(389 SNbim) Sminthurinus bimaculatus (Axelson, 1902)

*biflavopunctatus Collinge & Shoebotham, 1909
*fenestratus Börner, 1909

Sminthurinusspecies are very variable in colour pattern and it is essential to examine the presence or absence of ventral subapical setae on the dens in order to make a correct identification.
The Sminthurinus 'aureus -group' includes species of Sminthurinus without ventral subapical setae on the dens. According to Bretfeld (1999), specimens without clear patterning on the abdomen should be recorded under the name Sminthurinus aureus. Specimens with clear patterning on the abdomen should be recorded under the names Sminthurinus elegans (four longitudinal bands), Sminthurinus signatus (two longitudinal bands) or Sminthurinus bimaculatus (black with a pronounced white spot on either side of the abdomen). However, it is possible that all these 'species' are simply colour varieties of one taxon that should be called Sminthurinus aureus. For the moment, I have decided to key them out separately.
Apart from the colouration, the morphology of Sminthurinus bimaculatus is identical to that of Sminthurinus aureus. It reaches 0.7 mm in length. The fourth antennal segment (ant4) is NOT subdivided. The outer margin of the mucro is smooth and the inner margin is serrated. The female sub-anal appendages (SAA) are feathery at the tip and the long setae surrounding the anus are expanded at the base. Ventral sub apical setae are NOT present on the dens. The empodium of the third leg (leg3) is slightly shorter than the claw, but is slightly longer than the claw on leg1 and leg2.
There are a few scattered literature records for Sminthurinus bimaculatusfrom hothouses, but also from localities out of doors. Most records are from flower pots. However, without checking the presence or absence of ventral subapical setae, it is impossible to know the identity of these specimens. They could have been confused with Sminthurinus trinotatus which also has two white spots (but has two ventral subapical setae on the dens).
There are no specimens of Sminthurinus bimaculatus in the NHML slide collection.

 

 

 


 
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