Identification of minor sex pheromone components of the poplar clearwing moth Paranthrene tabaniformis (Lepidoptera, Sesiidae)

A chemical analysis of the crude sex pheromone gland extracts of virgin calling Paranthrene tabaniformis females, obtained from the European part of Kazakhstan, revealed the presence of five compounds: (3E,13Z)-octadeca-3,13-dien-1-ol (E3,Z13-18:OH), (3Z,13Z)-octadeca-3,13-dien-1-ol (Z3,Z13-18:OH), (2E,13Z)-octadeca-2,13-dien-1-ol (E2,Z13-18:OH), (13Z)-octadec-13-en-1-ol (Z13-18:OH), and octadecan-1-ol (18:OH) at the ratios 64.0:32.4: 1.4:0.9:1.3, which are structurally related to sex pheromone components of clearwing moths. Our previous field tests showed synergistic effects of Z3,Z13-18:OH and E2,Z13-18:OH to attract P. tabaniformis males, when these compounds were tested in binary mixtures with the known sex pheromone E3,Z13-18:OH. The three dienic alcohols should all be considered as sex pheromone components of the P. tabaniformis species, while the role of Z13-18:OH and 18:OH remained unclear.     

An endemic population of western poplar clearwing moths (Lepidoptera: Sesiidae) invades a monoculture of hybrid poplar

Western poplar clearwing, Paranthrene robiniae (Hy. Edwards) (Lepidoptera: Sesiidae), is endemic in Pacific Northwest riparian habitats at low population densities. These moths have colonized commercial hybrid poplar (Populus spp.) plantings. Moth populations increased rapidly and became a major pest. Trap catches of male moths in mid-season surveys increased 190-fold from 95 in 2001 to >18,500 in 2002 across 6597 ha of poplars monitored. The outbreak of western poplar clearwings was widespread in 2002. Pheromone-baited traps placed one trap per 81.75 ha over 13,274 ha of commercial poplars captured >108,000 male moths in 2002. Damage to commercial poplars included girdling of saplings and burrows in limbs and trunks of trees. Repeated applications of chlorpyrifos failed to reduce the abundance of moths in 2002. Two management strategies over two separate plantations of approximately 6500 ha each were contrasted. Future control strategies recommend a halt to the use of contact insecticides that target adult moths. Short-term (3-5 yr) control should involve a pheromone-based mating disruption strategy followed eventually by selection of a clone that is less susceptible to P. robiniae attack.     

Susceptibility of apple clearwing moth larvae,Synanthedon myopaeformis (Lepidoptera: Sesiidae) to Beauveria bassiana and Metarhizium brunneum

Apple clearwing moth larvae, Synanthedon myopaeformis (Lepidoptera: Sesiidae) were found to be susceptible to infection by two entomopathogenic fungi: an indigenous fungus isolated from S. myopaeformis cadavers and identified as Metarhizium brunneum (Petch); and Beauveria bassiana isolate GHA. In laboratory bioassays, larvae exhibited dose related mortality after exposure to both the M. brunneum and Beauveria bassiana with 7 day LC₅₀'s of 2.9×10⁵ and 3.4×10⁵ spores/mL, respectively. Larval mortalities caused by the two isolates at 1×10⁶ spores/mL were not significantly different and 73% of the M. brunneum-treated, and 76% of the B. bassiana-treated larvae were dead 7 days post treatment, with LT₅₀'s of 5.5 and 5.1 days, respectively.     

Natural mortality of currant clearwing,Synanthedon salmachus (Lepidoptera: Sesiidae), in New Zealand

Abstract

In a wide-ranging survey of 11 blackcurrant blocks, mortality of currant clearwing, Synanthedon salmachus (L.), was found to range from 1.3% to 9.7% for larvae and from 5.3% to 23.0% for pupae. At least 51% of the mortality was caused by the fungal pathogens Beauveria bassiana, Paecilomyces farinosus, and Verticillium lecanii. One unidentified predatory carabid larvae was collected, and two parasites—Xanthocryptus novozealandicus and Diadegma sp.—were reared from clearwing larvae.     

A sampling plan for population dynamics studies on currant clearwing,Synanthedon tipuliformis (Lepidoptera: Sesiidae)

Abstract

Sampling techniques for eggs, larvae, and pupae of the currant clearwing, Synanthedon tipuliformis (Clerck), attacking blackcurrant were developed, and their precision was evaluated. Reliable population estimates for the egg and early larval stages (standard error < 10%) were obtained by sampling one cane with at least two age groups of wood from the north and south halves of seven bushes in nine blocks. Similar precision was obtained for post-winter larvae from samples comprising three canes from each half of the bushes, but using this sampling scheme a lower precision (S.E.?25–30%) had to be accepted for overwintering mortality factors. The pupal population was estimated from the numbers of live larvae at the end of the post-winter feeding stage, and cross-checked from the number of emergence holes in the 1-year-old wood taken for egg sampling the following year. This procedure gave estimates of similar reliability to those for the egg and larval stages.     

Life tables of currant clearwing,Synanthedon tipuliformis (Lepidoptera: Sesiidae), in blackcurrant in Canterbury

Abstract

Survivorship curves and life tables for the 1971-75 generations of currant clearwing in an unsprayed blackcurrant (cv. 'Cotswold Cross') plantation and for the 1972-74 generations in a sprayed blackcurrant plantation (cvs 'Cotswold Cross' and 'Magnus') are presented. The key element in the life cycle is identified as adult survival, and the density dependence of the various mortalities is identified by various indices. The possible effects on population levels of currant clearwing of the proposed pruning management for mechanically harvested blackcurrants is discussed.     

Susceptibility of the strawberry crown moth (Lepidoptera: Sesiidae) to entomopathogenic nematodes

The objective of this study was to determine the susceptibility of the strawberry crown moth, Synanthedon bibionipennis (Boisduval) (Lepidoptera: Sesiidae) larvae to two species of entomopathogenic nematodes. The entomopathogenic nematodes Steinernema carpocapsae (Weiser) strain Agriotos and Heterorhabditis bacteriophora (Steiner) strain Oswego were evaluated in laboratory soil bioassays and the field. Both nematode species were highly infective in the laboratory bioassays. Last instars were extremely susceptible to nematode infection in the laboratory, even in the protected environment inside the strawberry (Fragaria x ananassa Duch.) crown. Infectivity in the laboratory was 96 and 94% for S. carpocapsae and H. bacteriophora, respectively. Field applications in late fall (October) were less effective with S. carpocapsae and H. bacteriophora, resulting in 51 and 33% infection, respectively. Larval mortality in the field from both nematode treatments was significantly greater than the control, but treatments were substantially less efficacious than in the laboratory. Soil temperature after nematode applications in the field (11 degrees C mean daily temperature) was below minimum establishment temperatures for both nematode species for a majority of the post-application period. It is clear from laboratory data that strawberry crown moth larvae are extremely susceptible to nematode infection. Improved control in the field is likely if nematode applications are made in late summer to early fall when larvae are present in the soil and soil temperatures are more favorable for nematode infection.     

The biology and life history of currant clearwing,Synanthedon tipuliformis (Lepidoptera: Sesiidae), in Canterbury

Abstract

Details of the life cycle and biology of currant clearwing, Synanthedon tipuliformis (Clerck), in Canterbury, New Zealand, are discussed. The adults live for about 7 days, and are found from mid November to early January. The sex ratio approximates 1:1. Adults are active only when the air temperature exceeds 15°c, and peak flight activity is observed on cloudy days at 20-23°c. Males are attracted to females between 1400 h and 1600 h, and mating lasts for over 2 h. Fecundity averaged about 100 eggs per female, and fertility exceeded 98%. Egg incubation required an average of 19 days in the field; the thermal constant is 91 day degrees. The mean number of eggs per blackcurrant cane varied in different years from 2.68 to 13.54; there was no significant difference between blackcurrant varieties in the same year. Larvae entered the cane through openings or axillary buds and then fed on the pith until late April or May. Quiescence occurred during winter, and feeding resumed in late August or September. Larvae tunnelled 15.20 ± 0.74 cm of pith. It is suggested that there are six larval instars. Mean numbers of larvae per cane varied in the early stage from 1.91 to 7.36, and at the post-winter stage from 1.23 to 3.10. Pupation occurred in mid October, and the pupal stage lasted for up to 6 weeks; the thermal constant is 216 day degrees. Mortality factors discussed include establishment failure, parasites, pathogens, predators, larval combat, winter pruning, loss of pupae at cane breaks, and pupal eclosion failure. The first record of the fungus Cordyceps sp. attacking currant clearwing is reported.     

Sex attractants for six clearwing and tineid species (Lepidoptera, Sesiidae and Tineidae) from Kazakhstan and Lithuania

Sex attractants for 3 Sesiidae and 3 Tineidae moth species in West-Kazakhstan and Lithuania were discovered by field screening tests of (3Z,13Z)-, (3E,13Z)- and (2E,13Z)-octadecadien-1-ols and their acetates as well as of some binary mixtures of these compounds. Total amount of chemicals was 0.3 mg/dispenser. Males of Synanthedon serica were attracted by a 5:5 mixture of 3E,13Z-18:OAc and 2E,13Z-18:OAc, Chamaesphecia bibioniformis by a 9:1 mixture of 3Z,13Z-18:OAc and 3E,13Z-18:OAc, Paranthrene tabaniformis by a 1:9 mixture of 3Z,13Z-18:OH and 3E,13Z-18:OH, Tinea nonimella by a 1:9 mixture of 3E,13Z-18:OH and 2E,13Z-18:OH, Monopis monachella by a 1:9 mixture of 3Z,13Z-18:OH and 2E,13Z-18:OH, and Nemaxera betulinella by a 9:1 mixture of 2E,13Z-18:OAc and the corresponding alcohol. The periods of attraction to the traps were registered for males of S. serica and Ch. bibioniformis and were found to occur at 15-18 and 15-17 o'clock, local time, respectively.     

杨树截干上白杨透翅蛾的危害及防治

在内蒙古巴彦淖尔市杨树人工防护林区,采用杨树高枝截干是防治光肩星天牛Anoplophora glabripennis(Motschulsky)的有效手段之一。但在当年春季杨树截干上留下的机械伤口及新萌发枝条,为白杨透翅蛾Paranthrene tabaniformis(Rott.)的入侵提供了有利条件。白杨透翅蛾在1~3年的截干上发生密度较高,严重时影响到新萌发枝干的生长甚至死亡。2007年5月调查发现,在杨树截干上白杨透翅蛾的有虫株率达到89·17%,平均虫口密度达到(3·40±0·21)头/株,远远超过了0·3头/株的最低防治标准。最后,结合当地杨树人工防护林网的特殊环境条件,提出了针对性的防治措施。     

The distribution and dispersion of life stages of currant clearwing,Synanthedon tipuliformis (Lepidoptera: Sesiidae), in blackcurrant

Abstract

The distribution of life stages of currant clearwing, Synanthedon tipuliformis (Clerck), in blackcurrant bushes was investigated on two plots during 1971–75. Three ways of expressing the distribution are examined, none of which is totally acceptable. Generally less than 10% of eggs are found on the current season's growth, and since wood of this age group represents over 50% of the available universe, the proportion of eggs laid on it is relatively low. The proportion of the larval population in the younger wood increases until just before pupation, when over 80% of the population is in the most recent 2 years' growth. The 1-year-old wood harbours 50% of the early larval population, and a use for this information in assessments of the effectiveness of insecticide trials against adults is suggested. The dispersion of eggs and larvae of S. tipuliformis is shown by a number of indices to be aggregated. The frequency distribution is adequately described by the negative binomial. A common k, k _c, of 0.66 (95% confidence limits 0.57–0.80) for the egg stage was valid, but the k _c for the larval stage of 1.28 (1.09–1.56) was only marginally valid.     

Inter- and intraspecific activities of compounds derived from sex pheromone glands of currant borer, Synanthedon tipuliformis (Clerck) (Lepidoptera: Sesiidae)

Gas chromatography and mass spectrometry analyses of crude sex pheromone gland extracts revealed that virgin Synanthedon tipuliformis (Clerck), currant borer (Lepidoptera: Sesiidae) females, produced 6 compounds, structurally related to sex pheromone components of clearwing moths. By comparison of retention times and mass spectra of natural products with corresponding properties of synthetic standards, these compounds were identified as: (2E,13Z)-octadeca-2,13-dien-1-yl acetate (E2,Z13-18:OAc), (3E,13Z)-octadeca-3,13-dien-1-yl acetate (E3,Z13-18:OAc), (13Z)-octadec-13-en-1-yl acetate (Z13-18:OAc), (2E,13Z)-octadeca-2,13-dien-1-ol (E2,Z13-18:OH), (13Z)-octadec-13-en-1-ol (Z13-18:OH) and octadecan-1-ol (18:OH) in the ratio 100:0.7:2.7:3.2:traces:traces. The first 3 compounds were previously known to occur in the sex pheromone gland extracts of currant borers, while the last 3 chemicals are now reported for the first time. Trapping tests carried out in the black currant field revealed that E2,Z13-18:OAc, when tested separately, attracted S. tipuliformis males, while addition of E3,Z13-18:OAc to the main component increased the effectiveness of E2,Z13-18:OAc over seven times. The attractiveness of 6 component lures did not differ significantly from the one of the binary mixture, confirming that E2,Z13-18:OAc and E3,Z13-18:OAc in the ratio100:0.7 are essential sex pheromone components of S. tipuliformis. Trapping tests carried out at the dwelling place of Synanthedon scoliaeformis (Borkhausen) (Lepidoptera: Sesiidae) revealed that, in addition to intraspecific synergistic effect, E3,Z13-18:OAc increased the specificity of the pheromone signal of S. tipuliformis, acting by intraspecific mode as an attraction antagonist against S. scoliaeformis males. By this way, it ensured the specificity of the sex attraction signal of the currant borer. Consequently, both compounds E2,Z13-18:OAc and E3,Z13-18:OAc have to be present in pheromone formulations used for monitoring and/or control of S. tipuliformis to avoid effecting non-target species. Other compounds identified from the sex pheromone gland of S. tipuliformis did not show any significant interspecific activity for males of S. scoliaeformis, however, they provide a basis to achieve specificity of a pheromone signal of S. tipuliformis and could act as attraction antagonists against other clearwing moth species which, like S. tipuliformis, employ E2,Z13-18:OAc as their sex pheromone component.     

Notes on the biology and ecology of the parasitoids of the poplar clearwing moth, Paranthrene tabaniformis (Rott.) (Lep., Sesiidae) in Bulgaria. I. Apanteles evonymellae (Bouché, 1834) (Hym., Braconidae)

Aspects of the biology and ecology of Apanteles evonymellae (Bouché), a parasitoid of the poplar clearwing moth, Paranthrene tabaniformis (Rott.), were studied during the period 1987–96. One-year-old poplar ( Populus spp.) shoots infested with P. tabaniformis larvae were collected during the winter months at 11 localities in Bulgaria and examined in the field and laboratory. Apanteles evonymellae was recorded in all areas studied in Bulgaria. The mortality of P. tabaniformis caused by this parasitoid in various regions of Bulgaria varied from 2.4 to 35.4%; the average for the country was 17.3%. Laboratory observations showed that A. evonymellae is a solitary endoparasitoid of the poplar clearwing moth. It develops in early-stage (first- to fourth-instar) host larvae and overwinters as a larva in the host. Apanteles evonymellae is bivoltine, but only the second generation is associated with P. tabaniformis . In the field, adult parasitoids of first generation appear in April about 1 month before the emergence of P. tabaniformis . The longevity of A. evonymellae adults is a maximum of 6 days. Therefore, in the spring, A. evonymellae cannot attack neonate P. tabaniformis larvae and must develop in alternative hosts. Prior to their death the parasitized P. tabaniformis larvae construct conical structures, 'refuges' of frass and silk threads over the external openings of the larval galleries. Apanteles evonymellae pupates in these refuges after the host's death. This modified behaviour of the parasitized host larvae probably protects the pupae of A. evonymellae from hyperparasites and predators.     

Notes on the biology and ecology of the parasitoids of the poplar clearwing moth, Paranthrene tabaniformis (Rott.) (Lep., Sesiidae) in Bulgaria. II. Eriborus terebrans (Gravenhorst, 1826) (Hym., Ichneumonidae)

The biology and ecology of Eriborus terebrans (Grav.), a parasitoid of the poplar clearwing moth, Paranthrene tabaniformis (Rott.), were studied during the period 1987–98. One-year-old poplar ( Populus spp.) shoots infested with P. tabaniformis larvae were collected from poplar seedlings at 11 localities in Bulgaria and examined in both field and laboratory conditions. Eriborus terebrans was recorded in seven localities as a solitary internal larval parasitoid of P. tabaniformis which developed two generations in early and mid-stage host larvae. Eriborus terebrans overwintered as a larva in P. tabaniformis overwintering larvae. In the field adult parasitoids of the overwintering generation appeared between late April/early May, and June or July. The peak activity of E. terebrans adults only coincided with the beginning of host emergence, which resulted in low levels of parasitism, being no more than 6.2%. Parasitoid adults of the summer generation appeared in late June–mid August. In this period enough larvae of the host were suitable for attacking and parasitism reached 24.4–39% in some cases. The average mortality of P. tabaniformis overwintering larvae caused by this parasitoid in Bulgaria during the period of the study was 4.7%. A significant part of the parasitized P. tabaniformis larvae constructed tunnel structures of frass and silk threads over the external openings of the galleries. It is possible that these structures protect the parasitoid cocoons from natural enemies – hyperparasitoids and predators.     

Identification of the sex pheromone secreted by Synanthedon tenuis (Lepidoptera: Sesiidae)

The Japanese persimmon treeborer, Synanthedon tenuis (Butler) (Lepidoptera: Sesiidae), is a harmful pest of persimmon trees (Diospyros spp.). Because males of this species are known to be attracted by (3Z,13Z)-3,13-octadecadienyl acetate (Z3,Z13-18:OAc), a mating disruptant composed of a 1:1 mixture of Z3,Z13-18:OAc and the (3E,13Z)-isomer, the original target of which is an allied pest, S. hector (Butler), has been diverted to control S. tenuis. However, the sex pheromone secreted by S. tenuis females has not been characterized. Analyses of pheromone gland extracts using gas chromatography (GC) equipped with an electroantennographic detector (GC-EAD) and GC combined with mass spectrometry (GC–MS) detected only Z3,Z13-18:OAc, and no other known sesiid pheromone components were found. In a persimmon orchard, S. tenuis males were selectively attracted by a lure baited with Z3,Z13-18:OAc among four geometrical isomers of 3,13-octadecadienyl acetate, indicating that males strictly discriminated among the configurations of the two double bonds. Lures baited with single Z3,Z13-18:OAc attracted only S. tenuis. Further field experiments revealed that the attractiveness of Z3,Z13-18:OAc is significantly inhibited by the addition of the (3E,13Z) isomer or the parent alcohol.     

Biology and control of the raspberry crown borer (Lepidoptera: Sesiidae)

This study explored the biology of raspberry crown borer, Pennisetia marginata (Harris) (Lepidoptera: Sesiidae), in Arkansas and the optimum timing for insecticide and nematode applications. The duration of P. marginata's life cycle was observed to be 1 yr in Arkansas. Insecticide trials revealed that bifenthrin, chlorpyrifos, imidacloprid, metaflumizone, and metofluthrin efficacy were comparable with that of azinphosmethyl, the only labeled insecticide for P. marginata in brambles until 2005. Applications on 23 October 2003 for plots treated with bifenthrin, chlorpyrifos, and azinphosmethyl resulted in >88% reduction in larvae per crown. Applications on 3 November 2004 of metaflumizone, metofluthrin, and bifenthrin resulted in >89% reduction in larvae per crown. Applications on 7 April 2005 for metofluthrin, imidacloprid, bifenthrin, metaflumizone, and benzoylphenyl urea resulted in >64% reduction in the number of larvae per crown. Applications on 6 May 2004 did not reduce larval numbers. The optimum timing for treatments was found to be between October and early April, before the larvae tunneled into the crowns of plants. Applying bifenthrin with as little as 468 liters water/ha (50 gal/acre) was found to be as effective against larvae as higher volumes of spray. Nematode applications were less successful than insecticides. Nematode applications of Steinernemafeltiae, Steinernema carpocapsae, and Heterorhabditis bacteriophora reduced larvae counts per plant by 46, 53, and 33%, respectively.