“ Bioactive natural merchandises frequently occur as a works of a household of related molecules so that it is possible to insulate a figure of homologous and obtain structure-activity information ” ( Raaman, 2006 ) . Plants are known to be a really rich beginning of bioactive organic chemicals and more than 400,000 secondary metabolites may be present in the works land ( Swain, 1977 ) . Natural merchandises, which frequently have an ecological function in modulating the interactions between workss, micro-organisms, insects and animate beings ( Hanson, 2003 ) can be defensive substances, antifeedants, attractants and pheromones.
Plutella Xylostella ( L. ) ( =P. manulipennis ( Curt ) )
Common name – Diamondback moth
Family – Yponomeutidae ( Plutellidae ) ( Chand, 1995 )
Hosts ( chief ) – Brassicae of all species
( Alternative ) – A broad scope of wild and cultivated Crucifereae ( Dennis, 1983 )
Diamondback moth is perchance of European beginning but has become instead widely distributed, and is now found all over the Americas and in Europe, Southern Asia, Australia, and New Zealand. It was foremost observed in North America in 1854, in Illinois which was dispersed rapidly. In North America, everyplace where chou is grown, diamondback moth is now recorded ( John, 2001 ) . Yadav et al. , ( 1983 ) concluded that 25-26°C was about appropriate for development of moth in his survey about the consequence of temperature on growing of Plutella Xylostella.
Life rhythm of Diamondback moth
Harmonizing to John ( 2001 ) , the entire development clip, which depends on conditions conditions ( run about 17-51 yearss ) , from the egg to pupal phase norms 25-30 yearss. Annually, there are 4-6 coevalss ( Harcourt, 1957 ) . As with most moths, the Diamondback moth is active largely at twilight and at dark for coupling and puting eggs ( Pluke et al. , 1999 ) .
Diamondback moth eggs are egg-shaped and flattened, and step 0.44 millimeter long and 0.26 millimeters broad. They are xanthous or pale green in colour, and are deposited individually or in little groups of 2-8 eggs in depression on the surface of the foliages, or sometime on other parts of the workss ( John, 2001 ) . Incubation takes about 3-8 yearss ( Dennis, 1983 ) .
Diamondback moth has four instars. Average and scope of growing clip for a larva is about 4.5 ( 3-7 ) , 4 ( 2-7 ) , 4 ( 2-8 ) , and 5 ( 2-10 ) yearss severally. Throughout their development, larvae stay rather little and active ( John, 2001 ) . The lepidopterous insect larva wriggle violently if disturbed and frequently drop off the foliage, staying suspended from it by a silk yarn ( Dennis, 1983 ) . During the first instars, the larvae are colorless, but thenceforth they become green ( John, 2001 ) .
Pupation occurs in a loose silk cocoon which is normally formed on the lower or outer foliages. The xanthous pupa is 7-9 millimeter long. The period of the cocoon norms about 8.5 yearss ( run 5-15 yearss ) , but during this clip the insect is in the pre-pupal instead than pupal phase ( John, 2001 ) .
The grownup is a little, slender, grey-brown moth with distinguishable aerial. It is about 6 millimeters long, and marked with a wide pick or light-brown set along the dorsum. Moths normally mate at twilight, instantly after coming out from the cocoon. Flight and oviposition take topographic point from twilight to midnight, and the grownups can be found feeding at flowers on nectar. Moth males and females live about 12 and 16 yearss severally, and female sedimentation eggs for approximately 10 yearss ( John, 2001 ) .
Hosts and distribution of Diamondback moth in Mauritius
In Mauritius, Dunhawoor and Abeeluck ( 1997 ) stated that the insect was foremost identified in 1945 and has now turned into one of the most destructive plagues. In Mauritius, about all the possible methods and pest control engineerings have been investigated to pull off this serious plague ( Facknath, 1997 ) . Until 1980, this plague was controlled efficaciously by man-made insect powders ( Seewooruthun et al. , 1984 ) .
Damaged caused by Diamondback moth
John ( 2001 ) reported that Crotalus adamanteus moth was long considered a comparatively undistinguished insect. During the larval phase, there is most harm caused. Though the larvae are really little, they can be legion ; therefore, ensuing in complete remotion of foliar tissue except for the foliage venas ( John, 2001 ) . The seedlings are peculiarly spoiled, which may upset caput formation in chou, Brassica oleracea italica, and Brassica oleracea botrytis. Harmonizing to Dennis ( 1983 ) , terrible onslaughts sometimes occur, peculiarly in hot dry conditions.
Control of Crotalus adamanteus moth
Head and Savinelli ( 2008 ) stated that the major job is that these plagues have developed opposition to many conventional insect powders. Parasitic WASP are known to be the natural enemies of Crotalus adamanteus moth larvae ( Cranshaw, 1998 ) . Get downing a plantation with DBM-free workss will supply the greatest income for a husbandman ( Pluke, 1999 ) .
At University of Mauritus
Pathogens ( Bacillus thuringiensis )
Intercropping and usage of trap harvests
Combinations of above
Botanicals and cultural
At Ministry of Agriculture
Man-made pesticides and growing regulators
Table 1: Research Strategies soon being explored for the control of Plutella Xylostella.
Plant species ( Pitaya )
About unknown 15 old ages ago, Acanthocereus tetragonus ( different spellings are used: Pitahaya, pitaya, pitajaya, pitajuia or pitalla ) nowadyas occupies a turning niche in Europe ‘s alien fruit market ( Mizrahi et al. , 1997 ) every bit good as in the domestic markets of manufacturer states, such as Vietnam ( N’Guyen, 1996 ) , Colombia ( Mizrahi et al. , 1997 ) , Mexico ( De Dios, 2004 ) , Costa Rica and Nicaragua ( Daubresse, 1999 ) . Presently, Acanthocereus tetragonus has merely a few species normally found on the market: xanthous pitayaha [ S. megalanthus ( Schum. ) Britt & A ; Rose ] and ruddy pitayaha ( Hylocereus spp. Britt & A ; Rose ) ( Fabrice et al. , 2006 ) . There are 16 species of Hylocereus whose cosmetic value is because of the beauty of their big flowers ( 15-25cm ) ( Fabrice et al. , 2006 ) . Most Hylocereus species originate chiefly from Latin America ( likely from Mexico and Colombia ) , with others perchance from the West Indies ( Britton and Rose, 1963 ) . Hylocereus assortments can accommodate to different types of well-drained dirt ( Barbeau, 1990 ) .
Pitaya works worldwide
Pitaya is known to be the one of the most beautiful and widespread members of the household Cactacea ( Julia, 1987 ) . It is normally cultivated and naturalized throughout tropical American Lowlandss, the West Indies, the Bahamas, Bermuda, southern Florida and the Torrid Zones of the Old World.
The works is a mounting cactus known as ‘cactus torue ‘ and ‘raquette tortue ‘ ( MSIRI, 2006 ) in Mauritius which is widespread as a Hylocereus undatus ringer ( Govinden, 2007 ) .Pitaya grows wild in dry zone ( MSIRI, 2006 ) . During the Gallic colonisation, it has been introduced in Mauritius to feed elephantine land tortoises ( Govinden, 2007 ) . As the ringer Hylocereus undatus do non bring forth fruits usually, it must be crossed pollinated with a genetically- different ringer set of fruits ( MSIRI, 2006 ) . Now, subhumid zone is found to be appropriate for cultivation of Pitaya ( MSIRI, 2006 ) . Pitaya can be grown on all dirt types from sand to heavy clays ( Govinden, 2006 ) . This works does non necessitate any pest control apart from snails during the first twelvemonth and it produces its first fruit within a twelvemonth of plantation ( Govinden, 2006 ) .
Hylocereus undatus is a mounting works which does non hold foliages as other cacti ( Govinden, 2007 ) . The function of the foliages is given by the triangular-shaped, segmented and green succulent stems ( Govinden, 2007 ) . Pitayas have easy little detached spinal columns ( Pimienta-Barrtos and Nobel, 1994 ) , subdivisions, flowers and fruits ( Govinden, 2007 ) . The works has areoles spaced at 3 to 4 centimeters and each areole has 2 or 3 spinal columns in it ( Govinden, 2007 ) . They have magnificient white flowers that are dark blooming and really fragrant ( Morton, 1987 ) which are 29 centimeters long ( Fabrice et al. , 2006 ) . The fruit is non-spiny ( Morton, 1987 ) and is about 15-22 centimeter long ( Fabrice, 2006 ) . They are a ruddy fruit with comestible white flesh and bantam black seeds ( Govinden, 2007 ) .
Metabolites in workss
Plants synthesise a huge scope of organic compounds that are normally classified as primary and secondary metabolites although the precise bounds between the two groups can in some cases be slightly bleary ( Alan and Hiroshi, 2006 ) . Plants have many natural enemies, therefore they have to germinate mechanism to protect them.
Primary metabolites are compounds that have of import functions associated with photosynthesis, respiration, and growing and development ( Alan and Hiroshi, 2006 ) which are present throughout the life rhythm. They are simple compounds with direct connexions to the metabolic tract of the micro-organisms ( Schugerl, 1994 ) . Consequently, close relationships exist between growing rate and their production rate ( Schugerl, 1994 ) . Most primary metabolites exert their biological consequence inside the cell or being that is responsible for their production ( Hanson, 2003 ) .
Based on their biogenesis beginnings, works secondary metabolites can be divided into three chief groups: ( I ) flavonoids and allied phenoplast and polyphenolic compounds, ( two ) terpenoids and ( three ) nitrogen-containing alkaloids and sulphur-containing compounds ( Alan and Hiroshi, 2006 ) . In most workss, synthesis and accretion of secondary metabolites is controlled in infinite and clip ( Wink, 2010 ) . Secondary metabolites are complex metabolites ( Schugerl, 1994 ) .the terminal merchandises play no obvious function in the economic system of the being. Specific secondary metabolites may pull insects to peculiar workss in order to put their eggs ( Hanson, 2003 ) . The biogenesis of Secondary metabolites has no direct connexion to the cell metamorphosis ( Schugerl, 1994 ) . Other function of the secondary metabolites is to move as defense mechanism such as pigmentation or support.
Role of secondary metabolites
Whatever the initial ground for their development, secondary metabolites are now an indispensable portion of the armamentaria used by workss in the conflict to last and propagate, to the extent where the outgo of energy, photosynthate and foods for their production can be ‘cost effectual ‘ for that ( Chadwick, 1992 ) ) .
-Seed-dispersing animate beings
-root nodule bacteris
-Growth of seedlings
defense mechanism compounds
Figure 1: Ecological and physiological maps of works secondary metabolites ( Wink, 2010 )
Substances in workss which affect insect behaviour
Brian ( 1977 ) stated that during all phases of their life-cycles, workss are exposed to many potentially parasitic microorganisms. The thought that workss produce defensive chemical substances after infection was expressed by a figure of research workers in the first half of this century, but the construct was formalized by Muller and Borger ( 1941 ) ( Brian, 1977 ) . Alkaloids, sequiterpenes, flavonoids, limonoids, phenols, coumarins and stilbenes of works beginning possess toxic, antifeedant, and growing modulating effects against a broad scope of insect plague ( Hassanali and Lwande, 1989 ) . Highly luxuriant chemical defense mechanisms have been eveolved by workss against onslaught and these have provided a rich beginning of biologically actuve compounds which may be used as fresh crop-protecting agents ( Chadwick and A?hulA?phA?n, 1990 ) .
Antifeedants, known as the defence substances of higher workss against insects, protect the workss against plagues. Insect antifeedants have been studied as a portion of our attempts to support our harvests against pest insects ( Kenji, 2010 ) .
A dominant function is played by attractant in many critical facets of insect behaviour ( Jacobson, 1965 ) . The activity of insects in seeking nutrient, the opposite sex, or a topographic point to put their eggs are governed by attractants.
In add-on to the attractive olfactory properties, workss besides produce volatile chemicals that function as repellants ( from a distance ) or feeding inhibitors ( at near scope ) which form portion of the works defence mechanism against insect onslaught ( Hill, 2008 ) . Repellents are known to hold enormous practical importance ( Garson and Winkie, 1968 ) . Terpenes, tannic acids and assorted alkaloids are seemed to be the major chemical repellants in workss ( Hill, 2008 ) . Insect repellants are considered to be insect powders in a wide sense ( Troy, 2006 ) . The works must hold the ability to bring forth an adaptative balance in which it accumulates adequate pepellents to support itself but non plenty to poison itself ( Whittaker, 1971 ) .
Sondheimer and Simeone ( 1970 ) have stated that late, great potency for insect control has been shown by insect endocrines. The happening of insect sheding endocrines provide a absorbing penetration into the manner workss may be evolved in order to protect themselves from insect predation ( Hardorne, 1998 ) .recording have been made for works parallels of insect sheding endocrines in workss and it has a broad distribution. These substances may do asepsis and decease, as they have the ability to upset normal metabolism.
Defence mechanisms of works against insect plagues
Plants have developed over clip a figure of tactics that allow them to defy onslaught that are being attacked by insects. One or more of several different sorts of opposition mechanisms can do opposition to animal plagues ( Painter, 1951 ) . Separation, purification and designation of many different components present in workss need to be done by different methods ( Harborne, 1988 ) .
Extraction is a method whereby the coveted components of works are removed utilizing a dissolver. Organically soluble compounds are extracted with dissolvers ( Raaman, 2006 ) . There are several methods used for fixing infusions, including organic dissolver extraction, supercritical gas extraction and steam distillment ( Raaman, 2006 ) .
Organic dissolver extraction
Organic dissolver extraction is one procedure of dividing coveted substances from works stuff. Both fresh works and dried workss can be used for extraction ( Harborne, 1988 ) . In this method, the workss are first crushed and so carefully assorted with a dissolver such as hexane, benzine, methyl alcohol or ethanol inside a closed container. Raaman ( 2006 ) stated that the choice of solvent depends on several factors every bit good as the features of the components being extracted, cost and environment issues. The success of the extraction with intoxicant is straight related to the sum chlorophyll is removed into dissolver ( Raaman, 2006 ) . The infusion obtained is clarified by filtration, which is concentrated in vacuo in rotary evaporator ( Raaman, 2006 ) . Fungal growing is prevented by add-on of a hint of methylbenzene to the concentrated infusions and they are stored in icebox. As the dissolver is dissolved in the coveted substances of the works, it is called “ miscella ” . It is so separated from the works stuff. There are a figure of techniques for solvent extraction, which consist of maceration, infiltration and countercurrent extraction ( Raaman, 2006 ) .
This technique involves soaking and fomenting the dissolver and works stuff together ( Raaman, 2006 ) . The dissolver is so drained off ( Ramaan, 2006 ) . Staying miscella is removed from the works stuff through pressure ( Ramaan, 2006 ) .
Biochemically active natural groups
Tannins are divided into two groups: hydrosable and condensed tannic acids. Hydrosable tannic acids are acerb which have the ability to tan fell. Condensed tannic acids are related to flavonoids as they are polymers of phenolic compounds.
Heterosides are organic compounds found in workss. They make up the active constituents of many workss.
Terpenoids are by and large lipid-soluble which are located in the cytol of the works cell ( Harborne, 1998 ) . They are the largest group of secondary compounds ( Schoonhoven et al. , 2005 ) . They are of importance in works growing, metamorphosis or ecology.
Steroid is a group formed from triterpenoids which occur chiefly as glycosides.
Anthraquinones are known to be the largest group of of course happening quinine substances. They are used as laxative.
Alkaloids include the largest individual category of secondary works metabolites. The maps of alkaloids in workss are still mostly obscure, although single substances have been reported as growing regulators or as insect repellants or attractants ( Harborne, 1998 ) . Most alkaloids are physiologically active compounds holding a scope of toxic effects on animate beings ( Margaret and Michael, 1998 ) . Nicotine is a really several illustration of the authority of the insecticidal behaviour of alkaloids and was used extensively until its neurotoxic effects non merely on insects but besides on human, bird and mammals were discovered ( Regnault-Rogen and Philogene, 2008 ) . Many alkaloids have neuroactive belongingss and work together with the receptors at nervus terminations ( Hanson, 2003 ) . Alkaloids are thought to play a defensive function in the works against herbivores and pathogens as secondary metabolites ( Crozier and Ashihara, 2006 ) . They are known to barricade the ion channel, decelerate down enzymes or interfere neurotransmission. Alkaloids can besides bring forth hallucinations, failure of coordination, paroxysms and decease.
The flavonoids are all structurally derived from the parent compound flavones ( Harborne, 1998 ) . Flavonoids, which are by and large water-soluble compounds, can be extracted with 70 % ethyl alcohol. Flavonoids are phenolic and hence modify in colour when treated with base or with ammonium hydroxide ( Harborne, 1998 ) . They are at that place in all vascular workss. Flavonols appear to be important in modulating control of growing in the pea works ( Galston, 1969 ) and their inauspicious effects on insect eating ( Isman and Duffey, 1981 ) have indicated that they may be natural opposition factors.
Coumarin is an aromatic which work as pesticides in workss. These workss have ataractic belongingss and they besides increase the opposition of capillary walls.
Phenols are a broad assortment of secondary compounds that include glycosides, tannic acids, coumarins, quinines and flavonoids ( Facknath and Lalljee, 2000 ) . Phenolic merely tastes atrocious which block enzyme activity, slows growing and interfere with digestion.
Saponins are glycosides of both triterpenes and steroid alcohols which have been detected in over 70 households of workss ( Hostettmann and Marston, 1995 ) . They are known to be widely distributed in the works land ( Hostettmann and Marston, 1995. Saponins have frothing features.
MATERIALS AND METHODS
For this undertaking, the morphogenetic effects of Hylocereus undatus ( Pitaya ) were studied on the insect plagues DBM. The biological procedure that causes the insects ‘ being to develop its form, where cell growing and distinction is controlled, is known as the morphogentic consequence. Together with proving if Pitaya has bioactive compounds that can be used to command DBM, two other activities were undertaken: the raising of DBM larvae which was carried out at in the research lab and the growth of chou.
Round underside flask, mensurating cylinders, petri dishes, beakers, funnel, filter paper ( Whatmann, 18.5 centimeter diameter, pore size 42 ) , aluminum foil, trial tubings, conelike flask.
Solvents used: Methanol, ethyl alcohol, methylene chloride, hexane. These dissolvers were used for extraction of metabolites.
Sulphuric acid was used for rinsing glassworks, unit of ammunition underside flask, beakers and trial tubings.
Rotary evaporator was used to concentrate the infusions.
Trial insect: Diamondback moth
Diamondback moth, besides known as Plutella xylostella, was used as insect trial for this undertaking.
Categorization of Crotalus adamanteus moth
Kingdom: Animalia ( Animals )
Phylum: Arthropoda ( Arthropods )
Class: Insecta ( Insects )
Order: Lepidoptera ( Butterflies and Moths )
No Taxon: ( Moths )
Speciess: xylostella ( Diamondback moth )
Plutella xylostella ( Linnaeus ) ( Lepidoptera: Yponomuetidae ) normally called Diamondback moth ( DBM ) is believed to hold originated in the Mediterranean country, where most of the cruciferous harvest workss have originated ( Mukerji, 2004 ) .
Test being: Hyloceureus Undatus
The trial stuff whose pesticidal belongingss were evaluated is Hylocereus Undatus.
Categorization of Hylocerus Undatus
Hulocereus undatus was collected at Barkly Experiment Station. Immediately after aggregation, the specimen was brought in the research lab where it was watered n kept at room temperature.
Rearing of Crotalus adamanteus moth
Larvae Plutella xylostella were captured from chou workss and brought to research lab to be reared under conditions at room temperature in wooden coops ( 75 x 50 ten 50 centimeter ) covered with all right nylon mesh. The lepidopterous insect larvae were fed on clean foliages of chou. The grownups were fed on 5 % honey solution which was soaked in a cotton swab and untreated chou foliages were placed in little bottles filled with H2O in the coop for oviposition.
The eggs that were laid were transferred to another coop to let it to hatch into larva and provender on untreated foliages. After pupation of the larvae, they were transferred together with their foliages on moist filter paper and were allowed to emerge into grownups. Consequently, the grownups were breed to increase population.
Turning of chou
Categorization of chou
Species: Oleracea ( volt-ampere. capitata )
Common Name: chou
Cultivation of chou
Limit of land
( 10 x 10 m )
Planting distance was done and holes were dug
Holes were filled with manure and so convered with a bed of dirt
Seedlings were transplanted and watered
Seedlings were covered by seting subdivisions with foliages next to them to function as shading
After month, top dressing was carried out
Figure 2: Cultivation process
Method of extraction
Maceration is the procedure of pull outing metabolites with the dissolver with several yearss agitating or stirring at room temperature. Ideally, fresh works tissues should be used for phytochemical analysis ( Harborne, 1988 ) . Solvent chosen depends upon the features of the secondary metabolites in the works. Boiling ethyl alcohol is a good general-purpose dissolver for preliminary extraction ( Harborne, 1988 ) .
After add-on of each fresh dissolver, the mixture should be allowed to macerate nightlong. The dissolver is filtered and concentrated by a rotary evaporator. Anhydrous Mg sulfate is added to the filtrate to take the H2O added in it.
Method of separation
Hylocereus Undatus ( crushed )
Extraction with MEOH ( 70 % ) for 3 yearss
Extraction with ethyl alcohol ( 70 % ) overnight
Extraction with DCM ( 80 % ) overnight
Extraction with hexane ( 80 % ) overnight
Filtrate is concentrated separately in rotary evaporator
Figure 3: Extraction and portioning process
Phytochemical showing of the infusions
Trial for Tannins
50 milligram of infusion was dissolved in 5 milliliter of intoxicant and few fragments of Mg pulverization and concentrated Hydrochloric acid ( drop wise ) were added. The presence of tannic acids is revealed by the formation of any pink to blush coloring material.
Trial for Heterosides
10 cm3 of 50 % sulfuric acid was added to 1 cm3 of the infusion in a trial tubing. The mixture was heated in a boiling tubing H2O bath for 15minutes. 10 cm3 of Fehling ‘s solution was added and the mixture was boiled and observed for a brick ruddy precipitate.
Trial for Terpenoids
2ml of trichloromethane was added to the infusion followed by 3ml of concentrated sulfuric acid to organize a bed. A ruddy brown color is indicated as positive.
Trial for Steroids
3 beads of acetic anhydride and 1 bead of concentrated sulfuric acid were added to 1ml of infusion. The presence of steroids was detected by a color alteration from deep green turning to brown/dark brown.
Trial for Antraquinones
4 milliliter of hexane was shaken with 2 milliliters of infusion. The upper lipotropic bed was seperated and treated ith 4 milliliter of diluted ammonium hydroxide. The presence of anthraquinones is indicated by a color alteration of violet to tap in the lower bed.
Trial for Alkaloids
50 milligram of infusion was stirred in a few milliliter of dilute Hcl acid and so filtered. The filtrate was tested with Mayer ‘s trial and Wagner ‘s trial.
Wagner ‘s testA : A few beads of Wagner ‘s Reagent were added by the side of the trial tubing to a few milliliter of filtrate. The presence of alkaloids was confirmed by a red-brown coloring material.
Wagner ‘s reagent- 1.27 g of Iodine and 2.0 g of K iodide were dissolved in 5 milliliter of H2O and made up to 100 milliliter with distilled H2O.
Mayer ‘s testA : A bead or two of Mayer ‘s reagent was added to a few milliliter of filtrate. The trial is indicated as positive by a white/creamy precipitate.
Mayer ‘s reagent- 1.358 g of mercurous acid was dissolved in 60 milliliter of H2O and 5.0 g of K iodided was dissolved in 10 milliliter of H2O. The two solution were assorted and made up to 100 milliliters with H2O.
Trial for Flavoinods
2 milliliter of concentrated HCL and 0.2 g of Mg pulverization were added to 2 milliliter of infusion. The trial is indicated as positive by a color alteration to red/red-orange.
Trial for Coumarins
Some concetrated ammonium hydroxide is added to the infusion. A vilification of solution is placed on a microscope slide and viewed under long moving ridge ( 366nm ) UV visible radiation. The presence of coumarins is indicated by a green fluorescence.
Trial for Phenols
A few beads of Fe ( III ) chloride were added to 1 milliliter of the etxract. The presence of phenolic compound was confirmed by a chocolate-brown color.
Trial for Saponins
50 milligram of infusion was diluted with distilled H2O and made up to 20 milliliter. The suspension was shaken in a calibrated cylinder for 15 proceedingss. The presence of saponins was indicated by a two centimeter bed of froth.
HCL + magenisum pulverization
Fehling ‘s solution
Mayer ‘s trial
Mayer ‘s reagent
Wagner ‘s trial
Wagner ‘s reagent
Iron ( III ) chloride
Consequences of chemical trials on infusions of Hylocereus Undatus.
-A : indicates negative trial
+ : indicates hint of trial
++ : indicates positive trial