Small World Discoveries

HEMIPTERA > HETEROPTERA > CIMICOMORPHA > Miridae > Stenodemini

The Stenodemini tribe includes 19 mainly elongate species; vertex usually with a furrow and no pronotal collar.

The common Meadow Plant Bug, Leptopterna dolabrata is an attractive, sexually dimorphic, pale green species with greyish markings on the abdomen. The females are nearly always short-winged (brachypterous), whereas the males are fully-winged. The males darken with age, so occasionally you'll find individuals with orange-yellow forewings. They are very similar to Leptopterna ferrugata, although that species typically has reddish/pinkish forewings.

Both species are said to be common and widespread, and both are grassland bugs with the latter preferring drier habitats, whereas Leptopterna dolabrata occurs in both dry and damp areas.

The females can be distinguished by the markings on the exposed part of the abdomen. In this respect, the three different individuals featured here are clearly Leptopterna dolabrata as the markings are variable and broken, compared with Leptopterna ferrugata that has a pair of brownish, broad longitudinal stripes. Obviously, you can't see these marking in the long-winged males, but they can be determined by the length of the second antennal segment, which in Leptopterna dolabrata is distinctly longer than the length of the 3rd and 4th combined (as can be seen in the first photo). In Leptopterna ferrugata, the 2nd segment is about the same length as the final two segments which, coupled with the colour of the wings, should provide a positive id.

Leptopterna dolabrata is by far the more frequently observed species locally and, in fact, checking the NBN Atlas at the date of this revision, I discovered that Leptopterna ferrugata has only been recorded a handful of times from either Dorset (VC9) or South Hampshire (VC11) and with only two records in recent years.

The four Stenodema grass bugs are distinguished by their elongate form coupled with a longitudinal furrow between the eyes and a coarsely and densely pitted pronotum. They have a body length of around 7-9mm. The two common species Stenodema calcarata and Stenodema laevigata are very similar and could easily be confused, except that Stenodema calcarata has two spurs on the hind femora whereas Stenodema laevigata doesn't have any.

The other two species in the genus do not occur locally. Stenodema trispinosa has three femoral spurs, but is mainly confined to the south east, and Stenodema holsata, which is somewhat similar to Stenodema laevigata although a little shorter and broader, is more associated with upland habitats. These bugs overwinter as adults and emerge in the spring when the females of Steodema calcarata turn green while the males typically remain mostly straw-coloured, whereas with Steodema laevigata both sexes turn green, although males are often darker than the females. The new generation of straw-coloured adults start appearing in July or August.

Updated, Feb.25 (v.3)