Preventing Wing Damage In Emergence Cages

[ripheus11]

I’d like to open up an old topic in the hopes of learning more that will help me and other butterfly breeders!

Every year I raise a few hundred butterflies, and despite my best efforts at keeping them in good condition, they seem to get ruined almost immediately after they hatch. This is especially true with dark colored butterflies, which show wing wear quickly, and with tailed species. Some species like Pierids seem to remain calm all day long, and when they do fly they don’t seem to get damaged. But what can I do to prevent the larger and tailed species from quickly getting ripped in the cages?

My setup consists of placing a few dozen pupae into holders that angle them to fit right up to the netting. I use the large size reptarium cages that Clark mentioned a while back (about 4 feet long, 3 feet high, and 2 feet wide), but I’ve switched to a softer netting instead of the black rougher type that came on them. I also have some makeshift boxes with netting pinned on the sides. I have them facing a sunny window.

The butterflies emerge at sunup, and I wait about three hours before attempting to handle them for release or killing, to allow their wings to dry. To kill them, I place a killing jar into the cage and try to coax them in. Unfortunately, I sometimes damage them this way too. (Some people may use their hands, but whenever I’ve tried this, the butterflies just fly around or get scuffed from my fingers.) If I kill them at just one or two hours, they are still somewhat wet and the scales have not sufficiently adhered to the wings. If I wait several hours to half a day, then virtually all of them seem to fly and get ripped or scuffed, even if there’s only one in a cage! Even the three hour timeframe is problematic because some are still too wet, while others have already flown and become damaged.

In the old thread about this topic, some suggested placing the pre-emergence pupae into a dark room. I tried this, but I have found that this often stops them from hatching, or, if they do hatch they often fall and become crippled due to getting disoriented in the dark. And, it is really not practical when you raise several hundred to inspect and handle each one.

So, this is my dilemma! I am sure that mass breeders cannot experience the same problems that I seem to be having. Some of the huge breeders I’m sure don’t even use jars to kill them (though I don’t know what they do then), and they can’t watch every one that hatches and wait three hours to kill them! I hope some of you breeders out there can enlighten me as to how you get your butterflies to hatch and remain in good condition? I would say that even with my “three hour method”, I still get about 20% damaged, or more if I have a lot that hatch at the same time. Any help or suggestions would be greatly appreciated! Thanks!

[ladobe]

Interesting. I can share what my methods were if that might be of any help.

During my 20 odd most active lep years out of the 40+ I did them, in the wilds I reared as many as 20K-30K leps a year, and I seldom had any lost other than the few that didn't form completely due to unseen pupal injury or disease. In part maybe because when at home I used the same climate controllable cages for eclosion as was used for rearing most of my larvae. As a marine biologist first, then an engineer, I designed and built these cages from scratch of various sizes from about a foot square and 18" tall to much larger. They were four removable glass panels slipped in four aluminum corner moldings that held them securely over a screened water base with supported holes to put cut food plant stems through to the water, a screen top that could also be partially covered with glass,foil or whatever to help regulate temperature and humidity from the water base, and had both lighting and a boxer fan on timers on top. Making them very easy to quickly break down for sterilization was another goal, hence my design. As I could control all the environmental conditions in these cages, I could rear all year, even living in the deep snow country then. Pupae ready to eclose were simply kept oriented in rows in parted heavy cardboard sections or wood copies I made on the bottom, or in shredded newspaper/toweling, or hung on racks I made depending on which species, and with something for them to climb to spread and dry on. Sometimes just small dried branches or rough dowels leaned against the glass, sometimes eclosion stands I made in my wood shop. The key for eclosion was limiting numbers in each cage to what experience had proved to work best for that species, and the lighting on a timer as I could control when they eclosed to be only when I, my wife or son would be home. When I (or we) traveled the world to study and rear leps, stayed in hotels, motels, bungalows, cabins or even tents (or our RV) we were out in the field collecting more than at "home". So I made a large shock corded folding graphite tube frame that a sheet was clipped to for eclosion. It was leaned near a window with the drapes about half closed, and open racks of the pupae where lined up along the base of it (or when in tents the wall base of the tent)... with a "Do Not Disturb" sign hung on the door to keep housekeeping out in places rented. Worked very well and only occasional would a dried imago fly elsewhere in the room (usually just to the curtains). I also designed and built my own controllable pairing, laying and calling cages for the species I didn't hand pair. And had dozens of home made sleeves from small to big enough to enclose a small tree for use in the wilds, and sometimes I used them with controllable, small battery powered misters and fans to help keep whatever was contained "fresh" and active.

Maybe just from so many years doing it but I used my fingers or homemade "tweezers" to handle imago's and dispatch them, and rarely ever damaged one. Patience until a lep calms and a light touch is the key. My wife and son soon learned how as well. I personally do not care for chemical killing chambers for leps, dealing with poisons that can also effect mounting and preservation with some species. Closest I ever came to them was using hypo's filled with alcohol when black/mercury light night collecting to quickly dispatch large moths and Coleoptera. A small dose in the thorax is instant death, does no damage and easily evaporates without causing "grease" issues in large bodied leps.

Anyway, just like life you get out of leps what you put into them. This is what worked very well for me FWIW. YMMV

[ripheus11]

Thanks so much for the informative reply ladobe! I am amazed that you were able to successfully raise such numbers! I can not keep up with the food supply for the few hundred I have now. I can’t imagine raising thousands. Can I ask you, how long did you wait before dispatching them, and did you routinely raise any Papilios? With some families I have little trouble hatching them out and keeping them perfect, but with the Papilios and other tailed butterflies I’ve raised, they seem to break a tail after only the slightest amount of fluttering, and this happens even with only two in a cage. I am sure that darker lighting conditions would lessen the amount of flight, but I have also found that unless the room is quite bright, and bright for a photoperiod of at least 12 to 15 hours, Papilios won’t hatch.

As I have observed them in my cages, they have essentially no issues with emerging and crawling up on the netting. One thing I would say is that they do often remain just a short distance above the pupal skin and emergence blocks I have them in, and this can cause them to rest their wings on the blocks, which leads to incomplete wing expansion. However, the huge majority of the time they eventually crawl up a bit more and expand fully. If alone, some remain still for several hours, but if there are multiples hatching in the same cage, then they easily get disturbed and begin to fly. One bang into the netting, a fall onto the blocks, or even just a brief encounter with another individual results in torn wings. And, when one starts to move or fly, they all seem to join in.

[ladobe]

Jul 24, 2012 7:48:21 GMT -8 ripheus11 said:

Thanks so much for the informative reply ladobe! I am amazed that you were able to successfully raise such numbers! I can not keep up with the food supply for the few hundred I have now. I can’t imagine raising thousands. Can I ask you, how long did you wait before dispatching them, and did you routinely raise any Papilios? With some families I have little trouble hatching them out and keeping them perfect, but with the Papilios and other tailed butterflies I’ve raised, they seem to break a tail after only the slightest amount of fluttering, and this happens even with only two in a cage. I am sure that darker lighting conditions would lessen the amount of flight, but I have also found that unless the room is quite bright, and bright for a photoperiod of at least 12 to 15 hours, Papilios won’t hatch.

As I have observed them in my cages, they have essentially no issues with emerging and crawling up on the netting. One thing I would say is that they do often remain just a short distance above the pupal skin and emergence blocks I have them in, and this can cause them to rest their wings on the blocks, which leads to incomplete wing expansion. However, the huge majority of the time they eventually crawl up a bit more and expand fully. If alone, some remain still for several hours, but if there are multiples hatching in the same cage, then they easily get disturbed and begin to fly. One bang into the netting, a fall onto the blocks, or even just a brief encounter with another individual results in torn wings. And, when one starts to move or fly, they all seem to join in.

Raising in high numbers wasn't too much of a problem with a stay at home wife, and a son also helping before/after school as they also loved leps and traveled with me often for them. My wife even did the lions share of mounting for our synoptic collection. Her long thin fingers and nails, a light touch and on boards I modified to make mounting very easy made it easier for her. So it didn't take her long to fill up several of them. We had 40 of them in various sizes.

When we raised in high numbers it was moslty for restocking projects of colonies in decline that I collaborated on in my country as well as foreign countries. The few specimens we did add to our own SC from those we raised were allowed to fully form and dry undistubed, 3-4 hours usually. Sometimes longer if in a hotel, etc away from home and so out in the wilds collecting all day or night. Our SC contains only two pairs of most sp/ssp, and representative forms or abberations if found; a typical pair mounted dorsal and another ventral. The only long series mounting ever done was for specific studies I was involved in establishing between species intergrades and clines. For example, with the Hemileuciinae being another specialty for 40 years that has so many varables even within many of the same species, I did long series to establish what the dominate characteristics were in many specific colonies. One species in particular over many years rearing them I establish that females are the key to having a very good idea which colony they came from. My SC is a scientific one to help advance my studies and share with others doing the same, it is not a butterfly collection. But with so many years doing so many sp/ssp it is quite large.

I did rear a lot of Papilionidae over the years, the Parnassiinae where also one of my specialties for 40 years. But I always also did new species of Papilionidae when I found them the first time or for restocking, and both with worldwide species. Photoperiod is a major driving force for eclosion, but it is easily controllable. Overcrowding in an emergence cage or being a little too aggressive is probably your problem. They are mostly big bugs that need their own space AND patience with a light touch so as not to disturb then. Was seldom a problem for us anyway.
FWIW