NL9100688A - USE OF TERPENOID COMPOUNDS IN AGRICULTURAL OR GARDEN CONSTRUCTION AND FOR THE PREPARATION OF PREPARATIONS FOR THE CONTROL OF WHITE FLY SPECIES. - Google Patents

Description

Use of terpenoid compounds in agriculture or horticulture as well as for the preparation of preparations for combating white flying sports.

The invention relates to the use of terpenoid compounds in agriculture or horticulture as well as for the preparation of preparations for controlling whitefly species.

Certain terpenoid compounds, for example the sesquiterpene (E) - farnesene, are known to cause an alarm response in aphids. It is further known that (E) -p-farnesene, when contacted in a liquid form with aphids, exerts a lethal effect on these insects (cf. EP-A-0 073 080).

EP-A-0 266 822 discloses that farnesene, in particular Ε-β-farnesene, affects hormonal processes in insects and acarina. These processes are particularly concerned with development, reproduction and morphogenesis. In this hormonal application, the farnesene in the gaseous or vapor form is allowed to act on the animals to be controlled at a concentration higher than the concentration at which the farnesene acts as an alarm pheromone for aphids. A preferred concentration of at least 10 nanograms per ml of air is mentioned. Examples of insects and acarina, which can be controlled via the hormonal mechanism of action according to EP-A-0 266 822, are: whitefly (Trialeurodes vaporariorum), aphid (Myzus persicae) and generally the Homoptera, spider mite (Tetranychus urticae ). thrips (Thysanoptera), housefly (Musea domestica), fruit flies (Limosina sp.), tempex beetles (Alphitobius diaperinus), Diptera, Lepidoptera and Coleoptera, for example the cocoa moth (Ephestia elutella), the tobacco beetle (Lasioderma serricorus) (the rice rice) ) and the Khapra beetle (Trogoderma granarium). Furthermore, cockroaches (Dictyoptera), bugs (Heteroptera) and ants (Hymenoptera), and grasshoppers (Orthoptera) and Colorado beetles (Coleoptera) are mentioned.

It has now been found that certain terpenoid compounds, the structure of which is related to (E) -β-farnesene, can be used more successfully to control whitefly species.

The invention therefore relates to the use of terpenoid compounds in agriculture or horticulture as well as for the preparation of preparations for controlling whitefly species, the terpenoid compounds having a structure of the formula (1) (0).

in which the dotted lines indicate the locations of possible C-C bonds.

Within the scope of the present application, the whiteflies belong to the entomological superfamily of the Aleurodinae; Of particular interest are the genera Bemisia and Trialeurodes, in particular Bemisia tabaci and Trialeurodes vaporariorum. The whiteflies belong to the Aleurodidae family.

The following terpenoid compounds used according to the invention can be mentioned:

a-humulene,

(J-humulene,

(-) - β-caryophyllene.

Of these substances, the caryophyllene in particular appears to have a rapid and effective action.

It has been found that the essential Ylang-Ylang oil, which includes a number of terpenoid compounds, exerts a toxic effect. This oil contains about 10% caryophyllene. For a more complete composition, please refer to the following overview:

Main components of Ylang-Ylang oil 8% p-methylanisole 2% & cadinene 19% linalool 3% ^ -cadenin + a-farnesene 10% (-) - β-caryophyllene 8% geranyl acetate 4% methyl benzoate 2% geraniol 3% a -humulene 2% (E, E) -farnesyl acetate 10% germacrene-D 1% (E, E) -farnesol 5% benzyl acetate 8% benzyl benzoate 2% benzyl salicylate

However, it has been found that the effect of Ylang-Ylang oil is stronger than can be explained by the presence of caryophyllene. This could indicate a synergistic action of other components present in Ylang-Ylang oil and / or an effect of other toxic components. Ylang-Ylang oil has very low toxicity to mammals including humans. Its use in the fragrance and flavor industry is well known, J. Agic. Food

Chem. 1986, 24, 481-487.

According to a preferred embodiment of the invention, the terpenoid compounds may be in the gaseous or vapor form. For example, the active substance in the vapor or gas form is introduced into horticultural greenhouses using a so-called time-release system. Automatic dosing takes place at intervals of, for example, 10 minutes.

This is continued for a few days, after which the greenhouse is vented. Parasites such as parasitic wasps may be used after treatment with the terpenoid compounds. Usually, such a completion of whitefly control is not necessary. However, it should be noted that the use of the terpenoid compounds combines well with biological control techniques.

The invention also relates to a method for controlling whitefly, wherein an active substance is allowed to act on the living space of the insects to be controlled, wherein as active substance at least one terpenoid compounds is used, which structure has the formula (1 )

(i), wherein the dotted lines indicate the locations of potential C-C bonds.

Preferably, in the method of the invention, the terpenoid compounds mentioned above are listed as preferred compounds, including the indicated Ylang-Ylang oil,

In an embodiment of the method according to the invention, wherein the sesquiterpenes are in the gaseous or vapor form, it is preferred that the concentration of the terpenoid compounds during the treatment is between 0.1 and 1000 nanograms per ml of air, ie that the concentration can even go up to the saturation concentration. The stated amounts were measured under standard conditions, i.e. a pressure of 1 atmosphere and a temperature of 20 ° C. The said active compound concentrations can be easily achieved using, for example, slow-release systems or the aerosol dispensing system described above. The use in the gaseous or vapor form can take place analogously to the methods described in EP-A-0 266 822. The method according to the invention can be carried out both in horticulture (indoor and outdoor greenhouse use) and in agriculture (open ground), although in the case of outdoor greenhouse use it will be more difficult to maintain effective vapor concentrations for a long time.

It should be emphasized that whitefly killing is also possible by direct spraying with the terpenoid compounds, for example by using a spray of very fine droplets of the substances. Tests have shown that all animals are killed by direct spraying.

Examples

In all experiments, whiteflies (Trialeurodes vapora-riorum) were grown on large tobacco plants (Nicotiana xanthi). About 1 week old adult whiteflies were collected from this mother culture and transferred to small tobacco plants. The animals were then used in the different experiments. All experiments were performed at a temperature of 18-20 ° C and a light regime of 18 hours light and 6 hours dark. The small tobacco plants were grown from seed in small 10 cm diameter flower pots under the light of a high-pressure mercury lamp. The lighting regime was identical to the one just mentioned.

Unambiguous and repeatable results were obtained in whitefly experiments on the aforementioned small tobacco plants.

The plants are placed in perspex tubes that are covered with nylon mesh from above. About 100 whiteflies were placed on one plant.

A filter paper on a stick was placed next to the plant in the ground with 1, 10 or 100 mg of the substance to be tested without solvent. A filter paper was placed in the control group in an identical manner without applying any substance to it.

Table 1 shows that caryophyllene is toxic to whiteflies: paralysis occurs among the animals from which they no longer recover. After 1 day, 82 # is already dead. The (E) -p-farnesene used for comparison is also toxic (see Table 1). Here we find 7 ^ # mortality after 2 days. The substance α-humulene has more of a long-term effect: a high mortality occurs only after 3 days. In this blank group, mortality remains low in this mode of administration.

Table 1

Results from experiments with a ten-fold lower dose are shown in table 2. Here the animals were followed for 11 days to observe any longer-term effects as well.

Table 2

* 100 mg of this oil was administered.

At a dose of 10 mg, effects that are not nearly as strong as at 100 mg are evident. Moreover, mortality also appears to be increasing slowly in the blank group. It is clear that (-) - β-caryophyllene, but especially Ylang Ylang oil works faster than the farnesene used for comparison.

Ylang-Ylang oil is infused here in 100mg. This amount of Ylang Ylang oil contains 10 mg of caryophyllene. However, the effects of Ylang Ylang oil are considerably stronger than those of using caryophyllene alone. After 1 day, 73% mortality is already found, while after 3 days all animals are dead.

Claims (10)

Use of terpenoid compounds in agriculture or horticulture and for the preparation of preparations for controlling whitefly species, the terpenoid compounds having a structure of the formula (1)

(1), in which the dotted lines indicate the locations of possible C-C bonds. Use according to claim 1, wherein the terpenoid compounds are selected from α-humulene, β-humulene and (-) - β-caryophyllene. Use according to claim 1 or 2, wherein the terpenoid compounds are in the form of Ylang-Ylang oil. Use according to claims 1-3. the terpenoid compounds being in the gaseous or vapor form. Method for controlling whitefly species, whereby an active substance is allowed to act on the living space of the insects to be controlled, wherein as active substance at least one terpenoid compounds are used, which have a structure of the formula (1)

(1), in which the dotted lines indicate the locations of possible C-C bonds. 6. A method according to claim 5, characterized in that the terpenoid compounds are selected from α-humulene, β-humulene and (-) - β-caryophyllene. A method according to claim 5 or 6, wherein the terpenoid compounds are in the form of Ylang-Ylang oil. 8. Method according to claim 5 “7. the terpenoid compounds being in the gaseous or vapor form. The method of claim 8, wherein the concentration of the terpenoid compounds is between 0.1 and 1000 nanograms per ml. The method of claims 5-8, wherein the insects are sprayed directly with a terpenoid compound, or a composition containing such a compound.