In the Agricultural industry, termites are regarded essential insects in fixing the soil ecosystems by improving the soil pH, organic carbon content, water content and porosity 123. However, termites are also known in causing detrimental effects in agriculture by destroying a number of food crops like maize cassava etc. 4567. Furthermore, termite activities can still be a menace in the urban set up where they are associated with destroying a variety of components from unprotected buildings 891011. These damages caused by termites on buildings are of great economic importance for home owners because the integrity of infested buildings get compromised, resulting into their loss in value 12131415. To date, it is estimated that billions of dollars are spent annually on the control of termites worldwide 161718.

In Australia and China, termite infestations are widespread, with an estimation of 20% of Australian homes and up to 90% of Chinese homes, south of the Yangtze River being affected by termite damage 192021. Termite infestation is also a major problem to urban buildings in many tropical countries including Malaysia 22. In particular, the termite damage to buildings in tropical countries is of serious concern, with losses sometimes approximated to 100% 23. However, there is paucity of data documented on the termite damage to buildings in the sub-Saharan countries 14. Of late, the available anecdotal data in Zambia, attest to a wide spread of termite infestations recorded on buildings including: houses, offices, libraries, gymnasium, warehouses, Bank, Universities and some Airports. Despite the alarming incidences on termite damage to infrastructure in Zambia, there is very little knowledge on the preventive measures to both the general communities and the building constructors. In most cases, no one seems bothered, even when severe termite damages are observed on important buildings in the country.

Until recently, chemical control methods, including organochlorines (OC) and organophosphates (OP) have been world-widely used on termite attacks during the past 30-35 years, with the OP subsequently replacing the OC 2425. Essentially, organochloride pesticides i.e. dieldrin, dichlorodiphenyltrichlothane (DDT), aldrin, endrin, lindane, heptachlor, etc. were used as pesticides in Australia and many countries for a number of decades but were later deregistered when they were observed to be persistent organic pollutants (POPs) 2627. In 2001, the USA manufactured organophosphates (OP) pesticides i.e. parathion, malathion, diazinon, fethion, diclorvos, etc. were also banned by the Environmental Protection Agency (EPA) due to similar reasons of POPs 2614. In recent years, the enhanced manufacturing of pyrethroid pesticides i.e. thiodicarb, fipronil, thiamethoxam, tebufenozide, methomyl, lambda, etc. which are more specific in action and friendly to human and environment 28. Among the over 700 banned or deregistered OC and OP pesticides, few are still being used in sub-Saharan Africa, Asia and USA, on special order and closely monitored in use by regulatory bodies 29. Ratios for water to chemical concentration of these pesticides vary and are always provided by the company manufacturing the chemical brand. To achieve better results, instructions on chemical to water ratios should be followed accordingly. While most of chemicals can be used in contact treatment, others may also be used in fumigation methods 28. However, the physical control method might not always be used as conventional treatment but rather as an auxiliary method for partial processing 27.

Due to concerns with the environmental pollution however, more and more attention on termite control are being concentrated on various biological control technologies. Despite some degree of safety recorded on pyrethroids, chemical use is always regarded dangerous because after continuous use, users might eventually experience some detrimental effects on health 26. The biological control methods, may be done by introducing parasitic nematodes, biological control agents such as disease causing fungi and bacteria such as Bascillus thuringiensis is also used 28. In some cases, these agents are released into the soil or injected into the above ground termite galleries 1430. With the new and safer methods of termite control being introduced, more research is needed in order to compare and determine advantages and limitations 18.

Recently, several research techniques have also been developed on the use of Integrated Pest Management (IPM) to avoid the use of chemicals 5625. Mostly, the liquid termiticides have negatively impacted on both the human health and the environment. This coupled with existing limitations recorded on both the non-repellant termiticides and pyrethroids, there is need for use of other IPM methods as an alternative control of subterranean termites 31. The IPM or rather natural methods are less harmful to both the environment and humans and are thereby widely used both in structural environments and agriculture 732333435.

The aim of this study was to conduct a preliminary survey, to assess the ⁱ distribution pattern of different sizes of termite mounds located at the new site of Ndola International Airport, ⁱⁱ geometric parameters affecting the size of each mound and nest habitat of termites, ⁱⁱⁱ colony sizes of termites per each nest located at the site, and ^iv provision of technical expertise, involving different and safer preventive measures of termites from buildings that are under construction.

Aerial surveys revealed a variety of 1,880 termite mounds, spreading over the landscape of 137.4km2at the site, with an average estimation of 14 mounds per 1km2(Figure 2 and Figure 3). Results further showed that out of 1,880 mounds captured on site, only 65% of them were occupied by termites while 32% and 3% were deserted and occupied by other creatures, respectively (Figure 11 and Figure 12). Out of the 1,222 mounds that were occupied by termites, 798 were larger mounds while 300 and 124 were small and medium, respectively. Similarly, the 602 deserted mounds comprised 546 larger mounds, in comparison to only 56 mounds which were medium sized (Table 1).

Progression on the volume of nests in bigger and smaller mounds, significantly tallied with the size of mound at p < 0.0121 and p < 0.0346, respectively (Figure 13). Similarly, the colony size of termites in small and larger mounds was significant at p < 0.002 and p < 0.001, respectively (Figure 14). The nest volume ratios of small, medium and large mounds were also markedly increasing with the size of mound at 1:8.7-small, 1:32.8 medium and 1:1,098.6-large, respectively (Figure 15). On the other hand, results on the trials conducted on the efficacy of fipronil (5% SC) showed that the chemical was 100% efficient in killing termites, within 10-15 days from the first treatment date (Table 2).

Key: S=small mounds, and L=Larger mounds

Key: S=small mounds and L=Larger mounds

Key: S=small mounds, M=Medium mounds, L=Larger mounds

It was evident from this study that only 65% of 1,889 mounds were actively housing termites while 32% of these mounds were seemingly deserted. Furthermore, out of 56 mounds that contained various occupants other than termites, 29 mounds contained ants while 21 mounds were occupied by rodents while 6 mounds housed snakes which were either in singles or several of them, suggesting that snakes and rodents can live and reproduce in termite mounds (Figure 12). It was unclear however, whether these intruders that were found in termite mounds, occupied them when termites had already deserted them or they entered mounds on a hunting mission, to capture termites for food and after they overpowered the occupants, they fed on them to the extinction of the entire colony and eventually decided to take over their habitat nest and tunnels after a fierce conquest battle.

It was unclear however, whether the 32% of mounds that were detected without termites had been indeed deserted or rather some of them had nests deeply located beyond the detection capability of the instrument we used. According to Lee et al., 37, and van Huis 38, some termites can establish their nests 10 -70m deep underground, in their quest to avoid intruders and also to enable them maintain the suitable moisture for tunneling. It is for this reason why we also felt that termite mounds could be used by mining prospectors in exploring for minerals like: gold, zinc, uranium and other important metals 39. To this effect therefore, termites can also make mineral prospecting easier because companies in this business, can save a lot of money from drilling deeper.

A number of anecdotal reports in the ecology of termites have exhibited conflicted results on whether the colony size would have an effect on the size of nest and size of mound. This study has confirmed results that smaller colony sizes are always associated with smaller nests and mounds, and vice versa with the larger colony sizes (Figure 13, Figure 14 & Figure 15). It was also interesting to observe that there were 546 of larger mounds deserted while only 56 of the medium sized were deserted and none of the smaller ones was deserted, suggesting that in smaller mounds, termites rarely desert for the reason that they were still establishing themselves (Table 1).

A spontaneous check at the Copperbelt University (CBU) buildings, revealed that some old office door-frames and boards were severely damaged (Figure 16). We assumed that there could be a widespread of unreported termite attack on important buildings in Zambia. To this effect, the home owners often get a rude shock at selling their property when evaluators tremendously undervalued them. Worse still, such buildings are death traps in that they are the ones that fall first in an event of a tremor or earthquake.

Our study concurs with that of van Huis 38 where it was reported that some termite mounds were found occupied by ants, rodents and snakes.

Although we finally used the general preventive measures of termites at the site, including both the mound building and the subterranean termites, we felt that our instrument used in the survey, might have not successfully captured some termite nests which were located 10-70m below the mounds 38. On this fact therefore, some of the 32% of deserted mounds could still house termites but which were not detected. In addition, our study mostly concentrated on mound building termites with less focus on subterranean termites 40, whose nests can be found below any surface soil.

(i) Not every existing termite mound is occupied by termites.

(ii) The size of nest proportionately increased with the size of mound.

(iii) The size of colony concurrently increased with that of the volume of nest.

(iv) This study unravels some intriguing and conflicting suggestions that smaller mounds can still have larger colonies underground and vice versa.

(v) These ecological studies on termite mounds, involving geometrics of nest habitats, coupled with the control measures in the infrastructural engineering are the first to be conducted in Zambia.

(i) There is need to carry out more research surveys on the termite prevalence and extent of attack on buildings and other plantations located in the two Cities of Ndola and Kitwe, together with their outskirts.

(ii) Follow up studies on the cause of termite desertion from mounds and hence with the occupation of other creatures can be studied further.

(iii) The termite identification of the species located at the new International Airport and the surrounding Cities will be carried out and reported in the subsequent paper.

(iv) Further studies involving soils as associated with termites in mounds might be beneficial to both the farming community, the mining companies and indeed to the general members of communities in Zambia, especially those that have the appetite of eating the mound clay soils.