106 



for varying postexposure times. The results indicated that Calco Oil Blue 

 1088, Alizarine Fast Blue RB, Oil Soluble Blue II, Blue No. 13897 and Calco 

 Oil Red N-1700 caused distinct coloration and low mortality. However, for 

 14 days postexposure only Calco Oil Red N-1700 produced longlasting colora- 

 tion. 



197. , and McKibben, G. H. 1969. A vacuum probe for manipulating insects. 



J. Econ. Entomol. 62: 267-269. • ■ . 



A simple inexpensive vacuum probe was made from the plastic guard of a 

 disposable spyringe to manipulate insects without harming them. The tip 

 is cut off perpendicular to the body of the guard with a sharp knife or 

 razor blade, and holes of the desired diameter are drilled in the tip of 

 the shank. Then either a piece of rubber tubing 1/8 inch in diam. is 

 Inserted into the inner part of the base of the probe and held with glue 

 or l/4-in.-diam. rubber tubing is forced over the outside base of the guard. 

 The rubber tubing is then connected to a vacuum source. A foot-operated 

 solenoid valve that can open and close the vacuum line is highly desirable. 



198. ; McKibben, G. H.; and McLaughlin, R. 1969. Development of the bait 

 principle for boll weevil control: Calco Oil Red N-1700 dye for 

 measuring ingestion. J. Econ. Entomol^ 62: 370-375. 



A simple and inexpensive technique for measuring ingestion by adult Antho- 



nomus grandis Boheman is described. Identical results were obtained using 



both the chromic oxide method and a red dye (Calco Oil Red N-1700®) . Recovery 



of dye injected into adult weevils averaged 98%. No evidence of metabolism ' , 



of the dye for as long as 8 hr post injection was observed. The dye has no 



deleterious effects on the boll weevil, is easily recovered, and does not ' 



require the use of dangerous chemical prepared reagents, or a chemical 



reaction. Suggestions are made for formulating the dye to obtain uniform 



dispersions in aqueous media. 



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