..,.. CHRIS OLUKAYODE ADEDIRE FESN B.Sc., M.Sc (Ilorin), Ph.D. (lfe) Professor- of Etitomology' " 2· _ place between individuals, between collectivities, or between individuals and collectivities. Intergroup as well as intragroup conflicts are perennial features of social life". In the present context, conflict may be conceptualised as competition for the same resources; notably food, water, nutrients etc - except mating partners and it is interspecific. The Bible attests to the fact that there was ecological equilibrium at the dawn of creation because God said that all the things He created were good (Genesis 1:3 I). However, a significant step in the cultural evolution of man is the development oflarge scale cu Itivation or crops or monoculture and the capacity to store the excess crops so produced. This step, ' significant as it is, also led to the creation of artificial environment for insects; thus resulting in ecological imbalances. The built-up environment, road constructions, impoundment of inland waterways and various other activities associated with human development have all created breeding sites for some insects and intermediate hosts of the causative organisms of diseases at the expense of their natural enem ies. It is apparent, therefore, that either overtly or covertly, many human activities result into conflict either with fellow humans or with other components ofhis other biotic or abiotic environment. Consequently, cdriflicts in this context may be perceived as an integral part of human existence and may not necessarily result in the destruction of human society even though they start and terminate with or without human intervention. Sandole (1993) suggested that nothing.was inherently wrong with conflict but, instead, it.is seen as a catalyst for promoting social development, higher degree social order and new awareness in cooperative living. These same observations are also true in case of man and the six-legged animals called insects. In many instances, man and insects have similar demands for food, water and nutrients from the biotic and abiotic ecosystem thus resulting into conflicts. Insect diversity and abundance have further exacerbated the situation. A case in point is the nutritional demand. Many monophagous and polyphagous insects are endowed with highly potent enzymes capable of efficiently extracting nutrients from crop plants, food items and livestock. Some of these enzymes are analogous to those in humans (Prosser 1973, Adedire, 1990a, b, 1994a). The kola nut weevil, Sophrorhinus insperatus Faust for example, has a wiele range of carbohydrases, lipases and proteinases that perform similar functions as those of the enzymes of human digestive tract (Adedire, 1990a, b, Adedire and Balogun, 1991, 1992, 1995) thus enabl ing them to extract their nutritional needs from kola nuts. 1.2 What are Insects? 1.2.1 The Taxonomic Position ofInsects: Among the invertebrates, insects are probably the most wrongfully identified and understood. This misconception arises from the fact that any invertebrate that bites or causes nuisance, jumps or crawls is often misconstrued to be an 4 insect; irrespective of whether they are mites, scorpions, centipedes or spiders. According to Ivbijaro (2003) insects have suffered a lot of condemnation and ill treatment from man who shares the same environment with them. However, to Zoologists, Entomologists or skilled eyes, insects actually belong to the Phylum Arthropoda (Stork, 1988). It is this same phylum that insects' cousins and relatives such as millipedes, centipedes, scorpions, mites and tick belong. Invertebrate species grouped together in the Phylum Arthropoda actually have some common characters; such as the possession of exoskeleton with chitin as its major constituent, a bilateral symmetry, a ventral nerve cord, a brain and jointed appendages modified for feeding. The word Arthropoda was coined from, two Greek words "Arthros" which means "joint" and "poda" which implies "legs" thus referring to the animals with "jointed legs" or "jointed appendages". Insects however differ from their close relatives with who they are often confused as virtually all insects (except some, such as fleas and lice) have well defined three body regions (tagmata): namely the head, thorax and abdomen (Figure 1). All mem bers of the Class Insecta (hexapoda) have three pairs of thoracic legs. The insect head bears a pair of antennae used for chemoreception (smell) or mechanoreception (tactile or hearing). The head also bears a pair of compound eyes called omatidia and some simple eyes called ocelli. The thorax bears two pairs of wings which may be modified, reduced or completely absent in some groups of species. The absence of wings among members of the Sub-Class Apterygota is a primitive characteristic whereas the absence of wings in pterygotes is a secondary character. Apart from members of the order Protura, Diplura,' Collembola and Thysanura which are primarily apterous, examples of modern day wingless insects are Termite (Macrotermes spp), ants (Oecophylla spp), Bed-bug iCimexspp) and lice (Pediculus spp). Insects are generally small-sized and their mouthparts are greatly modified for various types offeeding such as biting and chewing, piercing ancl sucking, lapping or sapping etc. They exhibit incomplete or complete metamorphosis while they use tracheal system for respiration. 5 aiofU:-ii.i/Hit-.a "'Q~i'~~i.. p'lt~e ""'~_ l.trAO .a.iJ:t:w..Mi __ 'C4lJIIj" '-._-- '''''-'«Q .....,•....... ,"OKAX l , "I ••. tk!lili( Ao.~)O<M a!!f"'4 ,...•. ~ih~lt4:. Figure 1: External Morphology of an adult insect species of its .genus-and.has about 4 billion individuals, insects constitute about three-quarters of the total described animal species (Figure 2). Thousands of insect species are believed yet to be described while the insect species already described exceeds the sum total of all other known animal species. Pyle et. al. (1981) reported that about one million insect species have been fully described and this number exceeds 70% of all described animal species (Figure 2). The hyperdiversity of arthropods, and by extension, the insects, is succinctly illustrated by Stork (1988) when he estimated that the number of arthropods to range between 10 and 80 million. In Nigeria, 22,090 animal species have been identified and insects account for 20,000 species or 90.54% (lvbijaro, 2003). The adaptive radiation of insects is quite remarkable when the number of described insect species is compared with other life forms (Table 1). Insects have great adaptability and have radiated into many terrestrial and aquatic habitats. They have an average density of24 million/ha in soil and 25,000 in air compared with human density ofO.14/ha on dry land. 6 Table]: Relative number of described species of Living Organisms. Group No. of described species Bacteria 5 x 10'" Insects 673,500 Plant and Algal species 3000,000 400,000 Other Animal phyla 228.500 Other Arthropods 136,500 Fungi 70,000 Viruses 2,000 ""'Of Pv1~ fth",OII',""I~ 611,000 '.500 Arth.opOd~ 810,000 "ioNUiCJ 70,000 Ann.lld. '.000 Figure 2: Relative sizes and number of animal species described for major phyla in the Animal kingdom 1.3 Beneficial relationships of insect with man The relationship between insects and man is not always adversorial. Many insects and their arthropod relatives exhibit relationships that are directly or indirectly beneficial to human beings, notable among which are: pollinators of crops and horticultural plants; some are thrash burners or scavengers thereby contributing to decay of organic matter and recycling of soil nutrients. Some insects and mites attack other insects thereby acting as biological control agents of injurious or pestiferous species. Insects are eaten as food and some of them produce useful products such as honey, silk and wax. Some insects and their products are useful in science and medicine. Insects have aesthetic value hence their importance in decorative art and culture. 7 1.3.1 Insect as human food It is estimated that over 1000 insect species belonging to about 370 genera are eaten all over the world; especially in Africa, Asia, Australia and Latin America (Defoliator, 1989; Gullan and Cranston, 2005; Van Huis, 2003). A list of some edible insect species is presented in Table 2. Some of these commonly consumed insects include grasshoppers, palm weevils, termites, crickets, locusts, moth larvae, rhinoceros beetles, Oryctes spp., bee brood etc. The act of eating insects or entomophagy is, not popular in Western Societies possibly for cultural considerations rather than any scientific or rational reasoning. This statement is true given the fact that crustaceans and molluscs are preferred culinary items in these societies. For about two decades, scientists and gourmet experts in the United States have made significant improvements in the preparation of food recipes from insects. In fact, fried grasshoppers, and grubs are now being promoted for cocktails, home use and during insect festiva Is. However, it is fairly well documented that generally insects are veritable sources of high dietary protein, energy, vitamins and minerals nutrients. In many parts of the world, an estimated 5-40% of human protein requirements are sourced from insects and are consumed in various forms. They may be eaten raw, roasted, dried (ir added to other foods or soups. Some insects are eaten during collection. A case in'point is termite: where both reproductives and the queen termite are eaten raw (Ajayi and Adedire,2007a). However