This week NAREI in Focus will begin a series on insect pest management in relation to pumpkins. We will be looking at the cricket and cutworm.
Vegetable production occurs within a relatively short time frame and as such yield losses due to pests may be substantial if the problem is not identified early, and remedial action not implemented on time. Correct identification of the pest and an understanding of its behaviour, including its most vulnerable stages, would provide insights into its management.

The early maturity of vegetables and short intervals between harvests during the cropping season impose constraints on the pest control strategy option. Care must be then taken if pesticide application is contemplated since there is the likelihood of high residual levels remaining in the product after harvest if an inappropriate formulation is used.

Pumpkin is subjected to, attack from many insect pests and diseases. The following is a detailed description of the major pests and the appropriate management strategies that may be employed for control.
1. Cricket Gryllotalpa spp. (Orthoptera: Gryllotalpidae) Acheta spp. (Orthoptera: Gryllidae) Symptoms Cricket attacks seedlings of all vegetables. Fully grown crickets are brown and are about 2.5 – 3.5 cm long. The various species of these insects usually live either in the soil, bushes or under decaying crop residues and vegetation.

Mole crickets, which have heavily sclerotised front legs that are adapted for digging, are usually common in sandy soils (Figure 1). All crickets are nocturnal, feeding at night and secluded by day, under the soil. They feed at or slightly below the soil surface and can cause considerable damage before being discovered. Seedlings may be denuded of leaves or cut below the soil surface without any trace of insect on them. Crickets spend their entire life cycle below the soil, which may be for a period of approximately 28 -35 days. They are termed soil insects.

Control
* Good field sanitation- rid the field of weeds and plant residues from previous crops.
* Cultural control: The areas where vegetables are grown should receive full sunlight, kept clean of weeds and all crop residues should be removed and burnt. Proper land preparation serves to control weeds, diseases, and soil insects, and also helps in the destruction of large soil clods, which act as hiding places for cricket.
Chemical control:
• Any approved soil insecticide at the recommended rate may be applied, such as Basudin 60% E.C (Diazinon) or Vydate L 40%E.C at the rate of 10 ml to 4500 ml water, to seedbeds and cultivated cropping areas.
2. Cutworm Agrotis spp. (Lepidoptera: Noctuidae) Symptoms
These are the caterpillars of various species of moth. They have a greasy appearance, are grey to brown with faint lighter-coloured strips, and when fully grown are usually the colour of the soil in which they live. They can be found on the soil surface, beneath leaves and under large soil clods. Cutworms are surface feeders and cut seedlings at or slightly above the soil surface. Evidence of cutworm presence will be greenish-black excreta pellets below the seedling. Most of its lifecycle is spent below the soil which is for a period of approximately 21-28 days.

Control
• Good field sanitation- rid the field of weeds and plant residues from previous crops.
Cultural control: • The areas where vegetables are grown should receive full sunlight, kept clean of weeds and all crop residues should be removed and burnt. • Proper land preparation serves to control weeds, diseases, and soil insects and also helps in the destruction of large soil clods, which acts as hiding places for cutworms.
Chemical control: • Any approved soil insecticide at the recommended rate may be applied, such as Basudin 60% E.C (Diazinon) or Vydate L 40%E.C at the rate of 10 ml to 4500 ml water, to seedbeds and cultivated cropping areas.