58 



Lattin: Introduction 



purposes which they are expected to serve. For 

 example, mosquito larvae collected on a malaria 

 survey might be stored in the original field-collecting 

 vials in 70 per cent ethyl alcohol. If rubber stoppers 

 are used, such material may be held for several years 

 in case further checking becomes necessary. More 

 permanent preservation for museum purposes would 

 require that the rubber stopper be replaced by a cotton 

 plug, then the vial (or vials) can be inverted in a 

 larger museum jar half filled with alcohol. This 

 facilitates storage in an arranged collection and 

 provides a ready means of checking against evap- 

 oration. Finally, such material (or representatives 

 of each species) might be mounted in one of several 

 media on microscope slides. 



Slide mounting techniques. — Although many methods 

 have been used for mounting small insects on slides, 

 only a few will be described. Intro, figures 83 and 84 

 show a common method of preparation: 1) clear spec- 

 imen in 10 per cent potassium or sodium hydroxide, 

 either cold overnight or hot for 5-10 minutes (wet 

 dried specimens in detergent solution before clearing); 

 2) transfer to small dish' and remove body contents 

 under microscope by means of small needles (intro. 

 fig. 83); 3) place in acetic acid to neutralize alkali; 

 4) transfer to oil of cloves until specimen becomes 

 transparent (15-60 minutes) (intro. fig. 84a); 5) rinse 

 in xylol to remove oil (intro. fig. 845); 6) transfer to 

 drop of Canada balsam on glass slide (intro. fig. 

 84c); 7) arrange on slide with legs and antennae 

 extended (intro. fig. 84rf); 8) put on glass cover slip 

 avoiding air bubbles (intro. fig. 84e); and 9) label 

 with necessary information (intro. fig. 84/) and place 

 slide in drying oven for 3-7 days. 



The following method may be used for mounting 

 larvae of large size from either fresh or alcohol 

 preserved material: 1) slit specimens to ensure ade- 

 quate penetration of reagents; 2) place in hot 10 per 

 cent potassium hydroxide for 15 minutes; 3) transfer 

 to water and remove body contents; 4) place in 70 per 

 cent alcohol for 10 minutes, 80 per cent for 15 minutes, 

 95 per cent for 15 minutes; 5) stain in Gage's stain 



e odd cover slip 







Genus 



n 



¥) 



species 

 Anita 



Habitat 



Locality 



Date. 







Collector 



f 



Intro, fig. 



Syracuse watch glass 



83. Equipment used in preparing small 

 for slide mounting (Ross, 1953). 



Intro, fig. 84. Steps used in mounting small insects on slide: 

 o, clove oil for clearing; b, rinse in xylol; c, transfer to balsa 

 on slide; d, orient specimen on slide; e, put cover slip ovi 

 mount; f, label slide with necessary information (Ross, 1953 



for 3-5 minutes; 6) destain in 95 per cent alcohol 

 7) rinse in Euparal solvent; 8) mount in Eupara 

 (Verde); and 9) put on cover slip and place in dryin 

 oven for 3 days. 



Carpenter and LaCasse (1955) recommend th 

 following technique for mounting mosquito larvae 



1) remove from storage in 70-80 per cent ethyl alcohol 



2) slit body; 3) place in cellosolve (ethylene glyco 

 monoethyl ether) for 10 minutes; and 4) mount i 

 Canada balsam. The specimen should be oriente 

 on the slide and the tip of the abdomen partly severe 

 to enable the siphon to lie flat. Male genitalia c 

 mosquitoes are mounted by means of the first metho 

 given. 



Dried material is likewise susceptible to variou 

 levels of care and handling, depending on the purpose 

 of the collector or collection. For an ecologies 

 study dry mounting should be limited to such form 

 as moths, mosquitoes, and a few other types of insect 



