88 First Report on Economic Zoology. 
serve as baits for any fresh beetles that might appear in the spring of 
the following year. In spite of the heavy dressing of gas lime, 
volunteer potatoes and weeds germinated freely, showing how 
uncertain gas lime is in its action. 
The length of the different stages of the beetle in England, as far 
as my observations go, are as follows : The egg stage, ten days ; the 
larval stage, from three weeks to a month or five weeks ; and the 
pupal stage, from a week to ten days in the summer. The eggs are 
usually laid on the under surface of the leaves in clusters of from 
nine to forty, but Mr. Craigie has observed the beetles at Tilbury to 
deposit a few on the upper surface as well. They are very conspicuous 
elongated oval orange bodies attached to the leaves, after the manner 
of those of the Lady-birds. The eggs were found at Tilbury also on 
the leaves of the Sow-thistle ( Sonchus ). There is some variation in 
their colour : some are deep orange, others pale orange, according to 
their age. 
All the beetles I brought away from Tilbury in the autumn of 
1901 went to earth by the middle of October and remained under 
ground all the time, except during a few warm days in November, 
when two appeared on the surface of the earth. They made their 
appearance above ground in April, but did not all come up until 
May 4th. They were kept until May 20th, when they commenced 
egg laying. These “ check ” specimens were then destroyed. 
At this date no beetles had made their appearance at Tilbury, so 
that the probability is that the drastic measures taken last autumn 
cleared off all those in the adult stage. 
According to Ililey, the beetle passes the winter only in the adult 
stage, and thus it was hoped that the measures taken had exterminated 
the pest in this country. 
But in May, 1902, beetles commenced to appear again at Tilbury. 
Those that I saw alive were certainly not hibernated specimens, so 
easily told by their dingy appearance. The specimens appearing at 
this time were without doubt freshly-hatched ones, the elytra being 
quite pale compared witli those that hibernated. It thus seems that 
the Colorado Beetle passes the winter also in the pupal stage in the 
soil. This will account for this second outbreak at Tilbury. There 
is no doubt that some larvae had already buried themselves deep 
in the soil previous to the plot being treated, and no doubt many 
of these were below the ten inches ploughed up, and so escaped the 
effects of the gas lime and paraffin. 
Professor Howard informs me that this is known to happen in 
America as well ; Professor Smith having observed the beetle to 
