Improved semiochemical-based trapping method for old-house borer, Hylotrupes bajulus (Coleoptera: Cerambycidae)

The old-house borer, Hylotrupes bajulus (Linnaeus) (Coleoptera: Cerambycidae), has been a very serious pest of structural timber in many parts of the world. The available semiochemical-based trapping method typically results in low capture rates. In this study, efforts were made to improve the semiochemical-based trapping method using screen cage assays conducted in the greenhouse. Ground traps baited with two vials of (3R)-ketol + 1-butanol (pheromone baited) caught >21.0% adults than the alternative trap and were seen to be superior to ramp traps baited with identical compounds. Based on adult catches with pheromone-baited traps with different colors, attraction of H. bajulus adults to black was significantly greater than other colors, followed by brown, gray and yellow, red, white, green, and blue. No differences were found in adult catches to pheromone-baited traps with respect to different trap sizes. There were no statistical differences between the different semiochemicals tested. Therefore, black ground traps baited with two vials of (3R)-ketol + 1-butanol plus two vials of ethyl acetate can be effective in the monitoring and potential control of H. bajulus.     

Soluble carbohydrates in the nutrition of house longhorn beetle larvae, Hylotrupes bajulus (L.) (Col., Cerambycidae): from living sapwood to faeces

Abstract: Water-soluble carbohydrates from (a) living sapwood of Scots pine ( Pinus sylvestris L); (b) dry sapwood blocks from Scots pine (EUROPEAN STANDARD EN 46, 1988); and (c) faeces from Hylotrupes bajulus (L) larvae feeding from these blocks were analysed. Living sapwood contains high amounts of sucrose, glucose, fructose and starch. These carbohydrates seem to be hydrolysed and metabolized during the production of the sapwood blocks. The faeces contain carbohydrates which are not present either in living sapwood or in the sapwood blocks: xylose and an oligosaccharide of uncertain composition. This oligosaccharide is the dominant water-soluble carbohydrate in the faeces. In contrast to living sapwood and sapwood blocks, the faeces contain considerable amounts of soluble β-glucans. The results show that the composition and the amounts of carbohydrates differ significantly from that in the sapwood blocks (fodder for the larvae). The α-glucans (starch) present in the wood are not significantly utilized by the larvae. Regarding soluble carbohydrates, diet wood has only little in common with the living wood of the standing tree.     

Body size,male aggression,and male mating success in the cottonwood borer,Plectrodera scalator (Coleoptera: Cerambycidae)

The natural history and mating system ofPlectrodera scalator exhibit several unusual characteristics. Larvae and adults feed on the wood and foliage, respectively, of the same plant,Populus deltoides. The population sex ratio, based on censuses of oviposition areas, is female-biased. Females are significantly larger than males, yet males are intensely aggressive. Larger males tend to win escalated battles, which involve grasping of antennae with mandibles, but smaller males can defeat larger males if they grasp their opponent's antenna first. Most escalated fights involve possession of a female, but prior possession does not play a role in determining the outcome of these fights. The size-dependent fighting advantage does not translate into a mating advantage for larger males. There is no significant difference in elytron length or body mass between mating and single males. Larger females are not preferred as mates. The mating system appears to be a mixture of female-defense and scramble-competition tactics. One advantage to males of aggression may be in its effect on sperm precedence. Males appear to be able to remove previously deposited sperm from a female's reproductive tract.     

Localization and fine structure of the female sex pheromone-producing glands in Bruchidius atrolineatus (PIC) (Coleoptera : Bruchidae)

The sex pheromone glands of female Bruchidius atrolineatus (Coleoptera: Bruchidae) have been localized by recording the electric response of the antenna of males subjected to a stream of air, containing the volatile sex pheromone (electroanntennography-EAG). Some 50 unicellular glands are distributed irregularly in the ventral and dorsal intersegmental membranes situated at the extremity of the pygidium, each gland containing a short ductule with an evacuation pore, 0.5–1 μm in diameter. The receiving canal is composed of a network of fine epicuticular filaments. The glands are type 3. The ultrastructure of these sex pheromone-producing glands is described in females whose production-emission activity had been previously verified with EAG. Deep basal invaginations and inflated intercellular spaces indicate the transport of substances from the hemolymph to the gland cells. The presence of numerous elongated mitochondria, diverse inclusions, vesicles containing crystalline bodies, and abundant apical microvilli, all reveal elevated cellular activity, which is never observed in young or diapausing females that do not produce sex pheromone. The ultrastructural differences in different types of females (sexually active or diapausing), combined with comparative EAG recordings obtained with intact females or those in which the suspected glandular zone was masked, made it possible to localize the glands.     

Metasternal gland secretion of the locust tree borer, Megacyllene robiniae (Coleoptera: Cerambycidae)

1. The volatile components of metasternal gland extracts of male and female Megacyllene robiniae have been analyzed by gas chromatography-mass spectroscopy. 2. The major component was identified as 2-(1,3-hexadien-1-yl)-5-methyltetrahydrofuran, a new natural product. 3. 1-Phenylethanol is present only in male extracts. 4. Acetates of hexadecanol and octadecanol are also present.     

Body size influences mating success of the Eucalyptus longhorned borer (Coleoptera: Cerambycidae)

Both sexes of adultPhoracantha semipunctata F. (Coleoptera: Cerambycidae) congregate on stressedEucalyptus that are the larval hosts. In a field study, 721 adultP. semipunctata captured on host trees varied considerably in body size with the largest individuals being about twice the length of the smallest. Females that were paired with a mate were similar in size to solitary females, suggesting that the probability of a female being mated was not affected by her size. However, large males had greater success than smaller males in obtaining mates. MaleP. semipunctata rely on antennal contact to locate and identify females on the larval host. Therefore, the rate at which males search for mates is a function of the area swept by their antennae per unit time. Because of their greater antennal spread, large males were able to search for females at double the rate of the smallest males. Large males also dominated in aggressive contests for females. The superior abilities of large maleP. semipunctata in both locating and defending mates account for the influence of body size on mating success.     

Acoustic detection of stem and root borer Neoplocaederus ferrugineus (Coleoptera: Cerambycidae) in cashew

Stem and root borer Neoplocaederus ferrugineus (Linnaeus) (Coleoptera: Cerambycidae) is a severe pest of cashew (Anacardium occidentale L), which affects the cashew tree heavily. The larvae are tissue borers that remain concealed inside the tree and are very difficult to detect at the initial stage of infestation. Adult attractants are not identified, and manual checking of each tree in a plantation is not feasible and laborious. Acoustic technologies have been developed for the non-invasive and early detection of wood borers. The present study was conducted to characterize the acoustic sounds of various larval instars, tissues and field evaluation of the commercially available acoustic device. Burst analysis of different larval instars in cashew logs shows that there are no significant differences between the number of bursts and various larval instars. A relatively less number of bursts are found when the larvae are in the sapwood region than the cambium region. The empty cashew log and healthy trees do not produce any significant noise. The number of burst counts and impulses are used to predict the likelihood of infestation. The detection performance of the acoustic device under field conditions shows that infested trees are correctly detected with 91% accuracy. The possibility of not detecting healthy trees is 85%. This is the first report on the acoustic behaviour of cashew stem and root borer. The results of the study will help in better understanding the acoustic behaviour of the hidden pest and also be useful in the timely identification of stem and root borer-affected trees in cashew plantations.     

Fine structure of the female sex pheromone-producing glands in Sesamia nonagrioides lef. (Lepidoptera : Noctuidae)

The morphology and cytology of the female sex pheromone-producing glands of Sesamia nonagrioides (Lepidoptera : Noctuidae) consist of modified intersegmental membranes; they are unusual compared with those described in other moths. There are 2 different glandular areas (a ventral area, GI, around the ostium bursae and a ring-shaped area, GII, around the ovipositor), instead of a single area (between segments 8 and 9 + 10) as in most other species. Ultrastructural features, such as developed basal invaginations and dilated intercellular spaces indicate transport of material from the hemolymph to the glandular cells, while the presence of abundant mitochondria, numerous free ribosomes, rough endoplasmic reticulum, and inclusions reveal high cellular activity. The smooth endoplasmic reticulum is absent in S. nonagrioides, in contrast to its extensive development in glands producing similar compounds in other moths. The cuticle, abnormally thick (7–8 times thicker than the glandular epithelium), is traversed by dilated pore canals forming cuticular gaps, connected with epicuticular canals. This system allows the storage and the passage of pheromone in and through the cuticle.     

Potential management strategies for the linden borer (Coleoptera: Cerambycidae) in urban landscapes and nurseries

The linden borer, Saperda vestita Say (Coleoptera: Cerambycidae), is a native insect species that is common throughout north central and northeastern North America. Over the past decade, increasing occurrence of damage associated with the linden borer has been reported on Tilia spp. in city street trees and nurseries throughout Wisconsin, probably because of increased use of these trees. Our objective was to gain a better understanding of the seasonal biology and potential management strategies for this important pest. We evaluated the effectiveness of three systemic insecticides, imidacloprid, thiamethoxam, and disulfoton, and a mechanical control method of chipping linden borer-infested wood as a means of reducing S. vestita larval survival, subsequent emergence, and oviposition. Autumn and spring soil injections of imidacloprid to linden borer-infested Tilia cordata'Greenspire' nursery stock (< 11.4 cm in diameter at breast height [dbh]) provided >90% control. Autumn soil injections of imidacloprid and thiamethoxam and a spring granular soil application treatment of disulfoton applied to larger (>22 cm dbh) Tilia spp. did not effectively control linden borer at the application rates tested. Chipping infested Tilia spp. effectively destroyed linden borer larvae, pupae, and adults. Arborists and landscape managers should consider chipping felled Tilia spp. trees infested with S. vestita to prevent adults from potentially attacking nearby susceptible trees.     

Reproductive strategy of the sugi bark borer,Semanotus japonicus (Coleoptera: Cerambycidae) on Japanese cedar,Cryptomeria japonica

The inner bark of Japanese cedar,Cryptomeria japonica D. Don., is the main food of the sugi bark borer,Semanotus japonicus Lacordaire, but may also be involved in resistance to attack by the borer. I used newly hatched larvae to inoculate cedar logs that had been cut 2-weeks to 12-months earlier, and undamaged living cedar trees. On living trees, all larvae were killed by resin flow from the traumatic resin canals between the outer- and inner bark or between the inner bark and cambium. In logs that were cut more than 4 months prior to inoculation, larvae were unable to complete development. In logs cut 2 weeks prior to inoculation, almost all larvae were able to reach the adult stage but they were smaller in size than adults from living trees damaged by this borer. These results suggest that poor nutrient conditions in the inner bark of logs affected development and survival of the borer. Because of its nutritional advantage, living cedars provide a better environment for the sugi bark borer. However, all larvae are killed by resin flow, suggesting that this insect is “in between” being primary and secondary with respect to living trees, or a “weak” primary insect. The sugi bark borer seems to develop early in the season so that early instar larvae encounter reduced amounts of resin flow and so that late-instar larvae feed mostly in summer when nutrient levels in the inner bark are at their highest.     

Optimization of sampling methods for within-tree populations of red oak borer, Enaphalodes rufulus (Haldeman) (Coleoptera: Cerambycidae)

In the Ozark Mountains of northern Arkansas and southern Missouri, an oak decline event, coupled with epidemic populations of red oak borer (Enaphalodes rufulus Haldeman), has resulted in extensive red oak (Quercus spp., section Lobatae) mortality. Twenty-four northern red oak trees, Quercus rubra L., infested with red oak borer, were felled in the Ozark National Forest between March 2002 and June 2003. Infested tree boles were cut into 0.5-m sample bolts, and the following red oak borer population variables were measured: current generation galleries, live red oak borer, emergence holes, and previous generation galleries. Population density estimates from sampling plans using varying numbers of samples taken randomly and systematically were compared with total census measurements for the entire infested tree bole. Systematic sampling consistently yielded lower percent root mean square error (%RMSE) than random sampling. Systematic sampling of one half of the tree (every other 0.5-m sample along the tree bole) yielded the lowest values. Estimates from plans systematically sampling one half the tree and systematic proportional sampling using seven or nine samples did not differ significantly from each other and were within 25% RMSE of the "true" mean. Thus, we recommend systematically removing and dissecting seven 0.5-m samples from infested trees as an optimal sampling plan for monitoring red oak borer within-tree population densities. This optimal sampling plan should allow for collection of acceptably accurate within-tree population density data for this native wood-boring insect and reducing labor and costs of dissecting whole trees.     

Wood penetration ability of hydrogen cyanide and its efficacy for fumigation of Anoplophora glabripennis,Hylotrupes bajulus (Coleoptera), and Bursaphelenchus xylophilus (Nematoda)

Pinewood nematodes (Bursaphelenchus xylophilus) and Asian longhorned beetles (Anoplophora glabripennis) are the primary regulated pests for packaging wood and timber in the EU, while the house longhorned beetle (Hylotrupes bajulus) is the most important cosmopolitan pest of construction wood. Gaseous hydrogen cyanide (HCN) is one of the few fumigation alternatives to the banned ozone-depleting chemical methyl bromide (MBr). This study reports the results of HCN fumigation experiments in a hermetically sealed steel chamber regarding (1) the penetration and absorption rates of HCN in wooden blocks, and (2) the biological efficacy of HCN against the wood-infesting pests B. xylophilus (in sawdust), A. glabripennis, and H. bajulus (in wooden blocks). A concentration equilibrium for HCN (at 20 g m⁻³) between the fumigation chamber headspace and the center of the treated spruce blocks (100 × 100 × 120 mm) was reached after 48 h in the saturated atmosphere. A dose of 10 g m⁻³ in the center of the spruce blocks was reached for both saturated and non-saturated atmospheres after 24 h of fumigation. The wood tested absorbed approximately 40–45% of the HCN, until equilibrium was reached. The highest tested HCN dose (20 g m⁻³) led to 100% mortality of the A. glabripennis and H. bajulus larvae after less than 1 h of exposure. For 20 g m⁻³ and 1 h exposure the Ct product was <18.66 g*h/m³ for H. bajulus and <17.67 g*h/m³ for A. glabripennis. Hydrogen cyanide doses of 10 g m⁻³ and 20 g m⁻³ led to 100% B. xylophilus mortality in 40 and 18 h, respectively. For B. xylophilus the Ct product was <424.00 g*h/m³ for 20 °C and 10 g m⁻³ and <349.51 g*h/m³ for 25 °C and 20 g m⁻³. The initial results are promising in terms of establishing an alternative technology and protocol to MBr for timber fumigation.     

Secretion in the male accessory glands of Aedes aegypti (L.) (Diptera : Culicidae)

The objective of this work is to determine the nature, the mode of synthesis, and release of the secretion of accessory glands of the male mosquito, Aedes aegypti (Diptera : Culicidae). Cytological studies revealed that each of the 2 glands has 2 morphological types of regionally specialized secretory cells, each type differing in the nature, and the release of its products. The anterior region (AR) cells secrete small (0.3–1.3 μm) electron-lucent granules, which during the peak period of synthesis seemed to transport the flocculent and fibrous granular substance to the apical cytoplasm of the cell by means of binary fusions. This cytoplasm, when filled with secretory granules, pinches off and falls freely into the lumen of the gland, thus, exhibiting a macroapocrine mode of secretion. The posterior region (PR) cells, however, elaborate large (mean diameter 2 μm) electron-dense granules, which are released into the lumen essentially by rupture of the cell membrane at the apical end. In males mated to depletion, the volume of the gland is reduced by 67%; there is no subsequent recovery of secretory capacity.     

Biogeography of the phoracanthine beetles (Coleoptera: Cerambycidae)

Six biogeographic subregions of the phoracanthine beetles are proposed on the basis of 136 valid species in all eleven genera of this Australasian group of insects: the Kosciuskan, Western, Eyrean, Torresian, Timorian and New Guinean. Both phenetic and cladistic approaches are employed in the biogeographic study of these beetles. Phenetically, the Kosciuskan and Torresian fauna are the most similar and the least faunal similarity occurs between the New Guinean subregion and all others. Cladistically, two distinct peripheral faunas are divided: the southern Western+Kosciuskan and the northern New Guinean+Torresian+Timorian. The Eyrean fauna in the central Australian continent is more distantly related to the remainder than the latter are to each other. Biogeographic history of the phoracanthine beetles is discussed extensively.     

青杨脊虎天牛对植物源挥发物的EAG和行为反应

测定了青杨脊虎天牛Xylotrechus rusticus （L.）雌、雄成虫对其寄主杨树中的水杨醛（0.95 μmol/μL）和非寄主植物中0.3 μmol/μL的叶绿醇、0.4 μmol/μL的水芹烯和0.6 μmol/μL的 R 型α-蒎烯、S 型α-蒎烯、S型β-蒎烯、3-蒈烯、罗勒烯、香草烯和松节油等10种植物挥发性气味物质的触角电位（EAG）反应。结果表明,与对照相比,这10种植物挥发物多能引起成虫明显的EAG反应( P<0.05,P<0.01 ),其中雌虫对松节油、水杨醛、R 型α-蒎烯和 S 型α-蒎烯的EAG反应较强; 雄虫对 R 型α-蒎烯的EAG反应最强,松节油次之。根据雌虫对这10种挥发物EAG反应的强弱,进一步测定了雌虫对0.00006、0.0006、0.006、0.06、0.6、0.12 μmol/μL的松节油、R 型α-蒎烯、S 型α-蒎烯以及0.000095、0.00095、0.0095、0.095、0.95、0.19 μmol/μL的水杨醛的EAG和行为反应。结果表明,雌虫对松节油、水杨醛和 R 型α-蒎烯的EAG反应随气味物质浓度的增加而增加,水杨醛浓度增加到0.95 μmol/μL、松节油和 R 型α-蒎烯浓度增加到0.6 μmol/μL以后,EAG反应值趋于平稳;对 S 型α-蒎烯的反应随浓度的增加而呈线性增加。水杨醛浓度低于0.095时,对雌虫没有明显的定向作用( P>0.05 ),高于此浓度时表现为驱避作用( P<0.05 ); 松节油在浓度低于或等于0.6 μmol/μL时对雌虫表现为驱避作用,浓度为0.6时驱避效果最佳（ P<0.01 ）。雌虫对 R 型α-蒎烯和 S 型α-蒎烯没有明显的定向行为反应。