30 December 2024

Orthetrum glaucum vs Orthetrum luzonicum

It is quite a challenge for laymen to tell apart Orthetrum glaucum from Orthetrum luzonicum because both (matured males) are light blue in colour. Actually, we are still able to distinguish them if we look at them carefully. Orthetrum glaucum is slightly larger than Orthetrum luzonicum. The hindwing base of Orthetrum glaucum has dark patch, but this is absent in Orthetrum luzonicum. Apart from that, the abdomen of Orthetrum luzonicum is slightly slender if compared to Orthetrum glaucum.


Orthetrum luzonicum (male; left) and Orthetrum glaucum (male; right)
UKM Bangi, Selangor

29 December 2024

Archibasis rebeccae

I saw this Archibasis rebeccae female performed an act to grab a small spider resting on its net. The Archibasis rebeccae approached the spider net skillfully so that it was not stuck herself on the net of the spider. Hovering at the same level as the spider (the spider net was at the vertical position), she suddenly pushed forward her legs to grab the spider and then retreated herself away from the vertical spider net so that she did not crush into the spider net.  

Archibasis rebeccae - female
feeding on a small spider
UKM Bangi, Selangor

26 December 2024

22 December 2024

19 December 2024

Xiphiagrion cyanomelas

Xiphiagrion cyanomelas
being preyed - the male has lost his thorax and head and the female has lost her abdomen
Imbak Canyon, Sabah

17 December 2024

Pseudagrion pruinosum

I witnessed partial submerging oviposition of Pseudagrion pruinosum. I believe in rare occasion it will do a total submerging oviposition.



Pseudagrion pruinosum - oviposition
UKM Bangi, Selangor



P/S:
I searched the internet for information on the egg laying of Pseudagrion pruinosum. So, it has been recorded that Pseudagrion pruinosum does total underwater oviposition with the male individual also down into the water. Click here for the paper about the egg laying of Pseudagrion pruinosum

14 December 2024

02 December 2024

Oviposition of Vestalis amoena

I observed the mating of a pair Vestalis amoena by the shore of a stream (Sg Durian). Right after the mating, the female was laying eggs on the leaf substrate in the stream. The male was perching at another leaf to guard the female.  


Vestalis amoena
left bottom = female; right top = male
Sg Durian, Lintang, Perak

23 November 2024

Lestes praemorsus

Lestes praemorsus - female
a failed larval emergence - left hindwing is still in the wing sheath of the exuvia
UKM Bangi, Selangor

Indothemis carnatica

Indothemis carnatica - mating
UKM Bangi, Selangor

19 November 2024

Genitalia of Orthetrum testaceum and Orthetrum chrysis

Orthetrum testaceum and Orthetrum chrysis are red dragonflies. Click here to see the slight difference of colour marking between these two species. Their genitalia are also between (see below). 


Left side lateral view of genitalia. A is Orthetrum testaceum and B is Orthetrum chrysis.

16 November 2024

15 November 2024

Larva - Indaeschna grubaueri

Indaeschna grubaueri - female
Taman Pertanian Sekayu, Terengganu

click here to see the adult of Indaeschna grubaueri

12 November 2024

06 November 2024

05 November 2024

29 October 2024

28 October 2024

25 October 2024

Vestalis amethystina vs Vestalis amoena

Peninsular Malaysia has three Vestalis species - Vestalis amethystina, Vestalis amoena and Vestalis gracilis. Vestalis gracilis is easily told apart from the previous two species based on the thoracic marking. However, both Vestalis amethystina and Vestalis amoena are similar to each other in overall marking. The only character used to distinguish both the species is their anal appendages.


Vestalis amethystina - male
Hutan Simpan Gunung Tebu, Terengganu


Vestalis amoena - male
Taman Negeri Rompin, Pahang



The anal appendages of Vestalis amethystina and Vestalis amoena are different (see images below). Close inspection on the anal appendages is needed for proper species identification. 


anal appendages of Vestalis amethystina. top = lateral view, middle = dorsal view, and bottom = ventral view

anal appendages of Vestalis amoena. top = lateral view, middle = dorsal view, and bottom = ventral view