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Yangshuo Day 07 – White Mountain & The Egg

Long Legs

There were all sorts of insects around, from those that buzzed around our heads to those that slowly crawled under our feet. The ones that immediately caught my attention were the one with long, long legs. There was one stick insect (Order : Phasmatodea) in particular that seemed very curious and wandered over to our bags and crawled over our climbing rope, whilst a harvestman (Leiobunum sp.) scuttled around in the underbrush.

Like spiders, harvestmen are arachnids. Arachnids are distinguished from other insects by several features, namely their four pairs of legs instead of three, and the fact that their head and thorax are fused into something called a cephalothorax, leaving them with two body segments instead of three. Harvestmen are not spiders though. Their body segments have taken it one step further and seem to have fused into just one segment. This is not the case of course, the connection between their abdomen and cephalothorax is just a lot wider, which makes it seem as if they just have one body segment. Harvestmen also do not have silk glands and as such are unable to build webs. Some harvestmen have been known to sway their bodies in order to confuse their predators, a tactic that is similar to that of some spiders!

A curious stick insect (Order : Phasmatodea); the joint between the body segments of this harvestman (Leiobunum sp.) is not obvious..

..whereas it is quite apparent on this orchard spider (Leucauge sp.)

All Shapes & Sizes

There were also several leaf-footed bugs (Family : Coreidae)--which are actual bugs--that were climbing over the plants around us. Most people tend to confuse them with stink bugs (Family: Pentatomidae) as their morphology is quite similar. One quick way to tell them apart is by the number of segments of their antennae: leaf-footed bugs have four segments, whilst stink bugs have five. In fact, the name that has been given to the family that comprises stink bugs, Pentatomidae, literally means 'five sections' in Greek!

Mictis gallina nymph (5th instar). The enlarging wings can be seen emerging from the posterior region of the metathorax,
and will eventually cover the abdomen; yellow marmorated stink bug (Erthesina fullo) nymph (4th instar)

Weevils also seemed to be relatively commonplace here. They are easily identified by their distinctive long snouts which they use to bore holes into plants before they lay their eggs. After hatching, the larvae then goes on to eat the plant from the inside out. As such, a lot of weevils are considered serious pests by the agricultural industry; even I have had my own fair share of gripes when dealing with the rice weevil (Sitophilus oryzae). One strange weevil that I came across was a female leaf rolling weevil (Subfamily: Apoderinae). The giraffe weevil is sexually dimorphic, and the neck of the male is most often multiple times the length of that of the female--hence the name.

Hypomeces weevil (Hypomeces sp.); female leaf rolling weevil (Subfamily: Apoderinae)

Next : Yangshuo Day 7 (Part 3) - The Egg