The probing behaviour of nymphs of Vanduzeea arquata and Enchenopa binotata (Homoptera: Membracidae) on host and non-host plants

1. Nymphs of Vanduzeea arquata Say have been found to be more host-specific in nature and to show a higher degree of selectivity in host discrimination experiments than nymphs of Enchenopa binotata (Say), It was hypothesized that this differential selectivity would be reflected in the probing behaviour of individuals placed on twigs of host and non-host plants. Probing behaviour was examined by direct observation of nymphs and by sectioning and staining the probed plant tissues. 2. All nymphs probed readily and for extended periods on both host and non-host twigs. E.binotuta nymphs showed no consistent differences in probing behaviour on hosts versus non-hosts, but V.atquuta nymphs were more likely to withdraw their stylets within 60 s when on non-host twigs and produced honeydew only when on their host species. V.urquatu nymphs reached the phloem sieve elements only when on host twigs and broke many cells in peripheral plant tissue layers while probing. E.binotata nymphs broke few cells and often reached the phloem of non-host as well as host plants. 3. Nymphs of V.arquata always reject non-host plants, apparently in the course of probing and prior to encountering the phloem sap. Chemical compounds released from ruptured parenchyma cells may act as probing stimulants or inhibitors. E.binotura nymphs often feed on non-host plants in a non-choice situation; their preferential settling on host twigs in discrimination experiments may reflect a tendency to abandon non-host twigs more readily than host twigs.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/72791/1/j.1365-2311.1984.tb00840.x.pd

Revis\ue3o de Alchisme Kirkaldy (Hemiptera, Membracidae, Membracinae, Hoplophorionini)

<abstract language="eng">Thirty four (34) species of Alchisme Kirkaldy, 1904 are presented with descriptions, illustrations, and key for identification, except for two of them which were not seen, A. truncaticornis (Germar, 1835) and A. intermedia (Distant, 1881). The following nomenclatural changes are introduced: Achisme intermedia (Distant, 1881), sp. rev.; A. testacea (Fairmaire, 1846), sp. rev.; Alchisme apicalis (Walker, 1851) = A. costaricensis Goding, 1929, syn.n.; A. inermis (Fairmaire, 1846) = Triquetra nigrocarinala Fairmaire, 1846, syn.n.; A. rubrocostata (Spinola, 1852) = A. neuquina Remes-Lenicov, 1978, syn.n.; A. turrita (Germar, 1835) = Triquetra submaculata Buckton, 1901, syn.n.; A. ustulata (Fairmaire, 1846) = Triquetra virgata Fairmaire, 1846, syn.n.; A. virescens (Fairmaire, 1846) = Alchisme spinosa Funkhouser, 1940, syn.n.; Alchisme banosiensis sp.n. (from Ecuador); A. bordoni sp.n. (from Venezuela); A. colombiana sp.n. (from Colombia); A. salta sp.n. (from Argentina); A. cultellata sp.n. (from Venezuela); A. deflexa sp.n. (from Venezuela); A. erecta sp.n. (from Venezuela); A. frontomaculata sp.n. (from Brazil); A. goiana sp.n. (from Brazil); A. henryi sp.n. (from Venezuela); A. insolita sp.n. (from Colombia); A. mackameyi sp.n. (from Ecuador); A. onorei sp.n. (from Ecuador); A. schuhi sp.n. (from Peru)

Novos gêneros e espécies de Hoplophorionini (Hemiptera, Membracidae, Membracinae) New genera and new species of Hoplophorionini (Hemiptera, Membracidae, Membracinae)

<abstract language="eng">Two new genera - Potnioides gen.n. and Sakakibarella gen.n. - and five new species are proposed: Potnioides corniculatus sp.n. (Peru, Cuzco), Sakakibarella seminigra sp.n. (Costa Rica, Turrialba), S. costaricensis sp.n. (Costa Rica, Heredia), S. elongaia sp.n. (Costa Rica, Alajuela) and S. maculata sp.n. (Colombia, Huila)

Revisão do gênero Potnia Stål (Homoptera, Membracidae, Membracinae, Hoplophorionini) Revision of the genus Potnia Stål (Homoptera, Membracidae, Membracinae, Hoplophorionini)

<abstract language="eng">Fifteen species of Potnia Stål, 1866 are presented with descriptions, illustrations and a key for identification. The following nomenclatural changes are introduced: P. knightae sp.n. (from Guiana), P. miracyae sp.n. (from Costa Rica), P. diringshofeni sp.n. (from Brasil), P. webbi sp.n. (from Brazil), P. turrialbensis sp.n. (from Costa Rica), P. pinheiroi sp.n. (from Brazil), P. tapuruquarensis sp.n. (from Brasil), P. cornigera sp.n. (from Brazil) and P. inca sp.n. (from Peru). Potnia venosa (Germar, 1821) = Aconophora nigrivittata Walker, 1851, syn.n. = Potnia perobtusa Fowler, 1894, syn.n.. Potnia brevicornis Fowler, 1894, sp. reval. = Potnia brunneifrontis Funkhouser, 1943, syn.n. = Potnia maculata Funkhouser, 1943, syn.n.. Potnia jacula (Fabricius, 1803) = Potnia orthosoma Fonseca & Diringshofen, 1974, syn.n