“Lestes dorothea” Fraser – A new addition to the odonata (Insecta) fauna of Kerala

Rison Thumboor¹ and Jeevan Jose²

¹[email protected]; ²[email protected]
   
Published in: Malabar Trogon 16(2): 17-19. PDF

Ovipositing

It  was an unexpected trip on July 29, 2018 to Athirappilly Forest Range along with K. C. Raveendran, a nature observer, after a long time. Athirappilly Forest Range is located in Chalakudy Taluk, Thrissur district in Kerala.  The weather was not too bad as there was only a slight drizzle. Light was not particularly bright. Munippara (10°17’59.9”N; 76°24’56.3”E ) and Thumboormuzhy are located en route Athirappilly. We stopped at Munippara to look for dragonflies on a temporary pond filled with rain water. There were some dragonflies flying around. Among them I noted a pair of Spreadwings (Lestidae) which were quite similar to Lestes praemorsus, but their size seemed to be slightly larger. I saw them laying eggs on Chromolaena odorata about four feet high from the pond and Melochia corchorifolia, Spermacoce latifolia in or near the pond. Later, I saw another couple of them in tandem position and a male damselfy alone flying around.    Later while examining the photographs, I noted an unusual mark on the synthorax of the female damselfly. The images were sent to Jeevan Jose and a Thai odonatologist, Noppadon Makbun. Both of them confirmed my observation as Lestes dorothea.

 

Lestes dorothea is a damselfly species in the family Lestidae. It is distributed from south (Karantaka) and northeast India to Thailand and Malaysia (Fraser, 1933; Subramanian, 2010; Subramnaian et al., 2018). It is a large damselfly: the male has an abdomen length of 40 mm compared to the similar looking species Lestes praemorsus which has an abdomen length of 32-35 mm. Its head is black and matured males have deep sapphire-blue eyes as in L. praemorsus. Its thorax is black, pruinosed white laterally, citron-yellow beneath. The dorsum of the thorax is marked with a pair of metallic green antehumeral stripes shaped like those seen in L. praemorsus. The mark on each side is followed by a diffuse black stripe on the humeral suture, a large diffuse black spot just in front of the upper part of the postero-lateral suture, another smaller spot at the middle of the antero-lateral suture, and a third spot over the spiracle. L. praemorsus lacks this black stripe; have only several irregular spots present on both sides. The thorax of matured males are heavily pruinosed, obscuring all these markings. Wings are hyaline and pterostigma is black. Abdomen is blue or greenish-blue marked with black. Segment 8 is with a fine basal blue ring, segments 9 entirely black, and segment 10 is black with pruinosed white on the dorsum. In L. praemorsus, segment 9 has very large lateral spots of blue. Anal appendages are bluish during life, broadly black at base and apex. Female thorax is olivaceous green, pale greenish yellow laterally. The markings are broader and more visible compared to the males. Anal appendages are small and black in color. Its much larger size, the absence of markings on segments 8 and 9 in the male, diffuse black stripes on the humeral suture, and higher postnodal index will serve to distinguish it from L. praemorsus. It breeds in well vegetated temporary ponds and similar habitats.

Lestes-dorothea
Lestes-dorothea

Subsequently, on 5th August 2018, the second author (JJ) also observed three ovipositing pairs and two males in a pond in Kadavoor village (10° 00’ 10.73’’ N, 76° 44’ 00.52’’ E) in Kothamangalam Taluk at the eastern border of the Ernakulam district of Kerala. It was a well vegetated artificial pond. They laid the eggs randomly on leaves hanging to the pond from the plants on the banks. The leaves were about one meter above the water and the oviposition continued for several hours. A male and female were collected and sent to ZSI, Kozhikode for further studies.

References

  • Fraser, F.C 1933. The Fauna of British India, including Ceylon and Burma, Odonata Vol. I. Red Lion Court, Fleet Street, London: Taylor and Francis. pp. 35–36.
  • Subramanian, K.A. 2010. “Lestes dorothea”. IUCN Red List of Threatened Species. IUCN. 2010: e.T167323A6328768. Retrieved 2018-07-30.
  • Subramanian, K.A., Emiliyamma, K.G., Babu, R., Radhakrishnan, C. & Talmale, S.S. 2018. Atlas of Odonata (Insecta) of the Western Ghats: 1-417. (Published by the Director, Zool. Surv. India, Kolkata)