Rearing Problems

Leptraps at Leptraps at
Sun Sep 26 13:45:05 EDT 1999

Response to weak adults:

When rearing Lepidoptera indoors or outdoors in gages, the loss of larva and 
pupa from bacteria is very common. I have been told that newly emerged adults 
that appear weak have actually fought off a bacteria attack, have emerged as 
adults, but the bacteria wins anyway because the adult is too weak to 

There are several methods to improve your rearing success. Cleanliness is 
number one. I change host plants and rearing containers daily. Also, I only 
place a small number of larva in each container. I then take a used contain, 
wash it with soap and rinse. Then soak the container over night, allow to dry 
for 24 hours and it is ready to use. The bleach will evaporate and have no 
effect on the larva. I have used this method for over twenty years and have 
great results. However, I am rearing from ova field collected material. I am 
not rearing for mass production (this may explain the Black Helicopter 
syndrome). I also sleeve out lots of larva when possible. 

Rearing larva on live plans also improves success. When rearing larva from 
cuttings, cutting are often placed in zip-lock bags and placed in a vegetable 
draw of a refrigerator. A refrigerator is a breeding ground for bacteria. 

There are numerous ways to prevent bacteria from attacking larva, this one 
works for me.

One suggestion for adults that emerge weak. I learned this trick from the 
late Dave Winter: I you want ova, feed your females. Mix 2 oz. of water, one 
egg white (protein source) and 1/2 teaspoon of sugar. Place drops on a glass 
slide. Hold wings over back with forceps, extend proboscis with insect pin 
until of proboscis contacts liquid. Once the individual begins to draw up the 
liquid, relax your hold with the forceps and she will sit and intake the 
liquid. I also rinse them off in a glass of distilled water after feeding to 
remove any sugary liquid which may harm the individual when the liquid dries. 
The egg white provides protein to the adult and she will oviposit without 
much effort on your part. oh yes, always put the females in the morning sun 
for a short time after feeding. She will oviposit readily. Do not leave her 
in the sun to long or she will over heat and die. You may try this concoction 
on weak adults. Let us know the results.


Leroy C. Koehn
Lake Worth, FL

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