Hyalophora cecropia L3 Rearing Notes (5/30/17-6/11/17)

Rearing notes for our third instar cecropia moth (Hyalophora cecropia) larvae. These originated as eggs from New York, June 2016.

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Rearing Notes 5/30/17-6/11/17:

6/11:

• A few more larvae entered apolysis; the one that did yesterday still hasn't molted but has slightly wrinkly integument now, so probably getting close 

6/10:

• One of the third instar on apple entered apolysis for fourth instar; it measures about 25 mm in length, though it is definitely not the largest individual (some younger larvae already measure 28 mm); the tubercles are swollen, especially at the base, and the integument is very tight and shiny
• The other larvae on apple are all doing very well, still forming small aggregations and stripping the top leaves of all the branches
• The larvae on plum are quite interesting in that the ones sleeved since birth n the shade are extremely melanic now that they are third instars - one is practically like a blackish second instar but with the third instar tubercles
• Unfortunately, the larvae on willow and sweet gum all got diseased and died - seems we should've just stuck with the apple all along and sleeved them!

6/9:

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• It seems the larvae that were sleeved outside since birth have now fully caught up to the ones raised until third instar indoors despite being about a week behind back in second instar; their thermoregulation is probably well suited to the outdoor temperatures now after being outside for weeks, so they don't mind the cold nights and hot days, while the indoor ones that are now sleeved as third instars seem to be in shock due to the extreme temperatures and have thus slowed down at bit

6/8:

• The third instar larvae display are large variation in scoli size, even among those of similar body sizes; some are large and vibrant, while others are small and dull
• A few larvae on plum molted to third instar and are catching up fast, likely to surpass those on willow which seem possibly diseased

6/7:

• Larvae are slightly larger as always; the blue on the dorsal side is really starting to come in now

6/6:

• It seems only the larvae on apple, both indoors and sleeved outdoors, will be decently successful at this rate along with the few larvae sleeved on plum
  
• The rest of the hosts are just no good - the larvae on alder already died (learned the hard way that this host plant is real nasty), the ones on sweet gum couldn't utilize the host very well based on their incredibly slow growth rate and have just recently started dying off as well, and the ones on willow have reached third instar, but several already died from disease

6/5:

• Many of the apple larvae that were sleeved from birth molted quite synchronously into third instar and are very healthy from the good ventilation
• The largest third instars have become much more vibrantly colored, especially the tubercles which have noticeably enlarged and become brighter when compared to newly molted third instars (center photo)

6/4:

• The apple larvae are growing rapidly now, consuming large portions of the leaves and becoming yellow green laterally and turquoise dorsally; those on willow don't like quite so good - at least a few died of disease and possibly more will, though the largest few still look healthy
• The plum larvae are making quite a comeback and are nearly full grown in second instar now; those on sweet gum and alder, however, look diseased so it won't be surprising if we loose them all before even the third instar

6/3:

• The apple third instars still look very strong and healthy, becoming firmer and greener; those on willow are mostly healthy as well, though likely because of indoor rearing, a few look possibly diseased
• The larvae on plum are doing well and have surpassed those on sweet gum and alder which have had several diseased looking individuals die

6/2:

•  All the larvae have grown a lot since yesterday due to the warmer temperatures today (mid-high 70s day); it was definitely on the cold side before so they really needed the warmth
• The apple larvae are all growing very well now, so we decided to sleeve the third instars and largest seconds outside as there should be no risk of desiccation or stunted growth now
• The larvae on willow seem especially melanic, as some third instars look almost like second instars, with a yellowish body and black head capsule, and black tubercles in place of blue ones

6/1:

• The third instars on willow fed minimally today which is somewhat unsettling, as Hyalophora larvae typically start having disease problems at this instar
• The third instars on apple look quite healthy and have become plumper and smoother; they still seem loosely gregarious
• The larvae on plum, sweet gum, and alder remain mid second instar, though the ones on plum have made surprising progress compared to how slow they were going in first instar

5/31:

• Two more larvae on willow molted into third instar and another one did on apple (indoor) as well; the the older third instar from yesterday has become slightly greener 
• The larvae on sweet gum have picked up speed a little now that they are all third instar though it's still very apparent their growth on it is much slower than on willow and apple

5/30:

• One of the larva on willow molted into third instar after spending eight days in second instar; the third instar is dramatically different than the second instar, being yellowish green with much larger, rounder, and brightly colored tubercles - red dorsal thoracic, yellow dorsal abdominal, and blue lateral; the black intertubercular spots have remained but are bluis, and the head capsule still has some black on it but is now  greenish, though less melanic individuals will likely have less or no black on the head capsules and reduced black spots (this individual is definitely a melanic one, as it was nearly entirely black in the second instar rather than yellow)
• The larvae outdoors on apple are surprisingly large now - not much smaller than the ones indoors despite being very small when first molted; the ones indoors are still ahead though, with a few that will likely molt into large third instars tomorrow
• The larvae on plum and sweet gum are still small, but growing steadily; the larvae on alder are still feeding normally and only a few small individuals were dead today, so perhaps they might not actually be diseased

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Authors
Alan Liang
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