DE1007554B - Substances obtained from ants for the control of insects - Google Patents

Description

For the purpose of correctly assessing the discovery that new insecticidal substances were obtained from the animal kingdom a few general considerations should be made beforehand.

Valuable insecticides are currently available in agriculture as well as in cities and homes, but in general the ideal parasite-exterminating agent is still a long way off; there are indeed many highly effective products, but the selectivity in their effect is low, i. i.e., they do not exert their poisonous effect only on the ζμ fighting insects, but also on other insects, such as natural enemies or Food competitors of the former, sometimes on the host plants, and, what is worse, on the people and the higher animals.

So while there are a large number of insecticidal substances, there are only from them Few of them can be used in practice - even if numerous hygienic precautionary measures are observed -, and very few can be used safely: the latter come from plants, and the most famous are the pyrethrins; but, their effectiveness, holds under that Exposure to atmospheric influences for such a short time that their usability because of this instability remains restricted to a very narrow area.

Insecticides have also been obtained from various insects, such as B. the cantharidin. However, this is not readily applicable to warm-blooded animals either, since it is extremely poisonous for them and on the other hand usually only has minor insecticidal effects.

It has now been found that insecticides which differ from formic acid are obtained from ants can be. These insecticides of animal origin have a marked selectivity, at least between warm-blooded animals and insects and also within the class of insects; in particular, it turns out that Iridomyrmecin, which was discovered in Iridomyrmex humilis Mayr and obtained for the first time from said insect Substances administered by the gastric route to the white mouse (Mus musculus albinus) are 6 to 7 times less toxic acts as p, p'-dichlorodiphenyltrichloroethane and as that Gamma isomers of hexachlorocyclohexane and is 120 times less toxic than O, O-diethyl-O-p-nitrophenyl thiophosphate. These new insecticides have high chemical and physical resistance Influences in contrast to the pyrethrins; this is one in terms of uses and an important feature on the economic efficiency of the treatment.

The insecticides to which the present invention relates are particularly quick to act; thus annihilated, for example Iridomyrmecin many economically very harmful insect species in a much shorter time than p, p'-dichloro

Substances obtained from ants
to control insects

Applicant:

Montecatini Societa Generale

per l'Industria Mineraria e Chimica,

Milan (Italy)

Representative: Dipl.-Ing. Dipl.-Chem. Dr. phil. Dr. techn.
J. Reitstötter, patent attorney, Munich 15, ■
Haydnstrasse 5 '

Claimed priority:
Italy 16 May 1951

Mario Pavan, Milan (Italy),
has been named as the inventor

diphenyltrichloroethane and in some cases even as γ-hexachlorocyclohexane; this is the characteristic of the Side of the pyrethrins, while the important organic synthetic insecticides work rather slowly.

Iridomyrmecin has a chemical composition that does not match that of any known insecticidal substance; it therefore represents a reorientation in the field of insecticides.

Iridomyrmecin (which does not contain chlorine) has been shown to be effective against strains of insects, those against p, p'-dichlorodiphenyltrichloroethane became resilient and in which a more and more visible resilience too against other insecticides containing chlorine in the molecule is under development.

It was known that many animal organisms have chemical attack and defense substances, as the ants do formic acid, but so far nothing was known about them.

By systematically examining a first group of over 50 animal species, it was discovered that Insecticidal agents that are previously unknown are present in numerous types, their properties are of great interest from the point of view of practicality.

For example, the presence of such insecticidal agents in extracts from various Species of insects of the genera Tapinoma, Liometopum, Iridomyrmex, all belonging to the Dolichoderinae belong, proven.

...,, 709 507/416

The substances extracted so far are low-molecular organic compounds which act as a powerful contact poison on insects or cause asphyxiation accompanied by clear signs of poisoning, although their toxicity for warm-blooded animals is only very low. For example, on the hemipteran Pyrrhocoris apterus L, p, p'- Dichlorodiphenyltrichloroethane at a dose of 10 y per cm ² in 6 hours produced no symptoms of intoxication, while an equal dose of iridomyrmecin produced general supination with clonic cramps in 4 hours.

To give another example of the toxicity to an insect going into agriculture, it should be mentioned that iridomyrmecin in vitro at a dose of 10 γ per cm ² causes lethal effects on Iridomyrmex humilis Mayr itself through contact, and indeed with much greater rapidity than equal concentrations of p, p'-dichlorodiphenyltrichloroethane and also faster than y-isomers of hexachlorocyclohexane in the same dose.

The active compounds according to the invention also act on species or races of insects which are resistant to the nowadays common, chlorine-containing synthetic insecticides, e.g. B. on p, p'-dichlorodiphenyltrichloroethane resistant house flies. For example, a strain of these insects that withstood contact with p, p'-dichlorodiphenyltrichloroethane in a dose of 10,000 γ per cm ^{2 for} 24 hours, had a residence time of 2 hours on those treated with iridomyrmecin in a dose of 6.5 γ per cm ² surface 93 ° / ₀ of the individuals in irreversible akinesia, 6% in supination with clonic contractions, 4% in temporary supination; in 2 hours with 3 γ per cm ² , 76% of the individuals are in irreversible akinesia.

The insecticidal ingredients are contained in the internal organs, and it is therefore for their utilization It is necessary to first finely divide the animals and then to extract them with suitable solvents or sublimation or other appropriate treatment.

More detailed information on the extraction of the active ingredients is contained in patent application M 31804 IVa / 451.

Claims (4)

PATENT CLAIMS: 1. Use of the ants possessing from anal glands, particularly from the Hymenoptera of the family Dolichoderinae, such as Liometopum microcephalum Panz, Tapinoma, nigerium NyI., Iridomyrmex humilis Mayr and similar, by extraction or just by mixing or grinding the insect bodies Substances obtained with extenders for the control of insects. 2. Use of a substance obtained from ants according to claim 1, characterized in that it has the gross formula C ₁₀ H ₁₆ O _2, has the features of a bicyclic lactone and is characterized by the following information: melting point 60 to 61 °, softening point 58 to 59 °, ability to rotate (a) | ⁰ = 210 ° (4% solution in ethyl alcohol), refractive index nf = 1.4607. 3. Use of a substance obtained from ants according to claim 1, characterized in that it has the gross formula C ₁₀ H ₁₆ O _2, has the characteristics of a lactone and is characterized by the following information: melting point 55 °, (a) l ° = - 52.5 ° (4% solution in ethyl alcohol). 4. Use of the substances obtained from ants according to claim 1 individually or mixed with one another or with other insecticides and possibly with carriers, diluents, Solvents, wetting agents, dispersants. Considered publications:
German patent specification No. 653 089. © 709507/416 4.57