The life table and parasitism rate of Diadegma insulare (Cresson) (Hymenoptera: Ichneumonidae), a larval parasitoid of the diamondback moth Plutella xylostella (L.) (Lepidoptera: Plutellidae), were studied at 25 ± 1°C, 65 ± 10% RH, and a photoperiod of 16:8 (L: D) h. The data were analyzed based on the age-stage, two-sex life table theory. Because the sex ratio of offspring varies with the age of the female parent, we used only female offspring to calculate the intrinsic rate of increase (r), finite rate of increase (λ), net reproductive rate (R₀), and mean generation time (T) by using the jackknife technique, the values of which were 0.18407 d^-1, 1.2021 d^-1, 17.94 offspring, and 15.69 d, respectively. We also calculated these parameters by using bootstrap technique. They were not significantly different from those estimated by using the jackknife technique. We included both male and female offspring in the calculation of the parasitism rate. The net parasitism rate (C₀) was 42.63 aphids. Moreover, population projection showed differences between simulated population based on total offspring and female offspring. Because both the offspring sex ratio and the parasitism rate depend on female age, it is necessary to use the age-stage, two-sex life table for a correct analysis. Frequency of the net reproductive rate estimated by using bootstrap technique fit normal distribution well, whereas frequency data estimated by using jackknife technique failed the normality test. We suggest that the jackknife technique should not be used for the estimation of population parameters.

Diastrophus japonicus Wachi, Ide & Abe sp. nov., a gall inducer on Rubus palmatus Thunberg, is described from Japan. This is the first reliable record of Diastrophus Hartig, 1840 (Hymenoptera: Cynipidae: Aylacini) from the Eastern Palearctic region. This article reveals that the genus Diastrophus is widely distributed from the Western Palearctic to the Nearctic regions through the Eastern Palearctic region. The causal process for the extant geographic distribution of D. japonicus was the opening of the Sea of Japan and dispersal during the Pleistocene. The phylogenetic relationships among the members of Diastrophus (D. japonicus and the species considered by a previous study) were inferred based on adult morphological and gall characters, but low consistency indices suggested that the characters exhibited homoplasy.

Original information on aphidiines parasitizing aphids on herbaceous and shrubby ornamental plants in southeastern Europe is presented. In total, 22 species are keyed and illustrated with scanning electron micrographs, stereomicroscope micrographs, and line drawings. The aphidiines presented in this work have been identified from 40 aphid taxa. Two hundred sixty-six aphidiine— aphid—plant associations are presented, out of which 126 are new. The results are discussed in relation to the overall parasitoid—aphid-plant associations in the area.

A new fossil species of the genus Anevrina Lioy is described from 40 million-year-old Baltic amber. It differs from the only other described fossil species of this genus, Anevrina oligocoenica Brues, by the setation of the tibiae and the structure of the male genitalia. The new species is most similar to the extant Anevrina olympiae (Aldrich), from which it differs by the darker color and details of the male genitalia.

A new genus of Corioxenidae, Malagasyxenos, is erected for a new species of Strepsiptera, Malagasyxenos gymnostoma n.s.p., from the Majunga provinces of Madagascar. Malagasyxenos is morphologically closest to Floridoxenos, both of which have antennae with seven segments and flabela on segments 3–6. However, Malagasyxenos is the only corioxenid with no visible mouthparts as well as other character differences. The family Corioxenidae is reviewed and a key is provided for the 13 genera.

Instar determination is fundamental to both basic entomological research and its application. The cockroach, Blaptica dubia Serville (Blattodea: Blaberidae), is a popular pet and an excellent feeder insect for many reptiles and amphibians. A new method using Gaussian mixture models to determine the number of instars in this species is developed. Application of the method is illustrated by analysis of data collected on B. dubia. The analysis indicates that there are seven instars in B. dubia and that the growth ratio follows the Brooks—Dyar rule. The growth ratio of pronotal length, pronotal width, and head width are 1.26, 1.24, and 1.19, respectively. Because B. dubia shares a similar growth pattern with other paurometabolous insects, this method may be applicable to other species as well.

The northern corn rootworm (Diabrotica barberi Smith & Lawrence) in eastern and central North America exhibits at least three distinct populations with respect to Wolbachia infection: uninfected, singly infected, and multiply infected. The infected states are associated with different mtDNA haplotypes and reduced mtDNA variability. The previous results demonstrated that the major mtDNA clades of D. barberi were infected with different variants of Wolbachia; however, the total amount of Wolbachia diversity was substantially underestimated. Here we report sequences of the Wolbachia wsp surface protein gene indicating that multiple infections are present. Analysis of the wsp sequences establishes the existence at least five distinct wsp variants. The recovery frequency of specific wsp hypervariable regions (HVR) obtained from several individuals was unequal. The most common was obtained 33 times, the least common only once. One of the Wolbachia variants was present in both singly infected and multiply infected individuals. A possible explanation for the frequency differences are that the frequency of each variant is not the same within each insect. An alternative possibility is that not all individuals are infected with all five variants and that different animals contain different combinations of the variants. The second scenario suggests that some variants are rare in the population. Comparisons of the wsp genes with sequences in GenBank show that two of the variants are most similar to variants infecting subspecies of the congeneric western corn rootworm (Diabrotica virgifera virgifera LeConte and Diabrotica virgifera zeae Krysan & Smith). Individual wsp HVRs were also aligned with GenBank sequences. The results provide evidence that some HVRs are much more common than others and that the HVRs can be shuffled to create new wsp genes.

Mites (Arachnida: Acari) are one of the most diverse groups of organisms associated with bark beetles (Curculionidae: Scolytinae), but their taxonomy and ecology are poorly understood, including in Canada. Here we address this by describing the diversity, species composition, and host associations of mesostigmatic and oribatid mites collected from scolytines across four sites in eastern Ontario, Canada, in 2008 and 2009. Using Lindgren funnel traps baited with α-pinene, ethanol lures, or Ips pini (Say) pheromone lures, a total of 5,635 bark beetles (30 species) were collected, and 16.4% of these beetles had at least one mite. From these beetles, a total of 2,424 mites representing 33 species from seven families were collected. The majority of mite species had a narrow host range from one (33.3%) or two (36.4%) host species, and fewer species had a host range of three or more hosts (30.3%). This study represents the first broad investigation of the acarofauna of scolytines in Canada, and we expand upon the known (worldwide) host records of described mite species by 19%, and uncover 12 new species. Half (7) of the 14 most common mites collected in this study showed a marked preference for a single host species, which contradicts the hypothesis that nonparasitic mites are typically not host specific, at least locally. Moreover, host records from the literature and those of this study together suggest that at a global scale, bark beetle mites have a broad host range, while at a local scale many species are host specific.

Pediobius ni Peck (Hymenoptera: Eulophidae) is a eulophid parasitoid indigenous to North America that was found attacking the invasive light brown apple moth, Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae), in California. We investigated host age suitability, fecundity, and temperature-dependent developmental time for P. ni as a parasitoid of E. postvittana. Parasitoid offspring survival was higher on E. postvittana presented as prepupa or young pupa (<3 d old) than older pupa (>3d old), and P. ni would not attack mature E. postvittana larva. Parasitoid developmental time increased with advanced host age. At 24°C, P. ni parasitized 6.8 ± 0.7 hosts, and produced 119.5 ± 16.8 offspring during a 21.5 2± 3.0 d adult lifetime when provided food and host pupae. The developmental rate of P. ni was a positive linear relationship between 15–28°C, but it failed to develop at constant temperatures >29°C. The estimated lower developmental threshold is 13.0°C, and degree-day requirements (DD) are 278 DD. As a comparison of host species suitability, P. ni was tested with obliquebanded leafroller, Choristoneura rosaceana (Harris) (Lepidoptera: Tortricidae); navel orangeworm, Amyelois transitella (Walker) (Lepidoptera: Pyralidae); omnivorous leafroller, Platynota stultana Walsingham (Lepidoptera: Tortricidae); orange tortrix, Argyrotaenia franciscana (Walsingham) (Lepidoptera: Tortricidae); and peach twig borer, Anarsia lineatella Zeller (Lepidoptera: Gelechiidae). The parasitoid readily attacked all tested host species; percentage parasitism was lower on A. lineatella than on A. transitella, P. sultana, and C. rosaceana, but similar among the other tested species. Clutch size generally increased with host size, but percentage adult emergence and sex ratio was not affected by host species. Exposure of hosts to multiple P. ni increased the numbers of emerged wasps per parasitized host without obvious costs to offspring fitness.

Most physiological processes to external stimulants rely upon intracellular signal transduction mediated by ligand binding of G-protein-coupled receptors. The G-protein signaling pathway is deactivated by arrestin-2 binding, which is indispensable for receptor internalization and recycling. We identified the full-length cDNA encoding arrestin-2 in Maruca vitrata F. using rapid amplification of cDNA ends. The open reading frame of MaviArr2 is 1,221 bp in length, encoding 407 amino acids. The alignment of the known arrestin-2 amino acid sequences from other insects revealed that MaviArr2 has the highest similarity (98.8%) to the monarch butterfly, but shows low homology (53.9–60.7%) with ants and bees. A certain number of highly conserved protein-binding motifs were identified from the deduced MaviArr2 amino acids, demonstrating their function as receptor deactivators in signal transduction pathways in cells. The genomic DNA sequence of MaviArr2, amplified by polymerase chain reaction, is 1,779 bp in size and is composed of six exons. Real-time quantitative polymerase chain reaction assay demonstrated a relatively higher expression of MaviArr2 mRNA in the late pupal stages, suggesting multiple developmental functions. Phylogenetic analysis showed the lepidopteran arrestin-2 protein sequence is closely related to that of Diptera, but distant from Hymenoptera arrestin-2. Intraspecific genomic sequence comparisons of MaviArr2 show a greater conservation of the gene in M. vitrata from Africa than those from geographical locations in Asia. These findings are a significant step forward in our understanding of arrestin-2 gene architecture and functions, which may provide a possibility to manage M. vitrata through molecular and phylogenetic techniques.

In this study, we analyzed the effects of cadmium (1.25, 2.5, 5, 10, 20, and 40 mg per 100 g of nutrient) on total protein, lipid, and glycogen levels, lipid peroxidation (MDA), superoxide dismutase (SOD) and catalase (CAT) activities, and metal accumulation in Galleria mellonella L. High concentrations of Cd (20 and 40 mg) significantly lowered total protein, lipid, and glycogen levels. MDA level significantly increased when the nutrient contained 5 mg and more of Cd, whereas SOD activity significantly increased at Cd concentrations starting from 1.25 mg. CAT activity significantly decreased at all concentrations. Metal accumulation also significantly increased in a dose-dependent manner. These changes observed on activity of antioxidant enzymes, energy reserves, MDA content, and accumulation levels of Cd can be used as a reliable biomarker of environmental heavy metal pollution in model insect G. mellonella.

Sensory neuron membrane proteins (SNMPs) play an especially important role in insect pheromone communication. However, the SNMPs for the Asiatic rice borer, Chilo suppressalis (Walker) (Lepidoptera: Pyralidae), a notorious rice pest, remain uncharacterized. Here we report the cloning and characterization of two novel SNMPs from the C. suppressalis, CsupSNMP1 and CsupSNMP2. The CsupSNMP1 and CsupSNMP2 cDNAs contained open reading frames (ORFs) of 1,572 and 1,569 bp, encoding proteins of 523 and 522 amino acid residues, respectively. The amino acid identity between the two deduced CsupSNMPs was low (30% identity), but they shared a high degree of similarity to previously characterized SNMP1s or SNMP2s from other moth species, which is consistent with phylogenetic analysis in which CsupSNMP1 and CsupSNMP2 are clustered into two distinct groups based on their amino acid sequences. The expression patterns of CsupSNMPs in various adult tissues and in different developmental stages were determined by real-time quantitative polymerase chain reaction. The results showed that both CsupSNMP1 and CsupSNMP2 were abundantly expressed in the male and female antennae, reaching their maximum in the adult stage, suggesting the two genes are involved in the process of olfaction. Low levels of CsupSNMP2 also were expressed in nonolfactory tissues such as legs and wings, implying possible gustatory roles of the protein in the moth.

Body size and development time are two critical phenotypic traits that can be highly adaptive in insects. Recent population genetic analyses and crossing experiments with the mountain pine beetle (Dendroctonus ponderosae Hopkins) have described substantial levels of neutral molecular genetic differentiation, genetic differences in phenotypic traits, and reproductive isolation. To determine whether genetic differences in adaptive phenotypic traits exist that correspond to reproductive boundaries, we conducted a common garden experiment with seven D. ponderosae populations previously used to identify reproductive incompatibilities. Genetic differences in development time were striking between faster developing, and more synchronized, northern populations and slower developing, and less synchronized, southern populations. Additionally, genetic differences in average body size were found between many populations. Differences in these two traits, however, failed to clearly demarcate populations that exhibit reproductive incompatibilities. Our results suggest that local selection pressures likely drive divergence in these two traits that is largely independent of the evolution of reproductive isolation in D. ponderosae.

Mate-seeking in Diaphorina citri Kuwayama, a vector of the economically damaging huanglongbing citrus disease, typically includes male—female duetting behaviors. First, the male calls by beating his wings at ≈170–250 Hz, producing vibrations that are transmitted along the host tree branches to the female. If receptive, she immediately replies, helping to direct the searching male toward her. The duetting and searching continues until the male locates the female. Males and females are similar in size and produce wingbeat vibrations with similar temporal and spectral patterns. A study of male and female responses to playbacks of recorded and synthetic mimics of different vibrational signals on citrus plants was conducted to better understand the range of signals to which D. citri respond and potentially to co-opt or disrupt their vibrational communication. In general, both sexes responded well to a variety of 0.3–0.5-s signals that included multiple harmonics of ≈200-Hz wingbeatfrequency chirps up to ≈1,400 Hz (where a chirp is a sine wave tone that sweeps across a narrow range of frequencies). There were only minor differences in female responses to signals containing different relative amplitudes of such chirps, and males readily located sources that played these multipleharmonic signals. The results are discussed in relation to mating-signal selectivity and the potential for developing automated methods to trap male D. citri by using vibrational signals.