The cytology of Actinidia, Saurauia and Clematoclethra (Actinidiaceae)

Meiosis and mitosis of six Chinese Actinidiaceae were studied: Saurauia tristyla DC., S. miniata C. F. Liang & Y. S. Wang, Actinidia chinensis Plach., A. deliciosa (Cheval.) C. F. Liang & A. R. Ferguson, A. indochinensis Merr. and Clematoclethra lasioclada Maxim. The chromosome numbers of Saurauia tristyla and S. miniata were 2 n  = 6 x  = 78, establishing a base chromosome number of x  = 13 in the genus, differing from the previous report of x  = 15. The chromosome number of Clematoclethra was first reported to be 2 n  = 4 x  = 48 ( x  = 12), while that of Actinidia was x  = 29, consistent with previous reports. The base chromosome number of Clematoclethra ( x  = 12) was derived from an aneuploid decrease from Saurauia ( x  = 13). Actinidia (x  = 29) was derived from the palaeotetraploid ( x  = 14), which was formed through the increase of the basic chromosome number x  = 13 to x  = 14 by aneuploidy and through the breakage of a centromere to add one more new chromosome. The chromosome data in Actinidia were consistent with the geographical and morphological evidence for the evolution of the three genera. The tropical American and Asian disjunct distribution pattern and the diversity of base chromosome numbers of Saurauia further support the probability that the genus was an early divergent from a common ancestor of Actinidia and Clematoclethra .  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 147 , 369–374.     

Sperm ultrastructure of five species of the Neotropical ant genus Pseudomyrmex (Hymenoptera: Formicidae)

The seminal vesicles of adult males of five species of Pseudomyrmex were prepared for light and transmission electron microscopy. The Pseudomyrmex spermatozoa are long and slender with similar morphology. The head region has an acrosome and a nucleus. In all the studied species, two morphologically distinct types of acrosomal vesicles were observed, a long structure, as observed in all known ants, and a pear‐shaped one, never before observed in ants. The nucleus is elongated and both condensed and loose chromatin are present. The flagellum has an axoneme, a centriolar adjunct, two mitochondrial derivatives and two accessory bodies. The centriolar, the mitochondrial derivatives and the accessory bodies are similar to observations in most ant species that have been studied. The axoneme presents an uncommon 9 + 9 + 1 microtubule arrangement and the central microtubule has 13 protofilaments. The acrosomal dimorphism and the different levels of chromatin organization are exclusive characteristics of Pseudomyrmex. Furthermore, the 9 + 9 + 1 microtubule arrangement is different from all Hymenoptera, as well as from most insects, which present a 9 + 9 + 2 arrangement. These new morphological characters that are specific to Pseudomyrmex, are valuable synapomorphies of the genus and can be used in taxonomic characterization of the Pseudomyrmecinae subfamily and in phylogenetic analyses in Formicidae family.     

Associations between genetic merit for milk production and animal parameters and the fertility performance of dairy cows

Relationships between genetic merit for milk production and animal parameters and various parameters of reproductive performance were examined using multilevel binary response analysis in a study of 19 dairy herds for three successive years, representing approximately 2500 cows per year. The proportion of cows intended for rebreeding that were back in-calf again within 100 days of calving (ICR-100) and the proportion of cows that reappeared again with 365 (RR-365) and 400 days (RR-400) of a previous calving were considered in addition to the traditional measures of reproductive performance. Each 100-kg increase in genetic merit for milk yield was associated with an increased interval to first service (IFS) and calving index (CI) of 1.4 ( P < 0.001) and 1.8 days ( P < 0.001), respectively, a 0.5% increase ( P < 0.05) in calving rate to first insemination (CR-1) and 0.8% increase in RR-400. Each £10 increase in £PIN (the economically weighted yield selection index used in the UK that takes account of butterfat and protein yields) was associated with an increased IFS and CI of 1.5 ( P < 0.001) and 3.0 days ( P < 0.001), respectively. Cows with increased genetic merit for milk yield and £PIN were more likely to re-calve (RR-overall; P < 0.001). Each 1000-kg increase in 305-day milk yield was associated with an increased IFS and CI of 3.2 ( P < 0.001) and 7.8 days ( P < 0.001), respectively, and a 13.6 ( P < 0.001), 22.4 ( P < 0.001), 19.9 ( P < 0.001) and 19.0% ( P < 0.001) decrease in CR-1, ICR-100, RR-365 and RR-400, respectively. A 10-kg increase in maximum yield was associated with a 6.6-day increase in CI ( P < 0.001) and a 14.9 ( P < 0.001), 18.3 ( P < 0.001), 9.6 ( P < 0.05) and 14.2% ( P < 0.001) decrease in CR-1, ICR-100, RR-365 and RR-400, respectively. Fertility performance was also associated with season of calving, lactation number and dystocia score. Level of production had a larger effect on fertility performance than genetic merit for milk production suggesting that infertility at an individual cow level is more likely to be associated with increased production and an inability to meet the nutritional requirements of the cow.     

Fine needle aspiration at a Regional Head and Neck Clinic: A clinically beneficial and cost-effective service

Background:  Fine needle aspiration (FNA) is an important adjuvant to the diagnosis of a palpable lesion which often permits the complete assessment of patients. The main objective of this study was to determine the clinical benefit of a dedicated FNA service at a tertiary referral Head and Neck Clinic and to assess if such a service is cost effective.
Methods:  All patients attending the Head and Neck Clinic during 2004 were prospectively assessed in this study. Patient records were analysed regarding investigative modalities including FNA, the subsequent cytology result and the requirement for further histopathological investigations. A cost analysis for all investigative procedures was performed.
Results:  A total of 135 patients (36 males) had FNAs performed during the study period. The median age was 51.5 years (range 17–92). Patients presented with lesions of lymph nodes ( n  = 46), thyroid ( n  = 41), salivary, parotid or submandibular glands ( n  = 22) and other cutaneous or cystic lesions ( n  = 26). Cytological grading results were; C1 = 26, C2 = 93, C3 = 8, C4 = 2 and C5 = 6. Patients with lesions C3 or above normally proceeded to further investigations. The overall cost of the FNA per episode in the out-patient clinic was £114 per episode compared to day case open biopsy per patient of £333 and an in-patient stay per patient was £2371. FNA provided sufficient pathological diagnosis to avoid day case surgery in 57 patients (42.2%), and inpatient surgery in 65 patients (48.1%) resulting in a total saving of £158 372 in 2004.
Conclusion:  This study demonstrates the clinical benefit and cost-effectiveness of FNA services in a dedicated Head and Neck clinic.     

On the identity of Festuca jubata Lowe (Poaceae) and the description of a new Festuca species in the Azores Islands

The majority of authors consider Festuca jubata Lowe as an endemic species common to Madeira and the Azores. Saint-Yves proposed that F. jubata was an Azorean endemic and described a geovicarious taxon in Madeira: F. filiformis C. Sm. ex Link in Buch ssp. mandonii St.-Yves. We undertook a complete bibliographical revision of the taxonomy, nomenclature, and chorology of F. jubata s.l. , and contrasted it with morphological and anatomical studies performed on samples from the Azores and Madeira. Azorean plants usually identified as F. jubata had a character combination distinct from that of those with a Madeiran provenance. Saint-Yves' proposal of two independent taxa was correct, but he erroneously considered F. jubata as an Azorean endemic because the name F. jubata was based on Madeiran plants. Consequently, F. jubata auct. pl. from the Azores belongs to a new species.  © 2008 The Linnean Society of London, Botanical Journal of the Linnean Society , 2008, 157 , 493–499.     

Novel fluorescence method for real-time monitoring of nitric oxide dynamics in nanoscale concentration

A novel assay was developed for the measurement of nitric oxide. The proposed method is based on fluorescence, using a fluorophore-heme dual functionality probe (FHP). The heme group can serve as an effective NO-trap, due to its very fast reaction with NO and the high stability of the resulting complex. Since the heme is connected with a fluorophore as a part of the FHP dual-functionality probe, the heme can quench the fluorophore fluorescence, under certain conditions, by a singlet–singlet energy transfer mechanism.

The proposed method was tested using myoglobin covalently modified by a stilbene label. The change in emission intensity of the stilbene fragment, versus an increasing concentration of NO precursors, clearly demonstrated the spectral sensitivity required to monitor the formation of a heme–NO complex in a concentration range of 10 nM–2 μM. Furthermore, the new methodology for NO measurement was also found to be an effective assay using tissues from rabbit and porcine trachea epithelium. The measured NO flux (in an initial time interval) in tissue sample from rabbit trachea epithelia and porcine trachea epithelia is  7.9 × 10^− 12 mol/s × g and  3.0 × 10^− 12 mol/s × g respectively.     

Ecological and morphological characteristics of the endoparasitoids of larval Acronicta rumicis (Lepidoptera: Noctuidae)

The Hymenopterans Glyptapanteles liparidis, Microplitis sp. and Diadegma sp. were found to be larval parasitoids and koinobionts of Acronicta rumicis (Lepidoptera: Noctuidae). Mesochorus semirufus is believed to be a new unreported hyperparasitoid of G. liparidis, which, along with M. semirufus, is a gregarious parasitoid. In contrast, the parasitoids Microplitis sp. and Diadegma sp. are solitary. All of the hymenopteran parasitoids are multivoltine insects that emerge from A. rumicis more than once. Compcilura concinnata, Euexorista sp. and Exorista sp. of the Diptera were found to be larval–pupal parasitoids, solitary parasitoids and koinobionts. These three species are univoltine, and emerge only once from A. rumicis. Morphological and life cycle data were collected for G. liparidis, and for the parasitoids of that species found in this study. The major and minor axes of an egg of G. liparidis were 0.10 and 0.02 mm, respectively, while the mean clutch size of G. liparidis was 67.71 ± 39.36 individuals. The body length of female and male G. liparidis were 2.25 ± 0.06 and 2.21 ± 0.12 mm, respectively, and the longevity of an adult was 2.93 ± 0.96 days. Among the parasitoids, the mean body length of an adult Microplitis sp. was 3.5 mm and adults lived for an average of 8.13 ± 3.54 days. The adult Diadegma sp. was larger (mean body length 6.5 mm) but lived for a shorter interval (3.33 ± 1.32 days). The body lengths of female and male M. semirufus were 3.16 ± 0.11 and 3.10 ± 0.23 mm, respectively, greater than the body lengths of female and male G. liparidis. The body lengths of adult C. concinnata, Euexorista sp. and Exorista sp. were 9.5, 9.53 and 8.68 mm, respectively. All of their pupae were dark brown.     

The effect of hind-tibial spurs on digging rate in female eastern cicada killers

Abstract.  1. The function of the large hind-tibial spurs of female eastern cicada killer wasps ( Sphecius speciosus ), thought to be adaptations to digging, was examined by measuring the effect of spurs on digging rate.
2. Spurs were removed from one group of wasps and left intact in control specimens.
3. Wasps with intact spurs removed soil from the burrow at a rate of 0.98 ± 0.11 (16) g dry mass min⁻¹ [mean ± SEM ( N )]. Removal of spurs results in an average digging rate just over one-half that, 0.54 ± 0.13 (9) g min⁻¹.
4. The difference in digging rate was primarily because of a twofold greater mass of soil unloaded by intact wasps each time they exited the burrow, rather than the rate at which such loads were delivered.
5. Such inefficiency results in an estimated additional 8.2 h requirement to fully excavate an average burrow, or a 1–4% reduction in time available for foraging in spur-ablated wasps.
6. Calculations suggest that the time lost to digging would result in a 3.9–19.5% reduction in foraging success for spurless females.
7. These temporal and resulting foraging advantages of hind-tibial spurs presumably provided selection pressure for their evolution from smaller, pre-existing setae.     

Cloning, purification and characterization of a thermostable amylosucrase from Deinococcus geothermalis

Amylosucrase is a transglucosidase that catalyses the synthesis of an amylose-type polymer from sucrose, an abundant agro-resource. Here we describe a novel thermostable amylosucrase from the moderate thermophile Deinococcus geothermalis (DGAS). The dgas gene was cloned and expressed in Escherichia coli . The encoded enzyme was purified and characterized. DGAS displays a specific activity of 44 U mg⁻¹, an optimal temperature of 50 °C and a half-life of 26 h at 50 °C. Moreover, it produces an α-glucan at 50 °C, with an average degree of polymerization of 45 and a polymerization yield of 76%. DGAS is thus the most active and thermostable amylosucrase known to date.     

The lesser wanderer butterfly, Danaus petilia (Stoll 1790) stat. rev. (Lepidoptera: Danainae), reinstated as a species

Abstract  The lesser wanderer butterfly, Danaus ( Anosia ) chrysippus petilia (Stoll) (Lepidoptera: Danainae), has been treated as a subspecies for the last 100 years. New mitochondrial DNA sequence data for D. petilia , in conjunction with allozyme, structural, morphometric and pattern characters, constitute a compelling case for its specific rank. The holotype of D. petilia has never been located and, as the type location is uncertain, a neotype is designated. Fresh material was collected and examined for this project. Danaus petilia and D. chrysippus have been separated at Lydekker's Line for an estimated 1.1 million years, and they remain interfertile. However, as an allopatric taxon, diagnosable from D. chrysippus , D. petilia merits specific status under the phylogenetic species concept. The following pairs of D. chrysippus subspecies are considered to be synonyms, the first member of each pair having priority: chrysippus  +  aegyptius (subspecies), klugii  +  infumata (hybrid phenotypes) and orientis  + liboria (subspecies).     

Variability in the life history of the water strider Gerris lacustris (Heteroptera: Gerridae) across small spatial scales

Abstract.  1. Variability in life-history traits of the common pond skater Gerris lacustris (L.) (Heteroptera: Gerridae) was investigated on a small geographical scale in Bavaria, Germany (≈ 49 °N). In an area of approximately 3.5 × 3.0 km, voltinism and wing length data of G. lacustris were recorded from 65 ponds located either in an open field or surrounded by forest.
2. Life history differed significantly between populations in the two habitat types. Gerris lacustris showed a bivoltine life-cycle in most of the field ponds with a high proportion of long-winged individuals in the diapause generation and a large increase of the short-winged morph in the midsummer generation. In contrast, almost all populations inhabiting forest ponds were univoltine. Only a few forest populations produced any second generation larvae. The long-winged morph dominated during the whole season in forest ponds.
3. The appearance of first-instar larvae was delayed by 3–4 weeks in forest ponds compared with field ponds. Presumably, low temperatures led to this reduction in the developmental rate of eggs and larvae. Consequently, 'field larvae' of the first generation developed under increasing daylight conditions (triggering direct reproduction and brachyptery) but 'forest larvae' developed under a shortening photoperiod (triggering diapause and macroptery).
4. Offspring raised from 'forest parents' in the laboratory showed the same variability in life history when reared in a cool (16.9 ± 2.4 °C) or warm (23.1 ± 1.8 °C) temperature regime.
5. Given the small spatial scale of the study, it is concluded that the variability in the life history of G. lacustris has a strong phenotypic component.     

An ancient African radiation of corvoid birds (Aves: Passeriformes) detected by mitochondrial and nuclear sequence data

The Malaconotidae, Platysteiridae and Vangidae represent an African and Malagasy assemblage of closely related corvoid taxa with distinctive morphology. Their relationships with their putative Asian closest relatives, and thus their biogeographic history, have not hitherto been thoroughly evaluated. We present evidence that the African and Malagasy groups originated through a single African colonization event c. 37.7 ± 4.6 Myr BP. Three main groups that differ in their foraging behaviour diverged c. 35.8 ± 4.5 Myr BP, suggesting that an African radiation occurred around that time. Several disperal events out of Africa to Madagascar (Vangidae) and Indo-Malaya ( Philentoma , Hemipus and Tephrodornis ) took place about 28.9 ± 4.0 Myr BP (Oligocene), a period when faunistic exchanges between Eurasia and Africa seem to have been common. Our estimation of the colonization of Madagascar by the Vangidae is 28.9 ± 4.0 Myr BP, in congruence with the estimated colonization of Madagascar by several African vertebrate groups (carnivorous mammals, snakes, sylvioid passerines, treefrogs, turtles).     

Satiation time and appetite revival of Coccinella septempunctata L. (Col., Coccinellidae), a predator of Lipaphis erysimi Kalt. (Hom., Aphididae)

After a 24 h period of starvation the Coccinella septempunctata grub satiated in 85 min after eating 31.57 ± 7.12 prey (aphids). After 6, 12, 18, 24, 30 and 36 h of prey deprivation, the grub consumed 14.31 ± 5.67, 22.05 ± 5.39, 27.10 ± 6.49, 31.57 + 7.12, 33.76 + 6.52, and 36.98 ± 8.56 prey, respectively. The voluntary intake (appetite) shows a sigmoid relationship with the time since the last meal, with an upper limit of 44.30 prey irrespective of the prey deprivation period. As maximum appetite was attained after 24–36 h of deprivation, it is recommended that C. septempunctata grubs should be starved for 24 h prior to release in the biological control programme of Lipaphis erysimi.     

Chromosomal evolution of South American frugivorous butterflies in the Satyroid clade (Nymphalidae: Charaxinae, Morphinae and Satyrinae)

We describe the chromosome numbers of a monophyletic group of Satyroid subfamilies of primary fruit-attracted butterflies from South America: Charaxinae, Morphinae (including Brassolini) and Satyrinae. The charaxines do not have a distinct modal number. Their chromosome numbers are in the range n  = 6–50, with n  = 7–9, n  = 12, n  = 16, n  = 19–21, n  = 26, and n  = 28–31 being the most common numbers. Within the Morphinae, the Morphini have a modal n  = 28 and the Brassolini a modal n  = 29, with few exceptions. The Neotropical satyrines, in particular the basal species, have a weak modal n  = 29, which is a strong modal number in Palearctic satyrines. The African satyrines have an equally strong modal n  = 28. Most Neotropical satyrines have, like charaxines, chromosome numbers lower than the weak modal n  = 29, and often half this modal, but there are genera with stable numbers among the satyrines and charaxines. Evidently, the Neotropical satyroids descend from basal Nymphalidae with the typical lepidopteran modal number of n  = 31, which have also given rise to the Heliconiini with modal n  = 31 and 21 and Ithomiinae with modal numbers of n  = 14–15.  © 2007 The Linnean Society of London, Biological Journal of the Linnean Society, 2007, 92 , 467–481.     

Studies on the Robertsonian chromosomal variation of Mus musculus domesticus (Rodentia, Muridae) in Greece

The karyotype of the house mouse, Mus musculus domesticus , was examined in 282 specimens from 44 localities, in an effort to gain better understanding of the Robertsonian (Rb) variation known to exist in Greece. We consider that an Rb system exists in Peloponnisos, southern Greece, distributed in an area that is substantially larger than previously known. It consists of at least three Rb races with 2 n  = 30, 2 n  = 24 and 2 n  = 28, respectively, the last being reported for the first time in this paper and carrying Rb(3.6), Rb(8.12), Rb(10.14), Rb(13.15), Rb(9.16) and Rb(11.17) in a homozygous state. Additional instances of variation in this Rb system include individuals with 2 n  = 31 and 32 of variable Rb constitution and hybrids between the Rb races with 2 n  = 30 and 2 n  = 24. In southern Peloponnisos, Rb(10.14) was found in either a homozygous or a heterozygous state (2 n  = 38 or 39). The relationships among the Rb populations of Peloponnisos are discussed and hypotheses for their evolution are proposed. Rb variation was also recorded in two new locations of eastern Sterea Ellas (2 n  = 28 and 29) and one in Ipiros, north-west Greece (2 n  = 38). These findings corroborate the existence of two separate Rb systems in those two areas. Moreover, among a number of islands surveyed, Rb variation was only found in Kythira island, with Rb(10.14) in a heterozygous state (2 n  = 39). Finally, the typical all-acrocentric karyotype (2 n  = 40) was found in 51 of the animals studied from 13 localities. © 2005 The Linnean Society of London, Biological Journal of the Linnean Society , 2005, 84 , 503–513.     

Chromosome study of the fern genus Cyrtomium (Dryopteridaceae)

Cyrtomium (Dryopteridaceae) is an Asiatic genus comprising about 40 species characterized by having anastomosing veins that form areolae with included veinlets. Twelve chromosome counts representing 11 taxa were made in the present study. The chromosome numbers of six species endemic to China are reported for the first time: C. uniseriale , 2 n  = 164; C. guizhouense , 2 n  = 82; C. shingianum , n  = 82, 2 n  =  c .164; C. chingianum , 2 n  = 164; C. urophyllum , 2 n  = 82 and C. aequibasis , 2 n  = 123. The results were used to show that (1) C. uniseriale should be reduced to varietal status under C. balansae ; (2) subseries Balansana is not closely related to any other Cyrtomium species and should be separated from Cyrtomium ; and (3) C. guizhouense and C. lonchitoides are basal groups when subseries Balansana is not considered. These results were also supported by morphology. A high level of differentiation is a distinct characteristic in Cyrtomium . The genus has two reproductive types: sexual and apogamous. Sexual species are distributed mostly in China. Southwestern China is a modern diversity centre of Cyrtomium , with 80.6% of known species occurring there. Many species are endemic, most of which are sexual tetraploids or apogamous triploids. Both the apogamous reproductive type and polyploid species are adaptions to limestone habitats.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 150 , 221–228.     

Acetate transport and utilization in the rat brain

Acetate, a glial-specific substrate, is an attractive alternative to glucose for the study of neuronal-glial interactions. The present study investigates the kinetics of acetate uptake and utilization in the rat brain in vivo during infusion of [2-¹³C]acetate using NMR spectroscopy. When plasma acetate concentration was increased, the rate of brain acetate utilization (CMR_ace) increased progressively and reached close to saturation for plasma acetate concentration > 2–3 mM, whereas brain acetate concentration continued to increase. The Michaelis–Menten constant for brain acetate utilization (      = 0.01 ± 0.14 mM) was much smaller than for acetate transport through the blood–brain barrier (BBB) (      = 4.18 ± 0.83 mM). The maximum transport capacity of acetate through the BBB (      = 0.96 ± 0.18 μmol/g/min) was nearly twofold higher than the maximum rate of brain acetate utilization (      = 0.50 ± 0.08 μmol/g/min). We conclude that, under our experimental conditions, brain acetate utilization is saturated when plasma acetate concentrations increase above 2–3 mM. At such high plasma acetate concentration, the rate-limiting step for glial acetate metabolism is not the BBB, but occurs after entry of acetate into the brain.     

Periphyton as alternative food source for the filter-feeding cladoceran Daphnia magna

1.  Daphnia magna , a well-studied primary consumer, is mainly known as a filter feeder. In this study, we investigated the ability of D. magna to use periphyton as an alternative food source to phytoplankton. We examined the development of laboratory populations fed with different food sources ( Desmodesmus subspicatus and/or periphyton or neither) over a period of 42 days, and observed the behaviour of the daphnids.
2.  The addition of periphyton to phytoplankton food led to an increase of daphnid population biomass. When fed with periphyton as the only food source, a small but stable D. magna population developed.
3.  The behaviour of daphnids fed with both food sources revealed a preference for feeding on D. subspicatus . Only below a concentration of D. subspicatus of approximately 0.05 mg C L⁻¹ (0.4 × 10⁷ cells L⁻¹) did D. magna use periphyton as an alternative food source.
4.  Periphyton showed distinct reactions to grazing by D. magna . The thickness of the periphyton layer was reduced from about 4 to 1 mm and we observed a change in species composition due to grazing.
5.  The ability of D. magna to graze on periphyton could serve to stabilize its population density and reinforce its competitive advantage over other cladocerans. By switching between food sources, D. magna can act as a coupler between pelagic and benthic habitats and food webs.     

Colony productivity and foundress behaviour of a native wasp versus an invasive social wasp

Abstract.  1. Colony productivity, prey utilisation, and foundress behaviour of a North American native wasp ( Polistes fuscatus ) versus an European invasive wasp ( Polistes dominulus ) were investigated in a controlled field experiment with optimal versus natural foraging conditions. Colonies with the optimal prey foraging conditions were provided with prey ad libitum within an enclosed area. The other colonies foraged in the adjacent field–woodland but had the same nest conditions as the other treatment.
2. When given prey ad libitum , both wasp species captured similar amounts of prey and the conversion to total offspring biomass was similar. But P. dominulus colonies produced 2.5 times the number of workers as P. fuscatus colonies, reflecting the smaller size of P. dominulus wasps.
3. Foundresses of P. dominulus were observed more often building or repairing the nest, thereby contributing to the production of colonies with twice as many cells as colonies of P. fuscatus . Foundresses of P. dominulus showed more acts of aggression toward workers than did P. fuscatus foundresses, which was not a function of adult density on the nest.
4. At the end of the experiment, P. dominulus colonies with optimal prey foraging conditions still had a high level of egg-laying and peaked in the number of pupae then, whereas egg-laying and the number of pupae per colony of the other treatments began to decline 2–3 weeks earlier. These results indicate that P. dominulus is more opportunistic than P. fuscatus , which may account in part for P. dominulus 's success as an introduced species in North America.     

Effects of acclimation and diapause on the cold tolerance of Trogoderma granarium

Khapra beetle, Trogoderma granarium Everts (Coleoptera: Dermestidae), is a pest of stored grain in Africa, Asia, and Europe. It is a quarantine insect for much of the rest of the world. Control of T. granarium can be achieved with methyl bromide, but this fumigant is an ozone‐depleting substance and is being phased out worldwide. Thus, there is an urgent need to find new methods of control, including the use of low temperatures. Here, we assess the effects of diapause and cold acclimation on the cold tolerance of T. granarium. The percentage of larvae in diapause increased with larval density, reaching 57.3% when reared at a density of 73 larvae g^?1 diet. The cold tolerance of T. granarium was assessed by the supercooling points (SCPs) of various life stages. The SCP of non‐acclimated insects ranged from ?26.2 ± 0.2 °C (mean ± SEM) for eggs to ?14.4 ± 0.4 °C for larvae. The lowest SCP for larvae, ?24.3 ± 0.3 °C, was obtained for diapausing‐acclimated larvae. Based on mean LT₅₀ values, the most cold‐tolerant stage at ?10 °C was the diapausing‐acclimated larvae (87 days) followed by non‐diapausing‐acclimated larvae (51 days), diapausing non‐acclimated larvae (19 days), adults (4 days), non‐diapausing non‐acclimated larvae (2 days), pupae (0.4 days), and eggs (0.2 days). The estimated times to obtain 99.9968% mortality (Probit 9) for diapausing‐acclimated larvae are 999, 442, 347, 84, and 15 days at 0, ?5, ?10, ?15, and ?20 °C, respectively. Probit 9 is an estimated value used by quarantine experts to estimate conditions that are required to kill all insects. In light of the long exposure time needed to control T. granarium even at ?20 °C, cooling to below ?27 °C (i.e., below the SCP of eggs) will quickly kill all life stages and may be the best way to control this insect with low temperatures.