ODONATOLOGICA Journal of the Societas Internationalis Odonatologica

Contents Volume 34, Issue 1 2005

Cordero Rivera, A.; Lorenzo Carballa, M.O.; Utzeri C; Vieira V. Parthenogenetic Ischnura hastata (Say), widespread in the Azores (Zygoptera: Coenagrionidae) p. 1-9. Literature and personal information on the distribution of I. hastata and other odon. spp. in the Azores is reported. I. hastata and I. pumilio are recorded for the first time from the islands of Corvo and Sao Jorge, respectively. L hastata appears the most common and abundant sp. and its population is formed by only females (no males were ever recorded). The asexual reproduction of these populations was demonstrated by means of laboratory rearing during several generations. The dispersal ability of this sp. and the possible origin of parthenogenesis after its colonisation of the Azores are briefly discussed. The possible causes of threat are identified and the need for conservation measures is outlined.

Dijkstra, K.-D.B. The identity of some widespread and variable Phyllomacromia species, with a revised grouping of the genus (Anisoptera: Corduliidae) p. 11-26. Many Phyllomacromia spp. appear to be more variable than was hitherto realised. This has lead to the description of paler and darker forms as distinct spp. Fortunately, the genus is rich in morphological characters in both sexes. P. melania and P. overlaeti were described from female female and both have been allied with non-conspecific male male, leading to great confusion. P. melania is the female of the sp. known as P.funicularia rather than that of P. contumax, while P. overlaeti matches and not P. subtropicalisP. schoutedeni. With the identity of these female female clarified and the variation considered, many synonyms arise: R.funicularia, P. bredoi and P. martorelli are synonyms of P. melania; P. biflava, P. nyanzana, P. bifasciata, P. reginae, P. halei and P. leoni of P. contumax; and P. onerataP. clymene of P. monoceros; and P. subtropicalis, P. paludosa and P. royi of P. overlaeti. P. paludis is not synonymous with P. contumax but with P. paula. The taxonomy of this large genus is briefly discussed and a new species grouping is proposed.

Hofmann, T.A.; Mason, C.F. Competition, predation and microhabitat selection of zygoptera larvae in a lowland river. p. 27-36. The microdistribution of 4 lotic spp. was investigated in the field. Microhabitat selection of Calopteryx splendens and Erythromnia najas was further examined in the laboratory, individually at different larval densities and in the presence of the other species and a predator.  E. najas, Ischnura elegans and Platycnemis pennipes showed significant preferences for particular aquatic macrophytes compared to others in the field, whereas C. splendens did not discriminate between the investigated plant species. Only limited spatial separation was apparent between the larvae of different species, as preferences for the same macrophyte species were found.  When kept separate and at low densities, larvae of C. splendens and E. najas inhabited significantly different microhabitats in the laboratory. At high intraspecific abundances, spatial overlap between the two species became apparent as both increasingly occupied less preferred substrata, which is in concurrence with the ideal free distribution model of habitat selection. E. najas showed no change in perch selection in the presence of C. splendens at high densities.  In this instance, intraspecific competition therefore appeared to be more important than interspecific competition with other Zygoptera in determining the microdistribution of E. najas. In the field, the niches of the two species may be more adequately separated on the basis of prey selection or hunting behaviour. E. najas also actively reacted to the presence of a predator, indicating some flexibility of response regarding perch selection.

McKee, D.; Harvey, I.F.;Thompson, D.J.; Sherratt, T.N. Frequency of female colour morphs in populations of four coenagrionid damselflies (Zygoptera: Coenagrionidae). p. 37-49. Knowledge of naturally occurring andromorph and gynomorph frequencies in populations of coenagrionid damselflies is important for understanding the evolution of female-limited polymorphism. Here are reported the frequencies of andromorphs and gynomorphs in populations of Coenagrion puella, C. mercuriale, Xanthocnemis zealandica and Ischnura u-viatilis and a review is presented of the literature for other coenagtionid spp. It is shown that ratios of andromorphs to gynomorphs are often unequal with andromorphs generally being the uncommon morph. Significant inter- and intra-population variation in morph frequency sometimes occurs but is of low magnitude. No evidence was found for spatial segregation ofandromorphs and gynomorphs. Andromorph frequency could not be significantly related with sex ratio or male density.

Costa, J.M.; and Regis, L.P.R.B. Description of the last instar larva of Perithemis lais (Perty) and comparison with other species in the genus (Anisoptera: Libellulidae) p. 51-57. The external morphology is described, illustrated and compared with that of the congeners. A note on the habitat of P. lais is appended.

Machado, A.B.M. Peruviogomphus bellei spec. nov. from the Amazonian region of Brazil (Anisoptera: Gomphidae). p. 59-63. The new sp. is described and illustrated (holotype male: Brazil, Amazonas, Tefe,I-1958, A.L. Carvalho leg., deposited in collection A.B.M. Machado). By its size, colour and structure of the anal appendages, P. bellei sp. n. is closest to P. moyobambus Klots, 1944, but it can be separated mainly by the presence of a well-developed expansion on abdominal segment 8. It differs from the other 2 congeners by the presence of a denticulated area in the mid-part of the inner hindwing margin. The significance of this character for gomphid taxonomy is discussed.

Paulson, D.R.; Von Ellenrieder, N. Synonymy of Subaeschna Martin, 1908 with Gynacantha Rambur, 1842, and a new species of Gynacantha from Peru (Anisoptera: Aeshnidae). p. 65-72. Subaeschna Martin, 1908, is synonymized with Gynacantha Rambur, 1842, and its only sp., S. francesca Martin, 1909, becomes Gynacantha francesca (Martin). G. bartai sp. n. is described from 5 specimens (holotype male and allotype female; Peru, Madre de Dios, Explorer's Inn; deposited in the NMNH, Washington, DC, USA) from southern Peru. It is characterized by very small size, unmarked thorax, straight cerci, and abdomen constricted in male and unconstricted in female.

Pessacq, P.; Muzon, J.; Von Ellenrieder, N. Description of the last larval instarof Acanthagrion ablutum Calvert (Zygoptera: Coenagrionidae). p. 73-76. The final larval instar is here described for the first time and it is compared with the other known Acanthagrion larvae. It differs from them mainly in the number of palpal and premental setae and shape of head posterolateral margin.

Villanueva, R.J. Amphicnemis braulitae spec. nov. From Camiguin Island, The Philippines (Zygoptera: Coenagrionidae). p. 77-81. The new sp. is described, illustrated and compared with the other 3 spp. of the Amphicrientis forcipata. Brauer-group. Holotype 6: Philippines, Camiguin, Guinsiliban, Lilob, 30-IV-2003; deposited in RMNH, Leiden. A few notes on the ecology are provided.

Odonatological Abstracts p. 83-102.

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