Melon crops are very sensitive to pests and diseases, and if the necessary measures to combat them are not taken, a significant part of the crop of melon crops may be lost or the plant will not produce a full crop. Several dozen sucking and gnawing pests feed on gourds, the most dangerous of which is considered the melon beetle. The biological and ecological features of this Zarafshan fauna in the conditions of the Zarafshan oasis are practically not studied, effective and environmentally friendly measures to combat them have not been developed.

    Therefore, we consider it relevant to study the biological and ecological characteristics of the melon beetle in the conditions of the Zarafshan oasis and develop environmentally friendly control measures. To do this, it is important to study the influence of environmental factors on the duration of the pest development phases.

    The beetle has a local name "Kakana", an insect from the Coleoptera family, the Coxinylidae family, the genus Epilachna. In the Zarafshan oasis, 37 of its species were identified.

    The beetle damages the aerial organs of gourds, cucumbers, watermelons, pumpkins and other gourds from the moment of their germination until the moment of harvest.

    Beetles and pest larvae gnaw through the leaves of the plant, leaving only the veins of the leaves, depressions form in the fruits, and the fruit rots, the yield drops sharply.

    The melon beetle causes great harm to the sprouts of melons, pest beetles completely eat the young sprout. Most often, the complete death of the plant is observed when the melon beetle and its larvae are damaged at the very peak of the growing season. Melon beetles cause especially great harm to late-ripening crops of gourds. At this time, a large number of beetles gather in the fields. On some plants, up to 43 beetles and up to 200-300 larvae of ground beetles can be counted.

    At the end of the harvest period, the pest feeds mainly on young melon fruits.

    Damaged melon fruits become unsuitable for storage and transportation, while many of them rot at once. The affected plant usually ends in small and unripe fruits. Fruit quality is reduced and weight is reduced. Severely affected plants do not bear fruit at all.

    The beetle and its larvae willingly eat melon leaves. In field conditions, it damages the leaves of melons most often by 95-100%.

    In the conditions of the Zarafshan oasis, the Beetle gives 4 full generations. The duration of the stages of development of the melon beetle depends on the ambient temperature and the relative humidity of the air, and the development of the larvae of the first generation lasts much longer than the 2nd and 3rd generations. The duration of the embryonic development of the eggs of the melon beetle of the 1st generation compared with the 2nd and 3rd generations differs only by a day, depending on the air temperature. And in the field, the difference in the duration of development of eggs and larvae stretches for 2-3 days.

 

Burkhon Fayzullaev

Samarkand State University

Associate Professor of the Department of Ecology and Life Safety