COCCID^. 331 



able period, the respective stages of the metamorphosis are often 

 variable in point of time, resulting in 'an irregular appearance of the 

 adults. 



Hitherto I have dealt with a group of insects which spin a covering 

 or scale, in addition to using cast-off larval moults, to protect their 

 bodies. Xow we come to a group in which the actual body of the 

 female is transformed into a covering or " scale " for the protection of 

 eggs and larvae. This group is known 

 as the Lecaniina% of Avhich fig. 307 

 represents a typical example of a 

 Lecanium scale found on sycamore. 



The scales of the genus Lecaniuni, 

 or " brown scales " of the gardener, 

 are found on sycamore, hawthorn, 

 hazel, and other plants. They have a 

 general resemblance to brown dead 

 buds. If a few of these scales are 

 placed in a glass-covered box about 

 the middle of July, we should find 

 that towards July 25 or so the box 

 would be literally swarming with small 

 chocolate-brown coloured active larva'. 

 They are very small mite-looking crea- 

 tures, measuring about yi^ of an inch 

 in length. These small mite-like larvae 

 are the first stage of the "brown 

 scales " referred to ; and as there is a f'-^- :i07.--Fc7,ifi?e sccdes of Lecaui 



' ciipreit', " hroivH scale, on syoamore. 



great difference in size and apparent 



structure between the small active larvae and stationary brown dead- 

 like scales, it would be well for the student to study the development 

 of a Lecanium scale. 



Under the one-inch objective the structure of the larvie will be 

 seen to resemble that of the larvae of Chionaspis. In their natural 

 state they move about very actively for a time, and then settle down 

 and begin to imbibe the juices of the plant. 



As it is rather difficult, more especially for a beginner, to follow out 

 the life-history of a Lecanium on a forest tree, it is best to have 

 recourse to stove or greenhouse specimens, and get a [ilant which is 



