Control decision rule for European chafer (Coleoptera: Scarabaeidae) larvae in field corn

After greenhouse and outdoor microplot experiments, a critical density of two third instars per microplot for third instars of European chafer, Rhizotrogus (Amphimallon) majalis (Razoumowsky), in corn, Zea mays L., was derived. On average, the number of missing or damaged plants increased approximately 8% from zero to two larvae per 900 cm2. Furthermore, 23 fields in 2 yr were sampled for larvae along transects by using a golf cup cutter as the sampling tool and the critical density of 0.2 larva per sampling unit as the critical density. The sampling unit was one golf cup cutter with a diameter of 10.8 cm or 91.4 cm2 (10 sampling units approximately 900 cm2 approximately 1 foot2). Fieldwide means and variation were modeled to Taylor's power law, a = 1.42 and b = 1.47, and 20 of 23 fields fit the negative binomial probability distribution. Wald's formula for a sequential sampling plan was most accurate and least time-consuming, according to the operating characteristic and the average sample number function, relative to Iwao's and converging lines formulae. Percentage of sand, topography, soil bulk density, and proximity to trees were measured as potential predictors of areas with high larval density. Percentage of sand and soil bulk density were significant predictors, and topography and proximity to trees were not significant predictors. Field areas where the percentage of sand is high and the soil bulk density is low to moderate or where the percentage of sand is moderate and the soil bulk density is low should be chosen as sampling locations.     

Efficacy of botanical insecticides from Piper species (Piperaceae) extracts for control of Ruropean chafer (Coleoptera: Scarabaeidae)

Biopesticides, including botanicals, can offer a safe and effective alternative to conventional insecticides for controlling major insect pests within an integrated pest management program. The current study highlights the practical application of a botanical insecticide for controlling a major insect pest of turfgrass: European chafer, Rhizotrogus majalis (Razoumowsky). Greenhouse and field trials were conducted to test the efficacy of a botanical formulation based on black pepper, Piper nigrum L. (Piperaceae), seed extracts to R. majalis larvae. The 7-d P. nigrum extract LC50 for R. majalis third instars was 2.5%. Successful treatment in the field was accomplished with the application of a 2% P. nigrum formulation to turfgrass infested with R. majalis second and third instars, whereas 4% extract was required in a second field trial with older third instars. The 2% pepper extract activity was comparable with the conventional insecticide diazinon in the first field trial. However, the 4% pepper extracts significantly affected the earthworm populations in treated plots compared with diazinon in the second field trail. The analysis of soil residues for piperamides in the P. nigrum extract determined a half-life of 1 - 2.6 d in the first and second field trials, respectively. This confirmed the expectation that under field conditions the residual activity would be less than conventional insecticides, thereby reducing the environmental risk associated with pesticide use. We recommend the pepper formulation for spot treatment applications when population densities reveal an epicenter of infestation rather than broadcasting over large areas, thus helping to minimize cost and negative affects on nontarget invertebrates.     

Some tethered flight characteristics of a rose chafer beetle,Pachynoda sinuata (Coleoptera: Scarabaeidae)

• 1.1. The relationships between wingspan, body mass and wing-beat frequency for the beetle. Pachynoda sinuata, have been established.
• 2.2. Thrust and lift generated during tethered flight have been measured using a simple technique and the beetles' responses to the unnatural constraints are discussed.
• 3.3. The biophysical correlates of P. sinuata tethered flight are compared with similar relationships obtained from flying animals and machines.

     

暗黑鳃金龟对性信息素的触角电生理及行为反应

为了分离鉴定暗黑鳃金龟的性信息素成分并对其功能进行验证,本研究对比摸索了3种触角的处理方法,并进行同一浓度（30 ng·μL^-1）二元混合物、不同配比的触角EAG测试。结果包括: 建立了一种鳃叶状触角的触角电位（EAG）测定方法,即将暗黑鳃金龟Holotrichia parallela触角的各鳃叶用针分离开后进行测定,这种方法测得的触角电位反应值较高。雄虫触角对L-异亮氨酸甲酯和(R)-(-)-芳樟醇为7∶1的二元混合物的反应值最高,和暗黑鳃金龟雌虫性信息素25个腺体提取液的EAG反应相当;对同一配比（7∶1）不同剂量刺激液的EAG测试表明,雄虫对浓度为30 ng·μL^-1的二元混合物刺激液的反应值最高。嗅觉反应结果进一步证实,试虫对L-异亮氨酸甲酯和(R)-(-)-芳樟醇7∶1的选择最高,选择系数达93.3%。研究结果为利用性信息素防治暗黑鳃金龟技术的开发提供了基础。     

Euserica modesta Fairmaire (Coleoptera: Scarabaeidae): a new record for a chafer insect pest attacking citrus orchards in Egypt

Many pests and diseases are widely spread and attack several plants and agricultural products. During September 2008, a new chafer insect pest, Euserica modesta Fairmaire (Coleoptera: Scarabaeidae) was recorded for the first time in the south Sinai region, north of Egypt. This insect was shown to attack and destroy flowers and leaves of citrus orchards. It was identified by the Department of Classification, Plant Protection Research Institute, Agriculture Research Center, Giza, Egypt. In the present study, preliminary investigations offered some information about infestation symptoms. Sites of damage in the host plant and suggested control of the pest E. modesta were described.     

Activity of conventional and reduced-risk insecticides for protection of grapevines against the rose chafer, Macrodactylus subspinosus (Coleoptera: Scarabaeidae)

Abstract:  Bioassays were conducted to compare the residual toxicity and leaf protection activity of conventional broad-spectrum and reduced-risk insecticides against the rose chafer, Macrodactylus subspinosus . Insecticides were applied to a Vitis labrusca (F.) vineyard and residues were aged for 1, 3 or 7 days before leaves were collected and exposed to beetles in no-choice tests. Azinphosmethyl caused rapid knockdown and mortality for up to 1 week after application, with 1-day-old residues providing 95.6% protection against feeding, dropping to 51.6% when residues were a week old. Fenpropathrin caused mortality and knockdown after beetles had been exposed to fresh residues for 72 h. Although these effects diminished as residues aged, this compound provided the best protection of leaves against beetle feeding, with 77.9% reduction in feeding compared with the control after 7 days of aging in the vineyard. Of the reduced-risk insecticides, imidacloprid caused the greatest initial mortality and knockdown of beetles, providing protection against feeding that was equivalent to azinphosmethyl. Exposure to azadirachtin caused a low level of knockdown and mortality when residues were 1- and 3-days old. Protection against feeding was also low, lasting for only 3 days. Beetles were minimally affected by capsaicin and kaolin, with mortality and knockdown seen only when beetles were exposed to 1-day-old residues for 72 h. Foliage protection from these compounds was minimal, with between 10 and 15% reduction in feeding injury. Results are discussed in relation to development of semi-field bioassay methods for evaluating reduced-risk insecticides, and the management of M. subspinosus within grape pest management programs.     

Rearing Costelytra zealandica (Coleoptera: Scarabaeidae)

Interaction between larvae can be a cause of mortality when scarabaeid larvae are concentrated in a confined volume of soil. Larvae of Costelytra zealandica (White), the New Zealand grass grub, were held for 30 days at population densities between 1 and 50 larvae per 200 ml of medium, and the effect of crowding on their survival and weight change was assessed. Larval density had no effect on survival in soil plus chopped sheep dung (3 :1), with up to 10 2nd‐instar larvae or 5 3rd‐instar larvae per 200 ml of medium. Larval survival and weight gain were increased by adding germinating ryegrass seed (Grasslands Ruanui) to the medium base, but the effect of density did not diminish. Weight gain of 3rd‐instar larvae decreased as their density increased. When the amount of germinating ryegrass seed in the medium was varied, there was no significant difference between the survival of larvae held in treatments with 5, 25, and 50 g of seed per litre of medium. Survival was significantly lower with 0 and 100 g of seed per litre of medium. It is concluded that, in rearing conditions, the final density of fully grown 3rd‐instar larvae should be a maximum of about 20 per litre of medium to prevent mortality caused by larval interaction—provided that adequate food is available.     

Heat tolerance may determine activity time in coprophagic beetle species (Coleoptera: Scarabaeidae)

Although reports have documented loss of species diversity and ecological services caused by stressful temperature changes that result from climate change, some species cope through behavioral compensation. As temperatures and magnitudes of temperature extremes increase, animals should compensate to maintain fitness (such as through temporary behavioral shifts in activity times). Appropriate timing of activity helps avoid competition across species. Although coprophagic dung beetles exhibit species-specific temporal activity times, it is unknown whether temperature drives evolution of these species-specific temporal activity times. Using nine dung beetle species (three each of diurnal, crepuscular, and nocturnal species), we explored differences in heat stress tolerance measured as critical thermal maxima (CT_max; the highest temperature allowing activity) and heat knockdown time (HKDT; survival time under acute heat stress) across these species, and examined the results using a phylogenetically informed approach. Our results showed that day-active species had significantly higher CT_max (diurnal > crepuscular = nocturnal species), whereas crepuscular species had higher HKDT (crepuscular > nocturnal > diurnal species). There was no correlation between heat tolerance and body size across species with distinct temporal activity, and no significant phylogenetic constraint for activity. Species with higher CT_max did not necessarily have higher HKDT, which indicates that species may respond differently to diverse heat tolerance metrics. Acute heat tolerance for diurnal beetles indicates that this trait may constrain activity time and, under high acute temperatures with climate change, species may shift activity times in more benign environments. These results contribute to elucidate the evolution of foraging behavior and management of coprophagic beetle ecosystem services under changing environments.     

Investigations on bacteria as a potential biological control agent of summer chafer, Amphimallon solstitiale L. (Coleoptera: Scarabaeidae)

Studying the bacteria of hazardous insects allows the opportunity to find potentially better biological control agents. Therefore, in this study, bacteria from summer chafer (Amphimallon solstitiale L., Coleoptera: Scarabaeidae) we isolated and identified the insecticidal effects of bacteria isolated from A. solstitiale and Melolontha melolontha L. (common cockchafer, Coleoptera: Scarabaeidae) and the mixtures of these bacterial isolates were investigated on A. solstitiale larvae. Crystals from Bacillus sp. isolated from M. melolontha were also purified, and tested against the second and third-stage larvae of A. solstitiale. The bacterial isolates of A. solstitiale were identified as Pseudomonas sp., Pseudomonas sp., Bacillus cereus and Micrococcus luteus, based on their morphology, spore formation, nutritional features, and physiological and biochemical characteristics. The insecticidal effects of the bacterial isolates determined on the larvae of A. solstitiale were 90% with B. cereus isolated from A. solstitiale, and 75% with B. cereus, B. sphaericus and B. thuringiensis isolated from M. melolontha within ten days. The highest insecticidal effects of the mixed infections on the larvae of A. solstitiale were 100% both with B. cereus+B. sphaericus and with B. cereus+B. thuringiensis. In the crystal protein bioassays, the highest insecticidal effect was 65% with crystals of B. thuringiensis and B. sphaericus isolated from M. melolontha within seven days. Finally, our results showed that the mixed infections could be utilized as microbial control agents, as they have a 100% insecticidal effect on the larvae of A. solstitiale.     

Male mate searching behavior in the black chafer Holotrichia loochooana loochooana (Sawada) (Coleoptera: Scarabaeidae): response to pheromone lures of various colors and intensities

In order to understand the visual orientation mechanisms of the male black chafer Holotrichia loochooana loochooana to females, we examined male behavioral response to colored objects (lures) when female sex pheromone was present. In the field, males landed more frequently on darker lures than on lighter ones of the same color. Among lures of different colors but with the same brightness, males preferred landing on black, blue, or red ones to green or grey ones. The reflectance intensities of preferred lures were weaker than those of green and grey in the range of 540–580 nm. This range is considered to affect choice by males. When females perch on the leaf edges of the food plant to adopt a calling posture, the dominant background color is that of the leaves (i.e., green). This means that the landing target forms a silhouette (dark spot) which is prominent against a background of green leaves, providing maximum visual acuity for mating.     

Pathogenicity of bacterial isolates to Cyclocephala signaticollis (Coleoptera: Scarabaeidae)

We describe the isolation and identification of pathogenic bacteria obtained from haemolymph of Cyclocephala signaticollis larvae. Two pathogenic bacteria, a Bacillus thuringiensis and an Arthrobacter sp. caused 90–100% mortality to C. signaticollis in 4 days after hemocoel injection, suggesting they might be useful as biological control agents.     

Chemical attractants for larvae of Costelytra zealandica (Coleoptera: Scarabaeidae)

In controlled laboratory tests, using shallow glass chambers containing a coarse river sand substrate between ‘blank’ and ‘test’ sample cages, 3rd‐instar larvae of Costelytra zealandica (White) were attracted to parsnip and carrot root, freshly ground nutmeg, and ß‐pinene (a constituent common to these materials). The terpenol a‐fenchol was strongly attractive to the larvae. Ryegrass root, α‐pinene, and limonene were not significantly attractive, and limonene may indeed have some repellent effect.     

Synopsis of Antitrogus Burmeister (Coleoptera: Scarabaeidae: Melolonthini)

Abstract The genus Antitrogus Burmeister is widely distributed in eastern Australia and, because some species are significant pests of sugarcane, pastures and pineapples, it has attracted considerable research interest. This paper reviews the systematics, biology, ecology and management of the genus. The morphology of the 22 known species is described and a further species, A. gubbi sp. n. from south-eastern Queensland which was previously confused with A. robertsi Britton, is described. These species clearly divide into two species-groups: (i) those from south-eastern Queensland, eastern New South Wales and south-eastern Australia, which sometimes have closely related species pairs; and (ii) a more diverse group of species from central and northern Queensland. The latter is linked to A. villosus Allsopp from western Victoria, and this may indicate that further species await discovery in western New South Wales. Known life cycles are of 1 or 2 years. Adults fly for short periods following rain in spring or summer and do not feed. Adult females tend to disperse poorly, and this, coupled with ephemeral and localised rainfall, has probably contributed to speciation. Larvae feed on the roots of grasses and other similar plants. Insecticides are widely used to control them in sugarcane, but are too expensive for use on pastures. Integrating new controls with an emphasis on cultural controls is seen as the best way of managing these pest species.     

白星花金龟对寄主植物挥发物的电生理反应

[目的]白星花金龟Protaetia brevitarsis是我国经济上重要的农业害虫.本研究拟鉴定苹果、葡萄和玉米3种果实在两种状态(健康与受白星花金龟成虫为害)下的挥发物中能引起白星花金龟雌成虫触角电生理反应的挥发物成分.[方法]采用动态顶空吸附法收集苹果、葡萄和玉米3种果实的挥发物,用气相色谱-触角电位联用技术(...     

Directional asymmetry reversal of male copulatory organs in chafer beetles (Coleoptera: Scarabaeidae): implications on left–right polarity determination in insect terminalia

During large‐scale examinations of male genitalia for taxonomic studies of Sericini chafers (Coleoptera: Scarabaeidae), we have found that reversals of directed left–right (LR) asymmetry in male copulatory organs are compared to other insects not common. However, such inversions do occur occasionally and they must be considered a significant ‘source of error’ in taxonomic studies. Our data indicate asymmetry reversal of male genitalia affects only the abdominal segments (genitalia) as changes in asymmetric structures of the head and thorax were not observed. Based on these observations, we believe that this partial abdominal LR asymmetry reversal of terminalia could be due to a local change in the polarity determining LR patterning in the growth zone of posterior abdominal segments as development of these segments begins.     

Pre-copulatory isolation in sympatric Melolontha species (Coleoptera: Scarabaeidae)

1 The two most abundant cockchafer species in Europe, the forest cockchafer Melolontha hippocastani Fabr. and the European cockchafer Melolontha melolontha L., tend to form calamitous mass breedings with casual reports on sympatric and simultaneous occurrence. 2 Both species are known to use feeding‐induced green leaf volatiles (GLV) as primary attractants (sexual kairomones) for mate finding. The attractiveness of GLV is enhanced by the sex pheromones 1,4‐benzoquinone in M. hippocastani and toluquinone in M. melolontha. Phenol attracts males from both species. All three compounds are present in females of both species. 3 In the present study, it is confirmed that only male M. melolontha perform the typical swarming flight at dusk, as has already been shown for M. hippocastani. Furthermore, whether swarming Melolontha males were cross‐attracted to heterospecific females, and whether males could discriminate olfactorily between conspecific and heterospecific females, was tested in the field. 4 Males of both species preferred females when given the choice between females and males of the other species. However, they preferred conspecific females when females from both species were offered simultaneously. 5 The results suggest that species‐specific pheromone blends contribute to precopulatory reproductive isolation in sympatric populations of M. melolontha and M. hippocastani, but are not mutually exclusive or indispensable prerequisites for mate finding as in other insects.     

Diverse cuticular hydrocarbons from Australian canebeetles (Coleoptera: Scarabaeidae)

Abstract  Cuticular hydrocarbon components in beetles of six Australian melolonthines whose larvae damage sugarcane, Antitrogus parvulus (Britton), A. consanguineus (Blackburn), Lepidiota negatoria (Blackburn), L. picticollis (Lea), L. noxia (Britton) and Dermolepida alborhirtum (Arrow), are identified and compared. These species demonstrate species-specific cuticular hydrocarbon profiles with a number of unprecedented structures. Major components have been identified as polymethylated hydrocarbons, 3-methyl substituted n -alkanes, 9,10-allenes and the corresponding C9 alkenes. The similarity of these compounds shows some correlation with the phylogeny of the beetles, but two polymethylated C₂₂ hydrocarbons are unique to A. parvulus. One C₂₅ allene is shown to have a potential role in mate recognition in A. consanguineus.     

Enhanced toxicity of Bacillus thuringiensis japonensis strain Buibui toxin to oriental beetle and northern masked chafer (Coleoptera: Scarabaeidae) larvae with Bacillus sp. NFD2

Bacillus thuringiensisjaponensis strain Buibui (Btj) has the potential to be an important control agent for pest scarabs. Bioassays using autoclaved and nonautoclaved soil showed there were always lower LC, values associated with nonautoclaved soil. We identified five other bacteria found in the hemolymph of insects killed by Btj and used them in bioassays to see whether we could enhance the control achieved with Btj alone. One bacterium, designated NFD2 and later identified as a Bacillus sp., showed the greatest enhancement of Btj in preliminary experiments and was used in bioassays with Btj versus oriental beetle, Anomala orientalis (Waterhouse), and northern masked chafer, Cyclocephala borealis Arrow (Coleoptera: Scarabaeidae), larvae. This bacterium alone was nontoxic to grubs in bioassays. A combination of this bacterium with Btj in nonautoclaved soil resulted in a significantly lower LC50 value (0.23 microg toxin per g soil) from all other treatments for A. orientalis with one exception; the LC50 where NFD2 was added back into autoclaved soil (0.29 microg toxin per g soil). A combination of this bacterium with Btj in nonautoclaved soil resulted in a significantly lower LC50 value (48.29 microg toxin per g soil) from all other treatments for C. borealis with the exception of the treatment where Bacillus sp. NFD2 was added back to autoclaved soil (96.87 microg toxin per g soil) with Btj. This research shows that other soil bacteria can be used to enhance the toxicity of Btj and possibly other Bts.     

Evaluation of baits for trapping of Neotropical flower chafer beetles (Coleoptera: Scarabaeoidea: Cetoniinae)

The lack of a standardized protocol to efficiently capture flower chafer beetles (Coleoptera: Scarabaeoidea: Cetoniinae) in the wild limits studies regarding the ecology of the group, as well as systematic collections seeking species surveys for taxonomic studies, especially in the Neotropical region. We investigate the efficiency of different baits to capture flower chafer beetles in the Brazilian Cerrado: (i) banana; (ii) banana + sugarcane juice; (iii) pineapple; (iv) pineapple + sugarcane juice; (v) sugarcane juice; or (vi) water (control). From January to December 2014, we sampled these beetles using a typical aerial fruit‐baited trap, every 15 days in ten sites of Brazilian Cerrado, in Aquidauana, Mato Grosso do Sul, Brazil. Traps baited with banana + sugarcane juice, pineapple + sugarcane juice and sugarcane juice alone sampled the greatest species richness and abundance of flower chafer beetles when compared to the other baits used. Our results indicated the importance of sugarcane juice, either used in isolation or as a coadjutant in the fermentation process of the tested fruits for efficient sampling of flower chafer beetle biodiversity. Finally, studies that investigate the addition of other substances in the fermentation process of the fruits, as well as the attractiveness of other native or exotic fruits that are widely distributed in the Neotropical region, can advance our knowledge of sampling of these beetles.     

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.