Sunday, 1 September 2013

caeruleopunctata

The form of Small Copper with little blue dots caeruleopunctata was evident at Mowsbury Hill today.

Meadow Grasshoppers

To continue the grasshopper theme, again at Mowsbury Hill, here's some photos of Meadow Grasshopper Chorthippus parallelus. I've no idea what is supposedly parallel, so can't help with a mnemonic for that.

This species has reduced wing lengths, slightly so in the case of the male, but greatly so in the female, rendering her essentially flightless. (There is a long-winged form that occasionally shows up, allowing dispersal of the species). I quite often see nymphs (the immature stages) of other species identified as Meadow Grasshoppers, because their short stubby wing buds have been misinterpreted as the adult wings of this species.

The shape of the pronotum helps with identification, in this species the front half is essentially parallel sided, but flares outwards in the rear half.

Like other grasshopper species this one has several different colour forms, a couple demonstrated here by the females.

Females:

Male (note the dark "knees" of the rear legs, a help in identification):

(Photos taken 03/09/13 retimed in the blog to bring grasshopper photos together)

Common Green Grasshopper

Another grasshopper species that can be found at Mowsbury Hill, Common Green Grasshopper, Omocestus viridulus. Here's a female. There must be males there too but I haven't spotted one yet. Will add a picture later when I've found one.


Lesser Marsh Grasshoppers

More scrabbling in the undergrowth, this time for Lesser Marsh Grasshoppers at Mowsbury Hill. This species may be found in long grassland over much of Bedfordshire and is not restricted to marshes.

These pictures show some of the colour variation. (Colouring doesn't really help much with ID'ing grasshoppers as several species have several colour forms).

This species' scientific name is Chorthippus albomarginatus, the second part meaning white-edged, which presumably refers to the white stripe along the wing edge in the female, not unique to this species though, so not a reliable characteristic. The male rarely has a white stripe.

The shape of the pronotum (the saddle-like covering of the thorax) is a help with identification in grasshoppers, in this species the front half has parallel sides and then it may be parallel or only slightly flared  outwards in the rear half. (Meadow Grasshopper flares out more).

This species is less hairy than the similar Field Grasshopper. (The pronotum of Field Grasshopper is quite differently shaped too - deeply pinched in the middle).

Females are larger and chunkier than the males. Males have proportionately longer antennae.

Females:

Males: