Discrepancy in O. alexandrae oviposition capacities

There is two strategies in butterflies, the first is to hatch with all the eggs matured and not feed, e.g. Saturniidae, overwintering species, the other is to feed and mature eggs during an extended life span. Ornithoptera like to visit flowers and I don't know about 'winter', so I guess them to be in the latter category. This would then explain how you can find this extremely low estimate of 27 (which would indicate capacity of mature eggs) and over 240 which sounds more reasonable for such a big butterfly. Of course this is just a guess based on my knowledge, I do not have any experience in breeding Ornithoptera.

I once collected and counted the eggs laid by a single female Papilio machaon from Belgium on fennel in a flight cage with plenty of flowers for nectar. Over about 10 days she laid over 400 eggs, which was many more than I had expected.

Adam.

I took a look at another of Straatman's Ornithoptera papers regarding O. goliath and O. chimaera, and for the former he wrote: "Largest number of eggs counted in a female
was 20, including immature eggs." This cuts away at the idea of O. alexandrae having a conspicuously low egg production capability and sets more clear that the author was simply referring to the female's total egg-carrying capacity at any given time. In this case, O. alexandrae has an actual larger capacity (and I imagine its abdomen would only be slightly bigger).

So with this I think it's more than fair to say I raised a non-issue and that the two authors are simply referring to different things, as I attempted to safeguard on my initial post.

You seem to be raising the distinction between the mentioned Ornithoptera species's different-sized eggs, which one is bound to assume affects their total egg-carrying capacity. I do not have any palpable idea of the variation in the egg size of Ornithoptera. Though Straatman states (for diameter) 4.7mm, 4mm and 3.5mm for O. goliath, O. chimaera and O. alexandrae respectively. Straatman has a paper on the first two species you observed but he does not mention egg size.

Now for the other part, I would have to disagree. The "initial question" was answered on account of confusion regarding O. alexandrae egg-carrying capacity and egg-laying numbers. The two authors must be referring to these different subjects by the reasons stated in the different posts.
However... that would have been my final statement if I hadn't come across this, found here: "Contrary to the rarer species of Ornithoptera, which generally lay but few eggs, the female of O. priamus may lay as many as fifty eggs, which appears more than sufficient to ensure species survival." I am effectively confused by this since here the author seems the clearest in regarding the genus as notoriously producing few eggs, adding to the fact he pressed that O. priamus' capability of laying around 50 eggs is distinctive. Parsons' information then clashes here the most, as with a +240 capability, the rarest birdwing produces by far the most eggs. The incongruence seems obvious.

Either I'm missing something here by rapid-reading these papers or the confusion not only persists as initially put, it increases.

Addition; further statement (related to oviposition) by Parsons on his paper about O. alexandrae: "In PNG, the eggs of swallowtail butterflies whose larvae feed on A. tagala (Atrophaneura polydorus, T. oblongomaculatus and O. priamus) are often subjected to between 50-90% mortality by a species of minute Ooencyrtus (Encyrtidae) parasitoid wasp. Other Ornithoptera are also known to suffer mortality at the egg stage from these parasitoid wasps, although none have yet been found to parasitize O. alexandrae eggs."

Specific to PNG or not, that's a very high mortality rate, I would say as high as any butterfly species endures from all predation and parasitism.

I'm curious as to what information you possess regarding the subject. Thank you for your availability.