Relationships between insect predator populations and their prey, Thrips tabaci, in onion fields grown in large-scale and small-scale cropping systems

Abstract

Onion thrips, Thrips tabaci Lindeman, is the primary pest of onion, which is grown in either large-scale, monoculture systems surrounded by other onion fields, or in small-scale systems surrounded by multiple vegetable crops. In 2011 and 2012, populations of insect predators and their prey, T. tabaci, were assessed weekly in onion fields in both cropping systems. Insect predator taxa (eight species representing five families) were similar in onions grown in both systems and the most commonly occurring predators were from the family Aeolothripidae. Seasonal population dynamics of predators and T. tabaci followed similar trends within both cropping systems and tended to peak in late July and early August. Predator abundance was low in both systems, but predator abundance was nearly 2.5 to 13 times greater in onion fields in the small-scale system. T. tabaci abundance often positively predicted predator abundance in both cropping systems.

Arthropod Communities in Urban Agricultural Production Systems under Different Irrigation Sources in the Northern Region of Ghana

“…First, we studied a highly mosaic-like, small-scale vegetable farming system characterized by a high spatial concentration of multiple crops with dozens of niches. This favors a homogenous distribution of most species in space and time, although changes in the dominance of specific feeding guild with crop type can be expected even in small-scale systems [ 79 ]. Plant species and their density affect arthropod communities significantly due to their variable plant architectures, specific traits, alternate microclimatic conditions, pest attractiveness, and nectar provision potential [ 80 ].…”

Interactions among genotype, environment and agronomic practices on production and quality of storage onion (Allium cepa L.) - A review

“…Thrips tabaci causes damage by feeding on leaf tissue and by transmitting other parasites, including Iris yellow spot virus (Gent et al 2006). The control strategies consist of: applications of predators of the genera Aeolothrips, Toxomerus, Sphaerophoria, Orius, Coleomegilla, Hippodamia (Fok et al 2014); chemical treatments with azadirachtin, spinosad, deltamethrin, methomyl, acephate and chlorpyrifos (Jensen 2005).…”

Detection and estimation of Mastigimas anjosi (Hemiptera: Calophyidae) populations on Cedrela fissilis trees

“…The highest number of individuals of natural enemies, collected in October, follows the same trend as the M. anjosi number due to the population dynamics of natural enemies being directly related to that of their prey or hosts. Larger pest populations support a greater number of natural enemies due to the increased supply of food/host, as observed for onion thrips, Thrips tabaci Lindeman, 1889 (Thysanoptera: Thripidae) and their predators from five families, including Aeolothripidae (Thysanoptera) on common onion plants, Allium cepa L. (Asparagales: Amaryllidaceae), with population peaks, respectively, in late July and early August in the central and western regions of New York, USA in 2011 and 2012 [ 49 ].…”