Elephant Hawk Moth Caterpillar -Deilephila elpenor (Gransden Wood WTNR)

 The caterpillars are seen from July to September and are very characteristic: greyish-green or brown with two enormous, black eyespots towards the head. When disturbed, they swell up to show these spots and scare-off predators. The caterpillars feed on willowherbs, fuchsia and bedstraw, and the adults feed on nectar. The caterpillars overwinter as chrysalides, hidden amongst low vegetation or in the soil.

To see the adult moth click here 

Rhingia rostrata- type of hoverfly (Gransden Wood WTNR)

Description
Wing length 7.5 to 9.5 mm. Similar to the much more common R. campestris, but in Rhingia rostrata the thorax is more bluish in colour, there are no dark edges to the abdomen, the legs have more orange and less black and it is generally brighter in colour being yellowy orange rather than a duller brownish orange.
Similar Species
Rhingia campestris

Habitat
It seems to be found mainly in woodland (especially semi natural woodland).
When to see it
April to October peaking in August and early September.
UK Status
This species has undergone a major range expansion and is now widespread across the southern half of Britain to North Wales.