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Description of Tanyzonus bolitophilae

The two insects in fine condition here described are undoubtedly ♂ and ♀, as shown by the circumstances attending their discovery. The apterous ♀ differs widely from the other sex, yet not more than in the other cases of sexual disparity with which we are familiar among the Proctotrypids ; the discrepancies are mainly due to the loss of wings, a degradation of structure always accompanied by an undeveloped thorax ; and in this instance by the almost total obliteration of the ocelli, which seem to exist as mere rudiments under the integument of the vertex, while in the ♂ they are external and fully formed.

The antennae of the ♀ are 15-jointed, and those of the ♂ have the 3rd joint (or 1st joint of the flagellum) emarginate ; characters which, at once refer the insects to the group of Belyta rather than that of Diapria. On comparing them with Forster's tables and observations in the Hym. Stud., Hft. ii, which remain to this day the best authority upon the subject, but contain only European forms, I cannot assign them to any established genus, and it is necessary to invent a new one. This I have named Tanyzonus, in allusion to the attenuated form of the female thorax ; I believe this compound word, however obvious, has not been used before. The genus being founded upon both sexes, and accompanied by a biological notice from Mr. Hudson, the discoverer, which gives a glimpse of the unknown habits of an entire group, possesses a degree of completeness and stability far from common amongst insects of this kind.


♀. Oculi pilosi. Ocelli obsoleti. Antennae clavatae, 15-articulatae. Thorax angustissimus, compressus, ubique in eadem planitie situs qua et caput et petiolus, caetero abdomine multo minus elevatus ; prothorax in colli speciem breviter productus ; mesonotum spina obtusa utrinque armatum ; scutellum nullum ; metathorax horizontalis, apice quadrispinulosus. Alae omnino nullae. Pedes graciles, subelongati, femoribus tibiisque clavatis. Abdomen capite cum thorace paulo longius ; segmentum 1um metathoracis fere longitudine, cylindricum, angustum, 3-canaliculatum ; pars posterior maxima, elliptico-globosa, thorace fere quintuplo latior, e segmentis 5 (ut videtur) superne confiata, quarum tria apicalia brevissima, annuliformia, suturis aegerrime distinguendis . Terebra occulta.

♂. Longe alius. Oculi vix pubescentes. Ocelli conspicui. Antennae longiores, filiformes, 14-articulatae, articulo 3° extus exciso. Thorax omnibus numeris absolutus, elevatus, capite multo latior ; mesonotum bisulcatum, ad paraptera spinula utrinque armatum; scutellum optime determinatum, fossula antecedente instructum ; metathorax declivis, petiolo plus duplo latior, apice bispinulosus. Alae amplae, nervis sicut in Belyta instructae, sed cellula radialis longissima, apice aperta. Abdomen quale in ♀, sed nusquam thorace latius ; pars posterior minus inflata ; segmenta apicalia in conspectu 5 brevissima, annuliformia.


♀ . Rufo-testacea, oculis nigris ; paulo obscuriores sunt antennarum radiculae, prothorax, metathoracis limbus undique, petioli basis cum segmenti 2di margine antico. Corpus totum Iaeve, pills pallidis plus minus obsitum.

♂. Niger, antennis, mesothorace, pedibusque rufis ; abdomen infra et apicem versus rufo-piceum. Alae subhyalinae, nervis et puncto stigmatico sordiderufo-testaceis; praesto sunt in ala anteriore nervus subcostalis ; radialis costae parallelus, ante alae apicem abruptus ; intercubitalis 1us curvatus, imperfectus ; cubitalis hasi et apice obsoletus ; praebrachialis completus ; analis basi incompletus : in ala posteriore nervus subcostalis, praebrachialis transversus. Long., ♂ ♀ , 2 lin. ; alar, exp., ♂, 41/2 lin.

I abstain from giving tedious details, as the accompanying outlines will give a better idea of these creatures than many words, and I flatter myself that they will now be unmistakeable, at least, until other species of the same genus shall be discovered. I have not taken any characters from the under-side, the specimens being carded ; hence the oral organs could not be described, but they may be pretty safely assumed to resemble those of Belyta, Anectata, &c., and their details would have been of little value. The under-side of the abdomen of the ♀ should, however, have been examined, in order to count the segments, the sutures being hardly visible from above. The 2nd and 3rd segments are soldered into one, which covers almost the whole abdomen like a shield, leaving only the narrow edges of the apical segments visible, and these, in the ♀, are not easily counted.


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Supplier: Katja Schulz

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