AGRICULTURE AND IRRIGATION

PESTS

Of Cereals.

There are three important pests of crops in Satara district and the Of Cereals. detailed information about them is given in the following paragraphs. The damage done by the different pests cannot be estimated precisely, as it depends upon the severity of infestation in a particular year. The remedial measures suggested against the different pests described below are such as can be adopted by the cultivators at a moderate cost.

Bin pankhi tol, the wingless grasshopper of the Deccan (colemania sphenaroides) is a serious and widespread pest. The pest is active from June to December and mostly attacks the crops of jowar and bajra in the kharif season. Its nymphs and adults do not possess wings. The head of the adult is pointed and conical and the body is elongated and greenish to straw coloured, with purple stripes behind the eyes and along the length. The eggs are laid in the soil at a depth of two or three inches along the bunds and in the field; and also in fallow land in batches of 40 to 60 during October to December. These eggs remain dormant in the soil till the following June, when they hatch soon after the early showers of the monsoon. Annually there is only one generation. The nymphs and adults feed on leaves and when the infestation is severe, they cause complete defoliation. The pest can be controlled to some extent by destruction of egg masses when they are laid in the soil, by ploughing and harrowing the affected field especially along the bunds soon after the harvest of the crops. The insecticidal measures are two, viz. (1) Dusting 10 per cent. Benzene hexachloride (BHC) in the early stages of the pest at the rate of 20 lbs. per acre. This is both effective and convenient and is adopted extensively. (2) Poison baits containing 5 per cent. BHC with rice husk or groundnut husk are spread in the infested field at the rate of 30 to 60 lbs. per acre. This bait may be prepared by mixing 10 lbs. of 5 per cent. BHC with 100 lbs. of husk soaked in water for about six to eight hours.

Hinge or bali, blister beetles (Zonabruis pastalata) affects the crops of bajra, jowar, cucurbits and beans. They are one inch and odd in length and about half an inch thick and are black in colour with yellowish brown stripes across their wings. The beetles emerge from pupae and remain active from August to December. The beetles feed on pollen and petals of flowers and affect the setting of grains in the ear-heads. Preventive measures consist of collection of beetles by means of a handnet and their destruction. The beetles are also attracted to coloured lights and therefore, light traps may also be used. However, light traps are not very effective. Insecticidal measures are more satisfactory and include dusting of 5 per cent. BHC dust at the rate of 20 lbs, per acre. If dusting is done properly, it is highly effective.

Lashkari alya, Army Worms (Cirphis lorei and Cirphis unipuncta), are caterpillars who appear in swarms and generally migrate from infested fields to non-infested fields. They feed on the tender leaves of the growing young shoots with the result that growing shoots are destroyed. Full-grown caterpillars are smooth and stout and are one to one and a half inch long. They are dark-greenish in colour with broad light coloured stripes running lengthwise on the body. They feed mostly at night time whereas during the day they remain underground hidden in the whorl or in the clods. Larvae pupate in soil. The pest is active during the kharif season. The preventive measures consist of (1) Collection of egg masses and their destruction. (2) In case the attack is localised, special labour may be employed to collect and destroy them. (3) After the harvest the infested fields should be thoroughly ploughed to expose the pupae from the soil. Similarly, caterpillars lying in the central whorls of plants are crushed. Insecticidal measures have been found very effective. If the affected crop is dusted properly with 5 per cent. BHC dust at the rate of 30 lbs. per acre, the pest can be controlled successfully. Dusting if done in the evening proves more effective as the pest is a night feeder. If water is easily available, 5 per cent. BHC wettable powder may be used as a spray after diluting one pound of powder in 25 gallons of water. About 80 to 100 gallons of spray per acre are required to control the pest, having regard to the size of the crop. Five per cent. BHC poison bait broadcast in the evening also serves to control the pest in case of crops like nachni, provided the soil is dry and it does not rain.

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