J. W. Evans.
The Inter-relationships of Certain Jassoid Genera (Jassoidea, Homoptera).
Psyche 48(2-3):113-121, 1941.

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19411 Jassoid Genera 113
THE INTER-RELATIONSHIPS OF CERTAIN
JASSOID GENERA (JASSOIDEA, HOMOPTERA)
Department of Agriculture, Hobart, Tasmania As a result of a study of Australian leaf-hoppers which has extended over several years, certain conclusions have been reached concerning the classification of this group of insects that disagree with the generally accepted ideas on the subject. These conclusions have already been published (Evans, 1939). The purpose of the present paper is to draw attention to the new proposed classification in so far as it affects certain genera represented in the North Ameri- can fauna. It is not intended to repeat the arguments on which the new system is based, nor to give lengthy diag- noses of characters. Instead, recourse is made to brief comparisons supported by illustrations. These it is hoped will suffice to stimulate interest in the new proposals, and help to pave the way to a system based more on genetic affinity than on superficial characteristics. The genera concerned are, Bythoscopinae : Bythoscopus Germ., Agallia Curtis, Idiocerus Lewis, Macropsis Lewis, Oncopsis Burm., Neopsis Oman ; Gyponinae : Gypom Germ., Penthimia Germ., Xerophloea Germ. ; Jassinae : Jassus Fabr., Euscelis Brull6, Dowcephalus Kirsch., Hecalus StAl, Spanbergiella Sign., Parablocratus Fieb., Nionia Ball; Koebelinae : Koebelia Baker.
Following Baker (1923), it has been found convenient to regard each of the more distinct groups of leaf-hoppers as a family unit, and the re-arrangement of the above genera into families on the basis of my system results in the following groupings :
f Hecalini - Hecalus, Parablocratus,
1 GypOninae
Spanbergiella
Gypmini - Gypom
Bythoscopidae Bythoscopinae
\
Bythoscopus
1 Penthimiini -- Penthimia
Penthimiinae
(Thaumatoscopini*)
*Not represented in North America.




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114 Psyche [ June-Sept.
Euscelidae, Euscelis. Agalliidae, Agallia. Macropsidae, Macropsis, Oncopsis, Neopsis. Idioceridae, Zdiocerus. Jassidae, Jassus. Thymbridae, Nionia. Ledridae, Dory- cephalus, Xerophloea. Stenocotidae, Koebelia. Whilst certain of the proposed changes, such as the separa- tion of Euscelis, Idiocerus and Jassus, have been suggested previously by other workers, others, in particular the associ- ation of Bythoscopus, Hecalus, Penthimia and Gypona, are original, and may at first sight appear absurd. If in time the alterations proposed should become accepted in whole or even in part, it will not be the first occasion on which a Figure 1. Head of a nymph of Tartessus sp. ac., ante-clypeus;
pc., post-clypeus; f., frons; cis., clypeal suture; fs., frontal suture; v., vertex ; cs., coronal suture ; eps., epicranial suture. knowledge of the Australian representatives of a group of organisms has led to a radical change being effected in the basic classification of the same group in other faunal zones. The usual arrangement of the various genera into sub- families on the basis of the position of the ocelli is clearly artificial and several workers have stressed this fact in the past. Nevertheless, whilst the position of the ocelli may be of little significance, the shape and structure of the head as a whole affords the most reliable single diagnostic charac- ter. Because certain terms will be used in referring to the head that are not commonly employed, a figure of the head of a nymph of Tartessus sp. is given with certain of the sutures and sclerites indicated (Fig. 1). This particular insect has been chosen for illustration as the front is present as a separate sclerite. With the backward migration of the dilator muscles of the sucking pump, the epistomal suture, which separates the clypeus from the frons, disappears;



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19411 Jassoid Genera 115
such a condition is found in all adult leaf-hoppers. The
sclerite made up in part of the frons and in part of the post- clypeus, will be referred to as the fronto-clypeus. It may be entirely central in position or extend onto the crown, and may, or may not, be directly continuous with the vertex. The morphology of the head of Homoptera has been fully dis- cussed in three recent publications (Spooner, 1938 ; Evans, 1938 ; Snodgrass, 1938.)
Figure 2.
a, b, e, Eurinoscopus puwtatus; c, d, g, Bythoscopus lank; f, Eurinoscopus sp., male genitalia; fr., fronto-clypeus. The principal features of the external structure of Bytho- scopus lanio (L.) and Eurinoscopus spp. are shown in Figure 2. Eurinoscopus Kirk. is an Australian genus which according to Oman (1936) is synonymous with Bythoseopws. In Figure 3 the corresponding parts of Reuteriella flavescens Sign. are illustrated. This is an Australian leaf-hopper, which, because of the marginal position of the ocelli, would presumably be placed in the Jassinae by most Hemipterists. It is unnecessary to do more than draw attention to the very close similarity between the two groups of illustrations. The differences are, that in ~thoscopus, a frontal and an epicranial, but not a coronal, suture are retained, the reverse being the case with Reuteriella. The ocelli in the two genera are in identical positions, as is shown by a comparison of Fig. 2, d with Fig. 3, e, except that the backward extension of the muscles of the sucking-pump and the accompanying



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116 Psyche [ June-Sept.
flattening and production of the head have changed their aspect in Reuteriella.
The process arising from the ventral internal margin of the pygophore of the male genitalia of R. ftwuescens is sec- ondary, and of only specific value as a diagnostic character. Quite apart from structure, in appearance, habits and colora- tion, Reuteriella spp. and Eurinoscopm spp. are very similar. Figure 3. Reuteriella flavescens; c, 2 ; d, 8. If it is accepted that Reuteriella should be grouped with Bythoscopus rather than in the Jassinae, there seems to be no good reason why Hecalus, Parablocratus and Spanber- giella should not also be placed in the Bythoscopidae. Al- though species in these genera may lack the character of having R4 + 5 fused apically with Mi + 2 in the wing, all have similarly shaped heads and pronota and flattened hind tibiae with an almost identical armature of spines. Furthermore, the tegminal venation is not basically dissimilar. Figures are given (Fig. 4, d-g) of Spanbergiella vulnerata (Uhl.) and Parablocratus glaueescens Fabr. (a Tunisian species). The relationship of Gypona to Bythoscopus is not quite so apparent, but it is believed that Krisna strigicollis (Spin.), which occurs in Borneo (Fig. 5 a-e), is close to Reuteriella. A comparison of these figures with Figure 5 ai-dl suggests that the two genera are not far removed from each other. Moreover, if Penthimia is grouped with Gypona, as is usually done, then the case for the inclusion of Gypona in the Bytho- scopidae is strengthened. A comparison of the head of



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19411 Jassoid Genera 117
Bythoscopus and Penthimia, illustrated in Figures 2, c and 4, b respectively, will show that the genera resemble each other in essential head structure. The occurrence of the hindmost part of the fronto-clypeus on the crown in Pen- thimia is a purely secondary feature brought about by the production and inflation of the fronto-clypeus. The Thau- matoscopini are a tribe comprising Australian genera that show complete gradation between species with ventral ocelli and rounded heads, and others with dorsal ocelli and spatulate heads.
Figure 4. a-c, Penthirnia americana; d, e, Spanbergiella vulnerata; f, g, Parablocratzis glauscens; h, i, Thamnotettix cockerelli. This family, which comprises genera related to Euscelis, such as Thamnotettix Zett., Eutettix Van D. and Delto- cephaLus Burm., though distinct from the Bythoscopidae, is probably an offshoot from it. It is almost certain that Hecalus, Parablocratus and Spanbergiella are nearer to Bythoscopm than to Eziscelis. For the purpose of com- parison, figures are given of Thamnotettix cockerelli Ball. (Fig. 4, h, i).
Agallia does not closely resemble Bythoscopus in shape, size, or coloration, nor in a single character of any signifi- cance; neither do any of the numerous genera usually asso-



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118 Psyche [ June-Sept.
ciated with Agallia. For comparison with the illustrations of Bythoscopus, figures are given of Euragallia farculata (Osb.) (Fig. 6, g-i).
Figure 5. a-e, Krisna strigicoLLis; a, Gypona scarlatina, b-d, Gypona 8-lineata.
Macropsis and Oncopsis likewise present no essential fea- tures in common with Bythoscopus. Oman (1936) has sug- gested that Neopsis Oman is intermediate in character be- tween Macropsis and Bythoscopus. Through the kindness of Mr. Oman I have been able to examine a specimen of the genotype, N. elegans Van D., and am of the opinion that without any doubt it should be placed in the Macropsidae, any resemblance it may have to Bythoscopus being purely superficial. All the Macropsidae have a character in com- mon that does not occur in representatives of other families. This is, that when the muscle impressions of the sucking- pump are visible on the fronto-clypeus, they are invariably confined with a pair of crescent-shaped markings. In 1936 Oman removed Idiocerus and related genera from the Bythoscopinae and referred them to the Eurymelinae. Whilst in agreement with the separation, I do not support



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19411 Jassoid Genera 119
the new combination. The following characters which occur in all the Eurymelidae are not found in Idiocerus'. in the head the epicranial sutures are invariably retained; in the tegmen the media has always two, and sometimes three, distinct branches; in the male genitalia the aedeagus is not in direct contact with the basal plates. Quite apart from these features, the Eurymelidae differ from the Idioceridae in shape, coloration and habits. Figures of Idiocerus dolosus Ball (Fig. 6, d-f), are given for comparison with those of Bythoscopus.
Figme 6. a, Macropsis tasrnaniensis; b, c, Oncopsis distinctus; d-f, Idiocerus dolosus ; g-i, Eura*gallia furculata. Figures are not given of a representative of this family, but there seems no good reason why genera such as Jassus Fabr. and Tharra 'Kirk. should be associated with forms such as Ezi~celis and Thamnotettix.
Oman, in referring to Nionia Ball, states that it was cor- rectly placed by Ball as a relative of Tartessus St%, but was more closely related to Thymbris Kirk. and Epipsychidion Kirk. I have not had an opportunity of examining a speci- men of Nionia, but, if it is closely related to Thyrnbris, it is



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120 Psyche [ June-Sept.
presumably a member of the Thymbridae, which contains several Australian genera and a single New Zealand genus. Thus it cannot be very close to Tartessus. The Tartessidae contain a number of genera which now occur in Australia, New Guinea, the Phillipines, New Caledonia and Mysol and which all have certain unique characteristics. One of these is the continuation of the ambient vein of the wing onto the anal area. The tegrnen of Mesojassoides gigantea Oman from Cretaceous deposits of Colorado figured by Oman (1937), is very similar to that of a present-day Tartessus, and suggests that this family had a wider distribution at one time than it has at present.
Figure 7. a-c, Xerophloea viridis; d, f, Rubric, sanguinea; e, g, Ledropsis crocina; h-j, Dorycephalus plut~yrhynchus. Xerophloea is usually placed in the Gyponinae because it has dorsal ocelli and is clearly not close to Cicadella Latr., Dorycephalus having marginal ocelli is placed in the Jassi- nae. Both genera are much closer to genera in the Ledridae, as may be seen in Figure 7, where figures of the Australian Ledrids Rubria sanguinea Stiil and Ledropsis crocina Dist. are placed beside others of Xerophloea viridis (Fabr.) and Dorycep halus platy~hynchus Osb.




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19411 Jassoid Genera 121
Baker (1923) considered Koebelia to be intermediate be- tween Ulopa Fall. and Paropia Germ. on the one hand, and Stenocotis Stgl on the other. For reasons previously given, (Evans, 1939), there would seem to be no justification for placing Koebelia californica Baker in a separate family, when it is essentially a Stenocotid.
Baker, C. F. 1923. The Jassoidea related to the Stenocotidae. Phil- lipine Journ. Sci. 23 (4) : 345.
Evans, J. W. 1938. The Morphology of the Head of Homoptera. Papers Roy. Soc. Tas. 1937-38: 1.
Evans, J. W. 1939.
A Contribution to the Study of the Jassoidea. Papers Roy. Soc. Tas. 1938-39: 19.
Oman, P. W. 1936. A Generic Revision of American Bythoscopinae and South American Jassinae. Bull. Univ. Kansas 37(14) : 343. Oman, P. W.
1937-
Fossil Hemiptera from the Fox Hills Sandstone (Cretaceous of Colorado).
Journ. Palaeontology 11 (1) : 38.
Snodgrass, R. E. 1938. The loral plates and hypopharynx of Hemiptera.
Proc. Ent. Soc. Washington 40(8): 228.
Spooner, C. S. 1938.
The Phylogeny of the Hemiptera based on a study of the Head Capsule. Illinois Biological Monographs 16 (3).




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