Integrated management of termites damaging wooden structures

Field experiment was set up in November 2011 and continued up to March 2013 on 324 m 2 backyard garden plot of a farmer‘s residential area. The experiment was laid in 6 m × 6 m Latin square design. The treatments were polyethelene bag covered wooden sticks, chlorpyrifos 48% E.C. treated and polyethelene bag covered wooden sticks, Masea lanceolata treated and polyethelene bag covered wooden sticks, chlorpyrifos 48% E.C treated planting hole, M. lanceolata treated planting hole and untreated check. Every three months, termite infestation, damage and damage severity were recorded. The chlorpyrifos 48% E.C. treated polyethelene bag covered wooden sticks (0.2) and the chlorpyrifos 48% E.C. treated planting hole (0.2) protected termite infestation and damage throughout the study period starting from six months after application of treatment. In the rest of the treatments, damage progressed towards the end of the experiment with no significant difference amongst them. The severity of damage was significantly lower in chlorpyrifos 48% E.C. treated polyethelene bag covered wooden sticks (3 and 1.3) and chlorpyrifos 48% E.C treated planting hole (4.4 and 2.3) than the other treatments starting from twelve to eighteen months after application of treatments. Conclusively, chlorpyrifos 48% E.C. treated polyethelene bag covered wooden sticks and chlorpyrifos 48% E.C treated planting hole protected the wooden construction materials from both genera of termites. However, the chlorpyrifos 48% E.C. treated polyethelene bag covered wooden sticks was superior in providing longer duration of protection and reduction of environmental hazards. In the former treatment, no chemical was in contact with soils that saves not only contamination of soils and ground water but also reduced the rate of the biodegradability of the chemical.


INTRODUCTION
With few exceptions, the main food of all termites consists of wood, the chiefly utilized being cellulose (Harris, 1971).Termites cause economic loss by damaging structures such as buildings, bridges, dams, and even roads or by damaging crops, forest trees, or rangelands (Harris, 1971;Pearce, 1997;Gurusubramanian et al., 1999).They are major pests of all kinds of woods and products of wooden origin.They also attack living *Corresponding author.E-mail: mulatuwakgari@yahoo.com.
Author(s) agree that this article remain permanently open access under the terms of the Creative Commons Attribution License 4.0 International License plants (Metcalf, 1967).Non-cellulose materials such as plastic pipes, electric and telegraph cables are also damaged by termites (Harris, 1971;Hickin, 1971).In vast tropical areas no wooden article is safe, especially if termites can gain direct access to it from the earth (Klots and Klots, 1959).Termites attack on field and tree crops and on forest trees especially in the semiarid and subhumid tropics.They cause significant losses and often a major constraint on reforestation (Logan et al., 1990).
Local houses are constructed using mud and termites can tunnel through these structures and eat wooden roof supports or thatching.Thatching in African houses can be expected to last 5 to 6 years.Wooden or bamboo poles incorporated in the mud or cement walls of traditional houses offer an easy means of entry to termites from floor level to other areas.In all kinds of buildings good design is important but this may still not stop termites invading (Pearce, 1997).
Ethiopia, as one of the tropical countries, suffers from termite damage to buildings, seedling and saplings for reforestation; loss of timber and agricultural crops and forestry trees.Termite damage is particularly serious in Western Ethiopia than other regions (Abdurahman, 1990(Abdurahman, , 1995)).
In Western Ethiopia where it is common practice to build houses and fences on untreated wood and grasses without proper foundation, thatched grass roof huts are destroyed in about five years while corrugated iron sheet houses survived about eight years.About 50% of the houses and fences require maintaining every year.Similar maintaining is required for stores, bridges crossing streams, electric and telephone poles and many others.As a result trees are cut frequently to replace structures destroyed by termites.Such practice would undoubtedly lead to deforestation and ecological disaster (Abdurahman, 1990).One could also imagine the labor force engaged and money spent in maintaining the structures destroyed by termites annually.These losses of labor, money and forest resources would obviously be very striking had it been properly estimated and reported as has been done elsewhere.
Generally, termite damage to buildings, electric and telephone cables, bridges crossing streams, standing trees, transplanted seedlings and so on in Western Ethiopia is apparent to anyone though significant research was not undertaken in the past and recently.Therefore, field experiment was conducted with the objective of evaluating chemical, mechanical, botanical and their combination on termites damaging wooden structures to address the urgent needs of the inhabitants of the Ghimbi district.

MATERIALS AND METHODS
Field experiment was set up in November 2011 on 324 m 2 backyard garden plot of a farmer's residential area.Wooden sticks of 1.25 m long with a diameter of 15 cm cut from six years old Eucalyptus tree were prepared for the experiment.The experiment was laid in 6 m × 6 m Latin square design.It required 36 wooden sticks each at 3 m intervals from one another 0.6 cm × 0.6 cm × 0.5 cm hole was dug for each wooden stick.A 19 m × 2 m twenty five micro polyethylene bag was prepared.The polyethylene bag was cut into 0.75 m × 1 m pieces (Figures 1 and 2).
Materials such as two 15 L plastic buckets and a 15 L Knapsack sprayer were prepared to begin the experiment.About 12.5 ml chlorpyrifos 48% E. C. was dissolved in one liter of water.Lower part of the six wooden sticks, each about 0.75 cm was sprayed with 12.5 ml chlorpyrifos 48% E. C. in a bucket and covered with polyethylene bag.The sprayed and covered wooden sticks were planted in their respective holes and any leftover chemical from each treatment was added to the hole and tightly covered with the soil.Similarly, the same amount of the chemical was sprayed in another respective six holes and barren wooden sticks were planted and covered with the soil.Another six untreated wooden sticks but that were covered with polyethelene bag were also planted in their respective holes and covered with soil.The fourth group of six wooden sticks each sprayed with 125 g M. lanceolata leaf powder in the same way with the chemical and covered with polyethelene bag and planted in their respective holes and covered with soil as usual.Another six holes each was also sprayed with 125 g M. lanceolata leaf powder in a similar manner to the chemicals but uncovered wooden sticks were planted and covered with the soil.Finally six uncovered and untreated wooden sticks were planted in their respective untreated holes for use as a control.Each wooden stake represents one experimental unit.The treatments were: 1. Polyethylene bag covered wooden sticks.2. chlorpyrifos 48% E. C. treated and polyethelene bag covered wooden sticks.3. M. lanceolata treated and polyethelene bag covered wooden sticks.4. chlorpyrifos 48 % E. C. treated planting hole. 5. M. lanceolata treated planting hole.6. Untreated check.
Every three months, the sticks were removed for inspection.A visual examination of the sticks was made during each observation period.Termite infestation, damage and damage severity were recorded.Hand lens was employed in the identification of smaller termites and termite damage.Termite specimens were collected and preserved in labeled vials filled with 80% alcohol for later identification in Insect Sciences Laboratory of Addis Ababa University.The collected data were analyzed using NCSS software for analysis of variance.

RESULTS AND DISCUSSION
The wooden sticks were infested with two genera of termites namely Macrotermes and Microtermes spp.Damage to the wooden sticks did not differ significantly among treatment means until six months after treatment.However, the damage on wooden construction material progressed in time from third month to six month after application of treatment as shown in Table 1 and Figure 1.The chlorpyrifos 48% E.C. treated polyethelene bag covered wooden sticks (0.2) and the chlorpyrifos 48% E. C. treated planting hole (0.2) protected termite infestation and damage throughout the study period starting from six months after application of treatment.These two  treatments did not differ significantly in protecting the wooden construction material from termite attack.In the rest of the treatments, damage progressed towards the end of the experiment with no significant difference amongst them.But chlorpyrifos 48% E.C. treated polyethelene bag covered wooden sticks seems to have better protection over extended period of time as compared to chlorpyrifos 48% E. C. treated planting hole and thus requires extended time of investigation.
The polyethelene bag covered wooden sticks and M. lanceolata treated polyethelene bag covered wooden sticks did not give any protection from both genera of termite attack.Polyethelene bag coverage did not protect termite attack.Nevertheless, termites were observed feeding on the botanical and the polyethelene bags themselves which was in accordance with Harris (1971), Hickin (1971) and Pearce (1997) who reported that termites feed on non cellulose materials such as plastic pipes, electric and telegraph cables.It also agreed with Sileshi Table 1.The effect of different treatments on presence of termite damage on wooden construction material starting from three months after application of treatments (starting from February 2012: Mean± se).Means with in a column followed by the same letter (s) are not significantly different at 5% Tukeys, studentized range test (HSD).James et al. (1990) who recommended the use of appropriate cultural methods combined with minimal modern pesticides in an integrated approach.

Treatments Months after Application of Treatment
The severity of damage done to the wooden construction material was analyzed starting from six months after application of treatments and continued at six months intervals.The severity of damage was significantly lower in chlorpyrifos 48% E.C. treated polyethelene bag covered wooden sticks (13.6 and 9.1%) and chlorpyrifos 48% E. C treated planting hole (20.9 and 10.6%) than the other treatments starting from twelve to eighteen months after application of treatments as shown in Table 2.The severity of damage increased starting from six months after application of treatments except for the two treatments.The least damage severity (9.1%) was recorded in the chlorpyrifos 48% E.C treated polyethelene bag covered wooden sticks and the highest damage severity was in the control plot (69.1%) toward the end of the investigation period indicating the promising effect of the Chlorpyrifos 48% E.C treated polyethelene bag covered wooden sticks over extended period of time that however requires further investigation.
Conclusively, chlorpyrifos 48% E.C. treated polyethelene bag covered wooden sticks and chlorpyrifos 48% E.C treated planting hole protected the wooden construction materials from both genera of termites.However, the chlorpyrifos 48% E.C. treated polyethelene bag covered wooden sticks was superior to the chlorpyrifos 48% E.C treated planting hole in two major aspects.These two treatments showed longer duration of protection and reduction of environmental hazards.In the former treatment, no chemical was in contact with soils that saves not only contamination of soils and ground water but also reduced the rate of the biodegradability of the chemical since it was not exposed to moisture and other elements in the soil that may facilitate the biodegradability of the chemical.Nonetheless, the duration of efficiency requires further investigation.
Haramaya University for the financial support and Dr. Abebe Getahun for facilitation of the research process.The author also thank Gimbi district agricultural and rural development for their unreserved support in providing field staff and motor bicycles.

Figure 2 .
Figure 2. Wooden construction material experiment layout (A) and termite infested planting hole after removing the wooden sticks (B) and termite damaged wooden sticks (C).

Table 2 .
The effect of different treatments on termite damage severity in percentage on wooden construction material (starting from May 2012: Mean± se).Means with in a column followed by the same letter (s) are not significantly different at 5% Tukeys, studentized range test (HSD).Data are square root transformed and numbers in parenthesis are actual values in percentage.