  Pesticides are a kind of agricultural input, whose use can greatly reduce
yield loss, regulate plant growth, effectively liberate agricultural
productivity, and improve food security. The availability of pesticides in
economies all over the world is ensured by pesticide redistribution through
international trade and economies play different roles in this process. In this
work, we measure and rank the importance of economies using nine node metrics
in an evolutionary way. It is found that the clustering coefficient is
correlated negatively with the other eight node metrics, while the other eight
node metrics are positively correlated with each other and can be grouped into
three communities (betweenness; in-degree, PageRank, authority, and
in-closeness; out-degree, hub, and out-closeness). We further investigate the
structural robustness of the international pesticide trade networks proxied by
the giant component size under three types of shocks to economies (node removal
in descending order, randomly, and in ascending order). The results show that,
except for the clustering coefficient, the international pesticide trade
networks are relatively robust under shocks to economies in ascending orders
and randomly, but fragile under shocks to economies in descending order. In
contrast, removing nodes with the clustering coefficient in ascending and
descending orders gives similar robustness curves. Moreover, the structural
robustness related to the giant component size evolves over time and exhibits
an inverse U-shaped pattern.

Physics and Society