Genetic population structure in a troglobitic beetle (Speonomus zophosinus)

Genetic variation of five variable loci was analyzed for troglobitic beetles within and between populations along the Salat and Arac Rivers in the central Pyrenees; the patterns of variation are described. Significant genetic differentiation was found for Speonomus zophosinus from populations in close proximity (10 km), largely due to differences between two groups of three populations. F_ST values range from 0.004 (Phi) to 0.354 (Est-6). Within a region, populations on opposite banks are genetically similar. Within populations genotypic frequencies were not in Hardy-Weinberg equilibrium. For troglobitic species such as S. zophosinus, gene flow is a function of intrinsic (active movement and reproductive strategy) and extrinsic factors (geologic structure of the subterranean environment). It seems that natural selection has played little, if any, role in generating the observed gene frequency patterns. The patterns of variation are most reasonably explained as having resulted from genetic dirft occurring between two areas separated by an inhospitable habitat which acts as a dispersal barrier or limits gene flow.     

Genetic divergence between populations of two closely related troglobitic beetle species (Speonomus: Bathysciinae,Coleoptera)

Genetic variability and divergence at 13 enzyme loci were studied in two species of troglobitic beetles (Speonomus zophosinus andhydrophilus 12 populations) collected from the Pyrenees mountains. These allopatric species exhibit a high degree of specialization to underground life and a very small geographical range. Four diagnostic loci arePgi, Est-2, Pac-1, Phi. Within each species polymorphic loci exhibited marked spatial variation of allele frequencies, sometimes over short distances (5–10 km). The levels of genetic variability are comparable to those observed in non-cave invertebrates (frequency of polymorphic loci: 0.31; average expected heterozygosity: 0.112±0.015). Moreover, a single species showed variability in the average level of heterozygosity (0.06 to 0.172). Patterns of genetic differentiation among species were also studied; mean genetic distance (D: 0.263±0.010) between the twoSpeonomus species was of the same order of magnitude as most data reported in the literature between species. A significant heterozygote deficiency occurs in local populations and for all loci. This deficit does not vary from locus to locus. Several hypotheses were examined in an attempt to account for these observations in connection with the species biology. This deficit probably is due to the breeding structure of the population (inbreeding and assortative mating) coupled with limited dispersal ability.     

Antennal sensory organs of a troglobitic coleoptera,Speonomus hydrophilus jeannel (Catopidae): An ultrastructural study by chemical fixation and cryofixation

The ultrastructure of 12 antennal sensory organs of the cavernicolous beetle Speonomus hydrophilus (Coleoptera : Catopidae) after chemical fixation or cryofixation is described. This work helps us to compare the results of the 2 types of fixation; cryofixation is more difficult and hazardous, but when it succeeds, the cell preservation is better than with conventional chemical fixation; the cell shapes are more regular and rounded, and some details, such as microtubule subunits, can be visible only after cryofixation. On the basis of these ultrastructural features, the sensory organs are functionally classified. The structures of these organs are compared in epigean and troglobitic Coleoptera.     

Potential resistance of crape myrtle cultivars to flea beetle (Coleoptera: Chrysomelidae) and Japanese beetle (Coleoptera: Scarabaeidae) damage

Field and laboratory studies were conducted to identify potential resistance among crape myrtles, Lagerstroemia spp., to Japanese beetle, Popillia japonica Newman and to flea beetles, Altica spp. Damage ratings revealed variation among cultivars in susceptibility to beetle feeding. Cultivars with Lagerstroemia fauriei Koehne in their parentage exhibited the least amount of damage in choice and no-choice experiments, with few exceptions. The data indicate that both beetle species cause more feeding damage on certain cultivars of Lagerstroemia indica L., such as 'Country Red', 'Twilight', and 'Carolina Beauty' than interspecific cultivars with L. fauriei in their parentage, such as 'Natchez', 'Tonto', and 'Muskogee'. When comparing the effect of parentage on all of the major pests of crape myrtle, L. faurei confers resistance to all pests except crape myrtle aphid. No correlation was found between leaf toughness, leaf color, and leaf nutrients in estimating flea beetle cultivar preference. With this information, growers can more effectively target scouting measures to the most susceptible cultivars. and breeders can select plants that will require the fewest chemical inputs.     

Genetic structure of populations of the Colorado potato beetle Leptinotarsa decemlineata (Coleoptera: Chrysomelidae)

The genetic structure of a Colorado potato beetle population from Kiev oblast was examined by cluster analysis of individual RAPD patterns. The obtained clustering indicates that the population is structured. This may be explained by adaptation to pyrethroid insecticides used for controlling the population size of this pest. Micro-evolutionary factors affecting the genetic structure of local populations of Colorado potato beetle are discussed.     

Stag beetle fauna of Cambodia (Coleoptera: Lucanidae)

To date, no species catalogue of stag beetles (Lucanidae) has been compiled for Cambodia. According to the available literature, we assembled the checklist based on the previously recorded and recognized Cambodian lucanid species in the country. In the present paper, we newly record four species from Cambodia: Falcicornis axisopsis (Séguy, 1954); Neolucanus similis Bomans & Ratti, 1976; Prosopocoilus suturalis (Olivier, 1789); and Prosopocoilus jenkinsi (Westwood, 1848). An updated checklist of the Cambodian stag beetles is given. The total number of the Cambodian lucanid species has now reached 29, but this species count is considerably less diverse than those in neighboring countries. Our study suggested that this poor diversity is not primarily due to biogeography or small country size but to a lack of research effort.     

Fine-scale genetic population structure of southern pine beetle (Coleoptera: Curculionidae) in Mississippi forests

The southern pine beetle, Dendroctonus frontalis Zimmerman, is the most destructive insect pest of pine forests in the southeastern United States, Mexico, and Central America. Southern pine beetle aggressively attacks pine trees, and when in epidemic stages, they are capable of killing even the most healthy pine trees in a short period of time. Despite the amount of destruction caused by the southern pine beetle and the amount of monetary loss faced by the timber industry and recreation, the population genetics of this species has been limited to comparisons among distant geographic locations. This study investigates the fine-scale genetic population structure of the southern pine beetle in Mississippi. Very little genetic differentiation was observed among samples. Bayesian assignment testing failed to detect multiple groups within all samples; estimates of genetic differentiation and genetic distance were very low in magnitude; and a Mantel test did not reveal a significant relationship between genetic distance and geographic distance. These results suggest that management of the southern pine beetle needs to consider the potential movements of individuals within and among national forests and should be focused on a large scale, at least as big as continuously forested areas and possibly even multiple forests. These results further suggest that removal of beetle-infested trees is important.     

The first fossil Athyreini beetle (Coleoptera: Geotrupidae)

The first fossil Athyreini in the subfamily of Bolboceratinae from the family of Geotrupidae, ?Amberathyreus beuteli Bai et Zhang gen. et sp. nov., is described based on a specimen from the mid-Cretaceous Myanmar (Burmese) amber from northern Myanmar. Its external morphology (including 3D reconstruction of the head and pronotum) was analyzed and compared with all known genera of Athyreini. ?Amberathyreus’ close relationship between Athyreini and Bolboceratini is supported. ?Amberathyreus was likely active at night and lived in a lowland environment. The finding of ?Amberathyreus greatly enrich our knowledge of Athyreini.     

The structure of feeding behavior in the colorado potato beetle,Leptinotarsa decemlineata (Coleoptera: Chrysomelidae)

Feeding behavior, in an ad libitum situation on potato plants in the laboratory, was continuously observed for approximately 7 h/day on 2 successive days for 18 adult femaleLeptinotarsa decemlineata. Additional behaviors were also recorded including resting, walking, biting, local movements, grooming, defecating, and regurgitating. These data were used to calculate a time budget for the various behaviors. The feeding data were analyzed to describe the structure of feeding for young adult females on their normal host plant. The criterion for a meal (minimum intermeal interval) was determined to be 286 s. This criterion was used to distinguish between intra- and intermeal interruptions in feeding for all subsequent analyses. Meals taken from leaves that were young, medium aged, or old did not differ, but on average beetles took 60% of their meals from young leaves. Meal size and meal duration were equally good predictors of when a meal would end. Feeding from stems was a prominent feature for most beetles. The stem meals had much longer durations than leaf meals, but stem feeding did not affect subsequent leaf feeding. The structure of feeding by these beetles is compared with that found in other insects, especiallyLocusta migratoria.     

Phylogeny and biogeography of the dung beetle genus Phanaeus (Coleoptera: Scarabaeidae)

Abstract The dung beetle genus Phanaeus as currently recognized by Edmonds (1994) consists of 51 species placed in 13 species groups and two subgenera. Here, I examine the phylogeny and biogeography of this genus by analysing the mitochondrial cytochrome oxidase subunit I (530 bp), nuclear large subunit ribosomal RNA (28S, D2 region), and 67 morphological characters for 28 species of Phanaeus. Both maximum parsimony and Bayesian analyses from the combined data yielded well‐resolved trees, although low bootstrap and posterior probability support were found for basal nodes. The phylogenetic hypotheses presented here suggest that the subgenera Phanaeus s.str. and Notiophanaeus should each be elevated to the status of full genus. With the exception of the eucraniine outgroups, the paleano species group of the genus Phanaeus is recovered as sister to all other taxa, including the outgroups Oxysternon, Sulcophanaeus and Coprophanaeus. High bootstrap values and posterior probabilities supported the species groups endymion, tridens and vindex. Biogeographical analyses suggest an ancestral distribution for Phanaeus in the Andes in South America, although numerous dispersal events evidently have produced a complicated biogeographical history.     

Carabid beetle (Coleoptera: Carabidae) conservation in New Zealand

An overview of carabid beetles in the New Zealand conservation context is provided. Processes for threatened species recovery within the New Zealand Department of Conservation are outlined, and the Department’s two major beetle-related recovery documents (The Conservation Requirements for New Zealand’s Nationally Threatened Invertebrates, and The Carabid Beetle Recovery Plan) are discussed. A subjective consideration of the merits and drawbacks of both the documents, and the systems that support them, is presented, along with an option for the way forward for threatened species conservation in New Zealand.     

Interspecific networks in ground beetle (Coleoptera: Carabidae) assemblages

Although changes to interspecific relationships can significantly alter the composition of insect assemblages, they are often ignored when assessing impacts of environmental change. Long-term ground beetle data were used in this study to analyse ecological networks from three habitats at two sites in Scotland. A Bayesian Network inference algorithm was used to reveal interspecific relationships. The significance and strength of relationships between species (nodes) were estimated along with other network properties. Links were identified as positive relationships if co-occurrences of beetles correlated positively, and as negatives relationships if there was a negative correlation between the occurrences of the species. Most of the species had few links and only 10% of the nodes were connected with several links. Calathus fuscipes, a common carabid in the samples, was the most connected, with nine links to other species. More interspecific relationships were found to be positive than negative, with 48 and 23 links, respectively. The modular structure of the network was assessed and eight separate sub-networks were found. Habitat preferences of the species were clearly represented in the structure of the sets of those five sub-networks containing more than one species and were in line with the findings of the indicator species analysis. In our study, we showed that generated Bayesian networks can model interspecific relationships between carabid species. Due to the relative ease of the collection of field data and the high information content of the results, this method could be incorporated into everyday ecological analysis.     

Molecular phylogeny of the beetle tribe Oxypodini (Coleoptera: Staphylinidae: Aleocharinae)

This is the first study to comprehensively address the phylogeny of the tribe Oxypodini Thomson and its phylogenetic relationships to other tribes within the staphylinid subfamily Aleocharinae. Using the hitherto largest molecular dataset of Aleocharinae comprising of 4599 bp for representatives of 22 tribes, the Oxypodini are recovered as non‐monophyletic. Members of the tribe belong to three distantly related lineages within the Aleocharinae: (i) the Amarochara group as sister clade to the tribe Aleocharini, (ii) the subtribe Tachyusina within a clade that also includes the tribes Athetini and Hygronomini, (iii) all other Oxypodini in a clade that also includes the tribes Placusini, Hoplandriini and Liparocephalini. Based on the inferred phylogeny, five subtribes of the Oxypodini are recognized: Dinardina Mulsant & Rey, Meoticina Seevers, Microglottina Fenyes, Oxypodina Thomson and Phloeoporina Thomson. The following changes in the classification of the Aleocharinae are proposed: (i) Amarochara Thomson is removed from the Oxypodini and placed in the tribe Aleocharini; (ii) the subtribe Taxicerina Lohse of the Athetini is reinstated as tribe Taxicerini to include Discerota Mulsant & Rey, Halobrecta Thomson (both removed from the Oxypodini) and Taxicera Mulsant & Rey; (iii) the subtribe Tachyusina Thomson is excluded from the Oxypodini and provisionally treated as tribe Tachyusini; (iv) the oxypodine subtribe name Blepharhymenina Klimaszewski & Peck is placed in synonymy with the subtribe name Dinardina Mulsant & Rey.     

Ecological genetics of the cave beetle Neaphaenops tellkampfii (Coleoptera: Carabidae)

Summary Genetic variability and similarity were examined in eight populations of the Kentucky cave beetle Neaphaenops tellkampfii (Coleoptera: Carabidae) using the technique of polyacrylamide gel electrophoresis. Results indicate that N. tellkampfii has high genetic variation within and high genetic similarity among local populations. These results are in sharp contrast to the patterns of low variability and similarity reported for other cave dwelling species in the same region. It is concluded that the differences in genetical population structure among cave species in the Central Kentucky Karst are related to ecological differences among the species.     

Ultrastructure structure of antennal sensilla of carabid beetle Carabus elysii Thomson, 1856 (Coleoptera: Carabidae)

The sensilla type, number and distribution in male and female adults of Carabus elysii Thomson, 1856 (Coleoptera: Carabidae) were studied using scanning electron microscopy. The results showed that there are seven categories and 12 types of sensilla in C. elysii adults: three types of S.Ch, three types of S.T, two types of S.B and one each of B.B, S.Co, S.Ca and S.Cam. There is no difference between male and female in the types of sensilla. Apart from the significant difference in the number and distribution of S.B.2, S.Co and S.Ca between male dorsal and ventral surfaces, there are no significant differences between male and female antennae. In general, the number of sensilla in females is larger than that in males. The results provide a basic reference for future ultrastructure, electrophysiological, and comparative behavioral studies of Carabus species.     

Spermatophore expulsion in the carrion beetle Silpha perforata (Coleoptera: Silphidae)

Silphinae (Coleoptera: Silphidae) is an abundant decomposer that plays important roles in the ecosystem. However, there is little information about the life history of this taxon. We found sperm displacement behavior in carrion beetle Silpha perforata. Copulating males bit the female's antenna strongly and inserted the penis into the partner's genital organ more than once. We found a white substance on the tip of penis during copulation. We examined whether this white substance is a previous male's spermatophore, which was removed from the mating partner. When females were dissected just after mating, the same substance that often presents on the penis of mating males was found in the bursa copulatrix of females, although the bursa copulatrix of virgin females was empty. Male behavior during copulation with females of different mating history was also observed to confirm that the removal of spermatophores was observed only in copulation with females that have the spermatophores of previous males. Consequently, we estimated that S. perforata males removed spermatophores of previous males from mating partners. In addition, we dissected the males frozen during copulation, and inspected the penis morphology. This observation revealed that the apical part of the penis was usually hidden in the basal part of penis, but expanded and appeared during insertion. This apical part had many spines, which play an important role in sperm displacement and sexual conflict in some species. These results indicate that there is the sperm competition in S. perforata. This is the first report on sperm competition in Silphinae.     

Thermal death kinetics of red flour beetle (Coleoptera: Tenebrionidae)

While developing radio frequency heat treatments for dried fruits and nuts, we used a heating block system developed by Washington State University to identify the most heat-tolerant life stage of red flour beetle, Tribolium castaneum (Herbst), and to determine its thermal death kinetics. Using a heating rate of 15 degrees C/min to approximate the rapid heating of radio frequency treatments, the relative heat tolerance of red flour beetle stages was found to be older larvae > pupae and adults > eggs and younger larvae. Lethal exposure times for temperatures of 48, 50, and 52 degrees C for the most heat-tolerant larval stage were estimated using a 0.5th order kinetic model. Exposures needed for 95% mortality at 48 degrees C were too long to be practical (67 min), but increasing treatment temperatures to 50 and 52 degrees C resulted in more useful exposure times of 8 and 1.3 min, respectively. Red flour beetle was more sensitive to changes in treatment temperature than previously studied moth species, resulting in red flour beetle being the most heat-tolerant species at 48 degrees C, but navel orangeworm, Amyelois transitella (Walker), being most heat tolerant at 50 and 52 degrees C. Consequently, efficacious treatments for navel orangeworm at 50-52 degrees C also would control red flour beetle.     

Effect of high and low temperatures on the drugstore beetle (Coleoptera: Anobiidae)

The drugstore beetle, Stegobium paniceum (L.) (Coleoptera: Anobiidae), is a pest of stored medicinal and aromatic plants. Generally, mortality of each stage increased with an increase of temperature and exposure time. Heat tolerance for different stages from highest to lowest was young larvae, old larvae, eggs, adult, and pupae. The mortality after 7 h at 42 degrees C for young larvae, old larvae, eggs, adults, and pupae, respectively, was 16 +/- 5, 31 +/- 6, 48 +/- 3, 63 +/- 8, and 86 +/- 2% (mean +/- SEM). Similar trends for stage specific mortality were seen with the lethal time for 90% mortality (LT90) at 42 degrees C; 773, 144, 12, and 11 h for old larvae, eggs, adults, and pupa respectively. Mortality was too low with young larvae to estimate LT90. The LT90 for young larvae at 42, 45, 50, 55, and 60 degrees C was 25, 20, 3.9, 0.18, and 0.08 h, respectively. The cold tolerance of different stages at 0 degree C from highest to lowest was adults, old larvae, young larvae, pupae, and eggs. The LT90 at 0 degrees C was 298, 153, 151, 89, and 53 h, respectively. The LT90 for adults at 5, -5, -10, and -15 degrees C was 792, 58, 2, and 0.8 h, respectively. The supercooling point of adults was -15.2 +/- 2 degrees C; young larvae, -9.0 +/- 0.8 degrees C; old larvae, -6.5 +/- 0.5 degrees C; and pupae, -4.0 +/- 1.4 degrees C. Heat treatments that control young larvae should control all other stages of S. paniceum. Cold treatments that control adults should control all other stages of S. paniceum. Dried plants stored at 5 degrees C for 45 d or 42 degrees C for 30 h and then kept below 18 degrees C throughout the rest of the year, should remain pest-free without any chemical control.     

Mycangia of the ambrosia beetle, Austroplatypus incompertus (Schedl) (Coleoptera: Curculionidae: Platypodinae)

Abstract  Ambrosia beetles have an obligate relationship with the ambrosia fungi that they feed on. This requires that the beetles have means to transport those fungi when they colonise new hosts. Some ambrosia beetles have special structures called mycangia to transport fungi in. This paper describes the mycangia of the ambrosia beetle Austroplatypus incompertus and illustrates how the mycangical hairs are probably used by the beetle to acquire fungal spores for transport. The mycangia and probable method of fungal acquisition of this species are compared with those of other ambrosia beetles.