23(j FIFTH KEPORT OF THE ENTOMOLOGICAL COMMISSION. 
Paris green injures the tree more than the Loudon purple. Three- fourths of a pound 
of Paiis green to ■ barrel (thirty-six or forty gallons) of water, with three quarts ef 
(tour or three-quarters of an ounce of Paris green to a bucket of water, may be regarded 
as a poison mixture of medium or average strength for treating elms affected by these 
beetles. 
When man;, trees are to be sprayed a cart orwagon may be used to haul the poison 
in a large barrel provided with a stirrer, force pump, skid, etc. The force pump was 
described and figured in the annual report of the entomologist for 1882. It isdonble- 
acting and very powerful, giving strong pressure to disperse tin- Liquid far and finely. 
and about a pailful of poisoned water w;is sprayed upon each tree. Wheu only two 
or three wore to be treated an aquapult or other bucket pump was used to force tin- 
poison from a bucket carried by hand. Connected with either pump is a long flexible 
pipe, with its distal part still', and serving as a long handle whereby to hold its 
terminal nozzle beneath the branches or very high up at a comfortable distance from 
the person managing it. To the hose is attached a bamboo pole, the partitions of 
which may lie burned out with a hot iron rod. With this apparatus a tree can be 
quickly sprayed, and a large grove or row of trees along a street treated in a short 
time. It is equally adapted for forestry use in general, and for orchards, when the 
i re. s are not in fruit. 
The eg<j. — In each group (Fig. 81 e, magnified), and so firmly fastened to the leaf that 
they can only be detached with great care without breaking the thin and brittle 
shell. The number of eggs in each group varies from four or five to twenty or more. 
Very rarely only three eggs are seen in one group, but we never found less than that 
number. The egg itself is oblong oval, obtusely, but not abruptly, pointed at tip, of 
straw yellow r color, its surface being opaque and beautifully and evenly reticulated, 
each mesh forming a regular hexagon, as shown, highly magnified, in Fig. 81 /. The 
form of the eggs is not quite constant, some of them, especially those in the middle 
of a large group, being much narrower than others. The duration of the egg state is 
about one week. 
Larva. — The general shape of the larva is very elongate, almost cylindrical, and 
distinctly tapering posteriorly in the early stages, but less convex and of nearly equal 
width when mature. The general color of the young larva is yellowish-black, with 
the black markings comparatively larger and more conspicuous, and with the hairs 
arising from these markings much longer and stiffer than iu the full-grown larva. 
With each consecutive molt the yellow color becomes more marked, the black mark- 
ings of less extent and of less intense color, and the hairs much shorter, sparser, and 
lighter in color. A nearly full-grown larva is represented iu Fig. 80 </, and in this the 
yellow color occupies a wide dorsal stripe and a lateral stripe each side. The head 
(excepting the mouth-parts and anterior margin of the front), the legs (excepting a 
ring around the trochanters), and the posterior portion of the anal segment are always 
black. The first thoracic segment has two large black spots on the disk, of varying 
extent, and often confluent. The following segments (excepting the anal segment) 
are dorsally divided by a shallow trauverse impression into two halves, and the black 
markings on these halves are arranged as follows: two transverse dorsal markings, 
usually confluent, as shown in our figure ; two round and sublateral spots ; the tips of 
the lateral tubercles are also black. The abdominal joints of the ventral surface have 
each a transverse medial mark, and two round sublateral spots of black color. Stig- 
mata visible as small umbilicate spots between outer sublateral seriesof dorsal mark- 
ings and lateral tubercles. The yellow parts of the upper side are opaque, but those 
of the under side shining. The black markings are polished, piliferous, and raised 
above the remaining portions of the body. 
Pupa. — Of brighter color than the larva, oval in shape, and strongly convex dor- 
sally. It is sparsely covered with moderately long but very conspicuous black bris- 
tles, irregularly arranged on head and thorax, but in a transverse row on each fol- 
lowing segment. The pupa state lasts from about six to ten days. 
