Invasion of the coccinellid community associated with a tropical annual agroecosystem

Abstract

1. Detailed understanding of the mechanisms enabling or limiting the impacts of invasive generalist predators is needed. Harmonia axyridis is an invasive generalist coccinellid predator that may have destabilised coccinellid communities worldwide and is an excellent candidate for investigating invasion dynamics.2. We evaluated four hypotheses: (1) Nine years after being detected in Central Brazil, Ha. axyridis has dominated the coccinellid community. This is facilitated by (2) its broader aphid prey range than the other aphidophagous coccinellids, (3) its superiority as an asymmetrical intraguild predator, and (4) the invasibility of the present coccinellid community.3. We sampled the invertebrate communities associated with six organic vegetable farms in Brazil during 2017 and 2018, conducted a feeding trial to measure prey niche breadth and overlap, and estimated intra-and interspecific interaction strengths corresponding to first-order Lotka-Volterra parameters to evaluate the strength of intraguild predation and create a community matrix. 4. We found (1) Ha. axyridis comprised ≤8.3% of the coccinellid community. (2) Hi. convergens had the broadest prey niche and dominated the prey niche of Ha. axyridis. (3) We could not determine from the population data if Ha. axyridis was the dominant intraguild predator because its density was too low and constant.(4) The community matrix indicated that the present-day coccinellid community was stable. 5. We conclude Ha. axyridis has not become invasive in Central Brazil, in part because it does not have the broadest prey niche breadth and the present coccinellid community is stable to the present perturbation of Ha. axyridis.

Landscape simplification, urbanization, biological invasions, and climate change: a review of the major threats to native coccinellids in Central Chile

“…Among coccinellids, the invasion of some very ubiquitous species, such as Coccinella septempunctata L. in the Nearctic region and H. axyridis worldwide, has resulted in a reduction in the abundance of native species and changes in local assemblages due to strong asymmetric interspecific competition and intraguild predation in favor of the invaders (Roy et al., 2016; Kenis et al., 2020; Brown et al., 2022; Soares et al., 2022). Nevertheless, this does not seem to occur in tropical countries, such as Brazil (Andow et al., 2023). In Chile, a population of H. axyridis was introduced from France in 1998, but it did not prosper.…”

Molecular characterization of mitochondrial COI gene sequences in Micraspis allardi from Pakistan

“…Ladybird beetles (Coleoptera; Coccinellidae) are found globally, with over 6,000 described species [1] classified in around 360 genera, of which 90% are regarded as beneficial with substantial agricultural significance in biological control programs [2,3] Micraspis allardi (Mulsant, 1866) is a predatory coccinellid with ecological distribution in Indonesia, Pakistan India, Nepal, Myanmar, Bangladesh, and Bhutan [4][5][6] with a host range consisting mainly of plant hoppers [7], aphids [8,9] and psyllids [10,11]. Although ecology, diversity and distribution of this species has been reported from Pakistan [4,12,13].…”