Mirid bugs as an emerging threat to bottle gourd cultivation: Dynamics and management

Abstract

First record of concurrent occurrence of mirid bugs Nesidiocoris cruentatus (Ballard) and Metacanthus pulchellus Dallas as serious and emerging pests of bottle gourd from Varanasi, Uttar Pradesh, India is reported hereunder. Studies carried out during 2016-17 indicated that about 70-80% fruits and 30% shoots were damaged by these bugs. Infested leaves showed, minute puncture spots with yellow hallows. Damage was more prominent on young fruits with typical brown puncture spots on the rind with sap oozing out were the characteristic symptoms of these sucking pests. Affected fruits therefore had significantly reduced market value. Studies on species composition of two mirid bugs showed that N. cruentatus was dominant species contributing overall 68.63% of the mirid bug population infesting bottle gourd followed by M. pulchellus (31.37%). N. cruentatus exhibited a strong diurnal activity as its incidence increased during day time gradually from 10 am onwards, with peak occurrence at 1 pm (3.88 bugs/fruit). Amongst the biopesticides evaluated under laboratory conditions, neem oil (1%) was found most promising with lowest median lethal time (50.31 h) followed by Beauveria bassiana (52.26 h) and Lecanicillium lecanii (56.59 h), whereas Flonicamid 50% WG and Spiromesifen 22.9% SC were most promising chemicals under field and laboratory conditions.

Keywords

• Bionomics
• Damage symptoms
• Entomopathogens
• Feeding preference
• Insecticides