PRESERVING HEMIPTERA 





Fig 873 Method of 



pinning a b I 



Tin' soft-l)o«lii'(l Bpecies of Aphis or plant-lice should be 

 preserved in alcohol, glycerine, or Canada / * 



balsam. Thej should be carefully watched — "ivA — 

 for their parasites, and can be easily kept 

 in slender glass dais, through which thej 

 can be observed. 



All the bugs should be pinned through 

 the distincl triangular scutellum, situi 

 in the middle at the base of the wings 

 (Fig. 273). The small, hard species of 

 leaf-hoppers should be pinned through the right wing- 

 cover. Various quadrupeds should be carefully examined 

 for lice, which may be preserved in alcohol, or mounted on 

 slides for the microscope. 



Examining Live Aphides Mi II .1 Slack says thai when we want 

 live aphides to examine under the microscope in a \ igorous condition, 

 we musl bandle them with extreme gentleness, or their sofl and deli 

 bodies will he injured and the creature killed. Their Brightness 

 of structure is, however, accompanied with great endurance of con 

 ditions that would be quickly fatal to manj stouter organisms Most 

 insects would be rapidlj killed by immersion in parafflne oil; but 

 young and vigorous aphid* 9 will often live for a me time, and 

 aionally for hours, in this Quid, such as is burnt in lamps. If tv. 

 three of the insects are very carefully placed in a little cork cell,* 

 filled with parafflne oil, and covered with thin glass, thej are in a 

 handy condition for examination. The result of numerous experi- 

 ments made with the best American petroleum oil, commonly called 

 crystal oil in the lamp shops, i* that the survivals are 'cry uncertain, 

 but sufficiently frequenl for the process to be well worth tr\im:. 

 They keep pretty quiet in the fluid, and it enables higher powers to 

 be used with convenience. A | inch objective, magnifying about 100 

 ir, with a full sized instrument, is very handy The illumination 

 should lie varied; hut one of the t >t— t ways i- to use both an achro 

 matic condenser and a lieberkuhn, or little silver reflector, at the end 

 ol the objective. The largest hole and central stop of thecond* 

 will give a tine dark ground illumination. When used in i onibic 

 with ihc lieberkuhn, it lights up the inside of the object, while the 

 less transparent parts receive reflected rays from the silver surl 

 The student will find a ureal many caa - in which this modi 

 ing a refractive and reflective object produces the best results The 

 e\ es of the Aphis, seen in thi- way. are like half mulberries, and the 

 little eye projecting from the coiner of the larger group is well dis- 



A vial-cork | inch in diameter cut acros make a disk 



,\. inch thick, witii an oblong hole in the cen n ind gummed on a 

 slide. The gum is not dissolved by parafflne oil. 



