Bugs at Belfairs

Dock Bug

As July’s theme is “Bug Bonanza”, this month we will focus on five “true” Bugs of the many "bugs" you can find here at Belfairs.

Dock Bug- Coreus marginatus

Bugs are insects in the order Hemiptera. These insects are characterised by their piercing, sucking mouthparts. The name “Hemiptera” comes from the Greek for “half wing” due to the fact that many Bugs have wings that are half hardened and half membranous- as can be seen in the photo of the Dock Bug Coreus marginatus below.

The piercing, sucking mouthparts of Hemiptera are often used for sucking out plant saps. There are nearly 2000 species of Hemiptera in the UK, many of which are quite specific in which plants they will feed on. For example, the Dock Bug will normally feed on plants in the Dock Family.

Dock Bug

Dock Bug

Cow-wheat Shield Bug- Adomerus biguttatus

The Dock Bug introduced above is oligophagous, meaning it feeds on a few different species. Here at Belfairs we have a Bug that largely only feeds on a single plant species; the Cow-wheat Shield Bug. Pretty much only feeding on Cow-wheat and generally found in sunny woodland clearings, this Bug is quite scarce in the UK but the coppiced woodland with abundant Cow-wheat that we have here at Belfairs means that we do find this attractive little Bug here.

Cow-wheat Shield Bug

Cow-wheat Shield Bug

Horned Treehopper- Centrotus cornutus

Not all Bugs are so specific in the range of plants on which they will feed. An example of a polyphagous Bug (one that will feed on many different plant species) found at Belfairs is the amazing Horned Treehopper, with young which feed on a variety of herbaceous plants and adults that feed on a variety of woody plants. There are only 2 species of Treehopper in the UK, the other being Gargara genistae. Gargara genistae is restricted to Southern England and associated with Broom, which there is a lot of at Belfairs- so this is definitely a species to keep an eye out for here too.

Horned Treehopper

Horned Treehopper

Willow/Umbellifer Aphids- Cavariella spp.

As mentioned above, young Treehoppers feed on herbaceous plants and adults on Woody plants. Many species of Aphids will also exhibit this alternation between woody and herbaceous hosts. However, Aphids tend to be much more host specific- there are over 600 species of Aphid in the UK, including 8 that alternate between Willows and Umbellifers alone. A further difference between the Treehoppers and the Aphids is that the host alternation in the Treehopper happens within a generation, with young Treehoppers switching food plants as they age, whereas Aphid host alternation is between generations. Many species of Aphid have interesting and complex reproductive and feeding ecologies with asexual reproduction occurring on a herbaceous host through the summer, prior to sexual reproduction occurring in the autumn followed by overwintering on a woody host. Through the summer here at Belfairs, keep an eye out for large aphid colonies occurring on Hogweed.

Aphid Colony on Hogweed

Aphid Colony on Hogweed

Black Cherry Aphid- Myzus cerasi

Further complexity in Aphid behaviour comes from the fact that the switching between hosts and reproductive method is influenced by environmental factors. This can be seen at Belfairs with a few species of Aphid that remain on their woody host throughout the summer. Some of the Cherry trees here at Belfairs have a number of curled up leaves that contain colonies of Myzus cerasi. The picture below shows one such colony.

 

Black Cherry Aphid

Black Cherry Aphid