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The oviposition behavior of the treehole mosquito Aedes triseriatus (Say) was studied by counting the eggs laid in 300 oviposition traps weekly for one season (May-October) in Illinois. Eggs were aggregated spatially among traps each week, and temporally among weekly samples and for individual traps over weekly counts. Aggregation could be associated with a nonrandom dispersion pattern of oviposition events and with the oviposition of 20-60 eggs per event. Thus, females were laying clumps of eggs in an overdispersed manner. The greatest number of eggs was found in late July when prevalence (proportion of traps with eggs) and intensity (number of eggs per positive trap) peaked simultaneously. Intensity also peaked in May and prevalence peaked in mid-June and early September. When traps from which eggs were removed each week were compared with traps in which eggs were allowed to accumulate, prevalence was naturally higher in the latter group. However, the intensity of eggs was similar in both groups, indicating that more eggs were laid in traps from which eggs were removed. Thus, the presence of eggs on oviposition surfaces was associated with a decrease in further oviposition.

A simple, rapid method using restriction fragment length polymorphisms (RFLPs) within the internal transcribed spacer (ITS) regions of the ribosomal DNA gene repeat allows identification of insects and other organisms. We used the method to identify the morphologically similar Diptera larvae that are important in forensic entomology for estimating the time and location of death. Polymerase chain reaction (PCR) was used to amplify a region from the 18S to the 28S rRNA genes. The ITS1 and ITS2 regions provided variation between species and homogeneity within species, with the exception of Cochliomya macellaria. Combinations of the restriction enzymes DdeI, HinfI and Sau3AI provided diagnostic bands for identification of the ten species from three families of Diptera (Calliphoridae, Muscidae and Sarcophagidae).

The dipteran family Therevidae (stiletto flies) is cosmopolitan and has been the focus of many taxonomic and phylogenetic studies over the last 25 years. Despite this work, questions remain concerning the relationships between subfamilies, genera and generic groups and membership of those groups. We use the supertree method to produce an inclusive phylogeny for the family Therevidae from 24 phylogenetic studies using matrix representation with parsimony (MRP) analysis. The supertree method, one of the most common approaches to calculating globally inclusive phylogenies from smaller more exclusive analyses, produced the therevid metaphylogeny despite only 34% of the terminal taxa being found in more than one source tree. We describe a method for handling low taxon overlap in supertree analyses, in combination with the parsimony ratchet and constraint tree techniques. The supertree presented here is an overarching phylogenetic hypothesis of the Therevidae, incorporating extensive sampling of major lineages and summarising past phylogenetic work on the family. The inclusive metaphylogeny for 362 therevid taxa robustly retrieves the subfamilies Agapophytinae, Phycinae, Therevinae and Xestomyzinae, and the tribes Cyclotelini and Therevini. The Phycinae and Xestomyzinae form a clade, sister to the remaining Therevidae. The Australasian and South American Taenogera Kröber genus-group is monophyletic and sister to a clade of Therevinae and the Australian endemic Agapophytinae. The Therevinae consists of the Anabarhynchus Macquart genus-group of Australian, South American, New Caledonian and New Zealand taxa as sister to the non-Australasian ‘higher Therevinae’, which contains the tribes Cyclotelini and Therevini. The Therevini includes the Hoplosathe Lyneborg & Zaitzev, Litolinga Irwin & Lyneborg, Baryphora Loew, Pandivirilia Irwin & Lyneborg and Thereva Latreille generic-groups. MRP supertree methods can be used to produce inclusive metaphylogenies in situations where source trees have poor data overlap and low taxon overlap, and are therefore valuable in species-rich groups such as arthropods. These methods may be necessary for constructing the ‘Tree of Life’, representing phylogenetic relationships among the millions of known species. However, our analyses show that in situations of source tree conflict, MRP supertree analyses present only the majority signal. We also show that conflict between source trees can be hidden in MRP supertrees, thus our results emphasise the need to evaluate the resulting clades with reference to the source trees.

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The therevoid clade represents a group of four families (Apsilocephalidae, Evocoidae, Scenopinidae and Therevidae) of lower brachyceran Diptera in the superfamily Asiloidea. The largest of these families is that of the stiletto flies (Therevidae). A large-scale (i.e. supermatrix) phylogeny of Therevidae is presented based on DNA sequence data from seven genetic loci (16S, 18S and 28S ribosomal DNA and four protein-encoding genes: elongation factor 1-alpha, triose phosphate isomerase, short-wavelength rhodopsin and the CPSase region of carbamoyl-phosphate synthase-aspartate transcarbamoylase-dihydroorotase). Results are presented from Bayesian phylogenetic analyses of approximately 8.7 kb of sequence data for 204 taxa representing all subfamilies and genus groups of Therevidae. Our results strongly support the sister-group relationship between Therevidae and Scenopinidae, with Apsilocephalidae as sister to Evocoidae. Previous estimates of stiletto fly phylogeny based on morphology or DNA sequence data, or supertree analysis, have failed to find significant support for relationships among subfamilies. We report for the first time strong support for the placement of the subfamily Phycinae as sister to the remaining Therevidae, originating during the Mid Cretaceous. As in previous studies, the sister-group relationship between the species-rich subfamilies Agapophytinae and Therevinae is strongly supported. Agapophytinae are recovered as monophyletic, inclusive of the Taenogera group. Therevinae comprise the bulk of the species richness in the family and appear to be a relatively recent and rapid radiation originating in the southern hemisphere (Australia + Antarctica + South America) during the Late Cretaceous. Genus groups are defined for all subfamilies based on these results.

The objective of this study is to update our knowledge of the distribution and natural history of Mecoptera, particularly in relation to the biogeographic history of Illinois. Synoptic descriptions, keys, and illustrations have been prepared to provide an insight into this primitive and interesting group of insects. The emphasis of this study is on the fauna of Illinois, but other species occurring in the Midwest have been included. Collecting data are listed for those Illinois species known from fewer than ten localities. Records for other species are plotted on distribution maps.