In order to be able to positively identify the Heliconius butterflies in my pictures, I did a little research on Heliconius. I found more info about the butterflies of this genus online than I was hoping for. However, the more I dug into it, the more confusion I got. At a result, I don’t feel comfortable “identifying” the species of Heliconius by their color patterns because they have geographic diversity in color pattern i.e. one species may look exactly the same as other species. Anyway, I’ll write down the name that I think is what likely to be the one under the corresponding butterfly, so don’t take it seriously.
釉蛺蝶屬 (Heliconius) 分佈在新世界的熱帶及亞熱帶地區。這類蝴蝶由於數量豐富，在實驗環境下易於繁殖，且有大量的擬態，遂成為進化生物學模式研究的好材料，以了解其多樣性與進化和遺傳的関係 (改寫自Wikipedia)。
1. 蛹交配 – 雄性的 Heliconius 四出尋找未羽化的雌蛹, 找到後每日均會來訪, 甚至每日數次。到雌蛹快成熟時, 雄蝶會在雌蝶羽化前或剛羽化而仍未展翅時與之交配。雄蝶是被雌蝶所散發的外激素所吸引, 所以通常會吸引很多的雄蝶, 先到達之雄性會用翅趕走其他企圖卡位的雄蝶。最妙的是有時是两隻雄蝶會合作共同趕走其他的雄蝶。交配時, 雄蝶傳入反激素(anti-aphrodisiac pheromone), 令雌蝶的外激素不生效應, 以後不再吸引雄蝶。
2. 採食花粉 – 一般蝴蝶的成虫期都以液態花蜜為食, 而其寿命約為2-4星期。Heliconius 的成虫除食用花蜜外, 很多種Heliconius有吃用花粉的習性, 而且它們的寿命較長, 有長達八個月者。
3. 幼虫聚居性 – 一般蝴蝶產卵時多會在葉底產卵一顆, 而 Heliconius 會在同一點產十多卵, 所以功虫成群居性(像蛾類)。
這些習性與遺傳基因有関。我找到的資料很多, 字又小, 看得人眼花撩亂。我無意成 Heliconius 專家, 所以暫時把資料搁下。有興趣的朋友, 可點擊下面藍色的Link看看。
As Chris Jiggins, Margarita Beltrán, and Andrew V. Z. Brower have mentioned, Heliconius melpomene is a widespread neotropical species well known for its geographic diversity in colour pattern. Throughout its range, H. melpomene is co-mimetic with Heliconius erato, and both species have around 30 named geographic sub-species.
The butterflies of this group have some interesting and unique behaviors:
1. Pupal mating – Heliconius males seek out female pupae prior to eclosion and competing to mate with uneclosed or freshly emerged females.
2. Nectar feeding – Heliconius butterflies collect and accumulate large loads of pollen and the production of abundant saliva helps keep pollen attached to the proboscis (Gilbert, 1972). This practice enables an adult Heliconius to live up to eight months in the field as compared to 2-4 weeks of a non-pollen-feeding counterpart.
Further reading – http://heliconius.zoo.cam.ac.uk/heliconius/biology/ecology/
3. Larval gregariousness – Female butterflies normally lay one single egg on the underside of a leaf of its food plant to ensure food abundance for the hatched larva. Some Heliconius lay a dozen or more eggs on the same spot resulting in larval gregariouness, similar to that of a lot of moths.
If you find this interesting and wish to read further, please click the following link.
Geographic distribution of Heliconius melpomene, by:
The photo below appears to be H. erato or the Small Postman. However, this also looks like a subspecies (rosina) of H. melpomene.
Heliconius erato 與Heliconius melpomene分佈相同地域, 相互間出現很多擬態, 亞種亦多。 H. erato是有進行蛹交配的品種。可能是外激素(pheramone) 的関係, 雌蝶(蛹)在交配後就不在有雄蝶糾纒。在我拍照的溫室內, 在不同的两處地方看到已羽化的Heliconius melpomene雌蝶被不同的雄蝶爭相与之交配。雌蝶吸引眾生浪蝶。有趣的是, 被吸引的不單是同種, 連同屬的H. hecale都來了。圖片放最後。
Heliconius charitonia, or the Zebra Longwing is used as a model to demonstrate pupal mating. Their behaviors, including fending off landing of another approaching male, are well documented.
這種稱斑馬長翅蝶的 Heliconius 常被用作研究蛹交配的材料。它們的蛹交配过程及如何擊退其他雄蝶均有很詳細的觀察紀錄。
Shall we dance? 釉蛺蝶之舞
In the conservatory where I took these pictures, they have nursery rooms for breeding larvae and pupae, meaning that there are no female pupae for butterflies like H. charitonia or H. erato to practice pupal mating. Females are released after eclosion to the show room where butterflies fly free. I have observed, in two different locations that a Postman (H. memphone) female posing a classic mating gesture, i.e. resting her wings flat on a leaf, with her abdomen raised. A few Heliconius males with color pattern similar to that of the Postman, the Piano Key and the Hecale (H. hecale) were hovering around the female while she was in that mating gesture. The males appeared to have been dancing together, but actually they were “combating” to win the mating opportunity with the female.
After a few test shots, I had decided to set my camera at 1/125 second and focused on the Heliconius melpomene female resting on the leaf. 1/125 allowed the movement of the males to show. You may say that using a video camera is a better way, but I prefer using a still camera with a lower shutter speed, this way you can see all the details of all the parties involved. However, The problem of close-up photography is the shallow depth of field. As you can imagine, trying to focus on a target with a hand-held camera for an extended period of time is not easy, particularly I had to adjust the angle trying to put the male on the same plane. Since there are a few ghost-like images and you may wonder if they are some kind of composite images. The answer is no, all the images of the butterflies are the real images of a single shot.
I am not sure if it is right, I used present tense in the captions to describe what was happening the moment I took the picture, you know, like a reporter writing his news.
下面紀錄釉蛺蝶屬交配的過程, 雖然沒有成功, 但可以看到雄蝶如果爭奪交配的機會。我把照相機調到1/125秒, 目的是捕捉靜態的雌性而同時展示出雄性的動態。