Photoperiod-temperature interaction-a new form of seasonal control of growth and development in insects and in particular a Carabid Beetle, <Emphasis Type="Italic">Amara communis</Emphasis> (Coleoptera: Carabidae)

Amara communis larvae were found to develop significantly faster and to have higher growth rate at short-day (12 h) as compared to long-day (22 h) photoperiods at all used temperatures (16, 18, 20, and 22°C). The coefficient of linear regression of larval development rate on temperature was significantly higher at the short day than at the long day. The thermal developmental thresholds appeared similar at both photoperiods. Body weight of young beetles reared under different photoperiods was almost the same. Thus, photoperiod does not simply accelerate or decelerate insect development, but modifies the thermal reaction norm. At short days, larval development becomes faster and more temperature-dependent, which provides a timely completion of development at the end of summer. The analysis of literature data has allowed us to find the photoperiodic modification of thermal requirements for development in 5 insect orders: Orthoptera, Heteroptera, Coleoptera, Lepidoptera, and Diptera. Modification may result in significant changes in the slope of the regression line, and hence the sum of degree-days, and in the thermal developmental threshold. Consequently, the thermal requirements for development in many insects gradually vary during summer under the effect of changing day-length, which may have adaptive significance. Thus, the photoperiodic modification of thermal reaction norms acts as a specific form of seasonal control of insect development.     

Adaptive latitudinal variation of the duration and thermal requirements for development in the ground beetle Amara communis (Panz.) (Coleoptera, Carabidae)

The data are obtained on development time at six constant temperatures (12, 14, 16, 18, 20, 22°C) and thermal requirements for preimaginal development in a ground beetle Amara communis from Arkhangelsk (64°34′N) and St. Petersburg (59°53′N). The larval and pupal development times were found to be significantly shorter in the Arkhangelsk than in the St. Petersburg population under all temperatures. As a result, total preimaginal development appeared to be shorter by 6.2–6.6% in the Arkhangelsk population. The regression lines of the larval, pupal and total (egg-to-adult) development rate on temperature for the Arkhangelsk population run above and steeper than the respective lines for the St. Petersburg population. Both populations share the similar values of the thermal thresholds (7.2–8.2°C). This explains faster preimaginal development in the northern population under all temperatures above the threshold. Thus, the slope of the regression lines increases, i.e., the sum of degree-days decreases, whereas the thermal threshold for development exhibited no distinctive changes from south to north in this species. Adults from Arkhangelsk reared in the experiments appeared heavier on the average in comparison with those from St. Petersburg, especially at 18–22°C. Temperature did not significantly affect adult weight, except the fact that the beetles were slightly heavier at 20 and 22°C. Consequently, the well-known “temperature-size rule” is violated in this species. Relative growth rate in larvae of A. communis increased considerably with temperature rise from 14 to 22°C. It was significantly higher in the beetles from Arkhangelsk at 18–22°C. There were no differences in larval growth rate between the two populations at 14 and 16°C.     

Tetracha hope 1838 of the Turks and Caicos Islands (coleoptera, carabidae, cicindelinae)

A new species, Tetracha (Neotetracha) naviauxi, and a new subspecies, Tetracha (Tetracha) sobrina caicosensis, are described from the Turks and Caicos Islands. The key to Tetracha species in Naviaux (2007) is adapted to accommodate Tetracha naviauxi. Tetracha sobrina caicosensis is compared to other Caribbean subspecies of Tetracha sobrina.     

Ground beetles (coleoptera,carabidae) of the Ola Plateau highlands,Kolyma Uplands

The ground beetle fauna was studied in 12 biotopes of the tundra belt on Ola Plateau, 130 km NW of Magadan. In all, 16 species were found above timber line (900–1220 m), which is comparable with the diversity in the mountain tundras of the upper reaches of the Kolyma (Berman et al., 1984; Bukhkalo, 1997), but the faunistic similarity of these regions is low (Jaccard’s coefficient 22–29%). Besides the widespread species, a group of ground beetles with limited ranges is present; it includes Carabus kolymensis Lafer, 1989 occurring in the East Siberian mountain tundras, the Siberian-Nearctic, mainly arctic Pterostichus agonus G. Horn, 1880, and the East Siberian Pterostichus eximius A. Mor., 1862. The use of the term “arctic species” in arealogical and ecological studies is discussed.     

Role of granivory and insectivory in the life cycle of the carabid beetle Amara similata

1. The cereal field carabid beetle Amara similata was selected to elucidate the role of seeds and insects as food sources. Three experiments were performed to rank different weed seeds and insects in terms of food value: (i) fecundity in relation to adult diet, (ii) larval survival in relation to diet and (iii) larval survival in relation to parental diet.
2. Seeds were found to be of high value and insects of low value both for adults and larvae. Adding insects to a seed diet gave no significant improvement. The value of single species of seeds varied within adults and larvae, but also between adults and larvae. This is the first report that Amara larvae are granivorous.
3. The value of different insects varied by species. Cereal aphid species were of the lowest value both for adult and larval beetles. On a diet of mixed insects, the adults were able to produce a low number of eggs but the larvae all died before pupation.
4. There was no simple relation between survival of the larvae and the quality of the parents' diet.     

Food preferences and the value of animal food for the carabid beetle Amara similata (Gyll.) (Col., Carabidae)

Abstract:  Several studies have shown that the mainly granivorous carabid beetles, e.g. Amara spp., include animal food in their diet to a considerable extent. We therefore hypothesized that the performance of these beetles would be enhanced by dietary mixing including both seeds and animal food. In order to test this, we conducted laboratory feeding experiments with adults and larvae of Amara similata . Both adults and larvae were subjected to different diet treatments including: seeds, houseflies, grasshoppers, earthworms, slugs and snails in pure and mixed diets. Larval survival, development time, pupal and teneral weights were used as indicators of food quality for the larvae. For the adult beetles, mass change was used as an indicator of food quality. We found seeds to be high-quality food, while all pure animal diets were of low quality for both adults and larvae. Animal foods added to the seed diet had both positive and negative effects. A mixed diet of all foods enhanced the mass gain of adults compared with the seed diet, but reduced larval performance dramatically. Earthworms and grasshoppers added to seeds increased the pupal and teneral weights, while reduced larval survival. Thus, A. similata is omnivorous with a mainly granivorous feeding habit. It may gain benefits on some fitness parameters and incur costs on others from preying or scavenging on animal food. Therefore, the overall fitness consequences of a mixed seed-animal diet are uncertain.     

Taxonomic revision of hispaniola tiger beetles in the genus brasiella rivalier 1954 (coleoptera, carabidae, cicindelinae)

The Brasiella tiger beetle fauna on Hispaniola, the second largest island of the Greater Antilles, has more species diversity than currently recognized as all populations previously have been assigned to the insular endemic Brasiella dominicana (Mandl). A comparative study of adult morphology, particularly male genitalic and female abdominal characters, for available Brasiella specimens from populations on Hispaniola, proposes eight additional new species also endemic to this island. Except for three sympatric species in the Sierra de Baoruco in southern Dominican Republic occurring in different habitats, all the Brasiella on Hispaniola appear to be allopatric. Most species occur in the major mountainous regions of Hispaniola. Two species, however, are known only from river floodplains in the southern coastal plain of the Dominican Republic. Brasiella dominicana (Mandl) and Brasiella ocoa, new species, occur along river floodplains emanating from the eastern end of the Cordillera Central in the Dominican Republic. Two new Brasiella species, Brasiella bellorum, and Brasiella philipi, occur in the Cordillera Central, Dominican Republic, the former species from central portions, and the latter species from north slopes of this mountain range, respectively. Three new Brasiella species, Brasiella rawlinsi, Brasiella iviei, and Brasiella youngi, are isolated in the Sierra de Baoruco, Dominican Republic, where each occupies a different habitat along an altitudinal gradient. The two new Brasiella species in Haiti are Brasiella darlingtoniana, in the Massif de la Selle, and Brasiella davidsoni, in the Massif de la Hotte. All nine Brasiella species on Hispaniola, along with Brasiella viridicollis (Dejean) and its two subspecies on Cuba, belong to the viridicollis species group of the genus Brasiella based on criteria presented in earlier published phylogenetic studies of Brazilian and West Indian tiger beetles. The subspecies Brasiella viridicollis fernandozayasi (Kippenhan, Ivie and Hopp) may represent a distinct species within this species group, whereas removal of Brasiella wickhami (W. Horn) from this species group seems warranted based on evidence presented. A general overview of species relationships for the Brasiella on Hispaniola are discussed, along with the current and ancestral geographic distributions of the Brasiella viridicollis species group in the West Indies.     

Humidity-invoked upwind orientation of shore insects (Bambidion obtusidens, coleoptera: Carabidae)

Because insects cannot rely solely on kinetic responses to locate upwind humidity resources, an alternative mechanism involving the perception of windborne humidity fluctuations was investigated. In a wind tunnel, upwind responses of adult shore insects (Bembidion obtusidens Fall, Carabidae, Coleoptera) were invoked by pulsed (1.25-Hz) increases (1.7%) of relative humidity at ambient relative humidities of 32, 42, 52, and 62% but not at 72 and 86%. Conversely, upwind responses to pulsed decreases (1.8%) occurred at 65, 72, and 86% but not at 32, 42, and 52% ambient relative humidities. These results suggest that perception by moist-air and dry-air hygroreceptors of turbulence-induced pulses of moist air or of dry air in their habitat trigger positive anemotactic orientation of these insects to upwind humidity resources.     

An established cell line from the beetle, Xylotrechus pyrrhoderus (coleoptera: Cerambycidae)

Summary A continuous cell line has been established from larval fat body tissues of the cerambycid beetle Xylotrechus pyrrhoderus Bates. These cells were cultured in MGM-450 medium. The cell line, designated as XP-1, showed a heterogeneous population consisting of spherical and spindle-shaped cells with some capacity to adhere and a doubling time of 5 d. The chromosome number of the cell line ranged from 18 to 42 with a mode of 20. Isozyme analysis showed that the cells had patterns distinctive from those of other insect cell lines. The cells were sensitive to insect hormones, and when continuously treated with 20-hydroxyecdysone and juvenile hormone, they assumed a floating elongated-spindle shape and became strongly adherent, respectively.     

Seasonal aspects of the life cycles of Carabus granulatus and C. glabratus (coleoptera, carabidae) in the northern taiga

The seasonal dynamics of the activity and the demographic structure of Carabus granulatus and C. glabratus populations was studied in the northern taiga of European Russia. The period of adult activity lasts for 90 days from early June to late August with the maximal activity observed in June. At the northern boundary of the range, the spring species Carabus granulatus retains its annual life cycle typical of this species in the other part of the range. At the same time, the reproductive period decreases, resulting in the synchronization of the development of specimens within the population. In the autumn species C. glabratus, a biennial life cycle with early summer reproduction is formed in the zone of broad-leaved forests of the northern taiga instead of the annual cycle. This species is characterized by the presence of two groups of individuals developing for two years each, but their development is shifted by a year. Such strategy results in the annual breeding of the species.     

The maxillary palp organs of a wood-boring beetle,Melittomma sericeum (coleoptera,lymexylonidae)

The complex and conspicuous basket-like structure attached to the third segment of each maxillary palp of Melittomma sericeum males is densely covered with tactile hairs on its outer or convex surface and with thinwalled chemoreceptors on its inner or concave surface. In a living male the structure is highly mobile and is extended laterally and ventrally. It evidently serves to detect odors produced by the female.     

Nonoccluded baculovirus- and filamentous virus-like particles in the spotted cucumber beetle,diabrotica undecimpunctata (coleoptera: chrysomelid)

Nonoccluded baculovirus-and filamentous virus-like particles were found in nuclei of hemocytes or midgut cells of field-collected spotted cucumber beetles. Each type of particle was associated with a different type of virogenic stroma containing various viral components similar to those referred to as capsid, nucleocapsid, viroplasm, and viral envelope in other known baculovirus infections. Nucleocapsids of the virus which occured only in hemocytes were rod-shaped particles approximately 230 nm long and 52 nm wide and were enveloped singly by a trilaminar unit membrane. Enveloped and partly enveloped particles appeared to be released from the nucleus to the cytoplasm by budding through the nuclear envelope acquiring additional membranes. The nucleocapsids of the virus which occurred only in nuclei of midgut cells were filamentous particles with an average diameter of 25 nm and variable length up to 2 μm. Some extremely long particles were bent almost 360° near the middle, resulting in a hairpin-like configuration. The particles were always enveloped singly. No particles budding through the nuclear envelope were observed.     

The fine structure of some carabid beetle eyes,with particular reference to ciliary structures in the retinula cells

Paired centrioles and associated ciliary root material occur in all eight retinula cells in the nine species investigated. In the diurnal Notiophilus, Elaphrus and Bembidion where the distal rhabdomere of cell 7 is fused with the proximal rhabdom formed by cells 1 to 6, the roots in cells 1 to 6 extend for the entire length of the retinula. In Notiophilus their arrangement around the rhabdom suggests a complementary mechanical relationship between the six large roots and the four Semper cell processes. In five relatively nocturnal species a retinula cell column separates the distal rhabdomere from the proximal rhabdom. In cells 1 to 6 root material is associated with the distally located centrioles as follows. In Leistus roots extend into the proximal rhabdom layer. In Loricera and Agonum roots at the level of the proximal rhabdom are not continuous with the rootlets or short roots associated with the centrioles. In Pseudophonus and Feronia, and in the diurnal Cicindela, short rootlets link the centrioles. Cell movements on dark-adaptation of Notiophilus and Cicindela include shortening of the crystalline tract. In Notiophilus the entire rhabdom is apparently displaced, whereas in Cicindela the narrow distal rhabdomere becomes dissociated from the proximal rhabdom.     

Characterization of cell lines developed from the colorado potato beetle, Leptinotarsa decemlineata say (coleoptera: Chrysomelidae)

In order to isolate new pathogens (viruses, microsporidia, etc.) or to evaluate the efficiency of some pathogens (serovarieties and mutants of Bacillus thuringiensis, fungi, etc.) in the control of Colorado potato beetle, an economically important pest, we established four cell lines from tissues of this insect. One was initiated from embryonated egg fragments in the M3 medium supplemented with 20% fetal bovine serum (FBS) and then transferred after several passages to the Ex-Cell 400 medium with 20% FBS. Another was initiated from larval hemocytes in Ex-Cell 400 with 5% FBS. Finally, two other cell lines were initiated from adult hemocytes: one in the Ex-Cell 400 with 20% FBS and 1% of lipid mixture and the other in the Ex-Cell 400 with 5% FBS only. These cell lines have been characterized by their morphology with light and electron microscopy, their karyotypes, cell growth, and isozyme analysis. Each cell line differed in morphologic, karyologic, growth, and isozyme patterns. The cell line initiated from embryonated eggs was growing slower than the three initiated from hemocytes. The cytotoxicity of solubilized crystal delta-endotoxins from different B. thuringiensis formulations (M-One, Trident, MYX-1806, Teknar-HPD, and Thuricide) and of destruxins, mycotoxins from Metarhizium anisopliae, was tested on these cell lines. They are sensitive to the solubilized toxins of some strains of B. thuringiensis (serovar. San Diego and serovar. tenebrionis) and to destruxins, and they can be used for the bioassay and detection of toxins and for the study of the mechanism of their action on coleopteran cells.     

Population ecology of the rare carabid beetle Carabus variolosus (Coleoptera: Carabidae) in north-west Germany

The declining European ground beetle Carabus variolosus, an indicator of undisturbed woodland brooks and swamps, is listed in the EU Species and Habitats Directive. Little is known about this flightless and endangered beetle, apart from its distribution range and habitat stenotopy. We present the results of a 2-year mark-release-recapture study on two neighbouring populations in Germany, which investigated basic parameters of population ecology that may be influential in the persistence of the beetle. Extremely small population sizes were the key findings. Since population densities corresponded to those of typical Carabus species, the size of the habitats was most probably the limiting factor. The risk of heavy losses during offspring development and hibernation may be alleviated by the considerable proportion of C. variolosus reproducing in more than 1 year. The fact that we did not recapture any marked specimens from the neighbouring population suggests a very limited dispersal power. The results imply a high vulnerability of the species, provide basic methodological information for an implementation of the EC Directive and for further research, and highlight the necessity to enlarge populated habitats.     

Genetic heterogeneity and adaptive strategies of the lady beetle Harmonia axyridis pall. (coleoptera, coccinellidae)

Analysis of microstatial variability of the phenetic composition of populations of the lady beetle Harmonia axyridis Pall. is performed in Baikal region of the Primorskii Krai. It is revealed that the phenetic composition of the Baikal H. axyridis population is significantly more labile than in Prumorie. In individual micropopulations the phenoimage is clarified because of the local increase of the frequency of the succinea morp. Individual and family testing of H. axyridis individual from the Primorie and Baikal populations is performed by the quantitative parameters affecting the adaptability--the larval and pupal survival at starvation, critical weight of pupation, the imago weight and fertility. At starvation of larvae of the IV age for 3-4 days, only the succinea morp Individuals from the Primorie population reached the imago stage. The egg-batch value in these imago corresponded to the mean for population (31.2 +/- +/- 1.06 eggs). The obtained result confirms the earlier expressed suggestion that the succinea morp is distinguished by a high ecologic plasticity. It is able to survive under conditions of the food deficit and is characterized by the intermediate, but stable reproduction.     

Diversity and seasonal fluctuations in dung beetle (Coleoptera) community in Kurukshetra,India

Five pitfall traps baited with 150–200 g of fresh cattle dung were installed for 24 h at weekly intervals. A total of 991 dung beetles from 11 genera, 31 species and three subfamilies was obtained. The community was dominated by Oniticellus spinipes individuals by 32.3%. Ten species appeared only once during the collection period and species composition and dominance changed throughout the period. The overall pattern we detected in the organization of the dung beetle community is that the species richness, abundance and diversity rise in September and the 2^nd week of October. The dung beetle community was found to be affected by season.     

Comparison of carabid beetle (Coleoptera: Carabidae) occurrence in rain forest and human-modified sites in south-eastern Madagascar

High species diversity and endemism make Madagascar one of the world's biodiversity hot spots. However, forest cover and, thereby, biodiversity are decreasing rapidly due to human activities. Most of Madagascar is now covered by secondary vegetation, which is species-poor and contains many introduced species. In this study, the effect of human impact through alteration in vegetation on carabid beetles (Coleoptera: Carabidae) was assessed. The study was conducted in montane rain forest in the Parc National de Ranomafana (south-eastern Madagascar), and in a nearby village area with various types of secondary vegetation. Beetles were collected by hand and by pitfall traps from ten sites from both areas. A total of 246 specimens belonging to 54 species were collected. Pitfall traps yielded only six specimens, which clearly shows that pitfall trapping is not a feasible method for catching carabids in such habitats. From the forest in the national park, 38 species were collected and from the village area 28 species. Species compositions and the dominant species were different: 12 species were found from both areas, while 16 species were unique to the village area and 26 species were unique to the forest. Half of the species were singletons and three most abundant species formed 31% of the total number of individuals. We conclude that because forest-dwellers do not occur in the human-modified environment, such species are at great risk of becoming extinct if current rates of forest decline continue in Madagascar.     

Heritability of wing development and body size in a carabid beetle,Pogonus chalceus MARSHAM,and its evolutionary significance

Summary The wing-polymorphic ground beetle Pogonus chalceus MARSHAM was subjected to crossbreeding experiments under different laboratory conditions in order to estimate the genetic and environmental contributions to the total phenotypic variance in different morphological traits related to relative wing development and body size. Heritability of relative wing development appears to be strong. Beetle size also seems genetically determined in some cases, but separation of male and female parent contribution invariably shows a maternal effect. These results are tested in a breeding experiment with a high number of progeny from one parental pair, reared at two temperatures and at two levels of food supply. Relative wing development is not influenced by these environmental conditions, as expected, but different temperatures add significant variance to the body size values. The experimental results are used to explain interdemic variation in these morphological traits, as observed in three isolated field populations. The reproductive effort under optimum breeding conditions is higher in macropterous beetles than in beetles with reduced wings, but this could result from their larger body size. Migtion seems to be the most plausible underlying evolutionary mechanism for the observed wing reduction in older populations.