Abstract:
An insecticidal composition comprising at least one attractant (0.05 to 95% w/w), at least one insecticide (0.05 to 1% w/w) and at least one stabilizer (0.1 to 5% w/w). The insecticidal composition may be used together with a suitable carrier to efficiently control flying insects. The viscous composition after being placed within a suitable carrier interacts with naturally occurring humidity whereby the outer layer of the composition loses its viscosity, diffuses downwards and occupies the entire area of the trap or suitable carrier, thereby releasing a small amount of composition. Control of flying insects using the composition together with a suitable carrier is comparable to spraying. Only small amounts of insecticide are needed which are released slowly by the composition.

Description:
FIELD OF THE INVENTION  
         [0001]    This invention relates to insecticidal compositions useful for combating flying insects.  
         BACKGROUND OF THE INVENTION  
         [0002]    Conventional control of all flying pests, and insecticides in particular, is usually done by chemical control of the pests. Since the beginning of the 20 th  century a few generations of chemicals for combating insects were used, for example, inorganic (lead arsenate, sodium fluorosilicate), chlorine-organic (DDT) and organophosphorous. New effective and environmentally safe, as well as new formulations for better compatibility insecticides, are constantly being developed. The commercial formulation may include, in addition to the active insecticide and stabilizers, also some kind of bait. The bait is either in the form of food, sex phagostimulant, attractants, or their combination. Despite the progress in new compounds and compositions, the mode of delivering the active material has remained much the same over time. The prevailing method for delivering the insecticides, despite its drawback, is by spraying the area with the most effective formulation. The apparent disadvantage of spraying is that it may be unsafe to the person carrying the spraying apparatus or to people in the vicinity of a sprayed area. Furthermore, spraying itself has a short-term non-specific effect, therefore, repeating cycles of spraying is needed. These repeated cycles, although overall provide satisfactory results, cause the use of large amounts of insecticides, of which only a small part is really effective (1-3%). Part of the hazardous nature of pesticides in general emerges from this ineffective route for their application. Another problem associated with their use stems from the fact that the entire vegetation, i.e. the fruit, vegetable, branches and leaves, and its vicinity (ground, and air) is coated with the active insecticide, as well as the draft. Thus, although it is well understood that an alternative route should be used, no other better route has been found to be as effective as spraying.  
           [0003]    Biological control of insects consists of either the use of natural pesticide, predators or genetic techniques such as the release of sterile fly males and/or females, counting on the fact that mating with the existing flies will lead to no progeny, and will thus ultimately decrease the insect population. Where the former approach may give good results subject to the known drawbacks of spraying (James R. Carey in California Agriculture, January-February 1992, pp. 13-17), the latter, is subject to technological and financial problems, and its success is problematic for many species (James R. Carey in California Agriculture, January-February 1992, pp. 13-17).  
           [0004]    Traps are another alternative approach to spraying. Means for attracting the flies to the traps consist of color, shape and attractants. The classical attractants are food or sex attractants. Color may also be an attractant as disclosed in IL 103,629 where a yellow panel, and a red sphere were found to be effective for attracting flies. After being attracted, the flies are eliminated either by physically being trapped within the trap, or by initially covering the trap&#39;s panel with glue, thus the attracted flies are stuck after their approach.  
           [0005]    These two approaches are associated with drawbacks. In the case of physically trapping the insects, the insects are indeed attracted to the near vicinity of the trap, however, very frequently do not find their way into the trap. If the entrance is made easy enough for the approaching insects then their way out is also facilitated. In case the flies are stuck in the glue, the efficiency is greatly reduced due to the fact that the glue is very non-selective. Thus dust, leaves and other non-target insects adhere to the trap in addition to the desired flies.  
           [0006]    Alternatively, the trap may be covered with a poisonous material and the insects are exterminated as a result of contact or consumption of an insecticide. U.S. Pat. No. 5,359,808 discloses such a trap consisting of a bag soaked prior to its use with insecticide where the approaching flying insects are exterminated upon contact with the bag. The attractants are immersed in water, the water serving as a source of humidity thereby being themselves an additional attractant. The use of such a trap is restricted to hot periods. Furthermore, the humidity has to be replenished in order to stay effective for long periods. Thus, to date, traps were found to be ineffective in large areas of vegetation, and their use is preferred in small confined areas.  
         SUMMARY OF THE INVENTION  
         [0007]    The present invention is based on the findings that a novel composition may be used for combating flying insects. The novel composition includes stabilizers, in addition to the effective insecticide and attractant. Thus, the present invention provides a novel insecticidal composition for controlling flying insects wherein the composition comprises of  
           [0008]    (i) 0.00002 to 95% (w/w) of at least one attractant  
           [0009]    (ii) 0.001 to 30% (w/w) of at least one insecticide; and  
           [0010]    (iii) 0.01 to 10% (w/w) of at least one stabilizer, wherein the at least one stabilizer expand s upon exposure with humidity;  
           [0011]    and said composition is released by diffusion upon contact with humidity.  
           [0012]    The at least one attractant is chosen from the group comprising of proteins, carbohydrates, feed stimulants, ammonia releasing source, pheromones, kairamones or mixtures thereof. Such a composition may also be used in association with alternative routes to conventional spraying. The results of using the novel composition of the present invention in such alternative routes, as measured by the percentage of infected fruit by insects, are compatible to those of spraying, where the overall quantity of the insecticides used by the present composition is much lower.  
           [0013]    Thus the present invention further provides an effective and environmentally safe route for combating flying insects. This is achieved by using the insecticidal composition in association with a suitable carrier. A suitable carrier may be any conventional carrier such as traps or posts, situated at appropriate distances within the vegetation, preferably the trap disclosed in IL patent application No. 129,634 (hereinafter “Nimrod Eliminator”). The environmental impact of the insecticide used is minimal if present at an since the overall amount of the at least one insecticide is very low. Upon interaction of the novel composition with humidity, the composition is slowly released from its storage and becomes available for action. The humidity may be either naturally occurring humidity or artificially obtained by irrigation. Release of the composition is temperature independent and the composition may be used at all seasons. The attracted insects are poisoned by swallowing, digesting said composition or by the mere contact with the composition.  
           [0014]    The invention still further provides an efficient and environmentally safe route for combating flying insects. This is achieved by spraying the insecticidal composition as baits, where its freshness, hence its ability to attract insects, is replenished with each renewed contact with humidity.  
         DETAILED DESCRIPTION OF THE INVENTION  
         [0015]    As stated above, the present invention deals with a novel insecticidal composition. The composition is a slow release composition and is formulated in a manner, which enables its use, bot in association with traps or a suitable carrier or by spraying as baits. The insecticidal composition may be used efficiently against Tephritidae and with some suitable modifications, against many other flying insects such as Cicadoidea, Aphidoidea, Diptera,  Cacopsylla bidens, Empoasca lybica, Edwardsina rosae , and  Lyonetia clerkella . The insecticidal composition of the present invention contains in addition to the active insecticide at least one attractant for attracting flies to the composition and at least one stabilizer which may interact with humidity. Agricultural-wise, the most destructive single pest is the Mediterranean fruit fly ( Ceratitis capitata ). A specific insecticidal composition may be formulated such that it will best attract these flies. However, minor modifications in several of its constituents may be made in order to direct the composition against other families of insects. In particular with regards to the Mediterranean fruit fly, it was found that the female, prior to oviposition must consume carbohydrates and proteins in order to lay her eggs. Thus these nutrients in addition to serving as essential food source may also serve as attractants to a certain extent. In addition to the essential nutrient composition, the insecticidal composition includes an attractant, preferably some source of ammonia known to attract insects. The attractant may also further include a pheromone, kairamone or some other attractant for the kind of insect that has to be exterminated or a combination thereof. Such an insecticidal composition was found to give very effective control of the Mediterranean fruit fly without effecting other beneficial insects such as bees. The attractant(s) and insecticide(s) in order to form the desired slow-release insecticidal composition are mixed together with a suitable stabilizer that may interact with humidity. The resulting composition is a viscous composition, which in one option according to the present invention may be placed inside a pocket of a suitable trap or any other convenient carrier capable of conducting the same action. Upon an interaction between the viscous composition placed in the suitable carrier, and naturally occurring humidity, the outer layer of the composition looses its viscosity and begins to diffuse out of the pocket. As the loss in viscosity occurs only at the interface, at each contact with external humidity only a small amount of the composition is released. The prerequisite of such a stabilizer is that the composition would not diffuse under warm conditions, only upon an interaction with humidity. Furthermore, the loss of viscosity at the interface is moderate, and the resulting diffusion is slow. The released composition slowly diffuses out of the pocket and spreads over the entire area of the trap or the carrier as a result of gravity and capillarity. Thus contrary to numerous slow-release compositions, the slow-release of present composition is temperature independent. Furthermore, the attracting composition is spread all over trap or the suitable carrier creating a large attracting area much bigger than the one created by the attractant released from a capsule. Any suitable stabilizer, which suits the prerequisites, as outlined above, may be used. Thus, any stabilizer that can expand upon contact with the environmental humidity under normal conditions may be used. Typically, this includes any naturally occurring polymer or an inorganic polymer capable of expanding upon contact with humidity, such as polysiloxanes, polyethers, cellulose derivative, gelatin, tectin or mixtures thereof. Naturally occurring humidity like rain or dew is sufficient for activating the composition and for inducing the release of the insecticidal composition, although artificial humidity from irrigation or even directed irrigation aimed at activating the composition may also be used. Such artificial irrigation is preferable in cases where the environment is especially dry. It should be understood that excessive amounts of humidity (strong rain or outstanding quantities of dew) might result in an enhanced release of the composition, which may eventually lead to occasional dripping. Such dripping is confined to the small area below the appropriate carrier and may be beneficial for providing a fresh quantity of the insecticidal composition.  
           [0016]    It should be noted that the composition might also be in dry form such as tablets or powder. Upon each contact of the outer layer of the composition with humidity the outer layer dissolves and begins to diffuse out and spread on the entire surface of the carrier by gravity or capillarity.  
           [0017]    It should further be noted that depending on the environmental circumstances, and also in case a more precise control of the release profile is desired, an additional type of stabilizer may be added. In such cases a stabilizer capable of solidifying the composition upon contact with humidity may be added. Thus the composition may further comprise humidity coagulating factors and/or solidifying factors in order to control the viscosity of the composition when in contact with the environmental humidity. A predetermined selection of the relative amounts of each stabilizer, coagulating and expanding, enables to direct the release of the composition at predetermined periods. For example, in case only an expanding stabilizer is added, then only in periods of humidity (during the night, rain or irrigation), the composition will begin loosing its viscosity at the interface. In case only a coagulating stabilizer is added, the presence of humidity will lead to further solidification of the composition. Thus these two negating stabilizers may be added at various relative concentrations to yield a composition that would be released at the desired periods.  
           [0018]    The present composition is an efficient alternative to spraying the entire vegetation and poisoning the fruit, vegetable, branches and leaves. Spaciously situated traps or suitable carriers of the composition of the present invention are placed in the area to be protected. Each such carrier is mounted with a suitable amount of the composition. Typically from about 15 to about 30 traps per 1000 m 2  are used, and the trap should be reloaded once in about 2 to 4 months.  
           [0019]    An alternative route for application of the insecticidal composition of the present invention is by spraying as baits. The sprayed bait particles may be sprayed humid or may be sprayed dry and activated by contact with natural or artificial humidity. Consecutive contact with humidity regains freshness and “reactivates” the composition. Thus the composition is effective for longer periods of time and there is no restriction to the time of its application, since it may always be reactivated.  
           [0020]    The use of the composition of the present invention in connection with its mode of action and the suitable stabilizer(s) is not limited to certain periods of the year and may be used all year long. The attracted insects are exterminated by either digesting or coming into contact with the lethal composition on the trap or the suitable carrier, however, the trap or the carrier themselves stay clean for the next flock of insects and the next portion of diffusing composition. The combination of the viscous composition or the dry formulation and the humidity is the key for keeping a constant concentration of an effective amount of available insecticidal composition at the entire area of the trap or the suitable carrier. Continuous contact with naturally or artificially applied humidity replenishes the trap or carrier with fresh active insecticidal composition released from the pocket or carrier. In contrast to previous insecticidal compositions used in association with traps, the present insecticidal composition is stabilized and not effected by heat.  
           [0021]    The insecticidal composition of the present invention may typically have the following ratio between its various components (w/w): 30 to 70% carbohydrate; 20 to 60% protein source; 0.001 to 30% insecticide; 0.00002 to 40% of a chemical attractant (depending on the nature of the attractant) and 0.01 to 10% stabilizer. A typical composition is given in Example 1. 
       
    
    
     EXAMPLE 1  
       [0022]    13 Kg of a carbohydrate source (64.5%), 6 Kg of a Buminal™ (protein hydrolisate) (30%), 20 ml of Tracer™ (Spinosad) (0.1%), 0.94 Kg Borax (4.67%) and 0.17 Kg Sodium salt of carboxy-methylcellulose (0.84%) were mixed together to give an insecticidal composition. An amount of between about 30 to about 150 g of the composition is placed in each pocket of the “Nimrod Eliminator”.  
         [0023]    In a similar manner to Example 1, the following insecticidal compositions are formulated where the amount of the carbohydrate, Buminal™ and Borax are practically the same.  
                                                     Example No.   Insecticide   Concentration                                2   Dimethoate   0.2%       3   Malathion   0.2%       4   Cryocide 1       2%       5   Azadirachtin     1%       6   Byfitos 2       3%       7   SureDay   4% (phloxine); 3% (uranine)       8   Fenthion   0.1%       9   Lufenuron     5000 ppm       10   Triflumuron   10,000 ppm       11   Borax 3       5%                                          
 
         [0024]    It should be noted that pheromones in an amount of 0.00001% to 0.03% may be added to the insecticidal composition as additional attractants.  
         [0025]    The overall amount of insecticide used with a composition of the present invention when applied in association with the “Nimrod Eliminator” compared with the amounts used in conventional spraying methods is shown in Table I. The displayed quantities arising from the use of the present insecticidal composition are displayed in bold and represent use of 0.30 traps in 1000 m 2 . The comparative compositions of prior art describe normal quantities used in aerial and ground sprays.  
                                                             TABLE I                                   Amount                       Concen-   per       Overall               tration   1000 m 2     Number of   amount       Plantation   Insecticide   (%)   (Kg/l)   Sprays   (Kg/l)                                Apple     1 ROGOR ™   0.1   0.2   16   3.2       Apple   ROGOR ™   0.1           0.0045           (Nimrod           Eliminator)       Nectarine   ROGOR ™   0.1   0.2   10   2.0       Nectarine   ROGOR ™   0.1           0.0045           (Nimrod           Eliminator)       Apricot   ROGOR ™   0.1   0.2    5   1.0       Apricot   ROGOR ™   0.1           0.0045           (Nimrod           Eliminator)       Apple   Malathion   5   0.15-0.2   24   3.6-6.0 2             (25 A.R.)       Apple   Malathion   95   0.025   16   0.4           (Technical)       Apple   Malathion   5           0.2 2             (25 A.R.)           (Nimrod           Eliminator)       Apple     3 TRACER ™   0.02   0.04   16   0.64       Apple   TRACER ™   0.2           0.006           (Nimrod           Eliminator)                                          
 
         [0026]    The overall amount of the insecticide used with the composition placed in the traps for ROGOR™ (Dimethoate) and TRACER™ (Spinosad) is between about 220 to about 710 times less than the amount used by the conventional spray methods. In addition to the use of a significant smaller amount of insecticide, the insecticide is not sprayed on the entire vegetation (locus, leaves, fruit etc.) and contamination of the ground including draft and air are avoided. Thus, the ecological advantage of using the insecticidal composition in association with the “Nimrod Eliminator” is clearly demonstrated. Furthermore, the use of the composition has an economical benefit, Aerial spraying is expensive both with regards to the quantities of insecticidal used and from the nature of their action. Ground spraying cause damage to a certain extent to die crops.  
         [0027]    The effectiveness of the compositions used together with the “Nimrod Eliminator” in combating Mediterranean fruit fly compared to conventional cover and bait spraying are shown in Tables II and III. Table II displays results done over a period of four years (1997-2000) at a certain location (Kibbutz Tzuba at the Judean Hills).  
                                   TABLE II                                   %   %                       Damage in   Damage in                   Nimrod   sprayed     4 Max.                   Eliminator   plots   fly       Year   Crop   Varieties   (1000 m 2 )   (1000 m 2 )   catches                   1997   Apple   Muli-Delicious   1-2 (1)   5-15 (19)   28               Gala   0 (1)   0 (9)               Golden-Delicious   0 (1.5)   0.5 (20)               Red-Delicious   0 (1)   0 (14)               Orliance   0 (0.5)   0 (4)       1998   Apple   Muli-Delicious   0.3 (1)   5-15 (19)   35               Gala   0 (3)   0 (9)               Golden-Delicious   0 (4.6)   5-50 (50)               Red-Delicious   0 (5)   0 (14)               Orliance   0 (1)   0 (4)           Nectarine   Flamekissed   0 (10)   0 (10)   50       1999   Apple   Muli-Delicious   0.3 (1)   5-15 (19)   1               Gala   0 (3)   0 (9)   53               Golden-Delicious   0 (4.6)   0.5-1 (50)               Red-Delicious   0 (5)   0 (14)               Orliance   0 (1)   0 (4)           Apple   Golden-Delicious   5-20 (21)   1 (8)   70           Nectarine   Flamekissed   0 (3)   0 (10)   55           Pear   Gentil   0 (0.25)   0 (0.2)   20               Spadochini   0 (2)   0 (1.3)   4               Costia   0 (1.4)   0 (1.4)               Spadona   0 (8.5)   0 (7.5)           Sweet-   7 varieties   0-2 (7)     2 —   88           Cheery 1                 5       2000   Apple   Muli-Delicious   1 (1)   —   46  3 N.E.                           — S               Gala   2 (3)   2 (9)   45  3 N.E.                           1 S               Golden-Delicious   0 (4.6)   0-3 (50)   137  3 N.E.               Red-Delicious   0 (5)   0 (14)   3 S               Orliance   0 (1)   0 (4)           Nectarine   Flamekissed   0 (3)   0 (10)   13  3 N.E.                           1 S           Pear   Gentil   0 (0.25)   0 (0.2)   22  3 N.E.               Spadochini   0 (2)   0 (1.3)   3 S               Costia   0 (1.4)   0 (1.4)               Spadona   0 (8.5)   0 (7.5)                                                  
 
         [0028]    Table III displays results done during the year 2000 at various locations in Israel.  
                                                                                           TABLE III                                       % Damage with       Max. flies                        Nimrod           catches/week                   Eliminator   Other       in Trimedlure       Site   Crop   Varieties   (1000 m 2 )   Methods   Method   traps                    Neve-Ya&#39;ar   Apricot   Several   0% (2)   1.5% (2)   Spray   1               varieties           Nectarine       1% (2)   61.5% (0.5)   No treatment   36           Peach       2.7% (2)   40% (0.5)   No treatment       Sosia   Apricot   Ra&#39;anana   2.5% (2)   15% (2)   Bio-Lure   8           Vineyard       8% (1)   25-40% (1)   Bio-Lure   139       Ofra   Sweet-   Several   0% (2)   0% (2)   Bio-Lure   43           Cheery   varieties       Kibbutz   Litchi   Maoricios   0% (5)   0% (30)   Spray   145       Lavi       Manara A   Apple   Muli-Deli-   0.8% (4)   7.3% (7)   Bio-lure   13               cious       10% (3)   Ground bait               Gala   0% (1)   0% (1)   Spray               Granny-   0% (3.2)   0% (30)   Spray               Smith       Manara B   Apple   Muli-Deli-   0.8%   0% (11)   Spray   3               cious   (2.5)               Star King   0% (3.8)   0% (14)   Spray               Granny   0% (2.4)   0% (5)   Spray               Smith       Manara C   Apple   Jonathan   0% (0.7)   0% (1)   Spray   3               Golden   0%   0% (1)   Spray               Delicious   (0.13)               Star King   0% (1.5)               Granny-   0% (2)               Smith       Sde Boker   Olive   Barnea   0.16%   0.14% (4)   Eco Traps   1       (1)           (4)                       0.04% (4)   Yellow Sticky                           Traps                       50% (4)   No treatment                       0.22% (10)   Spray       Nes Harim   Nectarine   Fantasia   0.5%   30% (10)   Spray   52                   1.5       Kfar   Persimmon   Izo   0.1% (8)   0.9% (12)   No treatment   42       Baruch       Trimuph   0% (0.1)       Kfar Bilo   Carambula   Unknown   0% (2)   0% (2)   Bio Lure   50                          
 
         [0029]    Thus, the insecticidal composition of the present invention, when used in association with “Nimrod Eliminator” are not only pronouncedly more effective Fan commercially used traps, but also display a comparable net result to conventional spraying in combating Mediterranean Suit fly in various vegetation.  
         [0030]    Important to note is that the composition of the present invention may also be used effectively, together with the “Nimrod Eliminator”, in combating additional to flying insects, other than Mediterranean fruit fly, in a manner comparable to spraying. Such results were obtained while carrying the experiments, the results of which are presented in Table III.  
         [0031]    In the first site, Neve-Ya&#39;ar, as a result of the “Nimrod Eliminator” containing the insecticidal composition there was no damage from empoasca spp. or any other leave pests  
         [0032]    In the second site, Sosia, two adjacent 1000 m 2  areas of vineyard covered with insect-proof net, were treated against Medfly comparing the efficiency of the conventional methods to the “Nimrod Eliinator”. The “Nimrod Eliminator.” had demonstrated superior results controlling the Medfly (table III). Furthermore, other pests were also exterminated and no further treatment was needed. Contrarily, the plot having the BIOLURE™ trap, in addition to the fact that the BIOLURE™ is less effective in treating Medfly, the plot had to be intensively treated against the leaf pest empoasca lybica.  
         [0033]    Referring back to Table II, since the beginning of the use of the “Nimrod Eliminator” Kibbutz Tzuba, there was almost no need to further treat the Pear against  Cacopsylla bidens  while in an adjacent plot treated in a conventional manner such a treatment was necessary. Likewise, in the Nectarine plot since the use with “Nimrod Eliminator” there was no need to further spray against Empoasca spp. or Thysanoptera while in an adjacent plot treated in a conventional manner such a treatment was necessary.  
         [0034]    Although the invention has been described in conjunction with specific embodiments, it is evident that many alternatives and variations will be apparent to those skilled in the art in light of the foregoing description. Accordingly, the invention is intended to embrace all of the alternatives and variations that fall within the spirit and scope of the appended claims.