Phyllopertha Horticola Research Articles

How to control nasty scarabs? Effectiveness of the generalist entomopathogenic fungus Metarhizium brunneum against garden chafer larvae

Several scarab beetles (Scarabaeidae) cause major damage in agriculture, horticulture, and forestry. Especially root feeding scarab larvae cause substantial economic losses on crops, forage plants and recreational areas. In Europe, the entomopathogenic fungi (EPF) Beauveria brongniartii and Metarhizium brunneum are applied against the most problematic, native scarabs, the common cockchafer (Melolontha melolontha) and the garden chafer (Phyllopertha horticola). While the control of cockchafer larvae with B. brongniartii is well-researched, conclusive results from field applications for the control of the garden chafer with M. brunneum remain elusive. We therefore assessed the performance of commercially available fungal strains of M. brunneum against garden chafer larvae in pot and large-scale field experiments.The application of M. brunneum significantly increased the abundance of fungal propagules in the soil by approximately a factor of ten, irrespective of high levels of naturally occurring Metarhizium spp. Furthermore, the applied strains infected and propagated on the larvae and the mortality of garden chafer larvae was slightly increased due to the fungal treatments. We found three other EPF species frequently infecting garden chafer larvae (mean infection rates: 13–25%), including B. brongniartii which is considered to be a specific pathogen of the cockchafer. Thus, the applied fungal strains were only part of a consortium of natural enemies which reduces garden chafer populations strongly as a whole. Hence, we suggest that the application of EPF may be advisable on areas with reduced natural enemies such as golf courses but is probably redundant on meadows harboring a diverse consortium of antagonists.

Studies on Potential Pests of Japanese Quince (Chaenomeles japonica (Thunb.) Lindl. ex Spach) in Latvia

Abstract The objective of this research was to study potential pests of Japanese quince (Chaenomeles japonica) plantations in Latvia. Studies were carried out in eight plantations during 2017–2019. Major pests that would regularly cause significant yield losses for this plant were not observed. Black-veined white (Aporia crataegi) was considered a local pest, mass outbreaks of which can occur in individual plantations and cause significant losses of plant foliage. Four species were considered minor pests: garden chafer (Phyllopertha horticola), yellow-banded weevil (Chlorophanus viridis), silver-green weevil (Phyllobius argentatus) and copse snail (Arianta arbustorum); they are also pests of plant foliage. The European red spider mite (Panonychus ulmi) was not considered as a pest of Japanese quince. A small population was observed in summers only in one plantation, which was located next to a heavily infested orchard. Overwintering eggs were not found on the plants in any year, and we concluded that the species was an accidental immigrant in this plantation. No aphid (Aphididae) colonies were observed on the quince plants. Monitoring and evaluation of potential harmfulness of four tortrix moths – large fruit-tree tortrix (Archips podana), rose tortrix (Archips rosana), codling moth (Cydia pomonella) and holly tortrix (Rhopobota naevana) – was done. It was concluded that rose tortrix is a minor fruit pest, but the other three species were not yet considered pests of Japanese quince. Significant pests of quince flowers and fruits were not detected in our study.

Behavioral response of three subterranean pests (Agriotes lineatus, Diabrotica virgifera virgifera, Phyllopertha horticola) to the fungal volatile organic compounds 1-octen-3-ol and 3-octanone

The volatile organic compounds (VOCs) 1-octen-3-ol and 3-octanone produced by the entomopathogenic fungus Metarhizium brunneum are known to have pesticidal properties at high doses against a range of invertebrate pests. Very little is known about their behavior-modifying (semiochemical) properties. This study focused on investigating the behavioral responses of three subterranean crop pests, wireworm (Agriotes lineatus), western corn rootworm (Diabrotica virgifera virgifera), and garden chafer (Phyllopertha horticola), to relatively low doses of 1-octen-3-ol and 3-octanone. The behavior of wireworms and corn rootworms were slightly influenced by the VOCs, yet not significantly. Western corn rootworms appeared to be slightly attracted by 100 µl and 200 µl 1-octen-3-ol and 100 µl dose of 3-octanone, respectively but slightly repelled by the higher dose of 3-octanone. Wireworms appeared to be slightly repelled by 1-octen-3-ol and high dose 3-octanone, but slightly attracted by the 100 µl dose of 3-octanone. The VOCs had no significant impact on garden chafer. In silico studies showed that corn rootworm odorant binding proteins (OBPs) had a strong binding affinity of 1-octen-3-ol and high dose 3-octanone, indicating that these VOCs can be detected and recognized by corn rootworm. OBPs are well conserved between species; thus, wireworm and garden chafer OBPs should also be able to bind with the VOCs. Further trials will be done to confirm that VOCs could be used as semiochemicals. Appropriate formulation of the VOCs should increase their efficacy and prevent rapid dissipation of the VOCs.

From lab to field: biological control of the Japanese beetle with entomopathogenic fungi.

The Japanese beetle, Popillia japonica, is an invasive scarab and listed as quarantine organism in many countries worldwide. Native to Japan, it has invaded North America, the Azores, and recently mainland Europe. Adults are gregarious and cause agricultural and horticultural losses by feeding on leaves, fruits, and flowers of a wide range of crops and ornamental plants. Larvae feed belowground and damage grassland. To date, no efficient and environmentally friendly control measure is available. Larval populations of other scarab species such as Phyllopertha horticola and Melolontha melolontha are controlled by applying spores of the entomopathogenic fungi Metarhizium brunneum and Beauveria brongniartii to larval habitats. Here, we tested this control strategy against Japanese beetle larvae in grasslands, as well as spore spray applications against adults in crops. Using both, large-scale field experiments and inoculation experiments in the laboratory, we assess the efficacy of registered fungal strains against Japanese beetle larvae and adults. Metarhizium brunneum BIPESCO 5 established and persisted in the soil of larval habitats and on the leaves of adult's host plants after application. However, neither larval nor adult population sizes were reduced at the study sites. Laboratory experiments showed that larvae are not susceptible to M. brunneum ART 212, M. brunneum BIPESCO 5, and B. brongniartii BIPESCO 2. In contrast, adults were highly susceptible to all three strains. When blastospores were directly injected into the hemolymph, both adults and larvae showed elevated mortality rates, which suggests that the cuticle plays an important role in determining the difference in susceptibility of the two life stages. In conclusion, we do not see potential in adapting the state-of-the-art control strategy against native scarabs to Japanese beetle larvae. However, adults are susceptible to the tested entomopathogenic fungi in laboratory settings and BIPESCO 5 conidiospores survived for more than three weeks in the field despite UV-radiation and elevated temperatures. Hence, control of adults using fungi of the genera Beauveria or Metarhizium is more promising than larval control. Further research on efficient application methods and more virulent and locally adapted fungal strains will help to increase efficacy of fungal treatments for the control of P. japonica.

Phyllopertha horticola Linné - Pest in blueberry plantations in the Mărişel area (Cluj County)


 Phyllopertha horticola Linné (Coleoptera: Scarabaeidae) is one of the most common phytophagous beetles in Central Europe. In 2020 the blueberry growers from the Mărişel area reported the presence of a new beetle that attacked the fruit’s flowers and leaves. The species was identified at the University of Agricultural Sciences and Veterinary Medicine in Cluj-Napoca as the garden chafer. In the following year, the plants attacked by the garden beetle were monitored in the blueberry plantation in the Mărişel area. For monitoring the garden chafer, three rows of land were randomly selected in each plot with intervals of 20 plants per row. Each plant was analyzed individually and the number of adult beetles reported on the plant was noted. The observations were made between June and July 2021. In the Elliot variety, the share of plants reported with adults of Phyllopertha horticola Linné was between 50% and 60%, the average being 55%. Regarding the maximum number of adults/plant, it was between 6 specimens (raw 1) and 9 adults/plant (raw 2). In the Bluecrop variety, the share of plants with adults of the monitored species was between 10% and 45%, with an average per variety of 25%.

Risk Assessment of the Biological Plant Protection Products Nemasys G and Nemasys H with the Active Organism Heterorhabditis Bacteriophora

Nemasys G and Nemasys H with the nematode Heterorhabditis bacteriophora as the active organism is applied for as a plant protection product in Norway. Nemasys G is intended for use against the garden chafer (Phyllopertha horticola) in lawns and Nemasys H against black vine weevil (Otiorhynchus sulcatus) in strawberries and ornamentals.
 VKM was requested by the Norwegian Food Safety Authority to consider the possible health and environmental risk related to the properties of Nemasys G and Nemasys H; in particular to evaluate if the nematode is naturally occurring in Norway, the potential for establishing and spreading under Norwegian conditions, possible taxonomic challenges and assessment of the health risk related to its use.
 The assessment was finalized in October 2014 by VKM’s Panel on Plant Protection Products.
 VKM’s conclusions are as follows:
 Natural occurrence of the nematode:
 The nematode Heterorhabditis bacteriophora has not been observed in Norway, but is widespread world-wide in regions with continental and Mediterranean climates. In Europe it has been isolated in France, Germany, Hungary, Italy, Moldavia, Spain, Switzerland and the UK.
 Potential for establishing and spreading of the nematode under Norwegian conditions:
 The thermal preference of H. bacteriophora restricts its establishing. Short term establishment in the growing season is possible in parts of Norway. This nematode has however poor long term survival in soil, especially in the absence of suitable hosts, and the potential for long term establishment in Norway is considered to be low.
 Taxonomic challenges:
 There are no taxonomic challenges related to assessment of this nematode.
 Human health risk for operators:
 Exposure of user is considered to be low. The use of plant protection products containing Heterorhabditid nematodes against insects has not been associated with health effects on humans. The symbiotic bacteria Photorhabdus luminescens has not been linked to pathogenic effects in humans. It is therefore the view of VKM that the use of the nematode Heterorhabditis bacteriophora with the symbiotic bacteria Photorhabdus luminescens will have minimal health risk for operators.

Fumigation of three major soil pests (Agriotes lineatus, Diabrotica virgifera virgifera, Phyllopertha horticola) with 3-octanone and 1-octen-3-ol enantiomers

ABSTRACT New pest management solutions are needed to control soil invertebrates (insects, nematodes, mollusks) in order to implement the goals of the European Green Deal. Natural volatile organic compounds (VOCs) such as 1-octen-3-ol and 3-octanone, emitted by the entomopathogenic fungus Metarhizium brunneum could be part of the solution. Three major crop pests, Agriotes lineatus (wireworm), Diabrotica virgifera virgifera (corn rootworm) and Phyllopertha horticola (garden chafer), were susceptible to fumigation with 1-octen-3-ol and 3-octanone. The toxicity of the VOCs was tested in soil-free arenas and in soils which differed in moisture content and porosity. The mortality rates were dependent on the interaction between the VOC treatment, dose and pest species. The insects differed in their sensitivity to these VOCs. A dose of 1.25 µl of 1-octen-3-ol applied in a closed glass tube was sufficient to kill D. v. virgifera and P. horticola in soil trials whereas 5 µl was needed to kill A. lineatus. The highest dose (20 µl) was highly toxic to all insects. Soil moisture content slightly influenced mortality rates whereas porosity had no obvious impact. The mode of action of the VOCs is unknown but the compounds are likely to cause tissue damage and loss of body fluids. This may explain the shrivelled appearance of corn rootworm and garden chafer and melanisation in wireworm. Both 1-octen-3-ol and 3-octanone show promise as biofumigants.

Common problems of <i>Rhododendron</i> L. in the Central Botanical Garden of the National Academy of Sciences of Belarus

Rhododendrons are some of the most attractive flowering shrubs in the landscape. The article presents the results of studying the common problems of Rhododendron collection in the Central Botanical Garden of the National Academy of Sciences of Belarus, conducted in 2012-2020. There are several diseases and pests that commonly occur on rhododendrons every year. These include powdery mildew (Erysiphe azaleae), fungal leaf spots (Pestalotiopsis rhododendri, Colletotrichum gloeosporioides, Alternaria spp., Sphaerulina azaleae, Phyllosticta concentrica, Phyllosticta rhododendricola), black vine weevil (Otiorhynchus sulcatus), garden foliage beetle (Phyllopertha horticola), click beetle (Hemicrepidius niger), red spider mite (Tetranychus urticae), physiological leaf spots, oedema, winter injury, chlorosis. Less common on rhododendrons are stem diseases (Botryosphaeria dothidea, Cadophora spp., Hymenoscyphus spp.), wilt (Fusarium oxysporum), bud blight (Seifertia azaleae), leaf and flower gall (Exobasidium rhododendri), rhododendron lacebug (Stephanitis rhododendri), greenhouse whitefly (Trialeurodes vaporariorum). There were identified that all evergreen and half evergreen rhododendrons have some resistance to powdery mildew, deciduous rhododendrons are more resistant to fungal leaf spots than evergreens. Damage to rhododendrons by insect pests usually does not cause significant harm but heavy feeding results in an unsightly plants.

Phyllopertha horticola (bracken clock)

This datasheet on Phyllopertha horticola covers Identity, Distribution, Hosts/Species Affected, Natural Enemies.

Phyllopertha horticola (Coleoptera: Scarabaeidae) larvae in eastern Austrian mountainous grasslands and the associated damage risk related to soil, topography and management

The soil-dwelling larvae of several Scarabaeidae species (white grubs), like the cockchafer (Melolontha melolontha) and the garden chafer (Phyllopertha horticola), are serious pests in European cultivated grassland, reducing grass yield and destroying the turf by root-feeding. Nevertheless, the factors responsible for the development of large grub populations and the associated damage risk are poorly understood. The objectives of the study were to survey grub densities in grassland sites with different damage histories and find correlations with environmental and management variables. Data on grub densities were collected at 10 farms in the eastern Austrian Alps in September and October 2011. At each farm, one recently damaged site (high risk) and one site at which grub damage had never been observed by the farmers (undamaged site = low risk; each site: 500 m2) were sampled. All sites were dominated by P. horticola (99% of 1,422 collected individuals; maximum density 303 grubs/m2), which indicates that grub damage there is mainly caused by that species. Recently damaged sites tended to higher grub densities than undamaged sites. However, 3 out of 10 undamaged sites harbored high grub populations as well. Humus content together with the depth of the A-horizon significantly explained 38% of P. horticola grub density variance, with highest densities in deeper humus-rich soils. The risk of grub damage was positively connected to the humus content and negatively related to the cutting frequency. For the investigated mountainous grassland sites, these results suggest an important role of humus for the development of high grub densities and an effect of management intensity on grub damage.

Нові дані щодо запилення Iris sibirica L. (Iridaceae)

The flowering period in the population of Iris sibirica in Drogobych district of Lviv region lasts for about 4 weeks, flowering of a five-flowered generative shoot – 10–12 days, flowering of a flower – about 32 hours. The main pollinators of Iris sibirica are Hymenoptera Apis mellifera Linnaeus and Bombus terrestris Linnaeus, and also Coleoptra Variimorda villosa Schrank, Phyllopertha horticola Linnaeus, Lasius niger Linnaeus, Aromia moschata Linnaeus. Protandry has no significant role in the pollination system of Iris sibirica because anther opening proceeds in the closed meranthiun where deposition of pollen on the insect is not possible. Each of three flower meranthium is only once visited by insect. In the studied isolated locality, the mostly geitonogenous pollination inside the individual or clone, as also xenogenous pollination inside the locality, are realized. The male and female reproductive success is higher in the first flower comparing to the fifth flower of the generative shoot, as also P/O index (515 to 338) is. According to the value of P/O index, Iris sibirica is recognized as facultative xenogamous species. Keywords : Siberian Iris, flowering, anthecology, reproductive success, floral sex allocation.

The effect of different entomopathogens on white grubs (Coleoptera: Scarabaeidae) in an organic hay-producing grassland

In 2011, a field block trial examined the biological control of white grubs of June beetle (Amphimallon solstitialis), margined vine chafer (Anomala dubia) and garden chafer (Phyllopertha horticola) on a permanent cut grassland in Gotenica (SE Slovenia). The efficacy of Beauveria brongniartii, Beauveria bassiana, Bacillus thuringiensis var. kurstaki and Heterorhabditis bacteriophora in the form of water suspension and infested grain was tested against a control treatment. The initial number of white grubs (April 12; 39 white grubs/m2) was reduced with all tested entomopathogens up until the third evaluation (May 26; 32 white grubs/m2). However, the studied treatments were not sufficient to reduce the white grub population in the soils below the economical threshold (20 individuals/m2). The average number of white grubs was affected mostly by the treatment where the active ingredient was B. thuringiensis var. kurstaki. With one application in April, only the abundance of overwintered white grubs was reduced. To decrease the summer generation of white grubs, an application of biological agents is also required at a later time. The 8% higher dry matter yield at the first cut (June 10) compared to the second cut (September 6) provided evidence for the prior statement.

Revealing species‐specific trophic links in soil food webs: molecular identification of scarab predators

Soil food webs are particularly important in terrestrial systems, but studying them is difficult. Here we report on the first study to apply a molecular approach to identify species-specific trophic interactions in below-ground food webs. To identify the invertebrate predator guild of the garden chafer Phyllopertha horticola (Coleoptera, Scarabaeidae) whose root-feeding larvae can be highly abundant in grasslands, a specific DNA marker was developed. It allowed detection of P. horticola egg and white grub meals within the gut content of Poecilus versicolor (Coleoptera, Carabidae) larvae for up to 24 h post-feeding. Soil samples from an alpine grassland revealed a diverse below-ground macro-invertebrate community with earthworms, P. horticola larvae, and centipedes as well as beetle larvae as the most abundant detritivores, herbivores, and predators, respectively. Garden chafer DNA was detected in 18.6%, 4.1%, and 4.4% of field-collected Geophilidae (n = 124), beetle larvae (n = 159), and Lithobiidae (n = 49), respectively. We conclude that most of the investigated predators actively preyed on P. horticola, as secondary predation is unlikely to be detected in below-ground systems. Moreover, scavenging most likely contributes only to a small percentage of the revealed trophic links due to the low availability of carrion. Sampling date did not influence prey detection rates, indicating that both P. horticola eggs and larvae were preyed on. Only 2.7% of the below-ground predators tested positive for earthworms, an alternative, highly abundant prey, suggesting that P. horticola represents an important prey source for centipedes and predatory beetle larvae during summer within the soil food web.

Response of garden chafer, Phyllopertha horticola, to plant volatiles: from screening to application

AbstractField tests were performed on a golf course and in an apple orchard to screen synthetic plant volatiles with respect to their attractiveness for the garden chafer, Phyllopertha horticola L. (Coleoptera: Scarabaeidae), and to investigate the possible application of plant volatiles for garden chafer control. The chemicals tested were green leaf volatiles (GLV), terpenoids, and phenylpropanoids. Funnel traps baited with the GLV (Z)‐3‐hexen‐1‐ol, 1‐hexanol (Z)‐3‐hexenal, and hexanal captured more P. horticola than unbaited controls. Furthermore, traps baited with all tested floral terpenoids (i.e., geraniol, geranyl acetate, citronellol, linalool, and nerol) and phenylpropanoids (i.e., eugenol, anethol, isoeugenol, eugenyl acetate, and isoeugenyl acetate) captured more garden chafers than controls. Different dispenser types loaded once with a mixture of (Z)‐3‐hexen‐1‐ol (50%), geraniol (11.5%), eugenol (27%), and 2‐phenylethyl propionate (11.5%) attracted P. horticola over a whole flight season. A commercially available membrane dispenser had the best properties, combining the highest number of captured beetles with a low release rate. A simple modification of the trap design, i.e., a reduction of the funnel outlet diameter, significantly reduced the capture of beneficial non‐target insects (Apoidea), without influencing the number of captured garden chafers. A mass trapping experiment in the apple orchard revealed that the use of attractant traps significantly reduced the percentage of apples disfigured by feeding holes of adult garden chafers (control area: 18.9%, test area: 11.6%). The possible application of synthetic plant volatiles in mass trapping and monitoring approaches for garden chafer control is discussed.

Larval morphology and biology of some European Anomalini (Coleoptera: Scarabaeoidea: Rutelidae: Anomalinae). A phylogenetical approach

AbstractThe third instar larvae of five anomaline species, Anomala dubia (Scopoli, 1763), Anomala quadripunctata (Olivier, 1789), Blitopertha lineata (Fabricius, 1798), Mimela rugatipennis (Graells, 1849) and Phyllopertha horticola (Linnaeus, 1758) are described as well as their biological data. The analysis of the morphology of the four distinct genera studied revealed diagnostic differences in leg morphology, last abdominal segment, and spiracles. An approach to the phylogeny of the group based on larval characteristics is provided. Finally, the systematic position of Blitopertha Reitter, 1903 is discussed.

Male-biassed response of garden chafer, Phyllopertha horticola L., to leaf alcohol and attraction of both sexes to floral plant volatiles

Field tests were performed to evaluate the response of the garden chafer, Phyllopertha horticola (Coleoptera: Scarabaeidae) to known scarab attractants and to investigate the influence of trap colour and height on the number of captured beetles. Both sexes were attracted by a lure mixture composed of geraniol, eugenol, and 2-phenylethyl propionate (PEP) (ratio 3:7:3). When testing floral volatiles individually, only geraniol, eugenol and methyl anthranilate but not PEP was attractive. Response of garden chafer to (Z)- 3-hexen-1-ol was strongly male-biassed. Both the response to floral volatiles and (Z)-3-hexen-1-ol was increased by using funnel traps with yellow instead of grey vanes. Traps positioned at 50 and 125 cm above ground captured significantly more garden chafers than those at 200 cm. The strongly male-biassed response to (Z)-3-hexen-1-ol suggests that in P. horticola (subfamily Rutelinae) orientation towards plant volatiles emitted upon mechanical damage of plants is part of the male mate finding strategy as recently demonstrated for cockchafers of the genus Melolontha (subfamily Melolonthinae). Possible application of plant volatiles for control of P. horticola is discussed.

Attraction of garden chafer, Phyllopertha horticola, to floral Japanese beetle lure

Abstract:Field experiments using funnel traps were performed on a golf course to investigate the attractiveness of a floral Japanese beetle lure for adults of the garden chafer, Phyllopertha horticola, a common European turf pest. Traps baited with 10 mg of the floral lure consisting of phenylethyl propionate + eugenol + geraniol (3 : 7 : 3) captured more adult garden chafers of both sexes than non‐baited control traps. In contrast, 1,3‐dimethyl‐2,4‐(1H, 3H)‐quinazolinedione, the sex pheromone of the closely related pale‐brown chafer P. diversa, neither influenced alone nor in combination with the floral lure the behaviour of adult garden chafers. The results suggest that the floral Japanese beetle lure might be used for monitoring or control of P. horticola.

Efficacy of the Entomopathogenic Nematodes Heterorhabditis megidis and Heterorhabditis bacteriophora for the control of grubs (Phyllopertha horticola and Aphodius contaminatus) in Golf Course Turf

Liquid culture-produced entomopathogenic nematodes, Heterorhabditis megidis and Heterorhabditis bacteriophora, were applied at 0.5 and 1.5 million dauer juveniles m-2 against Aphodius contaminatus and Phyllopertha horticola on a golf course. The reduction of A. contaminatus was found to be between 40 and 62%. P. horticola reduction reached 70% with H. megidis and 83% with H. bacteriophora. Turf damage caused by birds preying on the grubs was successfully prevented.

Selection of insect parasitic nematodes for biological control of the garden chafer, Phyllopertha horticola

AbstractLarvae of Phyllopertha horticola L. (Coleoptera: Scarabaeidae) cause increasing problems on sports fields and lawns in NW‐Europe. A biological control programme using insect parasitic nematodes is being developed. This paper contains the results of bioassays with various species and isolates of the nematode genera Heterorhabditis and Steinernema. In bioassays in small pots with moist sand, most of the nematode isolates gave 30–60% mortality against each of the three larval stages. The susceptibility of the grubs for nematode infection generally increased with larval development. H. bacteriophora, H. heliothidis, H. megidis, a Dutch Heterorhabditis isolate NLH‐E87.3 and S. glaseri 326 showed the highest mortality rates, with nearly 100% mortality of third instar grubs. The Dutch Heterorhabditis isolate NLH‐E87.3 and S. glaseri 326 were selected as candidates for further studies on their potential as biological control agents for P. horticola grubs in the field.

Effects of the insecticide thiodan 35 (endosulfan) on xenobiotic metabolizing enzymes from midgut and gut-free tissues of some coleopteran larva

1. Larvae of yellow mealworm ( Tenebrio molitor L.), European rhinoceros beetle ( Oryctes nasicornis L.), garden chafer ( Phyllopertha horticola L.) and summer chafer ( Amphimallon solstitiale) were kept in semi-natural substrates which had been mixed with varying amounts of Thiodan 35 (endosulfan). 2. The microsomal fractions from midgut and/or gut-free soft tissues were assayed for NADPH cytochrome c reductase (NccR) and aldrin epoxidase (AE), and the corresponding postmicrosomal supernatants were assayed for glutathione s-transferase (GST) using 1-ehloro-2,4-dinitro benzene (CDNB) and 1,2-dichloro-4-nitrobenzene (DCNB) as second substrates. 3. In gut-free soft tissues, activities of GST towards CDNB were 30-fold higher in garden chafer and summer chafer, and 5-fold higher in European rhinoceros beetle, compared to the corresponding value in yellow mealworm. 4. In midgut of European rhinoceros beetle, activities of NccR, AE and GST with DCNB as substrate were all 4–5 times higher than in gut-free soft tissues, while the GST activity with CDNB as substrate was similar. 5. Commercial endosulfan was an inducer of microsomal activities in gut-free soft tissues of European rhinoceros beetle and garden chafer, and in microsomes from gut-free soft tissues of yellow mealworm treated with technical endosulfan, elevated levels of a protein of 52 kDa was observed. This protein was suggested to be a cytochrome P450 isoenzyme.