GB1602267A - Combating insecta eggs - Google Patents

Description

(54) COMBATING INSECTA EGGS (71) We. FISONS LIMITED, a British Company, of Fison House, 9 Grosvenor Street, London W1S OAH, do hereby declare the invention, for which we pray that a patent may be granted to us, and the method by which it is to be performed to be particularly described in and by the following statement: Carbamate insecticides are well known. A surprising new use for certain of them has now been discovered.

Accordingly, the invention provides a method of combating Insecta eggs at a locus at which there is growing or is to grow a crop of maize, soybeans or fruit or a plantation or forestry crop, which method comprises applying to the locus an Insecta egg combating amount of a carbamate insecticide which is carbofuran, carbaryl or propoxur.

It has been discovered that these carbamate insecticides are surprisingly active against insect (Insecta) eggs, particularly of the order Lepidoptera. Coleoptera or Diptera, at a locus at which these crops are growing or are to grow.

The invention enables insect pests of these crops to be combated at the egg stage before they reach the damaging later stages. Preferably the carbamate insecticide is applied to the locus to be treated before substantial infestation with Insecta larvae occurs. For instance, on cotton plants one may apply the carbamate insecticide against Insecta eggs for instance 10-14 days before one would first apply against the later Insecta stages.

Carbofuran is 2.3-dihydro-2.2-dimethyl-benzofuran-7-yl methylcarbamate, carbaryl is l-naphthalenyl methylcarbamate, and propoxur is 2-[1methylethoxyjphenyl methylcarbamate. The carbamate insecticide is preferably carbofuran.

The present carbamate insecticides are active against the eggs of a wide range of Insecta, especially Insecta of the order Lepidoptera, Coleoptera or Diptera, e.g. European corn borer (Ostrinia ,luhilnlusl, Heliothis species (e.g. H. virescens or H. armigera), Alabama argillacea, the small white butterfly (Pieris rapae), the Mediterranean fruit fly (Ceratitis capitata) and the diamond-backed moth (Plutella maculipennis). Of particular interest is use against Insecta of the order Lepidoptera.

The carbamate insecticide is applied to a locus at which the specified crop is growing or less preferably is to grow. The insecticide can be used to combat Insecta eggs on these crops with outstanding safety to the crop. The crop is maize, soybeans or fruit (especially tree fruit such as apples or citrus fruit). or a plantation or forestry crop e.g. conifers, cotton or tobacco. Preferably the crop is cotton or maize.

In a preferred embodiment, Insecta eggs are combated on cotton plants by applying the carbamate insecticide to the plants.

The carbamate insecticide may be applied once or more than once. Thus, for some crops one may apply the insecticide periodically through the Insecta season.

Generally the carbamate insecticide is applied at a rate of 0.1-4, e.g. 0.5-1, kg per hectare.

The carbamate insecticide may be applied in the form of a solid, e.g. dusts or granules, or, preferably. a liquid e.g. an emulsifiable concentrate or wettable powder dispersed in water.

In a preferred embodiment. Insecta eggs are combated on maize plants by spraying onto the plants a liquid Insecta egg combating composition containing the carbamate insecticide.

The ovicidal compositions may be prepared by admixing the ingredients. Generally they contain 0.001 to 90% of the carbamate insecticide. Parts and percentages in this specification are by weight unless otherwise indicated. The composition applied to the locus may contain for instance 0.001 to 5% of the carbamate insecticide. The insecticide may be formulated as a concentrate, e.g. a wettable powder, which is diluted, generally with water, for application. A concentrate may contain for instance 5-90% of the insecticide.

The composition usually contains a surface active agent and/or a carrier. The carrier may be solid or liquid.

The composition may contain a fertilizer.

The carbamate insecticide may be used in sequence or admixture, particularly admixture, with another pesticide, e.g. an insecticide, acaricide or fungicide. In a preferred embodiment, however, the carbamate insecticide is the sole insecticide.

The invention is illustrated by the following Examples.

Example 1-10 A laboratory culture of cotton bollworm Heliothis annigera eggs was obtained by allowing the insects to lay their eggs on sheets of filter paper. Before the eggs were 24 hours old, filter paper pieces with eggs attached were dipped into aqueous suspensions of carbaryl, propoxur or carbofuran, of concentration shown in the table below. The carbaryl and propoxur suspensions were obtained by admixing the 50% wettable powder Sevin ("Sevin" is a Trade Mark) or Undene ("Undene" is a Trade Mark) respectively in water.

The carbofuran suspensions were obtained by grinding technical grade 2,3-dihydro-2,2dimethyl-7-benzofuran-7-yl methylcarbamate with water containing 0.5C/c of the nonylphenol/ethylene oxide condensate wetting agent Lissapol ("Lissapol is a Trade Mark), and then making up to the required concentration of carbofuran with more water containing 0.550 Lissapol. The tested filter paper pieces were placed in petri dishes and allowed to dry. The dishes were then closed. Mortality of the eggs was assessed 5 days after treatment. The results are shown below.

Concentration of Compound in Suspension, Cas Egg Mortality Example Compound parts per million Heliothis armigem Carbaryl 300 100 100 100 3 30 65 4 10 50 -'1 Propoxur 300 100 6 100 63 7 Carbofuran 300 100 100 100 9 30 100 10 10 50 Examples 11-14 Aqueous suspensions of propoxur or carbofuran, of concentrations shown in the table below were made up as in Examples 1-10. Filter papers were dipped into the liquid and placed in petri dishes. Whilst the filter papers were still wet, eggs of the Mediterranean fruit flv Ceratitis capitata were transferred to the filter papers using a soft paint brush. The eggs had been obtained as a laboratory culture by collection onto filter papers from the water into which they had been laid. The eggs were less than 24 hours old when treated with the insecticide.

The petri dishes were closed. During the course of the test, a very small quantity of water had to be added to the filter papers to maintain the level of moisture necessary for insect viability. Egg mortality was recorded after 5 days. In control treatments using filter papers dipped in onlv 0.5us Lissapol (nonylphenol/ethvlene oxide condensate wetting agent) in water, the larvae emerged after about 2-3 days. The results are shown below Concentration of Compound in Suspension No Egg Mortality Example Compound parts per million Ceratatis capitata 11 Propoxur 1000 95 12 100 65 13 Carbofuran 1000 100 14 100 78 Examples 15-18 Cabbage plants in cages in the laboratory were exposed to adult diamond-backed moths Plutella macu lip enn is for 24 hours. The leaves most heavily infested with eggs were then selected for tests. The eggs were less than 24 hours old when treated. Each leaf was dipped into an aqueous suspension of propoxur or carbofuran, of concentration shown in the table below. The suspensions were made up as in Examples 1-10. Each treated leaf was placed on a pad of damp cotton wool in a petri dish. A total egg count was carried out immediately after treatment, and 5 days later a total count was made of hatched but dead larvae which were not clear of the eggs and of unhatched eggs. The percent mortality was thus calculated and is shown in the table below.

Concentration of Compound in Suspension, % Egg Mortality Example Compound parts per million Plutella maculipennis 15 Propoxur 1000 100 16 300 100 17 Carbofuran 1000 100 18 300 100 WHAT WE CLAIM IS: 1. A method of combating Insecta eggs at a locus at which there is growing or is to grow a crop of maize, soybeans or fruit or a plantation or forestry crop, which method comprises applying to the locus an Insecta egg combating amount of a carbamate insecticide which is carbofuran, carbaryl or propoxur.

2. A method according to claim 1 wherein the Insecta are of the order Lepidoptera, Coleoptera or Diptera.

3. A method according to claim 1 or 2 wherein the carbamate insecticide is carbaryl.

4. A method according to claim 1 or 2 wherein the carbamate insecticide is propoxur.

5. A method according to claim 1 or 2 wherein the carbamate insecticide is carbofuran.

6. A method according to any one of the preceding claims wherein application is made before substantial infestation with the larvae of the Insecta occurs.

7. A method according to any one of the preceding claims wherein the crop is growing at the locus.

8. A method according to claim 7 wherein the crop is cotton.

9. A method according to claim 7 wherein the crop is maize.

10. A method according to claim 9 wherein a liquid composition containing the carbamate insecticide is sprayed onto the maize plants.

11. A method according to any one of the preceding claims wherein 0.1-4 kg of the carbamate insecticide are applied per hectare.

12. A method according to any one of the preceding claims wherein the carbamate insecticide is the sole insecticide applied.

**WARNING** end of DESC field may overlap start of CLMS **.

Claims (1)

1. **WARNING** start of CLMS field may overlap end of DESC **.

   Concentration of Compound in Suspension No Egg Mortality Example Compound parts per million Ceratatis capitata

   11 Propoxur 1000 95

   12 100 65

   13 Carbofuran 1000 100

   14 100 78 Examples 15-18 Cabbage plants in cages in the laboratory were exposed to adult diamond-backed moths Plutella macu lip enn is for 24 hours. The leaves most heavily infested with eggs were then selected for tests. The eggs were less than 24 hours old when treated. Each leaf was dipped into an aqueous suspension of propoxur or carbofuran, of concentration shown in the table below. The suspensions were made up as in Examples 1-10. Each treated leaf was placed on a pad of damp cotton wool in a petri dish. A total egg count was carried out immediately after treatment, and 5 days later a total count was made of hatched but dead larvae which were not clear of the eggs and of unhatched eggs. The percent mortality was thus calculated and is shown in the table below.

   Concentration of Compound in Suspension, % Egg Mortality Example Compound parts per million Plutella maculipennis

   15 Propoxur 1000 100

   16 300 100

   17 Carbofuran 1000 100

   18 300 100 WHAT WE CLAIM IS: 1. A method of combating Insecta eggs at a locus at which there is growing or is to grow a crop of maize, soybeans or fruit or a plantation or forestry crop, which method comprises applying to the locus an Insecta egg combating amount of a carbamate insecticide which is carbofuran, carbaryl or propoxur.

   2. A method according to claim 1 wherein the Insecta are of the order Lepidoptera, Coleoptera or Diptera.

   3. A method according to claim 1 or 2 wherein the carbamate insecticide is carbaryl.

   4. A method according to claim 1 or 2 wherein the carbamate insecticide is propoxur.

   5. A method according to claim 1 or 2 wherein the carbamate insecticide is carbofuran.

   6. A method according to any one of the preceding claims wherein application is made before substantial infestation with the larvae of the Insecta occurs.

   7. A method according to any one of the preceding claims wherein the crop is growing at the locus.

   8. A method according to claim 7 wherein the crop is cotton.

   9. A method according to claim 7 wherein the crop is maize.

   10. A method according to claim 9 wherein a liquid composition containing the carbamate insecticide is sprayed onto the maize plants.

   11. A method according to any one of the preceding claims wherein 0.1-4 kg of the carbamate insecticide are applied per hectare.

   12. A method according to any one of the preceding claims wherein the carbamate insecticide is the sole insecticide applied.

   13. A method according to claim 1 of combating Insecta eggs, which method is

   performed substantially as hereinbefore described.