Dead Insects Research Articles

Food storage and morphological divergence between worker and soldier castes in a subterranean myrmicine ant, Carebara perpusilla

ABSTRACT Food reserves and trophallaxis help insect colonies regulate brood development and survive starvation events. Unlike wasps and bees, ants do not store food in external structures within the nest. Therefore, an ant colony’s ability to store food is greatly enhanced by the development of highly dimorphic workers and soldiers that are able to store food within their bodies. Carebara perpusilla (subfamily Myrmicinae, Emery, 1895) has a subterranean lifestyle and three castes: workers, soldiers with a proportionally larger head and gaster, and large winged queens. Workers are minute (1.5 mm long) and can hunt solitarily on tiny arthropods such as springtails and scavenge in groups on dead insects of various sizes. Rather than carrying big corpses to the nest, they bury it with soil and only retrieve haemolymph and small solid pieces. Moreover, some soldiers and virgin queens have a distended gaster and function as repletes. Food dyes revealed the storage of fat in the crop. Using dissections supplemented by micro-CT visualisation, we compared the crop of workers, soldiers and virgin queens and its capacity for considerable expansion. We discuss the morphological specialisation of repletes in ants that do not collect honeydew. Natural history data of more subterranean ants are needed to understand the adaptive context of foraging and other behaviours.

Knockdown-Mortality Responses of Six Stored-Product Beetle Species on Different Surfaces Treated With Thiamethoxam, Using a Standardized Lethality Index

Bioassays were conducted to evaluate the effectiveness of thiamethoxam in different surfaces, against six stored-grain insects, Sitophilus granarius (L.) (Coleoptera: Curculionidae), Sitophilus oryzae (L.) (Coleoptera: Curculionidae), Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae), Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae), Cryptolestes ferrugineus (Stephens) (Coleoptera: Laemophloeidae), and Oryzaephilus surinamensis (L.) (Coleoptera: Silvanidae). Six different surfaces (concrete, plywood, galvanized steel, linen, plastic, and ceramic tile) treated with thiamethoxam at 0.05 and 0.1 mg/cm2 were used as substrate for adult exposure. Knockdown was recorded after 1, 3, and 7 d of exposure to the treated surface, in order to calculate a Standardized Lethality Index (SLI). Knockdown counts were ranked from '0' to '4', with '0' representing adult insects 'moved generally' and '4' representing dead insects. Based on the results, insect knockdown seems leading to mortality than to recovery and the SLI ranking of the target species according to their susceptibility to thiamethoxam showed that S. granarius being more susceptible and decreasing susceptibility in an order of S. oryzae > T. castaneum ≥ O. surinamenis ≥ C. ferrugineus ≥ T. confusum. In general, among the surfaces, thiamethoxam efficacy was lower on linen, wooden, and concrete surfaces, as compared to metallic and plastic surfaces. Nevertheless, at the end of 7-d exposure, all surfaces equally affected thiamethoxam toxicity.

Mortality and progeny production of four stored-product insect species on three grain commodities treated with Beauveria bassiana and diatomaceous earths

Laboratory bioassays were conducted to estimate the effectiveness of the entomopathogenic fungus Beauveria bassiana (Bals.-Criv.) Vuill. (Hypocreales: Cordycipitaceae) at 1.5 × 108 and 1.5 × 1010 conidia/kg grain alone or mixed with the diatomaceous earths (DEs) Protect-It at 150 ppm and DEBBM at 50 ppm against adults of the rusty grain beetle, Cryptolestes ferrugineus Stephens (Coleoptera: Laemophloeidae), the lesser grain borer, Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae), the red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) and the psocid, Liposcelis paeta Pearman (Psocoptera: Liposcelididae). The adult insects were exposed to treated grains for 7, 14 and 21 days. For progeny emergence data, the treated units were remained under the same conditions for 62 days for all beetles and 30 days for psocids. The results revealed significant differences in mortalities of insect species among treatments and grains. The combined use of B. bassiana, at the highest dose, and DE increased adult mortalities of all species. In general, the treatments were least effective against T. castaneum and most effective against L. paeta. More numbers of dead insects were found on wheat than on rice or maize. The emergence of progeny was considerably reduced on grains treated with B. bassiana, at the highest dose, plus DE. The results of the present study suggest that the effectiveness of B. bassiana is fortified by the addition of DEs, but it varies among exposed insect species and commodities.

Tanatologiens poetikk

Essayet har vært en måte å tolke mitt skapende arbeid på. Jeg tar utgangspunkt i egen kunstnerisk praksis, dvs. kunstnerisk utviklingsarbeid, og en fotografiserie med tittelen The Poetics of Thanatology. Teksten reflekterer over, og undersøker temaer som potensielt berøres gjennom fotografienes visuelle språk og den skapende prosessen. Jeg utforsker hvilke forbindelser som finnes mellom en hendelse i barndommen min, døden og fotografiet. Den antroposentriske tilnærmingen til virkeligheten sitter dypt i vår kultur og har skapt hierarkiske relasjoner - Vi og De andre. Gjennom stilleben-fotografi av døde planter og insekter undersøker jeg menneskets opplevelse av empati i forhold til ikke-menneskelige organismer. Jeg ser på mitt praktiske arbeid i fotostudio som et rom for kritisk refleksjon og som uerstattelige, meningsfulle og langsomme, sansende erfaringer. Disse erfaringene har utfordret min og mine kunststudenters antroposentriske tilnærming til verden.

Influence of Insecticides on Useful Entomofauna in Corn Crops

Goal. of research is to specify species composition of coccinellids of corn agrocenosis, to define insecticides influence on useful entomofauna, to estimate the profitability level of used preparation.
 Methods. Are the following: field accounting of insects in corn crops in accordance with the generally accepted methodology; experiment on the influence of insecticides on useful entomofauna in corn. Laboratory method that means identification of species composition of ladybirds.
 Results. Specified species composition of coccinellids in present conditions on corn crops. Educed six species of ladybirds, among them Coccinella septempunctata Linnaeus, 1758 was marked as dominant species, while Propylea quatuordecimpunctata Linnaeus, 1758 as subdominant species. Presented mean quantity of coccinellids, green lacewings, syrphids on the 3rd, 7th, 14th and 21st days after spraying of insecticides on corn. Specified correlation of coccinellids species before and after insecticide application. Presented correlation of entomophages (ladybirds, green lacewings, syrphids) on corn crops. Determined technical and economic efficiency after spraying of corn with insecticides Ampligo 150 ZC (Chlorantraniliprole, 100g/l+Lambda-Cyhalothrin, 50g/l), Belt 480 SC (Flubendiamide, 480 g/l), Coragen 20 SC (Chlorantraniliprole, 200 g/l).
 Conclusions. After insecticides application the highest mean quantity of coccinellids was observed in case of Coragen 20 SC — 2,4 exemplars/m2, after Ampligo 150 ZC it was 0,4 exemplars/m2, after Belt 480 SC — 0,7 exemplars/m2. The mean quantity of green lacewings and syrphids was low for all variants. The least toxic effect on quantity of entomophages had an insecticide Coragen 20 SC. The percentage of dead insects after its usage was the following: for imago of coccinellids — 43.4%, larvae — 79.5%, pupas — 54.2%; green lacewings — 68.2%, syrphids — 75.0%. Spraying of preparation Coragen 20 SC provided the level of profitability 440.16%, whereas profitability after Ampligo 150 ZC was 289.33%, after Belt 480 SC — 126.81%.

Extent and pattern of damage in wheat caused by three different species of storage insect pests

We investigated the extent and pattern of damage in wheat caused by Tribolium castaneum Herbst (Coleoptera: Tenebrionidae), Trogoderma granarium Everts (Coleoptera: Dermestidae) and Rhyzopertha dominica F. (Coleoptera: Bostrichidae) over a period of 75 d. Damage parameters included numbers of damaged grains, their weight; numbers of undamaged grains, their weight; frass weight and percent weight loss. Results showed after 75 d, maximum damaged grains were 125.17 ± 22.88 by R. dominica followed 80.50 ± 6.91 by T. granarium and least were 20.00 ± 2.61 after 50 d by T. castaneum. For R. dominica and T. granarium damage to grains increased with time (P 0.05). Maximum percent weight loss was 7.02 ± 1.87 g by R. dominica followed by 2.89 ± 0.33 g by T. granarium and least 0.65 ± 0.08 g by T. castaneum. Maximum dead insects percentage was 82% after 25 d for R. dominica, 59.67 ± 3.44 for T. granarium after 50 d and 100.00 ± 0.00 for T. castenum after 50 or 75 d compared to other time periods (P < 0.05). Percent increase in population was recorded for T. granarium but not for other two species during 75 d period. Microphotography of damaged grains after 75 d to compare damage pattern showed R. dominica made circular holes (Fig. 1), T. granarium made irregular holes (Fig. 2) and T. castaneum made circular damage but it did not traverse grains (Fig. 3). Radius length of circular damage was more for T. castenum compared with for R. dominica (P < 0.05). Damage area was maximum by T. granarium followed by T. castenum and least by R. dominica while perimeter of damage was greatest by T. granarium followed by T. castenum and least by R. dominica (P < 0.05).

Can electrostatic fields limit the take-off of tiny whiteflies (Bemisia tabaci)?

Electrostatic fields are abundant in the natural environment. We tested the idea that electrostatic attraction forces between tiny whiteflies (Bemisia tabaci) and the substrate could be substantial to the point of limiting their take-off. These insects are characterized by a very small body mass and powerful take-offs that are executed by jumping into the air with the wings closed. Wing opening and transition to active flight occur after the jump distanced the insect several body lengths away from the substrate. Using high-speed cameras, we captured the take-off behavior inside a uniform electrostatic field apparatus and used dead insects to calculate the electric charge that these tiny insects can carry. We show that electrostatic forces stimulate the opening of the insect's wings and can attract the whole insect toward the opposite charge. We also found that whiteflies can carry and hold an electrical charge of up to 3.5 pC. With such a charge the electrostatic field required to impede take-off is much stronger than those typically found in the natural environment. Nevertheless, our results demonstrate that artificial electrostatic fields can be effectively used to suppress flight of whiteflies, thus providing options for pest control applications in greenhouses.

Eksplorasi, isolasi dan identifikasi Jamur entomopatogen yang menginfeksi serangga hama

ABSTRACT&#x0D; Entomopathogenic fungi are classified as a fungus that infects insect pests. Hyphae color that comes out of the insect's body depends on the type of entomopathogenic fungus that attacks it. The purpose of this research is to explore, isolate and identify entomopathogenic fungi that attack insect pests. Samples of dead insects were taken from vegetable crops in the highlands of Pagaralam City and the lowlands of Ogan Komering Ilir Regency. In addition, exploration is also carried out using insect bait methods. This method is carried out on soils taken from the highlands of the fencealam area and Pekanbaru area. Based on the results of entomopathogenic expolation in vegetable plants that infect insects in the field there are 2 types of fungi that attack the insect. Two types of entomapatogenic fungi were found to have characteristics, namely the first hyphal color is rather green which covers the entire body of the insect and the second is white hyphae. The fungus that attacks the insect, then isolated to the GYA media found two entomopathogenic fungi namely, Metarhizium sp. and Beauveria bassiana. Meanwhile, through insect bait using soil T. molitor larvae, one species of entomopathogenic fungus was found, namely Metarhizium sp. The most infected T. molitor larvae in the soil of origin of Pekanbaru in the 2nd and 4th weeks, namely, 21.90 and 29.33 tails.&#x0D; &#x0D; .&#x0D; Keywords: Entomopathogenic Fungus, Insect Pest and Tenibrio molitor&#x0D;

Plant derived powders as alternatives for Sitophilus oryzae L. (Coleoptera: Curculionidae) control in stored maize grains

Maize is the major staple food in Africa. In developing countries, post-harvest losses due to insect pests are up to 40% of total production. Inert powders can be alternative tools in integrated pest management programs of stored cereals. The aim of this study was to assess the efficacy of ashes from cashew (Anacardium occidentale) branches, charcoal powder, dried and milled Eucalyptus citriodora leaves, and diatomaceous earth (standard check), for Sitophilus oryzae control on stored maize grains. The experimental design was completely randomized with 11 treatments and 4 replications. Insect introduction was carried out immediately after treatment application and at 30 and 60 days after. The mortality assessment was performed by counting the dead insects at 10 and 20 days after each infestation. The emergence of S. oryzae adults was also assessed at three different times. The germination of treated grains was also evaluated. Data analysis was performed on the SISVAR statistical package. Diatomaceous earth showed maximum control efficiency (73.75%) at 10-day evaluation, reaching total control at a 20-day evaluation. The remaining treatment control efficiency was below 50% in all concentrations and evaluations. The lowest insect emergence rates were observed in grains treated with diatomaceous earth or charcoal powder, which were more efficient than cashew ashes, Eucalyptus citriodora, and untreated control. There was no significant effect of the tested products on seed germination so, they can be used in smallholder farmers' grain storage. The results allow us to affirm that Eucalyptus citriodora charcoal powder, and cashew ashes can be used to reduce Sitophilus oryzae damage in traditional agricultural systems. Considering the reduction in the Sitophilus oryzae progeny, the potential use of charcoal powder should be considered, given the efficiency compared to that of the diatomaceous earth. Thus, the plant-derived products tested in this study has the potential to be used in the integrated management of Sitophilus oryzae in stored products. Key words: Ash, Charcoal, Diatomaceous earth, inert, dust, maize, storage, pest

Prophylactic Avoidance of Hazardous Prey by the Ant Host Myrmica rubra.

Ants are the hosts of many microorganisms, including pathogens that are incidentally brought inside the nest by foragers. This is particularly true for scavenging species, which collect hazardous food such as dead insects. Foragers limit sanitary risks by not retrieving highly infectious prey releasing entomopathogenic fungal spores. This study investigates whether similar prophylactic strategies are also developed for food associated with weak or delayed risks of fungal contamination. We compared, in Myrmica rubra ant colonies, the retrieval dynamics of dead flies that were (1) conidia-free, (2) covered with a low amount of Metarhizium brunneum entomopathogenic conidia or (3) recently fungus-killed but not yet sporulating. Foragers mostly avoided fungus-killed prey and delayed the retrieval of conidia-covered flies. A second sanitary filter occurred inside the nest through a careful inspection of the retrieved prey. Ultimately, ants mostly consumed conidia-free and conidia-covered flies, but they relocated and discarded all fungus-killed prey outside of the nest. Our study confirms that, as a host of generalist entomopathogenic fungi, Myrmica rubra ants have developed a prophylactic avoidance and a differential management of prey depending on their infectious potential. We discuss the functional value as well as the possible cues underlying pathogen avoidance and prey discrimination in ants.

Characterization of fungal flora associated with sternorrhyncha insects of cotton plants

In this study, 22 different fungal isolates associated with naturally dead insects of order Hemiptera including Bemisia tabaci, Aphis gossypii and Phenacoccus solenopsis were isolated from three different agroecological zones namely hot arid, cotton and central mixed zone. Fungal species were characterized morphologically on the basis of colony color, shape and spore structures through using different dichotomous keys. As a result fungi belonging to different species of Aspergillus, Acremonium, Beauveria, Cladosporium, Alternaria, Clonostachys, Penicillium, Trichoderma, Fusarium, Metarhizium and Verticillium were identified. All isolates of individual species were identical with respect to morphological differentiation. Principal component analysis (PCA) indicates strong correlation between Verticillium lecanii and Aspergillus fumigatus with respect to their isolation source (insect host). However, based on PCA, an uneven distribution of entomopathogenic fungi in different insect hosts is evident. Phylogenetic analysis revealed that Aspergillus fumigatus and A. nidulans are more closely related to different species of Penicillium, while Aspergillus oryzae and A. flavus formed separate clades, whereas different species of Alternaria, Cladosporium and Fusarium formed separate clades. Thus, the information generated will add to our understanding of the insect associated fungal communities for future development of potential biocontrol agents and their application as a vital component of sustainable agriculture.

Effect of Volatile Compounds of the Entomopathogenic Fungi Beauveria bassiana (Bals.-Criv.) Vuill. and Lecanicillium muscarium R. Zare et W. Gams on the Behavior of Sitophilus granarius (L.) (Coleoptera, Dryophthoridae) and Evaluation of the Virulence of Different Strains of These Fungi

Adult granary weevils feeding on grain responded selectively to the volatile compounds of different strains of the entomopathogenic fungi Beauveria bassiana and Lecanicillium muscarium. The mycelium of B. bassiana strains had a repellent effect or a neutral effect with a tendency toward repellency. The response to L. muscarium strains varied from weak repellent (G-033) and neutral (Vl 49) to attractive one (Vl 21). Beauveria bassiana strain Bb 17 showed the highest virulence after beetles were sprayed with conidial suspension containing 1.0 × 108 spores / ml: the mortality of the beetles on the 7th day reached 74% with extensive mycelial growth over the dead beetles, LT50 was 5.6 days for this strain and 23 days for strain Bb 13. The L. muscarium strains showed low virulence, with the exception of strain G-033 (LT50 15.3 days), and they also formed mycelium on the dead insects. The granary weevil response should be considered when assessing the potential of entomopathogenic fungi. Beauveria bassiana strain Bb 17 was selected as a promising pest control agent, since neutral reaction of the granary weevil to its mycelium facilitates the spreading of fungal infection.

Hermetic sealed storage IRRI super bag: Reduces post-harvest losses in seed grains

Post-harvest losses occur due to poor storage system, which deteriorates seed quality. All traditional storage systems like jute bags, PVC/woven bags, clay pots, drums etc. are not really hermetic and can’t store seed or grain safely for longer time. It would be difficult to measure the loss due to physiological changes in seed at the farm level. An attempt was, therefore, made to control the insect-damage, maintain germination and proper moisture level in IRRI Super bags at farmer’s level. Visualising this, the on-farm study at BAU, KVK Sabour, Bhagalpur and ICAR, KVK Buxar was conducted during 2015-16. Lentil seeds used for research in KVKs were initially dried to moisture content ranging from 12.1 to 13.9% and cooled in shade before storage. There was merely 0-1% increase in moisture-content after storage in Super bags, whereas it increased by 1.6-2.0% in jute bags which attracted more insect-pest infestation and reduced germination. There was no or negligible count of dead or alive insect-pests infesting Super-bag stored seed, while noticeable count of dead and live insects was recorded into grains. Seed germination ability remained unaffected in Super bags, but it drastically deteriorated (8.5-10.9%) in jute-bag stored seed at different locations. Discolouration of seed stored in Super bag was also lesser as compared to that stored in jute bag. It implies that IRRI Super bags are suitable for lentil seed storage in room condition. Though the cost of Super bag is a bit higher than jute bag, but its benefits well-nigh compensate the cost.

Screening of fungal strains isolated from dead insects for production of plant litter-degrading enzymes

Exploring the enzymatic capabilities of fungi is of great importance to better understand their ecological roles and improving their manifold usage in industry. Therefore, rapid and reliable screening methods to evaluate fungal enzymatic potentials are needed. In this study, 76 fungal strains were isolated and identified from insect pests from citrus plantations in Guilan province, northern Iran. All the strains belonged to Akanthomyces and Lecanicillium (Ascomycota: Hypocreales). Plate assay methods were applied to investigate fungal ability to produce the following enzymes: Endo-1,4-β-glucanase (CM-cellulase, endoglucanase and endocellulase), β-Glucosidase, Cellobiodydrolase, pectinase and laccase. The results showed that the majority of the strains were able to produce at least one of these enzymes. The cellulolytic activity was found in 33 % and laccase activity was detected in 11 % of all strains tested. Interestingly, the enzymatic ability of strains identified as A. muscarius and A. lecanii, were generally different, likely confirming their taxonomic position.

Review: Forensic Architecture: Violence at the Threshold of Detectability, by Eyal Weizman

Review: <i>Forensic Architecture: Violence at the Threshold of Detectability</i>, by Eyal Weizman

Insecticidal Efficacy of Essential Oils from Cinnamomum zeylanicum, Thymus vulgaris, Ferula assafoetida L on Callosobruchus maculatus F

Introduction: The plants have well-developed defense mechanisms against pests and are excellent sources of new insecticidal substances.&#x0D; Materials and methods: An experiment was conducted on Hamedan Agricultural Research Center, as factorial based on completely randomized blocks in 3 replications during 2009. Experimental treatments included 10 levels concentration with Cinnamomum zeylanicum (0, 5, 10, 15, 20, 25, 75, 100, 200, 300) µl, 7 levels concentration with Thymus vulgaris (0, 0.25, 0.50, 0.75, 10, 20, 30) µl, 6 levels concentration with Ferula assafoetida L (0, 30, 60, 90, 120, 150) µl as the time at 3 levels (8, 24, 48) hours as the second factor. 1 ml of solutiones were applied on filter papers with Whatman No. 1. Then each dried paper was placed and 10 C. maculatus adults was placed. Each set of treatment was repeated 3 times and number of dead insects in was counted at an interval of 8, 24, 48 hours respectively.&#x0D; Conclusion: Percentage mortality was calculated. It has been results that the C. zeylanicum, T. vulgaris, F. assafoetida L essential oils showed 13%, 56%, 10% mortality adult of C. maculatus at dose of 5 µl of C. zeylanicum, 0.25 µl of T. vulgaris, 30 µl of F. assafoetida L respectively. Further concentration increase to 300 µl of C. zeylanicum oil, 30 µl of T. vulgaris, 150 µl F. assafoetida L yielded mortality of 100% against adult C. maculatus respectively.

Molecular characterization and functional analysis of the Halloween genes and CYP18A1 in Bemisia tabaci MED

The ecdysteroid hormone 20-hydroxyecdysone (20E), a critical hormone in arthropods, plays an essential role in insect growth, molting and reproduction. A previous study showed that 20E is actually regulated by six P450 genes (five P450 genes belonging to the Halloween family and a CYP18A1 gene) in model insects. However, the role of the six P450 genes in Bemisia tabaci Q (also call Mediterranean, MED), an important pest of field crops, remains unclear. Here, six P450 genes were cloned by RT-PCR, and the phylogenetic tree indicated a close orthologous relationship of these P450 genes between MED and other insects. Spatiotemporal expression profiling revealed that five P450 genes (CYP18A1, CYP306A1, CYP307A2, CYP314A1 and CYP315A1) were expressed at significantly higher levels in the head than in the abdomen and thorax. Four P450 genes (CYP302A1, CYP307A2, CYP314A1 and CYP315A1) were expressed at the highest levels in males, and CYP18A1 was expressed at the highest levels in the 4th nymph stage. The molting process was delayed by approximately 1–3 days after knockdown of these genes at the 4th nymph stage, and the mean proportion of shriveled or dead insects reached 8.3% (CYP18A1), 20.8% (CYP302A1), 7.0% (CYP307A2), 31.8% (CYP306A1), 28.6% (CYP314A1) and 24.1% (CYP315A1). In addition, 20E rescued the negative effect of ds-CYP306A1, ds-CYP314A1 and ds-CYP315A1 on the eclosion rate. We concluded that these Halloween genes and CYP18A1 likely participate in the development of MED, and in particular, CYP306A1 could be used as a putative insecticide target for controlling this piercing-sucking insect.

Defect identification method for poplar veneer based on progressive growing generated adversarial network and MASK R-CNN model

As the main production unit of plywood, the surface defects of veneer seriously affect the quality and grade of plywood. Therefore, a new method for identifying wood defects based on progressive growing generative adversarial network (PGGAN) and the MASK R-CNN model is presented. Poplar veneer was mainly studied in this paper, and its dead knots, live knots, and insect holes were identified and classified. The PGGAN model was used to expand the dataset of wood defect images. A key ideal employed the transfer learning in the base of MASK R-CNN with a classifier layer. Lastly, the trained model was used to identify and classify the veneer defects compared with the back- propagation (BP) neural network, self-organizing map (SOM) neural network, and convolutional neural network (CNN). Experimental results showed that under the same conditions, the algorithm proposed in this paper based on PGGAN and MASK R-CNN and the model obtained through the transfer learning strategy accurately identified the defects of live knots, dead knots, and insect holes. The accuracy of identification was 99.05%, 97.05%, and 99.10%, respectively.

Entomopathogenic effect of Trichothecium roseum (Pers.) Link (Hypocreales: Ascomycota) against Pauropsylla buxtoni (Psylloidea: Hemiptera) infesting Ficus carica leaves and its potential use as biocontrol agent of the insect.

To isolate and characterize a native strain of Trichothecium roseum infecting the immatures of Pauropsylla buxtoni on fig leaves, to study the morphological features of the isolated strain, then to test the entomopathogenic effect of the isolated strain against the immatures of P. buxtoni on fig leaves. The isolated strain of T. roseum produced pink mycelial growth on culture medium with septate mycelium and conidiophores. It also produced two-celled conidia with elliptical to pyriform shape born at the tip of conidiophores. Molecular characterization of the isolated strain confirmed the identity of the strain as T. roseum. In bioassays, application of conidial suspension of the isolated strain against the 4th instar of P. buxtoni immatures infesting fig leaves showed an obvious entomopathogenic effect of the applied fungus strain against the targeted insect. This effect was exhibited by the death of treated P. buxtoni immatures with the fungus. The dead insects were characterized by the presence of pinkish mycelial growth on the outer surface which is characteristic to the fungus, in addition to the positive isolation of the fungus from internal tissues of treated insects after a proper external disinfection. Moreover, significant differences (at P<0·018) were obtained between the means of mortality % of P. buxtoni immatures treated with different concentrations of conidial suspension of the fungus. The overall results confirm the entomopathogenic effect of T. roseum against P. buxtoni immatures infesting fig leaves. Significant mortalities of P. buxtoni immatures were obtained when the different concentrations of the fungus conidial suspension were bio-assessed against the insect. The tested strain of T. roseum can be applied as biocontrol agent of P. buxtoni on fig leaves within an integrated control programme to reduce the impact of pest on fig trees.

A protocol for fast identification of larval tephritid flies with a community-wide COI reference bank

Identifying dead insect larvae by morphology is mostly challenging but often required in ecological studies, which entails a molecular method. In this study, we developed a protocol of Cytochrome Oxidase c Subunit I (COI) DNA barcoding that could quickly identify larval tephritid flies in a Tibetan alpine meadow. The protocol includes two major operations. The first is to build up a comprehensive reference library after identifying adults of tephritid flies to species by morphology and by COI DNA barcoding sequences. The second is to calculate species-specific delimitation criteria using the sequences in the library, such that COI DNA sequences of insect larvae could be assigned to species using local blast. This protocol was proved successful in the species identification of larval flies among 27 tephritid species belonging to nine genera of subfamily Tephritinae. We suggest that such a protocol can be widely applied to fast identification of insect larvae.