Search results for "beetle"
showing 10 items of 138 documents
Electrophysiological and behavioral studies in the evaluation of semiochemical attractants for Stegobium paniceum L. (Coleoptera: Anobiidae)
2017
Stegobium paniceum (L.) (Coleoptera: Anobiidae), also named drugstore beetle, is one of the major pests for a wide variety of dry and durable stored products. Females of this species produce a sex pheromone, (2S,3R,1’R)-Stegobinone that attracts males and elicit precopulatory searching behaviour. However, (2S,3R,1’R)-Stegobinone has eight possible isomers which are produced during its chemical synthesis and one of them inhibiting the pheromone activity, the (2S,3R,1'S)-Stegobinone form. In addition, the high costs of synthesis of (2S,3R,1’R)-Stegobinone suggest that alternative volatile compounds (e.g. those from food or oviposition sources) might be considered as attractant for traps. In t…
Do female leaf beetles Galerucella nymphaeae choose their mates and does it matter?
1998
The role of active female choice in sexual selection is frequently difficult to ascertain, and this is particularly the case for many insect species. Also, it is uncertain whether choosing between males would affect offspring viability. We designed an experiment to investigate the presence of female choice in a Coleoptera species (Galerucella nymphaeae). We also estimated whether mate choice would have any effect on offspring performance. Females were first placed with two males in a test arena to see which of the males copulated with the virgin female, and how quickly. Subsequently the loser male was offered a new virgin female to test for any change in latency time until mating. The two-m…
On the presence of the alien exotic sap beetle Phenolia (Lasiodites) picta (Macleay, 1825) (Coleoptera Nitidulidae) in Italy
2020
The exotic sap beetle Phenolia (Lasiodites) picta (W.S. Macleay, 1825) (Coleoptera Nitidulidae) is an alien species recently recorded in Europe (Spain, France, and Greece), and Turkey. For Italy, only a single record of P. cf. picta is reported from Sicily. In this paper, we studied this specimen confirming the presence of P. picta in Italy.
Species Composition and Structure of Beetle Associations in Caves of the Częstochowa Upland, Poland
2023
This paper presents the study’s results on beetles (Insecta: Coleoptera) inhabiting caves in the Częstochowa Upland, southern Poland. During two years of research, 2084 specimens, representing 105 species from 19 beetle families, were collected. The obtained results indicate that many beetle species choose to inhabit caves despite lacking specific adaptations for living in such environments. The cave entrance zone is the most attractive place for surface species to inhabit because its climatic conditions are more stable than outside the cave, some sunlight is present, and the availability of organic matter is high. In the deeper parts of the studied caves, the number of occurring species ra…
Beetles (Coleoptera) caught with pheromones of Gnathotrichus retusus and G. sulcatus (Col., Scolytidae) in southern Finland
2001
The ambrosia beetle Gnathotrichus materiarius, which originally came from North America, was discovered in southern Finland in 1996. In 1997, using Norwegian drainpipe traps baited with pheromones of Gnathotrichus retusus and G. sulcatus, we collected beetles in the region where the first specimen had been caught in order to determine whether this potential pest species had become established in the area. Samples from a total of 16 traps included 79 species of beetles and 719 individuals, but no specimens of G. materiarius. The most abundant species in the samples were the ambrosia beetles Xyleborus dispar and Trypodendron lineatum. Several predators and other associates of bark beetles wer…
Morphology and ultrastructure of paired prototergal glands in the adult rove beetle Philonthus varians (Coleoptera, Staphylinidae)
2002
Abstract Philonthus and other genera of Philonthina possess a pair of prototergal glands located in the first abdominal tergum and hidden at rest by hind wings and elytra. In Philonthus varians they occupy the whole length of the tergum and form a pouch-like invaginated reservoir with a scaly glandular zone and a smooth outlet. A grille of long setae covers the opening of each gland. The fine structure of these glands is given for the first time. Three types of cells are found in the glandular epithelium. Epidermal cells underlie the cuticular scales, numerous class 1 secretory cells open in the centre of calyces made of finger-like processes of the cuticle, and class 3 cells are connected …
Development and characterization of microsatellite markers in the Colorado potato beetle, Leptinotarsa decemlineata
2006
The characterization of 11 Leptinotarsa decemlineata microsatellite loci isolated using the fast isolation by AFLP of sequences containing repeats (FIASCO) protocol is reported. Three to 15 alleles per locus were detected in 54 beetles collected from four populations of L. decemlineata. The mean number of alleles was 7.4 ± 3.2 and the level of expected heterozygosity ranged from 0.451 to 0.798. The total exclusionary probabilities using these loci for the first and the second parent were 0.982 and 0.999, respectively. These are the first microsatellite loci characterized from the Colorado potato beetles that can be used for estimating genetic diversity, population structure and parentage an…
Glyphosate-based herbicide has soil-mediated effects on potato glycoalkaloids and oxidative status of a potato pest
2020
Glyphosate is the most used herbicide worldwide, targeting physiological pathways in plants. Recent studies have shown that glyphosate can also cause toxic effects in animals. We investigated the glyphosate-based herbicide (GBH)-induced changes in potato (Solanum tuberosum) plant chemistry and the effects of a GBH on the survival rate and oxidative status of the Colorado potato beetle (Leptinotarsa decemlineata). The beetles were reared on potato plants grown in pots containing soil treated with a GBH (Roundup Gold, 450 g/l) or untreated soil (water control). The 2nd instar larvae were introduced to the potato plants and then collected in 2 phases: as 4th instar larvae and as adults. The ma…
Egg and larval load assessment and its influence on oviposition behaviour of the leaf beetle Galerucella nymphaeae
1993
The oviposition behaviour of the water-lily beetle Galerucella nymphaeae was examined. This species is a specialist herbivore on the floating leaves of nymphaeids Nymphaeaceae and especially on the yellow water-lily, Nuphar lutea. Females lay their eggs in clutches on the leaves, and after hatching, the larvae feed on the leaves. The quality of the leaves decreases quickly after the larvae hatch, and eventually the leaves will sink below the water surface, whereupon the eggs, 1st-instar larvae and pupae are killed by drowning. The influence of conspecific eggs, larvae and feeding tracks on the oviposition preferences of the beetles was tested. Females were allowed to choose between fresh le…
Interactions between willows and insect herbivores under enhanced ultraviolet-B radiation
2002
We studied the effects of elevated ultraviolet-B radiation on interactions between insect herbivores and their host plants by exposing two species of phytochemically different willows, Salix myrsinifolia and S. phylicifolia, to a modulated increase in ultraviolet radiation in an outdoor experiment and monitoring the colonisation of insect herbivores on these willows. We examined the effect of increased ultraviolet-B (UV-B) radiation on (1) the quality of willow leaves, (2) the distribution and abundance of insect herbivores feeding on these willows, (3) the resulting amount of damage, and (4) the performance of insect larvae feeding on the exposed plant tissue. Six clones of each of the two…