DOI: 10.5061/dryad.1zcrjdfwb
title: Invasion of the coccinellid community associated with a tropical annual agroecosystem

description: To examine the potential effect of an invasive coccinellid (Harmonia
 axyridis) on the resident community of coccinellids, we sampled predators
 and prey associated with organic Brassica oleracea production on 6 farms
 during 2 years in the Distrito Federal, Brasil and conducted a food
 acceptability trial to estimate niche breadth and overlap among the
 coccinellids. The data are in two files. The first is a community sample
 data set, with columns describing the sample characteristics (year, farm,
 sample period) and the summed counts of all macroinvertebrates found on 30
 plants at each sample period, farm and year. There are 120 samples and 36
 populations of macroinvertebrates in the data set. The second data set is
 the acceptability of 4 aphid prey species to 3 stages of 4 species of
 coccinellids. There are 15 replicates of the 48 treatments. The data also
 include the biomass of the predators at the end of the experiment. Farms
 have been de-identified, and the data can be used by anyone without any
 legal or ethical considerations. The authors request that anyone who
 reuses the data provide and acknowledgement of this in any publication as
 well as a citation to the originating study.
description: Brassica oleracea production fields at six organic vegetable
 farms in the Distrito Federal, Brazil were examined during 2017 and 2018:
 15°39'06"S 48°06'33"W; 15°39'00"S
 48°12'01"W; 15°36'43"S 48°04'43"W;
 15°33'54"S 48°01'48"W; 15°44'18"S
 47°39'13"W; and 15°45'44"S 47°38'29"W. Data
 were collected under Brazilian authorization numbers SISBIO 36950 and
 IBAMA 02001.008598/2012-42. Crops were grown according to recommendations
 for organic production. Within each field, an area of about 200 m2 was
 designated as the sample area. Invertebrates were sampled at each farm
 every two weeks during the dry season (May to September, 10 sample dates
 total per year), because aphid populations, which are important pests of
 brassicas, are higher during the dry season. Each sample comprised a count
 of all invertebrates on 30 plants by visual inspection. All invertebrates
 were identified in the field to the lowest feasible taxonomic level based
 on pictorial keys and experts in the field. When aphids were sparse, we
 counted all aphids, but when they reached very high numbers we estimated
 the total population by subsampling the plant. We sampled 30 plants/sample
 time x 10 sample times/farm x 6 farms/year x 2 years = 3600 plants. For
 each sample date for each farm in each year, the per plant mean of each
 taxon was calculated. We determined the consumption of
 four species of aphids, Brevicoryne brassicae (L.), Lipaphis
 pseudobrassicae Davis, Myzus persicae (Sulzer) and Uroleucon ambrosiae
 (Thomas), by last instar larvae and adult males and females of four
 species of coccinellids, Hippodamia convergens (Guerin-Meneville), Eriopis
 connexa (Germar), Cycloneda sanguinea (L.), and the invasive Harmonia
 axyridis (Pallas). Previous research indicated that these aphids were
 consumed by all four coccinellids in agricultural habitats, including B.
 oleracea. Larvae were recently molted last instars, and adults were 5-10
 days old. All coccinellids were reared on field-collected aphids. Based on
 preliminary experiments, we placed 20 apterous aphids of one aphid species
 in a 15 cm petri dish with a moistened filter paper and one individual
 that had been starved for 16-18 h of either a larva, adult male or adult
 female of one of the coccinellid species starting between 9 and 10 am.
 After 4 h, we counted the number of remaining aphids. This design ensured
 that some but not all aphids were consumed by the coccinellids in the
 allotted time. All experiments were conducted at 25oC and the weight of
 the coccinellid was measured immediately after the experiment was
 completed. There were 4 aphids x 4 coccinellids x 3 coccinellid stages =
 48 treatments and 15 replicates of each treatment.
description: All data files are csv files and the contents of each are
 described in the README.txt file.