INGA Newsletter

Genitalia Dissection


A label with a unique slide number is affixed to the specimen selected for dissection, and a second label with the same number accompanies the abdomen throughout the dissection. A log book is maintained to record the slide number, family, species, sex, specimen data (minimum of collection location), name of dissector, and collection repository. The abdomen is removed from a mounted specimen using curved forceps that are gently pressed on the venter of the caudal end, placed into a vial tube with 5ml of 10% potassium hydroxide (KOH) solution, and soaked overnight or longer until extraneous tissue is digested. The softened abdomen is transferred to a watch-glass containing 5ml of glacial acetic acid. The scales and macerated contents of the abdomen is removed by using curved forceps and a camel’s hair brush (size 000) that has the hairs cut to about 5mm long. The descaled abdomen is cleaned further in 20% ethyl alcohol, and the genitalia is separated from the abdomen with forceps and needles. The genitalia are stained with eosin for a few seconds and then with chlorosol black for a few seconds. Following dehydration in 75% ethyl alcohol, the genitalia and abdomen are transferred to 100% ethyl alcohol and hardened overnight. The genitalia and abdomen are mounted in 1-2 drops of Euparal on a microscope slide, and the preparation is covered by a cover slip. A slide label with the preparation number and specimen data are attached, and the slide is air dried at room temperature.

Please view the video provided below for a demonstration of how to dissect moth genitalia. Although the video is about dissecting a moth in a different group, the same basic techniques are used.

Video of the Dissection of the Male Genitalia of the Cactus Moth, Cactoblastis cactorum

(This is an embedded Youtube video; if you cannot view this, please click here: MPEG-4)

by Richard L. Brown, Sangmi Lee, and Joe A. MacGown

This video describes tools, supplies, and techniques for dissecting the male genitalia of the cactus moth, Cactoblastis cactorum.  Structures of the genitalia can be used to differentiate Cactoblastis cactorum from other species of cactus feeding moths. The cactus moth is native to South America, but has been used as a biological control agent in Australian and other areas to control introduced species of prickly pear cactus. This moth was first detected in the Florida Keys in 1989.  It has since spread northward on the Atlantic Coast to South Carolina and westward on the Gulf Coast.  In 2008 it was detected on the coastal islands of Mississippi, and in 2009 in was detected in Jefferson Parish, Louisiana. This species is an imminent threat to native cactus and the desert ecosystem in southwestern United States as well as to cultivated cactus in Mexico.

 

Video of the Dissection of the Female Genitalia of the Cactus Moth, Cactoblastis cactorum

(This is an embedded Youtube video; if you cannot view this, please click here: MPEG-4)

by Richard L. Brown, Sangmi Lee, and Joe A. MacGown

This video describes tools, supplies, and techniques for dissecting the female genitalia of the cactus moth, Cactoblastis cactorum