DOI: 10.5061/dryad.rjdfn2zjj
title: Pathways for accidental biocontrol: the human-mediated dispersal of insect predators and parasitoids

description: The introduction of insect predators and parasitoids for biological
 control is a key method for pest management. Yet in recent decades,
 biological control has become more strictly regulated and less frequent.
 Conversely, the rate of unintentional insect introductions through human
 activities is rising. While accidental introductions of insect natural
 enemies can potentially have serious ecological consequences, they are
 challenging to quantify as their movements go largely unobserved. We used
 historical border interception records collected by the US Department of
 Agriculture from 1913 to 2018 to describe the diversity of entomophagous
 insects transported unintentionally, their main introduction pathways, and
 trends in host specificity. There were 35,312 interceptions of insect
 predators and parasitoids during this period, representing 93 families
 from 11 orders, and 196 species from these families. Commodity
 associations varied, but imported plants and plant products were the main
 introduction pathway. Most interceptions originated with commodities
 imported from the Neotropical, Panamanian, and Western Palearctic regions.
 Among the intercepted species, 27 % were found in material originating
 from more than one country. Two-thirds of species were polyphagous host
 generalists. Furthermore, 25 % of species had already been introduced
 intentionally as biological control agents internationally, and 4.6 % have
 documented negative impacts on native biodiversity or human society. Most
 of the intercepted species that have not been established in the USA are
 host generalists or have at least one known host species available. The
 unintentional transport of diverse natural enemy insects has the potential
 to cause substantial ecological impacts both in terms of controlling pests
 through accidental biocontrol and disrupting native communities.
 Characterising the insects being transported and their introduction
 pathways can inform biosecurity practices and management.
description: # Pathways for accidental biocontrol: the human-mediated dispersal of
 insect predators and parasitoids
 [https://doi.org/10.5061/dryad.rjdfn2zjj](https://doi.org/10.5061/dryad.rjdfn2zjj) This repository contains all the necessary files to carry out the analyses in "Pathways for accidental biocontrol: the human-mediated dispersal of insect predators and parasitoids." The code used is available in the "script_AB" R script. The commodities insects were intercepted are categorised according to the Harmonized Commodity Description and Coding System (HS), a six-digit code where 'HS-2' represents 2-digit 'chapters' describing commodity types (e.g. HS10 - Cereals). ## The data files uploaded are: families_type.csv - a list of intercepted insect families by order and type (predators or parasitoids). orders_interceptions.csv - the number of interception events and the number of unique families intercepted per insect order and type. orders_established.csv - the number of unique families and species established in the USA per insect order and type. regions_interceptions.csv - the number of interception events, and the percentage of total interceptions per biogeographic region. families_coms.csv - the number of interception events per insect family on each HS-2 commodity type. regions_coms.csv - the number of interception events, and the number of unique families intercepted per commodity class and biogeographic region. plant_coms.csv - the number of interception events, and the number of unique families intercepted per HS-2 commodity type classed as 'plants and plant products' and biogeographic region. ne_families_coms.csv - the number of interception events per insect family and HS-2 commodity type, for predator and parasitoid families intercepted at least 20 times. other_families_coms.csv - the number of interception events per insect family and HS-2 commodity type, for other insect families intercepted at least 20 times. species_coms.csv - the number of interception events per predator or parasitoid species and HS-2 commodity type, for species intercepted at least 10 times. specificity.csv - the host specificity and invasion status of the intercepted predator or parasitoid species. The variables in this file are: * specificity: the potential host range of each species (monophagous, stenophagous, oligophagous, or polyphagous) * biocontrol: whether the species has been intentionally introduced for biological control, or studied as a potential biocontrol agent globally * type: whether the species is a parasitoid or a predator of other invertebrates * US_established: whether the species has successfully established in the USA or not, based on 'United States Register of Introduced and Invasive Species (US-RIIS)' data * US_biocontrol: whether the species has been intentionally introduced for biological control within the USA or not * global_established: whether the species has successfully established anywhere outside of its native range or not * invasive: whether the species are listed as invasive by the 'Global Register of Introduced and Invasive Species (GRIIS)' * biocontrol_total: whether the species has been intentionally introduced for biological control, or studied as a potential biocontrol agent either globally or in the US * US_established2: whether the species has successfully established in the USA or not based on Turner et al (2021) 'International Non-native Insect Establishment Data'