Effect of attractants on activity and abundance of insect pollinators in cotton (Gossypium hirsutum)

Abstract

Cotton (Gossypium hirsutum L.) is regarded as partially cross pollinated and largely self pollinated crop; thereby enhancement in the activity of pollinators into the crop during flowering may result into increased quantity and quality of cotton seed. Therefore, the present study was carried out at the experimental farm of ICAR-Central Institute for Cotton Research (CICR), Regional Station, Sirsa, Haryana on a Gangetic alluvial soil during rainy (kharif) season (April– October) of 2016–17 and 2017–18 under split-plot design keeping genotypes as main plot treatments and spray of 3 attractants, hand pollination and a control as sub-plot treatments to study the activity of various pollinators in cotton and effects of various attractants on abundance of these pollinators. Honey bee, bumble bee, wasp, ants and others pollinators (butterfly, dragon fly, and carpenter bee) were recorded on cotton plant and flowers of different genotypes of cotton. The observations were recorded before and after spray of various attractants for different pollinators. Honey bees were the most abundant recorded species (mean pre-treatment population 0.22–0.23 per plant) of pollinators followed by wasp and others (butterfly, dragon fly and ants) which regularly visited the cotton. The various attractants, i.e. spray of molasses, sugar solution, rose extract @10% concentration, hand pollination and a control (natural pollination occurred) applied thrice during the season did not significantly affect the activity of the pollinators. The highest boll (72 and 63%) and seed setting (83.6 and 84.3%) was recorded in treatment where hand pollination was practised followed by application of molasses to attract the pollinators without any significant effect on yield.

Keywords

• Attractants, Bumble bee, Cotton, Diversity, Honey bee, Pollinators, Wasp