Insect (Lepidoptera - Family) Biodiversity Across Forest Canopy and Understorey in SE-Asia BIFA5_026

Study Extent

The study was conducted in the tropical forests of Mo Singto area at Khao Yai National Park (14N, 101E) and Klong Naka Wildlife Sanctuary (9N, 99E). Sampling took place in June and December 2019 at Khao Yai and March and September 2020 at Klong Naka.

Sampling

At Mo Singto, we conducted insect sampling within the 30-ha monitoring plot designed to study vegetation and vertebrate (mainly gibbons) communities (Brockelman et al. 2011). Similarly, we used the 20-ha monitoring plot established in 2019 at Klong Naka designed to study vegetation community dynamics. These monitoring plots are subdivided into 20 m x 20 m subplots. Within each monitoring plot, we set a 300 x 300 m square area and established nine sampling points (3 x 3 grid arrangements). We used nine of the sub-plots where these nine sampling points were located. At each of the nine 20 m x 20 m sub-plots, we found suitable trees where traps can be suspended at the canopy and understory strata. Understory traps were suspended at 2 m above the ground whereas canopy traps were suspended immediately below the canopy foliage. The height of the canopy traps changed depending on the tree height (the information on the height of the traps is provided in the sampling event data). We selected a tree whose top foliage received direct insolation, but we did not select midstory or emergent trees. The ropes to suspend the canopy traps were hung over the tree branches by first shooting the throw line (2 mm diameter, BARHAR, Dongguan, Guangdong, China) using an arborist slingshot (Big Shot Line Launcher, WesSpur Tree Equipment, Bellingham, WA, USA). The throw line was replaced with a nylon rope (approx. 8-10 mm diameters) to which the trap was attached and hoisted to the canopy stratum. A nylon rope was also used to suspend the traps at the understory. Our light traps were based on the light traps designed by Kitching et al. (2005) who modified Pennsylvania-style light traps for rainforest use. The light trap emits UV light from a fluorescent tube (Philips 8 Watt actinic light tube) run by a lithium-ion battery and a built-in timer. The trap consists of a metal drum (25 cm diameter, 34 cm long) in which a plastic collection bucket (24 cm diameter, 20 cm high) is set with a dichlorvos-infused wick as a killing agent. The bucket is covered by a plastic funnel with 4 cm bottom opening to capture the flying insects that were attracted to the UV light. Immediately above the plastic funnel, four clear acrylic panes (12 cm wide and 43 cm long with the bottom 10 cm cut to fit the shape of the funnel) set at right angles are erected. The metal rain cover (38 cm diameter) is placed above the plastic panes. The opening between the drum edge and rain cover is 30 cm long. In the collection bucket, a plastic egg carton cut to fit the bottom of the bucket was placed to prevent large beetles from damaging moth wings before they were killed. A sanitary napkin was placed on the egg carton below the funnel opening to absorb rainwater. The lithium-ion battery and a timer are set below the collection bucket. We set the time to run the light traps between 20:00 and 06:00, and repeated three times (three nights, but not necessarily consecutive nights). We did not use light traps one week before and after the full moon to minimize the influence of moonlight. The samples were kept dry in a plastic container and left in a deep freezer at minus 18-20 degrees Celsius. All moth specimens were taken, and representative specimens were dry-mounted for identification. We used the Moth of Thailand and The Moths of Borneo to identify the specimens to family and then morphospecies with assistance from the local taxonomists. All wet and dry specimens were stored at the Mahidol University Museum of Natural History. Brockelman, W. Y., Nathalang, A. and Gale, G. A. 2011. The Mo Singto forest dynamic plot, Khao Yai National Park, Thailand. Natural History Bulletin of the Siam Society. 57: 35-55. Kitching, R. L., Boulter, S. L., Vickerman, G., Laidlaw, M., Hurley, K. L. and Grimbacher, P. S. 2005. The Comparative Assessment of Arthropod and Tree Biodiversity in Old-World Rainforests. Cooperative Research Centre for Tropical Rainforest Ecology and Management. Rainforest CRC, Cairns, Australia. Holloway, J. D. 1986. The Moths of Borneo Part 1 to 18. Southdene, Kuala Lumpur, Malaysia.

Quality Control

The field surveys were mainly conducted by the local assistants and students, but supervisors visited both Mo Singto and Klong Naka to check the sampling areas and ensure that the fieldwork followed our sampling protocols described above. Taxonomic identification has been conducted by the students and they collaborated with local taxonomists to check their family-level identification.

Method steps

1. 1. At each of the nine 20 m x 20 m sub-plots, we found suitable trees where traps can be suspended at the canopy and understory strata. Understory traps were suspended 2 m above the ground whereas canopy traps were suspended immediately below the canopy foliage. The height of the canopy traps changed depending on the tree height (the information on the height of the traps is provided in the sampling event data). 2. We selected a tree whose top foliage received direct insolation, but we did not select midstory or emergent trees. The ropes to suspend the canopy traps were hung over the tree branches by first shooting the throw line (2 mm diameter, BARHAR, Dongguan, Guangdong, China) using an arborist slingshot (Big Shot Line Launcher, WesSpur Tree Equipment, Bellingham, WA, USA). The throw line was replaced with a nylon rope (approx. 8-10 mm diameters) to which the trap was attached and hoisted to the canopy stratum. A nylon rope was also used to suspend the traps at the understory. 3. We set the time to run the light traps between 20:00 and 06:00, and repeated three times (three nights, but not necessarily consecutive nights). We did not use light traps one week before and after the full moon to minimise the influence of moonlight. 4. The samples were kept dry in a plastic container and left in a deep freezer at minus 18-20 degrees Celsius. 5. Moth of Thailand and The Moths of Borneo to identify the specimens to family and then morphospecies with assistance from the local taxonomists.

Lepidoptera family level taxonomic coverage.

1. Bombycidae
   rank: family
2. Cossidae
   rank: family
3. Crambidae
   rank: family
4. Dalceridae
   rank: family
5. Erebidae
   rank: family
6. Geometridae
   rank: family
7. Lasiocampidae
   rank: family
8. Limacodidae
   rank: family
9. Noctuidae
   rank: family
10. Notodontidae
    rank: family
11. Saturniidae
    rank: family
12. Sphingidae
    rank: family
13. Zygaenidae
    rank: family

Lepidoptera superfamily level taxonomic coverage.

1. Bombycoidea
   rank: superfamily
2. Cossoidea
   rank: superfamily
3. Pyraloidea
   rank: superfamily
4. Zygaenoidea
   rank: superfamily
5. Noctuoidea
   rank: superfamily
6. Geometroidea
   rank: superfamily
7. Lasiocampoidea
   rank: superfamily

Mo Singto area at Khao Yai National Park (14N, 101E) and Klong Naka Wildlife Sanctuary (9N, 99E). In each location, a total of nine sampling points (300 x 300 m grid) were set within the forest dynamic plots (ForestGEO plots).