The finding of a micropterous new species in a flower-living thrips group species

A  new  species known only from micropterae, Kakothrips borberae,  belongs  to genus in which species live in the flowers of Fabaceae, and which is recorded mainly from South Europe  or the Mediterranean Region. This new species  was described from adults of both sexes that were collected in a small mountain area of Piedmont Appennines-about 1400 m asl-  called Valle di Borbera  (Alessandria, North- West  Italy). The  species was in Vicia flowers, and was found only in early  May  but in several years of collecting at the same locality. This might be an interesting  case of a short-winged species in a genus that is  known as having  only fully-winged  adults in both sexes.

Fig. 1. A. Female of Kakothrips borberae Marullo & Ravazzi.
B. Male of Kakothrips borberae Marullo & Ravazzi.

The presence of  wings in small and highly vagrant insects as thrips, increases their dispersive ability, but also it  has some effects on mating  systems and thus patterns of speciation. Moreover, wings can be reduced or absent in one or both sexes of many species, but  there is a very little  knowledge about the selective advantages of wing reduction or of the factors determing it. Intraspecific variation in wing length is probably  an ancestral   mode of thrips. However, within any species , wing development is usually monomorphic or dimorphic; rarely does any species exhibit more than two of the three potential morphs, macroptera, microptera and aptera. In a few species studied experimentally  for wing production and development , the influencing factors have been day length, population density and availability of healthy food. Increase in population density  and the reduction in the other two conditions favours the full development of wings. Identification of the new species is difficult: females  share the main morphological characters with other con-generic, southern European, species, in particular with Kakothrips acanthus Berzosa, K.firmoides Priesner and K.priesnerorum Bournier. However, K. borberae is distinguished by the colour of the third antennal segment, tibiae and fore tarsus, and the chaetotaxy of the pronotum and tergite IX. Males of K. borberae, firmoides and acanthus cannot be distinguished on the chaetotaxy of tergite IX or sternite IX. Only the shape of the sternal pore plates distinguishes males of the species  in Kakothrips genus, so that the availability  of males  is a  basic condition for the morphological diagnosis  of these species. The difficulties  of identification and the scanty knowledges on biology could  suggest to thysanopterologists to carry out molecular studies , through barcoding method (COI) both for diagnosis of a species and the possible intra-specific variation. Moreover, some ecological studies on these species  could be interesting in order to better understand environmental relationships and , in particular, the insect-host plant  ratio.

Rita Marullo
Department of Agriculture, Mediterranean University of Reggio Calabria, Italy

 

Publication

The first micropterous species of the southern European genus Kakothrips (Thysanoptera: Thripidae).
Marullo R, Ravazzi G
Zootaxa. 2016 Jan 25

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