Hexapoda

Morphological and molecular data are marshalled to address the question of hexapod ordinal relationships.  The combination of 275 morphological variables, 1000 bases of the small subunit rDNA (18S) and 350 bases of the large subunit rDNA (28S) are subjected to a variety of analysis parameters (indel and transversion costs).  Representatives of each hexapod order are included with most orders represented multiply.  Those parameters that minimize character incongruence (ILD--Mickevich and Farris, 1981) among the morphological and molecular data sets are chosen to generate the best supported cladogram.  A well resolved and robust cladogram of ordinal relationships is produced with the topology (Crustacea ((Chilopoda Diplopoda) ((Collembola Protura) ((Japygina Campodeina) (Archaeognatha (Zygentoma (Ephemerida (Odonata ((((Mantodea Blattaria) Isoptera) Zoraptera) ((Plecoptera Embiidina) (((Orthoptera Phasmida) (Grylloblattaria Dermaptera)) ((((Psocoptera Phthiraptera) Thysanoptera) Hemiptera) ((Neuroptera Coleoptera) (((((Strepsiptera Diptera) Mecoptera) Siphonaptera) (Trichoptera Lepidoptera)) Hymenoptera)))))))))))))).

The author surveys a number of morphological traits found in the Hirudinea which may indicate a phylogenetic link with arthropods, especially Insects/ hexapoda, and other Uniramia. Of special interest in this context is the presence of pre-lobopodia.

terrestrial ecosystems. Subfamily Rhyssinae contains the ichneumonids with bigger size, which parasitize borers in branches and logs of diverse trees; genus Megarhyssa contains 38 species and it has been obtained in all the zoogeographical regions. The objective of this paper is to report the species of Megarhyssa collected and described from Mexico. Since 1981, ichneumónidos have been collected with entomological nets and Malaise traps in different localities of the Mexican Republic, having more than 50,000 specimens in the Insects Museum of the Faculty of Sciences and Engineering, UAT, only two of Megarhyssa macrura donated by ITESM. In the Smithsonian Institution (Washington D.C.), Kasparyan found and described a new species; in 2012 the Essig Museum of the University of California – Berkeley was visited, where other new species from the State of Chiapas was found, which was described and it is deposited in the UAT Museum mentioned above, in Cd. Victoria, Tamaulipas. Therefore, in Mexico were found Megarhyssa macrura Linnaeus 1771, M. verae Kasparyan 2002 and M. gratiosa Khalaim & Ruíz 2013. In conclusion, only three species of Megarhyssa are known in Mexico, one genus with Cosmopolitan distribution but in the American Continent its more southern distribution is the State of Chiapas.

Hexapoda includes 33 commonly recognized orders, most of them insects.Ongoi ng controversy concerns the grouping of Protura and Collembola as a taxon Ellipura, the monophyly of Diplura, a single or multiple origins of entognathy, and the monophyly or paraphyly of the silverfish (Lepidotrichidae and Zygentoma s.s.) with respect to other dicondylous insects.Here we analyze relationships among basal hexapod orders via a cladistic analysis of sequence data for five molecular markers and 189 morphological characters in a simultaneous analysis framework using myriapod and crustacean outgroups.Using a sensitivity analysis approach and testing for stability, the most
congruent parameters resolve Tricholepidion as sister group to the remaining Dicondylia, whereas most suboptimal parameter sets group Tricholepidion with Zygentoma.Stable hypotheses include the monophyly of Diplura, and a sister group relationship between Diplura and Protura, contradicting the Ellipura  hypothesis.Hexapod monophyly is contradicted by an alliance between Collembola, Crustacea and Ectognatha (i.e., exclusive of Diplura and Protura) in molecular and combined analyses.

This study was conducted to evaluate the effect of a commercially available pyriproxyfen, an insect growth regulator (IGR) on the larvae of a dengue vector, Ae. aegypti. The study site was the surrounding area of the Medical Entomology Unit, Institute for Medical Research (IMR), Kuala Lumpur (N03°10.167′, E101°41.919′). Pyriproxyfen-controlled release blocks with dosages of 10% w/w and 20% w/w were used to treat a set of earthen jars placed outdoors. Untreated jars were also set up as controls. Fifty laboratory-bred 2nd instar larvae were introduced into each earthen jar and observed daily. The number of adults that emerged was recorded and the larval mortality was calculated. The indicators of effectiveness of IGR for these studies were: (i) duration of effectiveness, and (ii) percentage of emergence inhibition (El). There was a significant difference in the number of emerged adults obtained from the untreated and treated earthen jars up to 25 weeks (p<0.05). The duration of effectiveness of pyriproxyfen caused 80% emergence inhibition in earthen jars treated with 10% w/w and 20% w/w pyriproxyfen up to 22 and 25 weeks, respectively. Pyriproxyfen-controlled release block is an effective method of controlling mosquito larvae for several months. The method of application of the block is simple and straightforward and can therefore be used easily.

Study of all flies (Diptera) collected for one year from a four-hectare (150 x 266 meter) patch of cloud forest at 1,600 meters above sea level at Zurquí de Moravia, San José Province, Costa Rica (hereafter referred to as Zurquí), revealed an astounding 4,332 species. This amounts to more than half the number of named species of flies for all of Central America. Specimens were collected with two Malaise traps running continuously and with a wide array of supplementary collecting methods for three days of each month. All morphospecies from all 73 families recorded were fully curated by technicians before submission to an international team of 59 taxonomic experts for identification.        Overall, a Malaise trap on the forest edge captured 1,988 species or 51% of all collected dipteran taxa (other than of Phoridae, subsampled only from this and one other Malaise trap). A Malaise trap in the forest sampled 906 species. Of other sampling methods, the combination of four other Malaise ...

Hexapoda includes 33 commonly recognized orders, most of them insects.Ongoi ng controversy concerns the grouping of Protura and Collembola as a taxon Ellipura, the monophyly of Diplura, a single or multiple origins of entognathy, and the monophyly or paraphyly of the silverfish (Lepidotrichidae and Zygentoma s.s.) with respect to other dicondylous insects.Here we analyze relationships among basal hexapod orders via a cladistic analysis of sequence data for five molecular markers and 189 morphological characters in a simultaneous analysis framework using myriapod and crustacean outgroups.Using a sensitivity analysis approach and testing for stability, the most congruent parameters resolve Tricholepidion as sister group to the remaining Dicondylia, whereas most suboptimal parameter sets group Tricholepidion with Zygentoma.Stable hypotheses include the monophyly of Diplura, and a sister group relationship between Diplura and Protura, contradicting the Ellipura hypothesis.Hexapod monoph...

This study was conducted to evaluate the effect of a commercially available pyriproxyfen, an insect growth regulator (IGR) on the larvae of a dengue vector, Ae. aegypti. The study site was the surrounding area of the Medical Entomology Unit, Institute for Medical Research (IMR), Kuala Lumpur (N03°10.167′, E101°41.919′). Pyriproxyfen-controlled release blocks with dosages of 10% w/w and 20% w/w were used to treat a set of earthen jars placed outdoors. Untreated jars were also set up as controls. Fifty laboratory-bred 2nd instar larvae were introduced into each earthen jar and observed daily. The number of adults that emerged was recorded and the larval mortality was calculated. The indicators of effectiveness of IGR for these studies were: (i) duration of effectiveness, and (ii) percentage of emergence inhibition (El). There was a significant difference in the number of emerged adults obtained from the untreated and treated earthen jars up to 25 weeks (p<0.05). The duration of eff...

Among the many challenges in paleobiology is the inference and reconstruction of behaviors that rarely, if ever, leave a physical trace on the environment that is suitable for fossiliza-tion. Of particular significance are those behaviors tied to mating and courtship, individual interactions critical for species integrity and continuance, as well as those for dispersal, permitting the taxon to expand its distribution as well as access new habitats in the face of local or long-term environmental change. In this context, two recently discovered fossils from the Early Cretaceous amber of Spain (ca. 105 mya) give a detailed view of otherwise fleeting ethologies in Collembola. These occurrences are phylogenetically spaced across the class, and from species representing the two major clades of springtails—Symphypleona and Entomobryomorpha. Specifically, we report unique evidence from a symphypleonan male (Pseudosminthurides stoechus Sá nchez-García & Engel, 2016) with modified antennae that may have functioned as a clasping organ for securing females during mating on water's surface, and from an aggregation of entomobryomorphan individuals (Proisotoma commu-nis Sá nchez-García & Engel, 2016) purportedly representing a swarming episode on the forest floor. We demonstrate that the mating behavioral repertoire in P. stoechus, which is associated with considerable morphological adaptations, likely implied elaborate courtship and maneuvering for guarantee sperm transfer in an epineustic species. These discoveries reveal significant behaviors consistent with modern counterparts and a generalized stasis for some ancient hexapod ethologies associated with complex mating and courtship and social or pre-social aggregations, so critical to specific constancy and dispersal.

Background: Social insects maintain the integrity of their societies by discriminating between colony members and foreigners through cuticular hydrocarbon (CHC) signatures. Nevertheless, parasites frequently get access to social resources, for example through mimicry of host CHCs among other mechanisms. The origin of mimetic compounds, however, remains unknown in the majority of studies (biosynthesis vs. acquisition). Additionally, direct evidence is scarce that chemical mimicry is indeed beneficial to the parasites (e.g., by improving social acceptance).Results: In the present study we demonstrated that the kleptoparasitic silverfish Malayatelura ponerophila most likely acquires CHCs directly from its host ant Leptogenys distinguenda by evaluating the transfer of a stable-isotope label from the cuticle of workers to the silverfish. In a second experiment, we prevented CHC pilfering by separating silverfish from their host for six or nine days. Chemical host resemblance as well as aggressive rejection behaviour by host ants was then quantified for unmanipulated and previously separated individuals. Separated individuals showed reduced chemical host resemblance and they received significantly more aggressive rejection behaviour than unmanipulated individuals.Conclusion: Our study clarifies the mechanism of chemical mimicry in a social insect parasite in great detail. It shows empirically for the first time that social insect parasites are able to acquire CHCs from their host. Furthermore, it demonstrates that the accuracy of chemical mimicry can be crucial for social insect parasites by enhancing social acceptance and, thus, allowing successful exploitation. We discuss the results in the light of coevolutionary arms races between parasites and hosts. © 2011 von Beeren et al; licensee BioMed Central Ltd.