Rearing Notes 5/12/16-5/31/16:

Rearing notes 5/28/16-5/31/16:

Summer time is almost here and we have rediscovered the introduced Mediterranean Katydid (Phaneroptera nana) that we last encountered in 2014! Now that the hatching season has arrived, nymphs are now once again abundant here in Albany, CA.

Today (Memorial Day) the Albany Middle School campus was relatively empty and devoid of the normal sports activities, and as we did not have to go to school today, we decided to take our chance to forage for Anise Swallowtail (Papilio zelicaon) eggs and caterpillars around 11 AM.

As Albany Middle School alumni, we were extremely familiar with the campus setting. Like most school campuses, the Albany Middle School campus contains areas that field guides and ecologists categorize as "disturbed areas" -- open areas where plant matter and topsoil has been cleared away for urbanization purposes. These disturbed areas create an ideal environment for the opportunistic and invasive Wild Fennel (Foeniculum vulgare) that has seized Northern California in recent years. Needless to say, the perimeter of the school's parking lot and track field was a clear victim of F. vulgare. ​

Almost two years ago during the mid-summer of 2014 -- the last year we reared P. nana -- we had found our two katydids on this morning glory vine. But because we graduated from Albany Middle School in 2013, we rarely had a chance to visit the school since then. By the time we arrived on the scene today, we were skeptical about finding any because the morning glory appeared much less robust than we remembered.

​But to our surprise, a quick glance yielded not one, but two Mediterranean Katydid nymphs! While we are not entirely certain, we believe the first one was at least a third instar nymph while the other was second instar. ​​After searching for almost an hour, we found another nymph which we are almost certain was a newborn (not shown). We concluded that we had arrived just in time for their hatching season (seems to be slightly later than the native Mexican Bush Katydid). ​

We were able to collect two more young nymphs when we came back to look again this afternoon. We found one more around 6 PM in front of our home sitting on a fennel flower stock in our front yard.

We were very surprised to have found the P. nana to be so abundant as we normally only encounter Scudderia Mexicana. This year it seems to be the opposite in that we have found very few Mexican Katydids but a total of six Mediterranean Katydids in a single day! This lead us to wonder whether the nonnative species was beginning to out-compete the native species since just a few weeks ago we had also found a Mexican Katydid nymph on the same fennel plant -- a strong indicator that they may share a very similar ecological niche despite the fact, as we noted before, P. nana may hatch later. 

But at the same time, when upon close investigation of our Mediterranean Katydids, it appears that we may have encountered the species more frequently that we had previously thought. In 2009 (before we began photographic documentation), we found a handful of katydids on a different morning glory near Albany Middle School that we assumed were S. mexicana. However, we later noted that they appeared to be much more green in color and smaller in size than our other katydids that we had confirmed were S. mexicana which matches a description of P. nana. ​

- Brian

Rearing notes 5/27/16-5/30/16:

Most Orthoptera are herbivorous. At least, they usually are. Contrary to popular belief, almost all herbivorous animals are capable of carnivory during times in which plants are unavailable. Otherwise their meat-eating counterparts would never have evolved in the first place. For example, there are actually such thing as strictly carnivorous katydids and other Orthoptera that eat other insects and such. The Mexican Bush Katydid (Scudderia mexicana) is not one such example and are normally herbivorous.

So, we never expected that we would find one of our Mexican Bush Katydids happily devouring the cadaver of another katydid of the same species. . . .

As of two days ago, we still had two living Mexican Bush Katydids nymphs, both of which were wild-caught this year. The first one was much larger, at least one instar ahead of the other one. We had been keeping the two together in the same fruitfly bottle enclosure for as long as we have had them since there seemed to be enough space in there for such small nymphs.

But yesterday, the smaller one died a pretty horrible death. The thing must have been resting somewhere along the top of the container when the lid was not screwed closed. When we screwed the lid on not knowing that it was there, its abdomen got crushed very badly. The body was almost cut in two at the site of the injury with guts and body fluid trailing out of the wound. I guess it really would have made sense to remove the body at this time, but we didn't. We just left the poor thing crawl around frantically until it inevitably died from the injury by the end of the day. 

By today, however, the body was gone, but not because we took it out. It was completely missing with only a few scraps of the legs left at the bottom of the enclosure. The only logical conclusion we could make was that the other katydid have eaten the dead body! Boy, we were surprised. In the past, we had raised a larger number of Mexican Bush Katydids together in a tank where we had also witnessed some form of cannibalism in which the katydids would nibble at each other's legs and wings, often targeting victims that very recently molted. We had assumed that this was due to overcrowding and less-than-optimal living conditions since it is common for insects to eat each other when overcrowded. After all, we had even seen this happen in severely overcrowded, strictly herbivorous walking sticks too. However, overcrowding was not the case here as there were only two of them in a roomy enclosure. The other katydid must have simply took the rare opportunity to feast on a nice pack of fat and protein to supplement its normally leafy diet. 

After this, we begin to wonder that perhaps the particular species was, indeed, carnivorous to some extent in nature and normally scavenge for and feed on some small dead insects in the wild. Their closest Orthopteran relatives, the crickets, do this all the time. And perhaps by only feeding them an unvaried plant diet, we were depriving them of some nutrients and this was what may have actually encouraged cannibalism, and not any possible overcrowding. 

In any case, we decided to experiment. We have a hefty supply of fruitflies (Drosophila hydei) fruitflies that we regularly use to feed our European Mantises (Mantis religiosa) so we wanted to see whether the katydid would readily eat them as it had with its roommate. The procudure was simple. Basically, we just lightly crushed a fruitfly with a toothpick or our finger to kill it and draw out the liquid portions. Carefully, without causing alarm, we touched these liquid portions to the katydid's mouthparts to stimulate feeding, but did not forcibly feed the fly when it opened its jaws. 

What we found was that the katydid really did have an appetite for meat. It gobbled up four whole fruitflies in a row, effortlessly -- even more bestially than the much-touted praying mantis. Because insects do contain a lot of nutrients not available in plants such as chitin and animal protein (more variety of amino acids), we hoped that we had done the katydid a favor and it would grow to be healthier than the vegetarian katydids we had kept in the past. It's certainly nice to think it didn't just eat its roommate cadaver for nothing.

- Brian

Rearing Notes 5/18/16-5/25/16:

​All life cycle stages of Lepidopterans -- egg, caterpillar, pupa, and adult -- have been studied pretty extensively. There is a lot of information on where to go about finding each of them except for the pupal stage. Very little is known or written about the where caterpillars like to pupate in the wild let alone how to go about looking for one. So for a while now we have been curious about conducting an experiment to shed some light on this. Basically, we want to know what kind of angle Anise Swallowtail caterpillars (Papilio zelicaon) like to pupate at. 

The following is a basic concept or design of the upcoming experiment:

- Alan, Brian

Rearing Notes 5/14/16-5/22/16:

Rearing Notes 5/18/16-5/20/16: