The "egg-straction" container is a simple setup - a transparent plastic tub with lid - a large hole cut in the lid with netting taped over it for ventilation. Since the host plant cuttings were too large to fit in the container, I cut a hole in the bottom where the plant stems (with
partial roots) could protrude. The container is laid on its side and the protruding stem and root is draped with a wet paper towel, which is laying in a dish of water to keep it wet.
After only a couple of hours I noticed one female had assumed an ovipositing stance. As I watched, she continued to add to the mass she had already made. Shooting the photo through the plastic container made it somewhat foggy. Unlike many other species I have worked with, gabbii
females oviposit their eggs in large masses under the leaves. The ova are tiny and numbered somewhere between 50-75 ova per mass! 5-31-2006
Most of the time, the females crawled and hopped around the container and host plant, always trying to get close to the light source. I fed them a couple of times per day, by hand at first, and they gladly fed when offered the honey-water. After a while, I placed the red lid with the
honey water solution and a wadded-up paper towel into the container so they could feed as needed. The seemed to find it by "accident" as they hopped around the container, rather than identifying it and purposely going to it.
By the end of the second day, I inspected the host plant while the females were out of the container feeding. The find was spectacular. There were enough ova to supply several large populations for the following season! 6-2-2006
7 days later, I managed to spot one female just starting to oviposit an egg-mass. She would hold this position for nearly an hour while unloading 50+ ova. The first single egg can be seen in the right photo. 6-6-2006
On 6-8-2006, several of the egg masses had started development. It's interesting to note that what appeared to be one large mass earlier, is actually two or more masses, which become decernable as they change color at different times. Apparently, the same spot was attractive to the same or different females, causing additional masses to be added over time.
...and finally on 6-10-2006 they hatched. The teeny-tiny larvae exploded from the egg mass and promptly began stripping the host leaves. The tell-tale pattern of "leaf-mining" is a dead give-away that gabbii larvae are present. Later that week, I returned to the collection site to gather
more host and spotted the leaf-mining signs on some of the plants there. I was easily able to find more larvae right there in the field. The larvae are quite gregarious and stick together in tight masses most of the time.
They grow rapidly at first, and only 4 days later they had changed from a greenish yellow color to a darker greenish-black. The impact on the host plant leaves is still very noticable. When feeding they scattered somewhat but grouped back together when at rest. 6-14-2006
Some 10 days later I discovered more larvae in a different location while gathering more Aster host plant in Bouquet Canyon. I hadn't seen the adults fly in this particular location earlier in the season, but apparently they did! The host plant (Aster) is the grey-green feathery
plant in the center of the left and center photos. The gabbii larvae I found there is on the right. 6-25-2006
Here we are, almost a month after they hatched, and the larvae are mostly black now. They don't seem to be growing as rapidly as they did at first. Shortly after this photo was taken, they were moved into a
larger container due their huge numbers and amount of host needed to feed them! Fortunately, the host lasts for nearly a week if kept in water. There are at least 200 in this container! 7-2-2006
By 7-14-2006 the larvae are becoming reclusive, hiding in the curled-up dead leaves deep in the host plant, and appear to be ready for diapause...
These shots (from a subsequent project brood in 2009) show hibernating (diapaused) larvae being unwrapped from the paper towels they were stored in over the winter. The larvae were kept in closed containers in the lab refrigerator at 45F - 55F, with paper towels to prevent any moisture/condensation from forming. In Spring, around mid-February - mid March (depending upon how Spring is progressing), they are removed from the fridge and allowed to warm up to bring them out of diapause.
3-17-2007 The larvae are sleeved on a potted host plant (Aster) outside, where the warm spring sunshine helps wake them up...
4-9-2007 A few weeks later they are growing rapidly on the potted host...
4-14-2007 Some of the larvae had come out of diapause well before the others, and were WAY ahead of them in size and maturity...
4-20-2007 Some of the larvae are now mature. One has picked-out a place on the rearing container and 3 days later had pupated there.
4-30-2007 This female emerged a few hours after sunrise, and I was on-hand to watch and film the show...
Here's a great high-res shot of a pupa about ready to eclose as an adult...
...and that completes the rearing project for this species!