Declines in insect populations: consequences for parasites

Insect populations may be declining over large areas of the planet.
Recently, gene sequencing studies have suggested that a sizeable
proportion of insect species host unique parasite/symbiont species
(parasitoids, nematodes, mites, microsporidia, bacteria). This means
that Earth’s species richness is likely dominated by these parasites
and symbionts. Intuitively, insect parasites are likely to suffer even
more than their hosts from environmental change because they
generally only occupy a fraction of the host population. This suggests
that a large fraction (almost all) of Earth’s biodiversity may be at risk
from insect declines. However, conservationists have almost entirely
ignored how declines in host populations will affect parasites. This
project will seek to explore the consequences of insect declines and
current insect conservation strategies for the persistence of their
parasites. The work will inform conservation practitioners of the
consequences of current trends and practices for this largely ignored
majority of biodiversity. The project will use computer modelling
approaches to ask: (1) How is the persistence of insect parasites in
meta-populations affected by different likely scenarios of host insect
decline, including declines of different severity, changes to habitat
patch quality, patch number and size, and non-habitat matrix quality?
(2) How do different parasite biologies (parasitoid, symbiont,
pathogen) affect the probability of their persistence during host
declines? (3) How effective for the conservation of parasites are
conservation strategies that focus on the minimum viable landscape
for the host insect? The project will be mainly computer-based and
may involve some analysis of the published literature to find the most
realistic modelling parameters. The project will be suitable for a
student interested in computer modelling and conservation,
population and community ecology.