Observations on the biology of Afrotropical Hesperiidae (Lepidoptera). Part 9. Hesperiinae incertae sedis: Zingiberales feeders, genera of unknown biology and an overview of the Hesperiinae incertae sedis.

The Afrotropical genera that have been recorded to feed on Zingiberales are documented. Partial life histories are presented for Erionota torus Evans (a South-East Asian species established in Mauritius), Semalea arela (Mabille), S. pulvina (Plötz), Xanthodisca vibius (Hewitson), X. rega (Mabille), Hypoleucis ophiusa (Hewitson), Caenides dacena (Hewitson), Osmodes adon (Mabille), Gretna cylinda (Hewitson) and Moltena fiara (Butler). Additional notes from the literature are provided on the genera Leona and Rhabdomantis. Notes on natural enemies of E. torus and M. fiara are included. We find that the Zingiberaceae and Costaceae feeding genera, Semalea, Xanthodiscus, Hypoleucis and Caenides (part) are united by a C-shaped raised rim to the prothoracic spiracle of the pupa. The pupa of Osmodes adon indicates this genus may have no close affinities to other Afrotropical genera for which the life history is known. The pupa of G. cylinda is unlike any other that we have documented and may reflect that this is the only species which we have found to be formed on the open leaf under surface rather than in a shelter. The early stages of M. fiara indicate affinities with Zophopetes and related genera. The paper concludes with a brief comparative discussion of the early stages of the Afrotropical Hesperiinae incertae sedis as a whole. There appear to be useful characters to group species by the ova and pupae but less so by the caterpillars. Based on pupae alone, the Hesperiinae incertae sedis might be divided into nine groups.

Phytotelmatrichis, a new genus of Acrotrichinae (Coleoptera: Ptiliidae) associated with the phytotelmata of Zingiberales plants in Peru.

Phytotelmatrichis, gen. n. a new genus of Ptiliidae: Acrotrichinae with two species Phytotelmatrichis peruviensis sp. n. and Phytotelmatrichis osopaddington sp. n. is described and illustrated. The new species were found during a survey of insects in the aquatic environments that form in the hollows (phytotelmata) in the leaves and floral bracts of Zingiberales plants. The new taxa were found in the the Zingiberales genera Calathea (Marantaceae), Heliconia (Heliconiaceae), and Alpinia and Renealmia (Zingiberaceae) in southern Peru. Sampling of other habitats in the same areas over five years and using a range of different techniques did not yield more specimens of this new genus. This suggests that the new species are restricted to phytotelmata.

Experimental demography and the vital rates of generalist and specialist insect herbivores on native and novel host plants.

1. Colonization success of species when confronted with novel environments is of interest in ecological, evolutionary and conservation contexts. Such events may represent the first step for ecological diversification. They also play an important role in adaptive divergence and speciation. 2. A species that is able to do well across a range of environments has a higher plasticity than one whose success is restricted to a single or few environments. The breadth of environments in which a species can succeed is ultimately determined by the full pattern of its vital rates in each environment. 3. Examples of organisms colonizing novel environments are insect herbivores expanding their diets to novel host plants. One expectation for insect herbivores is that species with specialized diets may display less plasticity when faced with novel hosts than generalist species. 4. We examine this hypothesis for two generalist and two specialist neotropical beetles (genus Cephaloleia: Chrysomelidae) currently expanding their diets from native to novel plants of the order Zingiberales. Using an experimental approach, we estimated changes in vital rates, life-history traits and lifetime fitness for each beetle species when feeding on native or novel host plants. 5. We did not find evidence supporting more plasticity for generalists than for specialists. Instead, we found similar patterns of survival and fecundity for all herbivores. Larvae survived worse on novel hosts; adults survived at least as well or better, but reproduced less on the novel host than on natives. 6. Some of the novel host plants represent challenging environments where population growth was negative. However, in four novel plant-herbivore interactions, instantaneous population growth rates were positive. 7. Positive instantaneous population growth rates during initial colonization of novel host plants suggest that both generalist and specialist Cephaloleia beetles may be pre-adapted to feed on some novel hosts. This plasticity in host use is a key factor for successful colonization of novel hosts. Future success or failure in the colonization of these novel hosts will depend on the demographic rates described in this research, natural selection and the evolutionary responses of life-history traits in novel environments.

A synergistic aggregation pheromone component in the banana weevil Cosmopolites sordidus Germar 1824 (Coleoptera: Curculionidae).

Cosmopolites sordidus is an important pest on banana plantations worldwide. The chemistry of the aggregation pheromone of this insect has been recently resolved and here we present the first evidence from field trails that sordidin, a compound from the male released aggregation pheromone, attracts significant number of weevils only if host plant odors are also present. Sordidin attracts few insects when it is presented without the host plant tissue. However, the attractiveness of host plant tissue increases more than tenfold when it is presented simultaneously with sordidin in field traps. We confirm experimentally that sordidin may be used as part of a system for mass trapping and monitoring this insect.

A synergistic aggregation pheromone component in the banana weevil cosmopolites sordidus germar 1824 (Coleoptera: Curculionidae)

Cosmopolites sordidus is an important pest on banana plantations worldwide. The chemistry of the aggregation pheromone of this insect has been recently resolved and here we present the first evidence from field trails that sordidin, a compound from the male releases aggregation pheromone, attracts significant number of weevils only if host plant odors are also present. Sordidin attracts few insects when it is presented without the host plant tissue. However, the attractiveness of host plant tissue increases more than tenfold when it is presented simultaneously with sordidin in field traps. We confirm experimentally that sordidin may be used as part of a system for mass trapping and monitoring this insect.