HOW TO KNOW THE INSECS 



quiet the Insects. The contents of the net after a period of 

 sweeping may be emptied Into a separator . (See Fig. 11) 



A gas tight box large enough to hold several short handled 

 sweeping nets Is carried on the back of the automobile used for 

 the Iowa Insect Survey collecting trips. About two spoonfuls of 

 cyanogas Is wrapped In a paper sack or envelope and placed In 

 the box. The nets, after being used In sweeping, are put in the 

 box through the door at the end. In a few minutes everything Is 

 quiet and the Insects may be sorted without danger of any of them 

 escaping. This plan has proven very helpful particularly v:lth 

 bees and files. 



In using the sweeping net only a few strokes should be made 

 before emptying It as otherwise many specimens will be dam.aged. 

 At best the sweeping net offers too vigorous treatment for the 

 more delicate specimens. If one Is anxious to economize his 

 time a second net may be used while the insects in the first are 

 being killed or quieted. 



Twelve inches in diameter makes a favorable sized ring for a 

 sweeping net. Tastes differ as to the length of handle. While 

 som.e prefer a long handle (a yard or more) which pennits sweep- 

 ing low vegetation without stooping, most collectors favor 

 handles 18 to 24 Inches in length. The young collector can v:ell 

 afford to do some experimenting to find which works best for him. 

 One may readily saw off part of a handle that seem.s too long. 



The bag is subject to severe wear, particularly around the 

 ring, and needs to be of tough material. Rather heavy unbleached 

 muslin or light weight duck is good Light colored materials 



make the Insects more easily seen 

 for picking out. The bag when 

 finished should have a depth about 

 twice the diameter of the ring. A 

 quick and altogether satisfactory 

 way to make the bag is to lay out 

 the goods double in length twice 

 the diameter of the ring plus 2 

 inches for hem; width, when 

 doubled, 1 2/3 the diaineter of the 

 ring, as shovm (Fig. 8); sew along 

 the dotted line and cut out. An 

 inch and a half or two Inch hem at 

 the top readily permits threading 

 the bag on the ring. 



>f 



Hem 2." 



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Cufv, 



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2.0* 



vXlotk 



Some collectors desire a semi- 

 transparent net which permits 

 passing a killing bottle up into 

 the bag and catching the choice 

 specimens or those that sting, 

 while they are seen through the 

 fabric. It is a rather difficult 

 problem to find such transparent 

 material that Is strong enough to stand sweeping and not too 

 expensive. If the cost item does not Interfere, a good grade 

 of organdy or, better still, silk bolting cloth gives satis- 

 faction. 



Figure 8. Pattern for making 

 Sweeping net. 



11 



