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 Eiley, 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 with 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 larvce 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 



