Monday, October 14, 2013

Differentiating Grasshoppers

Even in the cool drizzle on a tiny patch of reconstructed prairie, our MN field trippers found several grasshoppers clinging to the stalks.  We tend to take them for granted, but grasshoppers have their own distinctive life habits.

Differential Grasshopper- Melanoplus differentialis
The differential grasshopper is easily identified by the chevrons stacked on its femur, the "Vs" pointing to its hip.  The early instars are brighter shades of yellow-green to brown, darkening with age.  They are found in much of the US, generally in grasslands and weedy areas.  They have one hatch a year, occuring in mid summer.

They eat a wide variety of plants, preferring ragweed and sunflowers, and grow faster when eating forbs (herbacaeous flowering plants) instead of grasses.  Unfortunately, it tends to be gregarious and has a taste for eating out in agricultural crop fields with friends, lots of friends.
"The young will feed upon various grains, alfalfa and hay crops while the adults will attack the corn, cotton and deciduous fruit crops. A single swarm can often deplete a younger crop to nothing in a matter of a few days. Because this species has a tendency to stay in large swarms while eating, it is a serious issue for farmers in most of its range."  Wikipedia
Admirable Grasshopper- male
At first glance, the other specimen pictured above is less distinguished, just another brown grasshopper.  Most notable is the angular pointed head with two short antennae.  Their legs are relatively longer than many other grasshopper species.  Looking closely it has black lines demarcating square blocks along the side of its abdomen. 

It is a male admirable grasshopperSyrbula admirabilis.  The females are bright green with brown legs and abdomen, quite different from the male.
Male Admirable- Shelly Cox, MDC

Female Admirable - Jon Rapp

So what is so admirable about them?  For one thing, their civilized behavior.  They tend to congregate in weedy areas and thus don't compete with us for commercial food resources, staying politely in their own niche.  They also are an important member of the food web, feeding a wide variety of insect predators.

Eats weeds and feeds wildlife - how much more admirable can a grasshopper get?


No comments:

Post a Comment