I have three issues to discuss with you. I know different people interpret in different ways. Hey that's OK. I am a hobbyist. I just wanted to know your "Opinion". Never mind what others think.
1. How does one generally describe the "Wing span of a butterfly"
2. How does one determine the largest or smallest butterfly in a region, say in India. Is it based on the individual specimen or based on general size of the species as such.
3. Is the following species Nacaduba berenice - Female? I am basing my assumption on the point of existence of Spot in costal region in line with basal band
All photos of the same specimen shot at Agumbe, on top of Western Ghats in Karnataka. Agumbe is considered as the place with highest rainfall in South India
1. The wingspan of a butterfly is determined in two ways.
A. In the old days of butterfly collecting the wingspan is the tip to tip measurement of a standard set specimen.
A standard set specimen is one with the FW lower margin (dorsum) set in a straight horizontal line.
This is the wingspan quoted in older reference books.
This is largely superseded by measurement of the forewing length. https://www.butterfliesandmoths.org/..._kondla1_1.jpg
2. The largest butterfly is based on the general size of the population. This is again based on one fixed criteria, wingspan. It does not matter if the butterfly is stoutly built like a Troides or slender like an Idea.
For example in Troides & Atrophaneura the male is described as smaller ,but often in body size it is the same .It just has smaller wings. https://www.insect-sale.com/photo/in...ra-nox-nox.jpg
I give here below 3 photos of the same specimen. Could it be a Female Pelopidas suochracea or P. conjuncta?
Guidance appreciated. Photo taken just below Western Ghats Kudremukh Ranges, at Mala near Karkala, Karnataka