Subterranean termites diversity in Mianwali District of Punjab, Pakistan

Subterranean termites cause destruction to the wooden structures and eat cellulose based products all over the world, causing economic loss on large scale. This study is conducted to observe the presence of subterranean termites and their species in district Mianwali Punjab Pakistan, from the months March to August, 2017. Manual method was used to collect the termites from herbs, weeds, shrubs, trees, plant debris, wooden logs and buildings of desert different areas of the District Mianwali. The population density of termites was estimated using Simpson’s diversity index equation. For further examination, the preserved (in 80 percent alcohol) termites were carried to Zoology Department, Lahore College for Women University, Lahore, Pakistan. The number of termites was maximum in the months of July and August.Five species of termites Coptotermes heimi (Wasmann),Microtermes mycophagus, Microtermes obesi(Holmgren), Odontotermes guptai and Odontotermes obesi(Ramber), were found in three tehsils of the District Mianwali. The most numerous termite species was C. heimi. The diversity and population density of termites in Tehsil Mianwali is more than Tehsil EsaKhel and Tehsil Piplan. The aim of the present study is to evaluate population diversity of termites in District Mianwali.


Introduction
Termites are social insects which live in colonies and consist of different castes. There are divisions of labour among workers, soldiers and reproductive (queen and king). The termite colonies occur in humus, wood debris, timber and other cellulose containing products [1]. They attack on wooden structures, wooden buildings, wooden furniture and paper products [2]. Local environmental factors, vegetation type, temperature, rainfall, and altitudes affect their number or assemblage in any area [3]. In Pakistan, various studies have been conducted to observe the swarming pattern of termites and have correlated it with rainfall and temperature [4]. Fifty species of termites have been recorded from different ecological zones of Pakistan [5]. Keeping in view their diversity and role as pest in different ecological zones of Pakistan, this study is conducted to observe the population density of termites in Mianwali District of Pakistan. The district Mianwali is situated in the south-western part of the Punjab province [6]. Average maximum temperature per annum is 47°C and minimum temperature is 19°C. Mean annual rain fall of the Mianwali is 3.3mm and maximum rain fall occurs in the month of July i.e., 6.6cm [7]. This study is conducted in keeping in view all the environmental factors which affect the distribution and diversity of termites in District Mianwali.

Materials and methods
Total number of 575 Termites was collected from all three Tehsils of the district Mianwali (Piplan, EsaKhel and Mianwali). The samples were collected manually, by using camel hair brush and wooden sticks. Wooden sticks to collect samples were used in another study by Henderson et al. in 2016 [8]. The pest activity was observed in deserts, riverine areas, pains and hilly area of the District Mianwali. The samples collected were preserved in 80 % alcohol in air tight glass bottles for laboratory studies. These termites were taken to the Department of Zoology, Lahore College for Women University, Pakistan for further lab examination. Their population density was simply estimated by dividing the total number of termites collected, with the area. In the laboratory, termites were further examined to study the different species under microscope. The termites were collected from the months March to August, 2017. Their percentage abundances were calculated in these months. Five different species of termites were examined and their diversity indices in the three Tehsils of District Mianwali were calculated by Simpson's index. Diversity index of number of individuals of five species of termites was also calculated by Simpson's index.

Results
The external environmental factors including temperature, humidity,texture of soil and wind speed affect the distribution and population density of termites. Population densities of three tehsils varied in accordance with the environmental condition of the areas (Table 1, 2 &3). It was observed that Termites were mostly found in the Tehsil Mianwali with 78.29 % by Simpson's diversity index (Table 4). Five termite species were identified from the samples collected from the different areas of the three Tehsils in different months.On Simpson's index high diversity value was observed in August (1-D= 0.7592) followed by July (1-D= 0.7511). The termite species Coptotermesheimiwas most abundant in April, June, July and August than other species (Table 5). In July, the number of termites of Microtermes obesus increased and in August, it became the most conspicuous species.. In July and August, the increased pest activity was observed ( Fig. 1). Diversity index of number of individuals of five species of termites shows that Coptotermes heimi was the most abundant species found in District Mianwali. Simpson's equation of index shows a value of D=0.2266 of collected sample of termites in district Mianwali. Coptotermes heimi, with a value of Pi= 0.0954, was more abundant than other species and the least abundant species was Odontotermes guptai with a value of Pi= 0.0084 and overall the Simpson's Scale diversity of termites was 77 % (Table 6).     Akhtar and Sarwar in 1993 [7]. In the present study, we found C. heimi, the most abundant specie, in contrast to the study conducted in Bahawalpur, where the specie M. mycophagus was the most dominant than other species [12]. Present study describes that most of the area of Tehsil Piplan is sandy so there is less number of termites as compared to Tehsil Mianwali, with fertile soil. Covering of the ground by the crops, protects the ground and reduces the evaporation of water and increases the humidity of the soil and it is the main factor for providing the habitat for termites [13]. Closer to river Indus and salinity of the soil is not favourable for termites so the density of termite's population is also low in Tehsil Esa Khel than Tehsil Mianwali.
Termites are found as decomposers in tropical regions and areas with thick vegetation [14]. Due  We found maximum numbers of termites in the months of July and August. In July and August, the increased pest activity was observed due to humid and warm environment and heavy rainfall [12]. The relationship between humidity and termites is positive while the atmospheric temperature has negative effect on termite's abundance. [16].

Conclusion
The high density population of termites is associated with the environmental factors of the specified area, which accelerate their reproduction and growth. This study provides useful information about biodiversity of termites in the district Mianwali. It is illustrated that diversity of termites was greater in Mianwali. The present study will be helpful in understanding the biodiversity and pest activity of different termite species in Pakistan.