Biotermiticides to Protect the Soil Health

Termites are a group of eusocial insects of infraorder Isoptera , or as epifamiliy Termitoidae within the cockroach order Blattodea (Beccaloni and Paul, 2013). They are of four groups: dampwood living and feeding in very moist wood, drywood termites do not require contact with moisture or soil and subterranean termites live and breed in soil, and arboreal/mound builders. Termite mounds are commonly found in Africa, Australia, Southeast Asia, and parts of South America (Krishna, 1969; Inward et al., 2007). They are polymorphic living in colonies comprising reproductives (king, queen) , soldiers and workers called castes . The queen in ‘Royal Chamber’ is very much bigger than the king and is capable of laying eggs at the rate of 36,000 a day for as long as 50 years. Single subterranean termite colony may contain millions of workers and may forage a distance of up to 100 m2. (Su & Scheffrahn, 1988). 

Termites help in aeration of the soil due to burrowing activities, the breakdown and release of organic matter as termites eat and digest soil, improvement of soil fertility when termite mounds, which are rich in minerals, are crushed down and incorporated into the soil, as a source of minerals for cattle who lick the mounds and as a source of protein rich food for many organisms including ants, guinea fowl and other mammals including humans (HDRA, 2001). It is also observed that termite in its natural environment; improve soil pH, organic carbon content, water content and porosity by recycling dead organics (Abdel and Skai, 2011). 

Although there are some benefits of termites in soil reclamation but they are often called the “Silent Destroyer” as they may be secretly hiding and thriving in homes without any immediate signs of damage. About 10% of species of the termite are economically significant as pests and consume cellulose-based plant materials and destroy valuable property, documents, furniture and furnishings anything that contains cellulose, silently and swiftly, before becoming aware of the damage done. Termites also cause damage to living trees, crop plants, wooden electric poles, railway sleepers, telephone and electrical cables, etc. (Krishna and Weesner, 1970; Pardeshi etal., 2010 ; Mitchell, 2003; Ogedegbe and Eloka, 2015). 

The economic losses associated with termite damage for Malaysia, India, Australia, China, Japan and the United States are 10, 35, 100, 375, 800 and 1,000 million US dollars respectively (Abdel and Skai, 2011). In Indian region about 35 species have been reported to damage about 10-25% agricultural crops andt imber in buildings (Rajgopal, 2002). It is observed that due to termite attack on wheat, paddy, cotton, sugarcane, groundnut, in Punjab, Rajasthan, Delhi, Uttar Pradesh, Andhra Pradesh, Bihar and Gujarat, Madhya Pradesh, and Maharashtra faced major loss in crop production (Patel and Patel, 1954; Chhotani, 1980; Verma etal. 2009). As many as 13 species of termite are reported to cause 30-60% destruction of buds of sugarcane in India (Roonwal, 1981) and are responsible for plant mortality (5-50%) and pod damage (46%) in groundnut (Rajgopal, 2002). Not only crops and wood but the cash, ornaments and saving documents kept in banks have been found attacked by termite in India ( Indian E xpress News, 22 Apr 2016, TNN. Apr 5, 2008).

Chemical termiticides used to control the termite include liquid termiticides, termite baits, building materials impregnated with termiticides and wood treatments. Chemical treatments on broad base can be of two types repellent termiticide and non - repellent termiticide. These chemicals do not kill the termites; they simply deter them from entering the treated soil and building tunnels. Ex. Cypernethrin, Bifenthrin, Fenitrothion, Permethrin and Fenvalerate, Chlorpyrifos. Non-repellent chemic als do not prevent termites from tunneling; they only kill the termites upon ingestion or contact. An example is imidacloprid, Aldrin, Heptachlor, Chlordane, Coppernaphthenate, Boric acid etc. Grace, et al.,(1993) reported that the toxicity of aldrin, chlordane, DDT, dieldrin and heptachlor was observed 17,20,24,28 and 33years after treatment in Hawaii. These are applied in huge quantity in soil or poured in mounds to destroy it. These chemicals are very toxic to all the biotic factors in soil and on the earth, leading to hazardous effects and diseases. This may is one of the threats to the human existence on the earth through soil pollution.

It is necessary to search the alternative safe termiticides to the commercial hazardous chemicals damaging soil health and ultimately the environment as a whole. Therefore the study was undertaken in the College of Agricultural Engineering and Technology, DBSKKV, Dapoli on, “Development of Cashew nut shell liquid based termiticide’. The main objective of study was developing and testing cashew nut shell liquid based termiticide by using Neemseed oil, Karanj seed oil and Markingnut shell oil in different proportions and field tested for termite response.