Content of review 1, reviewed on March 25, 2024
The manuscript explores data on introduced Hemiptera from selected regions globally and notes there are many invasive taxa. It is posited that patterns shown are due to a combination of traits related to the likelihood of being transported and species traits related to the likelihood of becoming invasive. This is an interesting analysis of an important group (particularly to production systems). Nonetheless it would seem more could be done to look at possible mechanisms or at least to develop testable predictions. To avoid an overly long discussion a summary table might be useful looking at hypotheses, expectations, evidence from the analyses presented here, and possible future tests?
A focus seems to be on the question of why propagule pressure might be high, but didn't go into much detail here. Taxa could be in the right place; were generally abundant; or are easily transported, etc... and likely a combination of these. Sinclair et al. (2020) might be a useful reference in this respect? It might be good to go a bit further so explicitly look at hypotheses, what data would be needed to differentiate them, and how addressing them would impact management. Are taxa easily detected so fewer missing samples, or a reduced time between introduction and detection? To what degree are the taxa flagged known as agricultural pests in their native range? Might be difficult to get at, but would provide an indication of whether the pattern in introduced ranges is exceptional.
All the comparisons inevitably have biases. But some here seem a bit hard to parse. Why might one assume native Hemiptera to be particularly related to alien Hemiptera or more so than numbers of alien plants (244)? One is a function of native biogeography the other much more a function of introductions per se. Could correct for differences in % introductions of different groups? Is this rather a function of the number of agricultural pests introductions? 308–314 I wasn't clear if the results could be used to separate the factors, particularly when one might suspect a mechanistic interplay between invasiveness traits and likelihood of transport and presence as pests on plants? So 407–408 more aliens plants is indicative of more movement of plants and insects could co-opt those pathways. Difficult to disentangle (is disentangling this important for management)?
Inferring introduction patterns based on detections. 379 might expect to see slower invasions play out and numbers catch up over time (so an influence of population growth rate). In addition to the reference to MacLachlan et al. 2021 (l436) a few potential references on how inferring introduction rates from data on new introductions is problematic (Belmaker et al., 2009; Solow & Costello, 2004), and within the context of indicators I've been involved in a recent paper on this (McGeoch et al. 2023).
What is the probability to see a shift onto a native plant host? To would degree is host specificity particular in relation to available hosts in a regions? I wasn't clear of the difference between established in cultivation (or on alien plants) and outside of captivity and cultivation (also on native plants)?
Finally an explicit pathway analysis might be useful. Discussed 309–310, but is what is seen unusual for that pathway?
Minor points
Perhaps in the abstract could include some quantitative results, e.g. as odds ratios, % established? Would be good to similarly provide odds ratios in the results.
31–32 How does p(interception) vary across the family?
38–40 maybe flag pathways? e.g., Hemiptera more likely moved as contaminants than other groups?
91 risks of introduction rather than invasion risks?
117 Global Register of Introduction and Invasive Species
147 lists are incomplete?
333–336 A very interesting point, is there any evidence for this? Samples from aerial plankton don't go back far enough and would be unlikely to pick up rare occurrences?
344 a more generic reference might be appropriate here? Perhaps use the recent IPBES Assessment (IPBES, 2023)?
381 agreed but why only a taxonomic shift? Need to link to native biogeographic patterns?
415 Really? Is competition an important mechanisms here? To what degree would they be regulating populations of other Hemiptera?
Figure 2 the colours chosen don't work well as grey-scale.
Figure 4 I found this hard to read, maybe larger panels in supplementary? One or two highlighted in the main manuscript to provide an indication or to note particularly important observations?
Figure S1 Maybe a plot of regions adjusted to the findings?
Best wishes,
John Wilson
(jrwilson@sun.ac.za)
P.S. For future reference, a new report out from South Africa was released a few weeks ago (Zengeya and Wilson 2023). The species list still has quite a bit to go but we should hopefully incorporate all relevant information in there in future.
Suggested References
Belmaker J, Brokovich E, China V, Golani D, Kiflawi M (2009) Estimating the rate of biological introductions: Lessepsian fishes in the Mediterranean. Ecology 90: 1134-1141. doi:10.1890/07-1904.1
IPBES (2023). Thematic Assessment Report on Invasive Alien Species and their Control of the Intergovernmental Science-Policy Platform on Biodiversity and Ecosystem Services. Roy, H. E., Pauchard, A., Stoett, P., and Renard Truong, T. (eds.). IPBES secretariat, Bonn, Germany. doi:10.5281/zenodo.7430682
McGeoch MA, Buba Y, Arlé E, Belmaker J, Clarke DA, Jetz W, Li R, Seebens H, Essl F, Groom Q, García-Berthou E, Lenzner B, Meyer C, Vicente JR, Wilson JRU, Winter M (2023) Invasion trends: An interpretable measure of change is needed to support policy targets. Conservation Letters 16: e12981. doi:10.1111/conl.12981
Sinclair JS, Brown JA, Lockwood JL (2020) Reciprocal human-natural system feedback loops within the invasion process. Neobiota 62: 489–508. doi:10.3897/neobiota.62.52664
Solow AR, Costello CJ (2004) Estimating the rate of species introductions from the discovery record. Ecology 85: 1822-1825. doi:10.1890/03-3102
Zengeya TA, Wilson JR (Eds) (2023) The status of biological invasions and their management in South Africa in 2022. South African National Biodiversity Institute, Kirstenbosch and DSI-NRF Centre of Excellence for Invasion Biology, Stellenbosch. , 122 pp. doi:10.5281/zenodo.8217182
Source
© 2024 the Reviewer.
Content of review 2, reviewed on June 10, 2024
The revised manuscript addresses the issues raised—I enjoyed reading it again. I had a few minor points and one slightly broader issue remaining.
The possible reasons for over-representation are much more clearly set out (89–90 and Table 1). Perhaps on Table 1 could separate into two columns, evidence and results from this analysis? Can then more clearly see what the contribution of this paper is? But in terms of reporting bias, this isn't mentioned in the abstract nor is there a specific analysis to test for it? I'm not sure there is one that can easily be performed (as previously parsing these things apart is tricky), but perhaps this can be made explicit, e.g. in the section 116–123 discuss potential for reporting bias but were not able to explicitly test for it? And on table 1 can discuss it, noting no specific test (340–341)? I'm not sure this is essential, but I suspect it would help a new reader?
Minor points
10 I know there isn't much room in the abstract, but quantifying the overrepresentation (20% greater than expected) seems to be important context?
21 regions rather than countries?
158+ maybe could include number (/relative number) of records and number of species? here (or perhaps in the results) so clear as to how big an issue each of these are? Conceptually removing eradicated species doesn't seem to be necessary if they had at one point been established (which is the thing tested here?), but I'm not suggesting to rerun all the analyses!
449 there is a new methods paper on this out (Buba et al. in press)
455–458 good point, but the sentence is a bit convoluted at present, maybe rephrase (trying to avoid too many negatives) or split into two?
Figures 3 and 5 To allow visual comparisons between establishment and interceptions, maybe plot together? Two panels on one page?
I look forward to see the manuscript in print soon.
Best wishes,
John Wilson
jrwilson@sun.ac.za
Buba Y, Kiflawi M, McGeoch M, Belmaker J. Evaluating models for estimating introduction rates of alien species from discovery records. Global Ecology and Biogeography, in press.
Source
© 2024 the Reviewer.
References
M., L. A., M., T. R., R., B. C., Cleo, B., E., B. R., G., B. E., E., C. C., N., M. J., H., M. S., F., N. H., L., O. C., S., P. D., Alain, R., A., S. S., F., S. A., Takehiko, Y. 2024. Why so many Hemiptera invasions?. Diversity and Distributions.