggs, and these eggs possess the possibilities of the same number of caterpillars. These caterpillars are never nakedly seen, for as soon as the young are excluded from the eggs they begin to form their sacks, and these they carry with them wherever they go, only protruding the head and the three thoracic segments of the anterior part of the body. No liquid or powdered remedy can reach them, nor can birds dislodge them from their habitacula. If these insects are permitted to continue on the trees to their injury, the responsibility must rest with those who own the trees they infest; for we know of no insect that is more accessible, especially during late fall, winter and early spring."