EA043784B1 - SALTS (C1-C2) OF ALKYL ESTERS OF NICOTINIC AND ISONICOTInic ACIDS FOR CATCHING SEVERAL SPECIES OF INSECT PESTS OF THE ORDER TRIPS - Google Patents

Description

The invention relates to the field of entomology, namely to the production of dispensers containing salt forms of esters of nicotinic and/or isonicotinic acids as an attractant for attracting thrips insect pests.

State of the art

Western flower thrips (WFT) Frankliniella occidentalis is included in the List of pests, plant diseases and weeds of quarantine importance for the Russian Federation, approved by Order of the Ministry of Agriculture of the Russian Federation No. 673 dated December 26, 2007. Currently, WFT is recognized as one of the most dangerous vegetable and ornamental pests and flower plants in protected soil. Western flower thrips damages cotton, cucumber, pepper, onion, tomato, strawberry, grape, peach and other fruit and vegetable crops, as well as numerous ornamental and flower plants. Larvae and adults suck cell sap from plant tissue and lead a hidden lifestyle, settling in flower buds, buds, flowers, and under various scales on plants. WCT is dangerous because it causes direct damage to plants and is capable of transmitting viruses that cause dangerous plant diseases (for example, Tomato Spotted Wilt Tospovirus (TSWV), which affects more than 360 plant species).

Visual detection of the pest for timely protection of cultivated plants is complicated by the small size of the insect and its secretive behavior. Therefore, for the early detection of SCT, the use of colored traps with an attractant is effective. The use of insecticides to protect crops is limited by the fact that ECTs quickly develop resistance, while the population of entomophages that restrains the growth of the amount of EBTs from insecticides suffers greater damage than EBTs. As a result, after treatment, a surge in the ZCT population is possible [1].

The use of blue traps with an attractant in combination with entomophages sometimes makes it possible to completely abandon the use of pesticides to keep the amount of ECTs on plants below the permissible level of economic damage [1].

It was previously established that, along with the components of natural oils, thrips are attracted to esters of nicotinic and isonicotinic acids [2, 3]. In experiments with an olactometer, it was found that ethyl nicotinoate exhibits attractiveness to ECT in a concentration range of 4 orders of magnitude. Most other fragrant compounds, including geraniol, exhibited attractiveness in the concentration range of 1-2 orders of magnitude. It is assumed that thrips have only one receptor for recognizing aromas and therefore there is no synergism when using several attractants [4]. Alkyl nicotinoates and isonicotinoates attract, along with WCT, many other types of thrips pests: tobacco thrips (Trips tabaci), New Zealand flower thrips (Trips obscuratus), calcific thrips (Trips calcaratus), Frankinieella intonsa, etc. [1, 3].

One of the companies producing integrated pest management products, Koppert B.V. in the Lurem-TR thrips dispenser, methyl isonicotinoate is used as an attractant (kairomone). The dispenser is manufactured using industrial equipment and is a plastic dispenser with a perforated membrane for the gradual distribution of the attractant. According to the manufacturer, adding a Lurem-TR dispenser to blue sticky traps increases the capture of thrips, while the unwanted capture of entomophagous and pollinating insects does not increase [5].

Despite the fact that specialists have been studying and developing methods for controlling WTP for more than 40 years, the problem of effective protection of cultivated plants from this pest has not been completely resolved and work in this direction does not stop. Evidence of the relevance of this problem is the relatively recent publication of dissertations for an academic degree and a general review [1, 6, 7].

Methyl isonicotinoate is characterized by high volatility. At a temperature of 25°C, 320 mg evaporates per day from cotton swabs, 40 mg from sealed plastic bags (150 microns), and 76 mg from Lurem-TR dispensers [1]. In the authors' opinion, the rate of evaporation of the attractant from dispensers is excessive, which leads to wasteful consumption of the substance. It is known that salt forms of amines are characterized by thermal dissociation. At room temperature, on an open surface, these salts also disintegrate and slowly release the amine into the surrounding space.

The object of this invention is to find a means to ensure the optimal rate of evaporation of alkyl nicotinoates and isonicotinoates by converting them into various salt forms.

experimental part

The dispensers used were 2x2.5 cm plates cut from commercially available York 17.5x15.5 cm sponge wipes. Alkyl nicotinoates and isonicotinoates and their salt forms were applied to the dispensers as a solution in methanol. After application, the solvent completely evaporated within 1 hour. Experiments on the evaporation of alkyl nicotinoates and isonicotinoates were carried out in a laboratory cabinet with an air flow velocity of 0.1-0.2 m/s. The air temperature was between 20-24°C. Relative air humidity ranged from 62 to 96%. Dispensers were hung on a wire at a distance of at least 4 cm from each other. For gravimetric analysis, ViBRA HT 224RCE analytical balances were used. Experiments were carried out with four parallel measurements. Processing the results

- 1 043784 was carried out using the standard statistical method. The relative standard deviation of the results did not exceed 10%.

A common technique for reducing the rate of evaporation of substances from a surface is to place dispensers in sealed plastic bags. The use of films of different thicknesses or multilayer structures allows you to change the evaporation rate. Increasing the amount of applied substance accordingly increases the time until its complete evaporation. Such studies have been published for methyl isonicotinoate [1]. Packaging dispensers in special plastic structures leads to a significant increase in the cost of the product.

In the case of amines, such as nicotinoates, another way to significantly reduce the rate of evaporation of the substance is to convert them into a salt form.

I - alkyl nicotinoate, R=CH ₃ , C2H5;

II - alkyl nicotinoate salt;

III - alkyl isonicotinoate salt.

The rate of thermal dissociation of various alkyl nicotinoate and isonicotinoate salts from the exposed surface is determined by many factors: temperature, evaporation surface area, air flow rate, amine volatility, acid strength and volatility. The purpose of the work was to select acids for the gradual release of alkyl nicotinoates from the dispenser over a long time, and not to establish precise physical constants. Therefore, the experiments are comparative in nature.

Organic acids are used: trifluoroacetic, citric, oxalic and inorganic: hydrochloric, sulfuric, phosphoric, hydrobromic. Salt forms of nicotinoates and isonicotinoates can be obtained either by dissolving ready salts or by applying acids and amines or their solutions separately, and the ratio may differ from equimolar or equivalent.

As an example, we present data from experiments with methyl nicotinoate. Methyl nicotinoate 150 mg (1.095 μmol) was applied to the dispenser as a solution in 0.5 ml of methanol. An equimolar amount of acid was added to the solution (the weight is indicated in Table 1). In the control experiment, methyl nicotinoate was applied as a base without adding acid.

Table 1

Evaporation of salt forms of methyl nicotinoate from porous sponges (2x2.5 cm) over time

No. p p Applied on a dispenser P acid, mg Weight of the substance (salt or acid) on the dispenser (average, n=4) after application after time (days), mg 0.5 h 1 2 3 6 8 12 15 19 21 3 5 41 4 5 5 2 1 55mg nsoon 205 83 18 1 2 66 mg AcOH 216 0 3 137 mg CF3CO2H 287 23 7 20 6 17 9 15 6 12 7 97 56 44 39 1 0 9 5 4 232 mg lemon juice 382 34 0 34 2 33 7 31 4 31 0 29 8 29 4 27 8 28 4 * * 5 88 µl conc HC1 190 16 3 14 4 13 0 87 64 48 thirty 20 15 2 6 113 mg H3PO4 263 19 3 18 5 17 2 16 4 16 0 15 1 14 1 12 8 * * * * * 7 0 150 0

* There is an organoleptic smell.

From the experimental data presented in table. 1, it can be seen that the salts of methyl nicotinoate with weak organic acids turned out to be unstable and completely evaporated in air from the porous plates in 1-3 days. In the control experiment without adding acid, methyl nicotinoate completely evaporated in 12 hours. The salt with hydrochloric acid evaporated for more than a month. The salt with trifluoroacetic acid evaporated for a month and a half. The weight loss of plates with salts of non-volatile acids, citric and phosphoric, was observed for 2 and 3 weeks, respectively. At the same time, an increase in the weight of the plates was observed with increasing air humidity. Probably, the plates with these salts exhibited hygroscopicity. To illustrate the dynamics of evaporation of methyl nicotinoate salts, the experimental results are presented graphically in the drawing.

Plates with salts of citric and phosphoric acids smelled like methyl nicotinoate for more than 50 days. Organoleptic analysis turned out to be a convenient method of control, since alkyl nicotinoates have a strong, distinct odor and are not toxic. It can be assumed that as long as the plates smell, they will attract ECG. The same gravimetric experiments were carried out with ethyl nicotinoate, as well as with methyl and ethyl isonicotinoates. The salts of the corresponding acids behaved in approximately the same way.

To test the effectiveness of dispensers with salt forms of methyl nicotinoate, tests were conducted to catch thrips on blue sticky plates in a greenhouse with cucumber plantings. Traps were placed at a distance of 5 m between each other and 5 m between rows. During the experiment, the traps were swapped by moving them by one position every day. There were 5 traps of each option. There are only 5 options along with control. The total number of thrips caught over 37 days of each variant and the ratio of this quantity to the control is given in Table. 2.

table 2

Field test results

Option Compound Number of thrips caught Increase in catch relative to control 1 150 mg Menicotinoate 4421 1.03 2 150 mg Menicotinoate + 113 mg H3PO4 7113 1.65 3 150 mg Menicotinoate + 221 mg CyNs 9372 2.18 4 150 mg Menicotinoate + 94 µl HC1 8068 1.87 5 Control 0 mg 4306 1

Conclusions.

Applying 150 mg of methyl nicotinoate to porous plates in the form of salts with hydrochloric, phosphoric, citric or trifluoroacetic acids makes it possible to make dispensers that gradually release methyl nicotinoate into the surrounding air for more than a month. This method makes it possible to produce long-lasting dispensers for catching ZCT, Thrips calcaratus, Frankliniella intonsa, Thrips obscuratus, Thrips tabaci and other insects. At the same time, designer dispensers have a simple design, unlike well-known commercial dispensers. Field tests have shown the effectiveness of using blue sticky traps with dispensers with salt forms of methyl nicotinoate in closed ground conditions.

Bibliography

Mette-Cecilie Krause Nielsen (2013) Factors affecting the response of thrips to an olfactory cue. A thesis submitted in partial fulfilment of Doctor of Philosophy (Ph.D.) at Lincoln University

D.R. Penman, G.O. Osborne, S.P. Womer, R.B. Chapman and G.F. McLaren

Ethyl nicotinate: A chemical attractant for Trips obscuratus (Thysanoptere:

Tripidae) in Stonefruit in New Zealand II J. of Chern. Ecology, 1982, Vol. 8, no. 10, pp. 1299-1303

D.A.J. Teulon, D.R. Penman, P.M. J. Ramakers and Volatile chemicals for Trips (Thysanoptera: Thripidae) host finishing and applications for trips pest management/ //

J. of Economic Entomology, 1993, V. 86. Issue 5, Pp. 1405-1415

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E.H. Koschier, W.J. De Kogel and J.H. Visser II Assessing the attractiveness of volatile plant compounds to western flower thrips Frankliniella occidentali J. of Chemical Ecology, 2000, Vol. 26, No. 12, pp. 2643-2655

A.M. Muvea, M.M. Waiganjo, H.L. Kutima, Z. Osiemo, J.O. Nyasani and S. Subramanian Attraction of pest thrips (Thysanoptera: Thripidae) infesting French beans to colored sticky traps with Lurem-TR and its utility for monitoring thrips populations International Journal of Tropical Insect Science Vol. 34, No. 3, pp. 197206, 2014

Clare Sampson (2014), Management of the western flower trips on strawberries. Thesis submitted for the degree of PhD, Keele University

Elisabeth H. Koschier. Essential oil compounds for Thrips control - a review. Natural Product Communications, 2008, Vol. 3, no. 7, pp. 1171-1182, bib. 105

Claims (5)

CLAIM 1. A dispenser for attracting insects Frankliniella occidentalis (western flower thrips), containing a salt of organic and/or inorganic acids of methyl and/or ethyl esters of nicotinic and/or isonicotinic acids. 2. Dispenser according to claim 1, where the salt of methyl and/or ethyl esters of nicotinic and/or isonicotinic acids is trifluoroacetate, citrate, oxalate, phosphate, sulfate, chloride, bromide, fluoride or a mixture thereof. 3. Dispenser according to claims 1, 2, where the base for applying the salt of methyl and/or ethyl esters of nicotinic and/or isonicotinic acids is a porous sponge. 4. Insect trap, including a dispenser according to claims 1-3. 5. Use of the trap according to claim 4 for catching insects Frankliniella occidentalis.