Responses of mosquitoes of the Anopheles farauti complex to 1-octen-3-ol and light in combination with carbon dioxide in northern Queensland, Australia

Abstract. In northern Queensland, Australia, three experiments were conducted to determine the response of mosquitoes of the Anopheles farauti complex to CDC traps baited with four attractant combinations: octenol + C0₂ and light; octenol and light; CO, and light; or C0₂ and octenol without light. A CDC-modified updraft light-trap was also trialled, but did not significantly enhance collections of An.farauti sensu lato. The combination of light, octenol and C0₂ caught significantly more An.farauti s.l. (both An.farauti No. 1 and No. 2 sibling species) when compared to C0₂ and light alone. Only small numbers of the An.farauti complex were captured when CDC traps were baited with octenol alone, i.e. no light or C0₂.     

The Hiletini, an ancient and enigmatic tribe of Carabidae with a pantropical distribution (Coleoptera)

Abstract. Species of the tribe Hiletini are rarely represented in collections. Of the twenty known species, only three have been adequately collected. These twenty species are here arrayed in two genera, Hiletus (six species in two spe'cies groups), Eucamaragnathus (fourteen species in five species groups). Hiletus species occur in tropical Africa. Eucamaragnathus species of the alluaudi group occur in tropical and southeastern Africa, those of the suberbiei group are found only in Madagascar, those of the bocandei group are found in tropical western Africa, species of the sumatrensis group occur in southeastern Asia (Burma, Vietnam, Sumatra and Borneo), and those of the batesi group are found in the western Amazon Basin, northeastern Amazon Basin, and along the Paraquay River drainage system. Four new species of Hiletini are described from the following type localities: Hiletus nimba, GUINEA, Nimba Mountains; Eucamaragnathus borneensis, BRUNEI, (BORNEO); E.jaws, BRAZIL, Parana; E.amapa, BRAZIL, Territory of Amapa. Most species of Hiletini live in tropical climates with a mean annual temperature above 21°C and mean annual rainfall above 200 cm (exceptions are noted in text). All species apparently frequent latosolic soils in broadleaf evergreen or deciduous forests or in grassland savannahs with scattered or gallery broadleaf evergreen trees. Records available indicate that pupation occurs during the dry season and that adults emerge with the onset of rains. The structure of the mandibles, other mouthparts, crop and proventriculus suggests that only liquid food is normally taken in, and it is probable that at least some preoral digestion occurs as in other carabids. A suite of newly discovered character states associated with the tarsal claws unites the Hiletini with Cnemacanthini, Elaphrini, Migadopini, Promecognathini, Pseudomor-phini, Scaritini and Siagonini. These stocks together form a sister lineage to the ozaenine-brachinine lineage, all having distinct epimera, brushy non-styliform parameres, long empodial unguitractor plates, but not having conjunct mesocoxae (type I). Hiletini is the sister group of the combined Scaritini-Cnemacanthini-Pseudomorphini stocks. We suggest that the origin of the Hiletini occurred at least as early as the Jurassic Period from an equatorial position near the centre of the combined Africa/South America landmass. By mid-Cretaceous, radiation of taxa occurred across southern Laurasia into the southeastern part of that landmass, but never leaving equatorial climates. Later in the Cretaceous or early Tertiary, when continents began their rapid break-up, hiletines were stranded in tropical parts of South America, Africa/Madagascar, and southeastern Asia where they still occur today.     

Infaunal communities and tiering in Early Palaeozoic nearshore clastic environments: trace-fossil evidence from the Cambro-Ordovician of New South Wales

Understanding of the palaeoecology of Early Palaeozoic shallow-marine communities in sandy habitats is incomplete. Reasons for this include the poor preservation of body fossils and the dominance of Skolithos piperock in sandstones of that age. Cambrian and Ordovician deposits preserving diverse nearshore trace-fossil assemblages are therefore of critical importance for assessing the early evolution of marine ecosystems. The basal part of the Cambro-Ordovician Bynguano Formation of the Mootwingee area (New South Wales, Australia) is a series of interbedded sandstones and mudstones, which were deposited under nearshore conditions. These strata provide an early example of the Arenicolites ichnofacies. Two ichnocoenoses are distinguished in the sandstones of this unit. A 'predepositional' ichnocoenosis, which reflects the benthic community prior to episodes of sand deposition, includes dense aggregations of Rusophycus with rare Planolites. The 'postdepositional' ichnocoenosis is more diverse and includes Thalassinoides, Arenicolites (various types), Monocraterion, Skolithos, Trichichnus , and epichnial grooves. The tiered structure developed in this ichnocoenosis is preserved as a 'frozen tiered profile' and is characterised by a Thalassinoides tier, 10–30 cm in depth, which is cross-cut by Skolithos and Arenicolitesin the middle tier, and by Arenicolites and Trichichnusin the shallowest tier. The pattern of tiering indicates that a complex ecosystem of opportunistic organisms, capable of exploiting shifting substrates, had evolved by the earliest Ordovician. □ Predepositional, postdepositional frozen tier profile, ichnocoenosis, nearshore clastics, RUSOPHYCUS, Cambro-Ordovician, Bynguano Formation, Mootwingee, New South Wales.     

Rates of progress up odour plumes by tsetse flies: a mark-release video study of the timing of odour source location by Glossina pallidipes

Abstract. The arrival of individually marked Glossina pallidipes Austen at a host odour source after their video-timed release from 30–75 m downwind was measured in the field in Zimbabwe. In the absence of odour, the proportion recaptured was <2% (= - random expectation); when synthetic ox odour was released, the probability of recapture at the source increased with proximity of release, from 6% at 75 m to 21% at 30 m (about twice this number arrived within ∼2 m of the source). There were two distinct distributions of recaptures: a 'fast' cohort which found the source within 40 s, and a 'slow' cohort which took from one to >20 min, with ∼50% of the flies in each cohort. The fastest flies probably reached the source in a single, mainly straight flight from take-off, at an overall average (straight line) displacement speed of 2.8-4.5 ms^-1 (i.e. close to the preferred flight speed of ∼5 m s^-1). The flies apparently maintained their ground speed largely independent of the wind speed they headed into. The 'slow' cohort had a constant probability of arrival at the source, presumably after losing and re-contacting the plume, and after having stopped at least once on the way. There were no marked correlations with wind parameters, although the probability of recapture increased slightly with the directness of the wind from the source, and the probability of 'slow' flight increased slightly with wind speed. It is inferred that a repeated sequence of anemotactic 'aim-then-shoot' orientation at take-off plus optomotor-steered in-flight correction of direction is used as a form of biassed random walk to bring the flies close to the odour source, rather than the use of moth-type anemotactic zigzagging.