Nine species of the gall-associated doryctine genus Allorhogas Gahan (Hymenoptera: Braconidae) are described from Brazil (A. clidemiae Martínez and Zaldívar-Riverón new species, A. granivorus Zaldívar-Riverón and Martínez new species, A. mineiro Zaldívar-Riverón and Martínez new species, and A. vulgaris Zaldívar-Riverón and Martínez new species) and Costa Rica (A. brevithorax Zaldívar-Riverón and Martínez new species, A. pallidus Martínez and Zaldívar-Riverón new species, A. psychotria Zaldívar-Riverón and Martínez new species, A. punctatus Martínez and Zaldívar-Riverón new species, and A. tico Martínez and Zaldívar-Riverón new species). We provide host plant records for the described species, including information that reveals that at least three of them feed on seeds. Allorhogas granivorus had previously been confirmed to represent a natural enemy of the invasive weed Miconia calvescens de Candolle (Melastomataceae). Updated keys to the species of Allorhogas from Brazil and Costa Rica are provided.

Two new species of egg parasitoids, Oobius saimaensis Yao and Mottern new species and Oobius fleischeri Yao and Duan new species (Hymenoptera: Encyrtidae), are described from eggs of Agrilus fleischeri Obenberger, 1925 (Coleoptera: Buprestidae). Agrilus fleischeri is a phloem-feeding woodborer of poplar (Populus Linnaeus; Salicaceae) in northeastern China. These two species can be distinguished morphologically as O. fleischeri has five tarsomeres and O. saimaensis has four tarsomeres. Although O. saimaensis is morphologically similar to its sympatric congener O. agrili Zhang and Hang, 2005, an important natural enemy of the invasive emerald ash borer, Agrilus planipennis Fairmaire, 1888, molecular phylogenetics and morphological data indicate that they are distinct species. Phylogenetic relationships among the new species and other closely related species are also inferred by using DNA sequence data from several ribosomal and mitochondrial genes. In addition, we expand the known distribution of Oobius primorskyensis Yao and Duan, 2016 to include South Korea.

The life cycle of the avian parasitic flies Philornis Meinert (Diptera: Muscidae) is poorly known, limiting the understanding of the ecology of these flies, including interactions with their hosts. We provide data on length and survival of pupal and adult stages and the duration of the pre-oviposition period of Philornis torquans Nielsen. Specimens were collected at larval and pupal stages from infested broods. The pupal stage lasted on average 10.5 days and adults lived up to 100 days in the laboratory. At least 90.2% of larvae pupated and 85.7% of the latter emerged as adults. For individuals collected as larvae, pupal mortality was 3.5 times higher than for those collected as pupae. Females laid from 1–8 clutches in their lifetime and deposited, on average, 41 eggs per female (range: 1–148). Females collected as pupae were larger and had shorter pre-oviposition periods and lifespans than females collected as larvae, but there were no differences in the total eggs laid by these females. This is the first information on reproductive parameters of a subcutaneous species of Philornis, and forms the basis for studies on conditions required for reproduction of this species in captivity.

Dipteran larvae from a number of families feed in aggregations. Rotation of blow fly (Diptera: Calliphoridae) larvae within an aggregation has been reported anecdotally many times. However, there is a lack of quantitative data on such larval movement, which is necessary to better understand the advantage of this gregarious behaviour. A recent development in tagging methods provided an opportunity to address this gap in knowledge. In 15 aggregations of 500 Lucilia sericata (Meigen) (Diptera: Calliphoridae) larvae, the location of four-tagged individuals was recorded at 10-minute intervals. All larvae were seen to rotate, alternating between the periphery and within. There was much variation in the relative proportions that larvae were seen in these two locations among aggregations (χ2=78.4, df=58, P=0.038), perhaps as a result of differences in mass shape and, therefore, surface area: volume ratio. There were also differences between larvae within aggregations (χ2=25.6, df=14, P=0.029), which may give rise to differences in development rate, perhaps as a result of intraspecific competition. Further work would be required to verify this competition, and to establish whether the limited resource is temperature, food, oxygen, or some other requirement.

Adult size is the trait most closely correlated with reproductive output in insects, but may also have important selective implications determining additional fitness gains. In longhorn beetles, adult size-mediated ultimate benefits may arise from mate choice, male antennal spread width or male fighting for mates. In this paper, we examined factors potentially shaping adult size of Cerambyx welensii Küster (Coleoptera: Cerambycidae), an emergent oak (Quercus Linnaeus; Fagaceae) pest. Sex ratio and adult length/weight allometric relationships were also explored. Overwintering adults were collected inside oaks in Extremadura (southwestern Spain) during 2011–2017 to ensure that larval development was completed in the wild. Sex, host species, and wood quality affected adult size, though some interactions occurred and among-host differences were weak. Adults collected inside older trees and wider branches were significantly larger. Adult size was unaffected by either elevation, aspect, or population density. There was a robust allometric scaling in both sexes between elytral/adult length and weight, females being heavier than males and males longer than females when adults were large. Female-biased sex ratios occurred in old/veteran trees and in dense/crowded larval populations. We discuss these results from an evolutionary perspective considering the potential impact of C. welensii adult size on population dynamics and management tactics.

More than a decade after its discovery in North America, the European woodwasp, Sirex noctilio Fabricius (Hymenoptera: Siricidae), has not been an aggressive tree killer in northeastern North American pine (Pinus Linnaeus; Pinaceae) forests. Concern that S. noctilio has potential to become a more aggressive pest as it spreads south, or as environmental conditions change, is warranted, because it has caused extensive pine losses on other continents that it has invaded. We observed S. noctilio impact and attack behaviour in eight pine stands throughout Ontario, Canada annually for a five-year period (2012–2016). Sirex noctilio impact was variable in unmanaged pine forests; it killed 3–48% of pine stems, and 3–36% of pine basal area. Most S. noctilio-caused mortality was limited to suppressed and intermediate trees. Of the 17% of pines in the entire study that were affected by S. noctilio, many (44%) were attacked in multiple years. Depending on the year, between 46% and 79% of trees remained alive in the year immediately after attack, which suggests that many study trees were at least initially resistant to attack by S. noctilio. Though its impact appears to be limited in most forests for now, we recommend that observations continue in future years.

Over 1000 species of arthropods have been recorded from cadavers worldwide. While conducting a study on the diversity and abundance of insects associated with pig (Sus scrofa Linnaeus; Mammalia: Suidae) carrion in the highlands of Chiapas, Mexico, we noticed the presence of thrips (Thysanoptera) in the collecting containers of traps. The thrips collected comprised the following species: Aeolothrips species (Aeolothripidae), Frankliniella brunnea Priesner (Thripidae), Frankliniella fusca (Hinds), Frankliniella trinidadensis Hood, Neohydatothrips portoricensis (Morgan) (Thripidae), Thrips simplex (Morison) (Thripidae), Wegenerithrips admirabilis Johansen (Thripidae), and Stephanothrips bradleyi Hood (Phlaeothripidae). These species were taken in Schoenly traps, a device designed to catch sarcosaprophagous insects. The thrips species reported in the present study have not previously been recovered from decomposing cadavers, and their occurrence suggests an attraction to one or more components of the trap, rather than an incidental presence. Albeit thrips are not considered forensically important, more studies are needed to elucidate their role in carrion ecology.

We made 37 collections and analysed the polytene chromosomes of salivary glands of 726 larvae of the Simulium arcticum Malloch (Diptera: Simuliidae) complex from 10 locations in an unstudied region from central Idaho and southeastern Washington, United States of America. We compared our results to previous population cytotaxonomic research on larvae of this complex from western Montana, northern Idaho, and eastern Washington, United States of America. We identified four sibling species, S. brevicercum Knowlton and Rowe, S. saxosum Adler, S. arcticum sensu stricto, S. apricarium Adler, Currie, and Wood; and three cytotypes, S. arcticum IIL-9, IIL-17, and IIL-79, previously described by us. We discovered a new cytotype, S. arcticum IIL-80, at three locations in the western region of our sample area. We also found combinational (ancestral) types between S. saxosum and S. arcticum sensu stricto and between S. saxosum and S. arcticum IIL-79, suggesting that ancestral populations of the complex still exist. Geographic structuring of these sibling species and cytotypes are documented given that S. saxosum occurred in western regions, S. arcticum IIL-79 in northeastern regions, and S. apricarium in southeastern regions of our study area.

Ommatissus lybicus de Bergevin (Hemiptera: Tropiduchidae) is a key pest of date palm (Phoenix dactylifera Linnaeus; Arecaceae) with worldwide distribution and various management strategies. To study genetic diversity of date palm hopper, a series of experiments was conducted on genetic structure and genetic diversity of 15 geographic populations of O. lybicus (Abu Musa, Bam, Bushehr, Behbahan, Tezerj, Fin, Jiroft, Shahdad, Jahrom, Ghire Karzin, Ghasre Shirin, Iran; Pakistan; Oman; Egypt; and Tunisia) by amplified fragment length polymorphism, cytochrome c oxidase subunit I (COI), and 28S rRNA markers. Analysis of molecular variance analysis of amplified fragment length polymorphism data and COI sequences revealed a significant variation among O. lybicus populations (94.12% and 65.08% similarities for amplified fragment length polymorphism and COI, respectively). The 28S rDNA sequences from different populations were identical. Phylogenetic network inferred from amplified fragment length polymorphism data and COI sequences grouped two geographically close populations (Tezerj and Bam) in the two distinct clades while far apart geographical populations bunched in the same or close clades. These two populations experience repeated exposure to heavy pesticide applications annually. In conclusion, study of the genetic structure revealed a considerable variation between O. lybicus populations under intensive chemical strategies.

Two new species of Eocene Eomerope Cockerell (Mecoptera: Eomeropidae) are described from the Ypresian Okanagan Highlands deposits of British Columbia, Canada: Eomerope simpkinsaenew species from the Allenby Formation near the town of Princeton, and Eomerope eonearcticanew species from the McAbee locality near the towns of Cache Creek and Ashcroft. Eomerope eonearctica is very close to the coeval Eomerope asiatica Ponomarenko from Primorskiy Kray in Pacific-coastal Russia, consistent with Eocene intercontinental dispersal, which is well documented in numerous plant and animal taxa.

The pepper weevil, Anthonomus eugenii Cano (Coleoptera: Curculionidae), is the most important pest of pepper (Capsicum Linnaeus; Solanaceae) crops in North America. Native to Mexico, the southern United States of America, and Central America, it is intercepted in Canada when peppers are imported to supplement domestic production. Given the proximity of greenhouse and field production to packing facilities, this pest poses a serious risk to the cultivation of peppers in Canada. Once established, it is difficult to control because immature stages of the weevil are protected within the pepper fruit. As such, chemical control targeting these life stages is not effective, and other strategies, including biological control, may prove useful. To explore the potential for biological control options to manage the pepper weevil in areas at risk in Canada, natural enemy surveys were conducted in southern Ontario following the reports of transient, localised field populations in 2016. Parasitoids belonging to three Hymenoptera families including Pteromalidae (Jaliscoa hunteri Crawford, Pteromalus anthonomi Ashmead), Eupelmidae (Eupelmus pulchriceps Cameron), and Braconidae (Nealiolus Mason species, Bracon Fabricius species) were reared from infested field-collected pepper fruits. Together, these new natural enemy records could facilitate the exploration and development of novel agents for the biological control of the pepper weevil.