The present study provides data to decide on the most appropriate method for sampling of ground-dwelling arthropods measured in a moist-deciduous forest in the Western Ghats in South India. The abundance of ground-dwelling arthropods was compared among large numbers of samples obtained using pitfall trapping, Berlese and Winkler extraction methods. Highest abundance and frequency of most of the represented taxa indicated pitfall trapping as the ideal method for sampling of ground-dwelling arthropods. However, with possible bias towards surface-active taxa, pitfall-trapping data is inappropriate for quantitative studies, and Berlese extraction is the better alternative. Berlese extraction is the better method for quantitative measurements than the other two methods, whereas pitfall trapping would be appropriate for qualitative measurements. A comparison of the Berlese and Winkler extraction data shows that in a quantitative multigroup approach, Winkler extraction was inferior to Berlese extraction because the total number of arthropods caught was the lowest; and many of the taxa that were caught from an identical sample via Berlese extraction method were not caught. Significantly a greater frequency and higher abundance of arthropods belonging to Orthoptera, Blattaria, and Diptera occurred in pitfall-trapped samples and Psocoptera and Acariformes in Berlese-extracted samples than that were obtained in the other two methods, indicating that both methods are useful, one complementing the other, eliminating a chance for possible under-representation of taxa in quantitative studies.

Life history, aggregation and dormancy of rubber plantation litter beetle Luprops tristis Fabricius, (Tenebrionidae: Coleoptera) is described from rubber plantation belts in the western slopes of Western Ghats from the south Indian state of Kerala. The life cycle lasted 12 months, including the 5 larval instars lasting 1 month, the 3 day pupal stage, and the adult stage that can last 11 months. The adult stage includes an inactive dormancy phase of 9 months in shelters and 1 month each of active pre-dormancy (feeding) and post-dormancy (feeding and reproduction) phases that occur in rubber plantation litter. Reproductive activities are confined to the post-dormancy phase. With the onset of summer rains, huge aggregations of adults invade residential buildings and enter into a state of dormancy for 9 months. Beetle aggregations were in the range of 0.5 million to 4.5 million individuals per residential building. Dormancy in L. tristis is best classified as oligopause, which is intermediate between quiescence and diapause. Adults and larvae feed preferentially on wilted rubber tree leaves. Age-specific variation in mortality during dormancy is distinct with higher survivability for adults that have a longer pre-dormancy period. Generations are non-overlapping.

Little is known about the ground-dwelling arthropod diversity in tropical montane cloud forests (TMCF). Due to unique habitat conditions in TMCFs with continuously wet substrates and a waterlogged forest floor along with the innate biases of the pitfall trap, Berlese funnel and Winkler extractor are certain to make it difficult to choose the most appropriate method to sample the ground-dwelling arthropods in TMCFs. Among the three methods, the Winkler extractor was the most efficient method for quantitative data and pitfall trapping for qualitative data for most groups. Inclusion of floatation method as a complementary method along with the Winkler extractor would enable a comprehensive quantitative survey of ground-dwelling arthropods. Pitfall trapping is essential for both quantitative and qualitative sampling of Diplopoda, Opiliones, Orthoptera, and Diptera. The Winkler extractor was the best quantitative method for Psocoptera, Araneae, Isopoda, and Formicidae; and the Berlese funnel was best for Collembola and Chilopoda. For larval forms of different insect orders and the Acari, all the three methods were equally effective.

Litter ant diversity and abundance in relation to biotic and abiotic factors were analyzed at five primary forest sites lying between 300 to 1650 meter above mean sea level in the Wayanad region of the Western Ghats in Kerala, southern India. Ant abundance and species richness peaked at mid-elevations influenced by the presence of favourable physical conditions and abundance of prey resources. Dominance of ants preferring termites and Collembola as prey at sites rich in their specific prey resources indicate the influence of local prey resource availability in determining ant distribution. Dominant species (Tapinoma sp. and Solenopsis sp.) had wider distributions, being present at all elevations. Physical factors (slope of the terrain, rainfall, moisture, humidity, temperature) and prey resource availability (insect larvae, termites, Collembola) influenced ant species abundance at a regional scale, whereas at local scales, site specific variations in the relationship between abundance of ants and prey-predators and physical factors were recorded. The present study highlights the need to consider site-specific abiotic and biotic factors while examining the distribution patterns of litter ants along altitudinal gradients in other regions of the Western Ghats, which is a recognised hot spot of biodiversity with wide regional variation in vegetation types and faunal distribution patterns.

The seasonality of litter insect abundance and its relationship with rainfall was analyzed in a wet evergreen forest on the windward side of south Western Ghats. Monthly litter samples were collected using Berlese funnels during 4 seasons of a year: southwest monsoon season June—August), northeast monsoon season (September—November), summer (March -May) and pre-summer season (December—February). Insect fauna as a whole showed no seasonal variation in abundance, however, some individual insect orders showed significant seasonal variation. Overall insect fauna and individual orders were distributed independently relative to rainfall. All insect orders with the exception of Psocoptera were present during all four seasons. Coleoptera (42%) was the dominant group in all seasons followed by Formicidae (12.3%), insect larvae (10.1%), Collembola (9.2%) and Thysanoptera (8.9%). Exceptionally high abundance of Ptiliidae contributed to the unprecedented abundance of litter Coleoptera. The aseasonality of litter insect fauna as a whole is attributed to year-round availability of rainfall and the absence of severe summer conditions.