Corresponding author: Atousa Farahpour-Haghani ( firstname.lastname@example.org )
Academic editor: Bernard Landry
© 2017 Atousa Farahpour-Haghani, Mahdi Hassanpour, Faramarz Alinia, Gadir Nouri-Ganbalani, Jabraeil Razmjou, David Agassiz.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation: Farahpour-Haghani A, Hassanpour M, Alinia F, Nouri-Ganbalani G, Razmjou J, Agassiz D (2017) Water ferns Azolla spp. (Azollaceae) as new host plants for the small China-mark moth, Cataclysta lemnata (Linnaeus, 1758) (Lepidoptera, Crambidae, Acentropinae). Nota Lepidopterologica 40(1): 1-13. https://doi.org/10.3897/nl.40.10062
Water ferns (Azolla spp., Azollaceae) are reported for the first time as host plants for the larvae of the small China-mark moth Cataclysta lemnata (Linnaeus) (Lepidoptera: Crambidae: Acentropinae) in rice fields and waterways of northern Iran. Cataclysta lemnata is a semi-aquatic species that has been recorded to feed on Lemnaceae and a few other aquatic plants. However, it has not been reported before on Azolla spp. Larvae use water fern as food source and shelter and, at high population density in the laboratory, they completely wiped water fern from the water surface. Feeding was confirmed after rearing more than eight continual generations of C. lemnata on water fern in the laboratory. Adults obtained this way are darker and have darker fuscous markings in both sexes compared with specimens previously reported and the pattern remains unchanged after several generations.
Cataclysta lemnata (Linnaeus) is a small semi-aquatic moth belonging to the Crambidae subfamily Acentropinae. Acentropinae, previously known as Nymphulinae, are distributed worldwide and reach their highest diversity in tropical regions of South East Asia/Malaysia and in the Neotropical Region (
The genus Cataclysta was described by Hübner, 1825 with Phalaena (Geometra) lemnata Linnaeus, as the type species. There are 18 described species assigned to this genus (
Cataclysta lemnata adults. 1. Female; 2. Male (live specimens above and prepared specimens below).
Azolla Lamarck is a genus of aquatic ferns and small-leaved ﬂoating plants divided into two subgenera: Euazolla, containing five species, and Rhizosperma with two species (
Azolla filiculoides is native to the tropics, subtropics, and warm temperate regions of Africa, Asia, and the Americas (
In Iran, A. filiculoides is considered an alien species (
Azolla spp. in natural habitats that seem to represent different species. 3. Different coloration of Azolla spp. in natural habitats; 4. Different size and shape of each type.
Stenopelmus rufinasus Gyllenhal (Coleoptera: Curculionidae), a weevil native to the USA, has had a huge impact on A. filiculoides as a biological control agent in Africa, USA, and some other regions (
Rearing: Laboratory colonies were established by collecting larvae and pupae from water fern collected in the Anzali (N 37°28’16”, E 49°27’44”) and Amir-Kelayeh (N37°20’35” E50°11’27”) wetlands, waterways and experimental rice fields at the Rice Research Institute of Iran (RRII) (N 37°12’22.2”, E 49°38’40.7”, 80 m) from September to November 2014 and 2015.
Larvae and pupae were kept in transparent plastic containers (16.5 by 25 cm, diameter by height) filled with 1500 ml of water and 40 g of water fern. These containers were used for rearing in all tests. After adult emergence, the males and females were transferred to the mating containers. We used transparent plastic cups (8.5 by 11 cm, diameter by height) filled with 200 ml of water and 3 g of water fern, and covered with transparent cellophane for mating and we made small holes with a needle in the cellophane for ventilation. Two or three males with one female were released in each container to maximize the chances of fertilising eggs. Cups were changed daily until the female died. Water fern was also renewed regularly. Eggs were counted and kept in the incubator until larval emergence. First instar larvae released in rearing containers and all life stages were surveyed daily. Rearing containers were renewed every five days in order to prevent the growth of fungi and bacteria.
Identification: Forty adults were used for preliminary identification based on wing venation and other morphological characters. Dissection of both male and female genitalia (Figs
Field observations: During 2014 and 2015, feeding damage observations by C. lemnata on water fern and other potential host plants were conducted in the waterways and experimental rice fields located at RRII.
Identification: Based on dissections of both male and female genitalia, the specimens were identified as Cataclysta lemnata.
Eggs: Less than 1 mm in diameter, globular, opaque to white (Fig.
Cataclysta lemnata eggs on Azolla. 5. A few hours after laying; 6. After 48–72 hours; 7. A few hours before hatching.
Larva: Newly hatched larvae are off-white, about 1.5 mm in length, with a black head capsule (Fig.
Pupa: Pupation usually occurs in shelters made from water fern leaves and a silky cover. As in other Acentropinae, the pupa of C. lemnata has chimney-like stigmata on abdominal segments 2 to 4. The pupa is reddish brown and approximately 7 mm in length (Figs
Cataclysta lemnata pupa. 10. Pupa; 11. Pupal shelter; 12. Inside the pupal shelter with a silky layer; 13. Pupa with chimney-like stigma.
Adults: The wingspan is 13–18 mm in male and 18–24 mm in female. Male with head and thorax light brown. Forewing off-white; costa fuscous, subbasal area with scattering of ochreous scales and dark brown patterns, discal spot with ochreous margin, median area with scattering of ochreous scales and antemedian ochreous spot, termen with a series of fuscous spots; fringe dirty yellow and brown alternately. Hindwing white with ochreous subbasal fascia, a scattering of pale fuscous scales, and one discal spot; termen with five conjoined black terminal spots, each with one silver dot; fringe white with dark line at base (Fig.
Evidence of damage on host plants: First instar larvae have been reported to be internal feeders on duckweed leaves (
The exotic aquatic fern, A. filiculoides, has invaded the Anzali Wetland. Since then, the overall ecological water quality, the habitat conditions, the numbers of migratory birds and fishes, and the aquatic plant diversity have declined in this ecosystem, particularly in the protected Selkeh wildlife refuge (
During the present study, we investigated the activity of C. lemnata on Azolla spp. in rice fields and waterways. The first studies on C. lemnata suggested that this moth is a stenophagous species on Lemnaceae (
Cataclysta lemnata effects on water fern in the laboratory tests. 15. Petri dish test with different population density; 16. Larvae consuming the floating layer during a week of artificial infestation with high-density larval population in laboratory.
The explanation for these external differences is unclear. Dissections of genitalia (Figs
Our study is the first to record Azolla sp. as a host plant for C. lemnata. However, there are 12 other recorded Pyraloidea that feed on Azolla spp.: Elophila enixalis Swinhoe, E. nigralbalis Caradja, E. responsalis Walker, E. turbata Butler, E. melagynalis Agassiz, E. manilensis Hampson (
Cataclysta lemnata male genitalia slides. 17. Ventral view with phallus; 18. Phallus; 19. Valva; Cor – cornuti; Coe – coecum; Vn. M – ventral margin; Sa – sacculus)
Cataclysta lemnata female genitalia. 20. Lateral view; 21. Last segments of the abdomen. Buc – bursa copulatrix; Du. Bc – ductus bursae; Apo – apophyses; Pap – papillae.
Although we briefly studied the biology of C. lemnata as a probable biotic resistance factor for water fern, many other important biological aspects such as population growth parameters and host preference in the natural habitat remain unclear. We could not find any specific parasitoid or predator for this moth although there are several generalist predators and parasitoids active in the rice fields (
Many studies have mentioned Azolla spp. as a weed (
We would like to thank Dr. Rodrigo Diaz, Assistant Professor of Entomology at Louisiana State University (Baton Rouge), for his advice and review of the manuscript, the University of Mohaghegh Ardabili and Rice Research Institute of Iran (RRII) for providing financial support, and anonymous reviewers for their comments.