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This study investigates the establishment and colonization dynamics of Beauveria bassiana as an endophyte in maize plants using various inoculation methods. Surface sterilization and fungal isolation confirmed B. bassiana as an endophyte, with isolates ChBb and NaBb exhibiting distinct colonization patterns. Notably, foliar spray demonstrated the highest initial colonization efficiency, with ChBb achieving 93.3% in leaves at 7 days post-inoculation (DPI), decreasing to 13.3% at 35 DPI. NaBb similarly exhibited high initial colonization via foliar spray, with 93.3% in leaves at 7 DPI, declining to 33.3% at 35 DPI. Molecular analysis using nested PCR confirmed the presence of B. bassiana DNA exclusively in treated tissues, with a consistent 300 bp PCR product observed in leaf, stem, and root samples. Phylogenetic analysis highlighted genetic relationships among B. bassiana isolates, underscoring their diversity and potential for biocontrol applications. Pathogenicity tests against Spodoptera frugiperda demonstrated significant mortality rates: ChBb achieved 77.20% mortality in direct contact assays (where larvae were exposed directly to the fungal spores) and 56.82% mortality in vivo (where larvae were fed plants colonized by the fungus), while NaBb resulted in 75.86% and 51.42% mortality, respectively. These findings emphasize the efficacy of B. bassiana as a biocontrol agent, particularly through foliar application for initial colonization in maize plants. [ABSTRACT FROM AUTHOR]

This study provides a molecular and phenotypic characterization of an entomopathogenic nematode-bacterium complex isolated from agricultural soil and nematode efficacy against Helicoverpa armigera. The nematode, identified as Steinernema anantnagense KP_CU, was characterized using the internal transcribed spacer (ITS) region of rRNA, revealing 100% similarity with the type population of S. anantnagense. Phylogenetic analysis confirmed its conspecific status within a clade including S. kushidai, S. akhursti, and S. populi. Concurrently, the associated bacterium, identified as Xenorhabdus sp. KP_CU, exhibited 100% similarity in its 16S rRNA sequence with Xenorhabdus anantnagensis XENO-2T, suggesting conspecificity. Phenotypic characterization aligned the bacterium closely with X. anantnagensis, highlighting typical traits such as rod-shaped, gram-negative cells and absence of bioluminescence. Biochemical tests further supported this identification, distinguishing KP_CU from other Xenorhabdus species based on citrate utilization, gelatinase, lysine decarboxylase, urease, arginine dihydrolase, ornithine decarboxylase, glucose oxidation, cytochrome oxidase and indole production. Phylogenetic analysis based on 16S rRNA sequences placed Xenorhabdus sp. KP_CU within a monophyletic clade with X. anantnagensis, along with sister relationships to X. japonica and X. vietnamensis. The bacterial strains also exhibited larvicidal activity against Galleria mellonella and even at the lowest optical density (OD590 = 0.125) induced over 80% larval mortality within merely 24 h post-injection, emphasizing its elevated virulence. The strain KP_CU could kill the wax moth larvae with 38, 16 and 9 IJs at 24, 36 and 48 h, respectively. The nematode isolate KP_CU demonstrated high virulence against H. armigera larvae, with complete mortality achieved within 60 h across all tested inoculum levels. Mortality began at 36 h post-inoculation at 100 IJs/larva and was reached within 24 h at 200 IJs/larva. LD50 values decreased significantly from 38 IJs at 24 h to just 9 IJs at 48 h, indicating potent lethality. Additionally, progeny production showed a dose-dependent increase, though slightly reduced at higher doses, suggesting a trade-off between virulence and reproductive success. These results suggest that S. anantnagense KP_CU could hold potential as a biocontrol agent for H. armigera in agricultural settings in India.

In order to identify nematodes associated with insects in the forested areas of Guilan province, Iran, soil, wood, and insect samples were collected. Nematodes were extracted using the insect-baiting method, and the obtained specimens were analyzed based on both morphological and morphometric characteristics. This investigation led to the discovery populations belonging to the genera Distolabrellus and Oscheius, identified as D. veechi and O. tipulae, respectively. Molecular identification was carried out through molecular analysis, encompassing the D2-D3 expansion segment of 28S, ITS, and 18S genes of rRNA. The phylogenetic analyses placed these nematodes within their respective clades with high bootstrap support, confirming their identity. This survey marks the first discovery of D. veechi and male O. tipulae in Iran, introducing them as new records for the country.

The Mediterranean fruit fly, Ceratitis capitata, is a severe pest of orchards around the world and has recently invaded orchards in northern Iran. The soil-dwelling larvae of this pest are amenable to control by entomopathogenic nematodes (EPNs) but have been studied only in tropical orchards. To assess the biocontrol potential of Iranian strains of two EPN species, Heterorhabditis bacteriophora (boj) and Steinernema carpocapsae (z1), for control of C. capitata, we conducted a series of laboratory and a field experiment. the highly virulent nature of S. carpocapsae towards C. capitata larvae was apparent, demonstrating near 80% efficacy at a concentration of 25 infective juveniles (IJs) per cm2 in loam soil, surpassing the 40% control exerted by H. bacteriophora. When tested at temperatures of 19, 25, and 30 °C, Steinernema carpocapsae caused the highest mortality at 25 °C (85%) and the lowest at 30 °C (58%), whereas control by H. bacteriophora was not affected by temperature (44–50%). Both EPN strains caused higher mortality in loam and clay loam soils than in sandy loam. Heterorhabditis bacteriophora produced significantly more IJ progeny from infected larvae than S. carpocapsae. Both S. carpocapsae and H. bacteriophora caused only moderate mortality of C. capitata pupae with 38 and 27%, respectively, at a rate of 50 IJs/cm2. Under field conditions, both species caused significant mortality when sprayed at a concentration of 25 IJs/cm2 on soil and tangerine fruits infested with C. capitata larvae, with 45 and 69% mortality for H. bacteriophora and S. carpocapsae, respectively. Our findings suggest that S. carpocapsae (z1) could be implemented as a biological agent in a C. capitata management program in temperate climate orchards. [ABSTRACT FROM AUTHOR]

We present the characterization of the entomopathogenic nematode isolate LD_CU, and its associated symbiotic entomopathogenic bacterium. BLASTn analysis of the ITS rRNA sequence of the nematode revealed 100% similarity with Steinernema siamkayai, confirming conspecificity. The pairwise alignment showed no nucleotide differences with the type population of S. siamkayai. Phylogenetic analysis based on ITS rRNA gene sequences supported these findings, placing isolate LD_CU in a monophyletic clade with S. siamkayai, which forms a sister clade with S. huense, S. cumgarense, S. tami, and S. minutum. Biochemical tests identified the associated bacterial symbiont as Xenorhabdus stockiae. The isolate tested negative for oxidase, catalase, nitrate reductase, O-Nitrophenyl-β-D galactopyranoside (ONPG), methyl red, tryptophan deaminase, indole production, ornithine, lysine, citrate, malonate, hydrogen sulfide, acetoin, and phenylalanine deaminase, but positive for urea and esculin hydrolysis, motility, and acid production from glucose fermentation. The bacteria exhibited neutral red adsorption on MacConkey agar and formed brownish pigmented colonies on nutrient agar. Molecular characterization using 16S rRNA gene sequences revealed 100% similarity with X. stockiae and 90% similarity with X. innexi, indicating significant divergence from other Xenorhabdus species. Phylogenetic analysis showed a close relation to X. stockiae VP-2016b and distinct differences from X. innexi DSM 16336T. Pairwise alignment confirmed no nucleotide differences between the present bacterial strain and X. stockiae. This detailed and comprehensive profiling supports the accurate identification of Steinernema siamkayai and its bacterial symbiont, Xenorhabdus stockiae, and contributes valuable information to the taxonomy and phylogeny of these organisms. [ABSTRACT FROM AUTHOR]

Entomopathogenic fungi (EPFs) are a significant group of insect pathogens that are used as microbial insecticides with distinct physiological mechanisms of pathogenicity. During our survey in the middle of March 2020 to early October 2022 on natural EPF as a biological control agent of the longhorn beetle (LHB) Osphranteria coerulescens, new isolates of EPFs were found on LHB larvae in apple orchards of Dargaz, Razavi Khorasan province, Iran. The nBLAST results of this these indigenous isolate indicated the highest similarity to Cladosporium sp. (Ascomycota: Davidiellaceae) with ON307222.1 access number and for EF-1α indicated the highest similarity to Cladosporium sp. with MH724951.1 access number. To assess the virulence of these indigenous isolates of EPF, a series of tests were conducted on the LHB larvae stages. Conidial concentrations 104, 105, 106, 107, and 108 (conidia/ml− 1) caused (10.21 ± 2.1), (23.44 ± 2.4), (28.72 ± 2.6), (33.23 ± 3.1) and (34.02 ± 2.8) % of mortality in LHB, respectively and there was no significant difference between 108 and 107 (conidia/ml−1) concentrations. The mortality results by the time showed that the process did not start until 3 days after treatment, and after that, it sped up. This research gathers new information about cryptic inhabiting larvae which shows considerable potential for this Cladosporium species to be implemented within the microbial control program of the LHB. This research is a new report isolating the pathogenicity of Cladosporium sp. on LHB. These fungal isolates have considerable potential for the microbiological control of the LHB. [ABSTRACT FROM AUTHOR]

The research objects were entomopathogenic organisms (Nematoda, Fungi, Bacteria, and Insecta) collected in agrocoenoses in different regions of Ukraine during 2016–2018 and 2020–2021. The following research materials were used: soil samples, soil live-traps, specimens of Galleria mellonella L., 1758 (Lepidoptera: Pyralidae) and potential host insects (Coleoptera: Elateridae, Tenebrionidae, Melolonthinae; Lepidoptera: Noctuidae). We analysed 312 samples (220 soil + 92 live-trap samples) and >100 specimens of potential host insects. Our data demonstrate that in soils of agrocoenoses, favourable conditions are created for the dispersal of entomopathogenic organisms. We report the frequency of occurrence of insect-pathogenic nematodes in agrocoenoses of Ukraine, and describe their identification and the specifics of pathology they cause to the insect Galleria mellonella in the context of other entomopathogenic organisms. The frequency of occurrence (% of samples) of entomopathogenic nematodes (genus Steinernema Travassos, 1927 and genus Heterorhabditis Poinar, 1976) in agrocoenoses was the highest among other organisms that caused infectious and parasitic diseases of insects and were found in 15% of the samples. Three species of entomopathogenic nematodes—Steinernema carpocapsae (Weiser, 1955) Wouts et al., 1982, Steinernema ex gr. ‘glaseri‘, and Heterorhabditis bacteriophora Poinar, 1976—have been identified. We have found 8% of samples to contain fungal disease-causing agents (genera Beauveria Vuill., 1912, Metarhizium Sorokin, 1879, and Akanthomyces Lebert, 1858). The frequency of occurrence (%) of all remaining causative agents of infectious and parasitic diseases of insects, namely bacterial diseases and myiasis (infection of a fly larva) (Diptera: Tachinidae) were 3% and 2%, respectively. A mixed infection was detected in 2.5% of the total number of analysed samples; nematodoses-mycoses mixed infections were most often recorded. We have recorded the phenomenon of hyperparasitism with nematodosis-entomosis co-infection inside dead G. mellonella larvae for the first time.

Abstract Iridovirus in Culex pipiens was reported for the first time in 2012. Later studies of horizontal transmission were performed, in which an interaction with the parasite Strelkovimermis spiculatus acting as viral vector was recognized. In the present study, we observed aspects of the pathology produced by an invertebrate iridescent virus in laboratory infected immature Cx. pipiens as well as in infected immature Cx. pipiens in the field. In the laboratory infected larvae, the infection and mortality were asynchronous. Signs of infection in larvae exposed to the virus were observed between the second and the fourth days post-exposure in 99% of the cases, while the highest daily record of visible infected larvae (52%) was observed on the third day post exposure. Moreover, 79% of confirmed virus infected larvae died in the first 10 days after exposure. The Median Lethal Time was eight days. Several tissues were found to be infected and the common sites of replication were the fat body, epidermis and epithelial derivatives, such as the imaginal discs and the tracheal epithelium. Moreover, infection in the salivary glands, gastric ceca and posterior gut have not been previously documented on other mosquito iridescent viruses.

Nosemosis is a microsporidian disease caused by Nosema ceranae and N. apis and transmitted via oral-fecal and oral-oral routes. It is globally distributed among adult bees in honeybee colonies. Considering the health importance of nosemosis in honeybees, the study aims to determine the frequency of Nosema spp. infection in migratory apiaries in Hormozgan province by microscopic and molecular methods. In the present study, 20 bees from ten randomly selected hives in 84 migratory apiaries were collected. In the laboratory, the abdomen of the bees was separated from the rest of the body with entomological tweezers and scissors and then ground up in a mortar containing saline serum. The prepared suspension was filtered by passing through a sieve, then the prepared suspension was transferred to test tubes and centrifuged. The pellets were repeatedly washed by saline solution and centrifuged. Finally, the pellets were examined for spores of Nosema spp. by light microscopy and conventional PCR. In microscopy, 38.2 % of apiaries were positive for Nosema spp. spores. By PCR however, DNA of N. ceranae was detected in 39.2. % of apiaries with no samples positive for N. apis. Due to the considerable frequency of infection in migratory apiaries in Hormozgan province, it is necessary to carry out appropriate health measures such as screening of apiaries with appropriate diagnostic methods and training of beekeepers to disinfect hives in order to control Nosema infection in Iranian apiaries by the veterinary health officials. [ABSTRACT FROM AUTHOR]

• Larval "soft rot" firstly reported from BSF mass production facilities. • Entomopathogen of "soft rot" was identified to be Paenibacillus thiaminolyticus. • Revealed incidence characteristics of Paenibacillus thiaminolyticus GX6 to BSFL. • Infection damaged the intestinal epithelial cells of BSFL gut. • Gut microbiome of BSFL was significantly changed by GX6 infection. The black soldier fly larvae (BSFL) can transform organic waste into high-end proteins, lipids, chitin, biodiesel, and melanin at an industrial scale. But scaling up of its production capacity has also posed health risks to the insect itself. In this investigation, larval "soft rot" which is occurring in mass production facilities that cause larval developmental inhibition and a certain degree of death was reported. Responsible pathogen GX6 was isolated from BSFL with "soft rot" and identified to be Paenibacillus thiaminolyticus. No obvious impact on larval growth was observed when treated with GX6 spores, whereas mortality of 6-day-old BSFL increased up to 29.33% ± 2.05% when GX6 vegetative cells (1 × 106 cfu/g) were inoculated into the medium. Moreover, higher temperature further enhanced the BSFL mortality and suppressed larval development, but increasing substrate moisture showed the opposite effect. The middle intestine of infected larvae became swollen and transparent after dissection and examination. Transmission electron microscopy (TEM) observation indicated that GX6 had destroyed the peritrophic matrix and intestinal microvilli and damaged epithelial cells of larval gut. Furthermore, 16S rRNA gene sequencing analysis of intestinal samples revealed that gut microflora composition was significantly altered by GX6 infection as well. It can be noticed that Dysgonomonas , Morganella , Myroides , and Providencia bacteria became more numerous in the intestines of GX6-infected BSFL as compared to controls. This study will lay foundations for efficient control of "soft rot" and promote healthy development of the BSFL industry to contribute to organic waste management and circular economy. [ABSTRACT FROM AUTHOR]

Host-pathogen infections and possible effects on co-evolutionary patterns depend on the genotypes of both host and pathogen. Obligate fungal pathogens of plants are often characterized by host-pathogen genotype-by-genotype (GxG) interactions, but whether these patterns exist in obligate insect fungal pathogens is unclear. We take advantage of the obligate insect pathogenic fungus Entomophthora muscae, where individual isolates are specific to different dipteran host species in nature but can cross-infect multiple fly species in the laboratory. We collected three new isolates of E. muscae from Drosophila species. Phylogenetic analysis showed that Drosophila-isolated E. muscae represents a distinct geographically widespread Drosophila lineage compared to the house fly (Musca domestica) or Delia species-isolated E. muscae. We used the three new E. muscae isolates from Drosophila spp. together with a genetically distinct E. muscae isolate from house flies and assessed their virulence in a cross-infection experiment using one house fly, three Drosophila suzukii, and two D. melanogaster genotypes as hosts. All fungal isolates successfully infected hosts, induced behavioural manipulation, sporulated in all fly hosts, and differed in virulence between host genotypes, revealing GxG interactions. While house flies were most susceptible to fungal infection with 99% mortality, we found a lower virulence of 49% and 25% mortality in D. melanogaster and D. suzukii genotypes, respectively. Furthermore, all isolates harboured a specific mycovirus (family Iflaviridae), but co-phylogenetic branching patterns did not support fungus-virus co-speciation. We show that the genetic makeup of both fungal pathogen and fly host influence E. muscae infectivity, confirming GxG interactions in obligate fly fungal pathogens., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Society of Evolutionary Biology.)

The leaf-mining moth, Stomphastis thraustica (Meyrick, 1908) was imported to Australia as a potential biological control agent of an exotic weed, bellyache bush (Jatropha gossypiifolia), from Peru. The insect colony has been maintained in the quarantine facility for over eight years but recently, significant mortality was observed in the culture. The larvae demonstrated swollen intersegments with a fragile integument. The infected larvae are cloudy muted green or yellowish whereas a healthy late instar larva is a vivid green. They slowly dehydrate and eventually die, at which point the larval body becomes rubbery and turns to black. We used next generation sequencing to identify the cause of mortality in the insects. Total RNA was extracted from 20 larvae in two cohorts, one with and one without apparent symptoms of disease, for deep sequencing on NovaSeq platform after eukaryote ribosomal RNA depletion. We identified several non-insect sequences belonging to viruses, bacteria, and fungi, but none of those showed significant abundance or enrichment in the infected dataset. The sequences related to a unicellular yeast, Saccharomyces cerevisiae, and they were among the highly expressed non-insect contigs; more than 5% of reads in both libraries mapped to the genome of this opportunistic microorganism.

Within the family Adeleidae, Adelina spp. belong to a group of arthropod pathogens. These parasites have been reported to have a wide geographic distribution, however, there are no reports of these protists in the Canary Islands, Spain. One of the peculiarities of the life cycle of Adelina spp. is the participation of a predator, because fecundation and sporulation occur inside the body cavity, and so necessitate destruction of the definitive host. The involvement therefore of a 'dispersion host', which eats the definitive host and spreads the oocysts through its faeces, is critical for the maintenance of certain Adelina spp. On the island of Gran Canaria, adeleid oocysts have been found in stool samples from four animals, three California kingsnakes (Lampropeltis californiae), and one feral cat. These animals were part of a larger coprological study of vertebrate parasites (117 snakes, 298 cats), where pseudoparasitic elements were also recorded. L. californiae and feral cats are invasive species which are widespread across the island and this novel finding of Adelina spp. oocysts in their faeces suggests that they could also serve as potential sentinel species for arthropod parasites. [ABSTRACT FROM AUTHOR]

Microcerotermes diversus Silvestri (Blattodea: Termitidae) is a worldwide destructive termite whose control by conventional methods is often difficult. Biological control using entomopathogenic fungi could be an alternative management strategy. Two species of entomopathogenic fungi, Metarhizium anisopliae and Beauveria bassiana, isolated from natural habitats of Mashhad and Lahijan regions, Iran. The fungi were characterized based on sequences of ITS gene as well as classic data. Then, the infectivity of both isolates of M. anisopliae and B. bassiana in different concentrations (1 × 104, 1 × 105, 1 × 106, 1 × 107, and 1 × 108 conidia/ml) were evaluated under laboratory conditions by two methods, including spray and pipetting against termite, M. diversus. Both entomopathogenic fungi species were capable of infecting and killing M. divesrus. In the pipetting method, the LC50 value for B. bassiana and M. anisopliae calculated 8.03 × 105 (conidia/ml) and 1.03 × 106 (conidia/ml), respectively. But in the spray method, the effect of M. anisopliae on M. diversus was more than B. bassiana. The LC50 value in the spray method for B. bassiana and M. anisopliae was 3.52 × 107 (conidia/ml) and 1.65 × 106 (conidia/ml). The mortality caused by the fungus was dose-dependent, with the highest mortality recorded at the highest concentration. In the pipetting method, the mortality rate for B. bassiana and M. anisopliae was 0 to 97.5% and 0 to 100% at 8 day post infection. In the spray method, the mortality percentage for B. bassiana was from 2.5 to 72.5% and for M. anisopliae was 0 to100% by 4 days post-infection. The results of this study indicated that B. bassiana and M. anisopliae are potentially useful biological control agents for M. diversus. Future studies with field trails will provide a confident approach toward termite management. [ABSTRACT FROM AUTHOR]

Polyphylla adspersa Motschulsky (Coleoptera: Melolonthidae) is the key white grub species in the Eastern part of Iran. Due to increasing concerns about its damage on different tree and crop species, addressing environmentally friendly management tactics including biological control has top priority. Here, we report new natural enemies of the white grub larvae in Razavi Khorasan province, North East Iran. The most prevalent natural enemies were entomopathogenic fungi including, Beauveria bassiana s.l. (Hypocreales: Cordycipitaceae) and Metarhizium anisopliae s.l. (Hypocreales: Clavicipitaceae). A parasitic nematode, Cephalobellus sp. (Oxyurida: Thelasto matidae) as well an insect pathogenic nematode, Heterorhabditis bacteriophora (Rhabditida: Heterorhabditidae) were collected as natural entomopathogens. Among protistans, two species of eugregarines, Stictospora sp. and Gregarina sp. were found as coelomic parasites infecting the larvae. A tachinid fly, Micro phthalma europaea (Diptera: Tachinidae) was identified as a koinobiont endoparasitoid of the larva and a humpbacked fly, Megaselia scalaris (Diptera: Phoridae) recognized as an ectoparasite. All records are presented as first associations with the P. adspersa. New information about all newly recorded taxa is provided here. This information is useful for designing future biological control programs. [ABSTRACT FROM AUTHOR]

Research pertaining to the two closely‐related microsporidian genera Nosema and Vairimorpha is hindered by inconsistencies in species differentiation within and between the two clades. One proposal to better delimit these genera is to restructure the Nosema around a "True Nosema" clade, consisting of species that share a characteristic reversed ribosomal DNA operon arrangement and small subunit (SSU) ribosomal DNA sequences similar to that of the Nosema type species, N. bombycis. Using this framework, we assess two distinct microsporidia recovered from the forest insect Bruce spanworm (Operophtera bruceata) by sequencing their SSU and internal transcribed spacer regions. Phylogenetic analyses place one of our isolates within the proposed True Nosema clade close to N. furnacalis and place the other in the broader Nosema/Vairimorpha clade close to N. thomsoni. We found that 25% of Bruce spanworm cadavers collected over the four‐year study period were infected with microsporidia, but no infections were detected in cadavers of the Bruce spanworm's invasive congener, the winter moth (O. brumata), collected over the same period. We comment on these findings as they relate to the population dynamics of the Bruce spanworm‐winter moth system in this region, and more broadly, on the value of ribosomal DNA operon arrangement in Nosema systematics. [ABSTRACT FROM AUTHOR]

Spodoptera littoralis (Lepidoptera: Noctuidae) Boisduval 1833 is a voracious leaf feeder and major agricultural pest attacking numerous crops. Development of insecticide resistance hampers management efforts for S. littoralis and entomopathogenic fungi represent one possible alternative management tool. Here, we quantified colonization of sugar beet, Beta vulgaris L, with two fungal entomopathogens, Beauveria varroae Vuillemin 1912 and Beauveria bassiana (Balsamo) Vuillemin 1912 (Ascomycota: Hypocreales), and examined their endophytic effects on biological and reproductive parameters of S. littoralis. Two methods were used to inoculate sugar beet: soaking seeds in spore suspension and spray application of conidia onto leaves. For both methods, fungal suspensions with concentrations of 1 × 104 and 1 × 108 conidia/ml colonized roots, stems, and leaves of sugar beet. The colonization rate increased over time. Following inoculation of seeds, weight gain of S. littoralis larvae fed on leaves infected with endophytic fungi was reduced compared with controls. Furthermore, protease and lipase activities in the gut of S. littoralis decreased with increasing concentration of fungus applied to plants. An increase in phenol oxidase activity in the gut also indicated increased defense response of larvae feeding on Beauveria -infected leaves. Both B. bassiana and B. varroae decreased the duration of larval and pupal stages, adult emergence, and oviposition by females. Incubation of sugar beet seeds with B. varroae or B. bassiana decreased survival of pupae and egg laying by female moths on endophyte-infested treatments by 30 and 50%, respectively, compared with controls. Furthermore, an initially female biased sex ratio decreased toward 50:50 over time in populations of S. littoralis reared on sugar beet colonized by fungal endophytes as compared with controls, which remained female-biased. Endophyte inoculation increased growth of sugar beet compared with controls. Our results indicate that B. bassiana and B. varroae affect survival of S. littoralis and may be useful for management of this pest. [Display omitted] • Beauveria varroae and Beauveria bassiana colonized roots, stems, and leaves of sugar beet. • Colonization of beets by endophytic fungi reduced feeding by Spodoptera littoralis larvae. • Both endophytes decreased the duration of the larval and pupal stages, adult emergence, and female oviposition. • The female: male sex ratio of S. littoralis reared on sugar beet colonized by fungal endophytes decreased over time. [ABSTRACT FROM AUTHOR]

The aphid species, Cinara pini (Linnaeus, 1758) reported in our previous work as a new aphid on pinus trees for Iran, was described using the classic method and through analysis of COI gene sequence. In the next step, we addressed the efficiency of the entomopathogenic fungus, Lecanicillium longisporum (Zimm.) Zare and Gams strain LRC 190, on the aphid. The fungus was administered to the second instar nymphs and adults using topical application procedure. The results indicated that the entomopathogen caused 90% mortality in adults over seven days at a concentration of 108 spores/ml, while the same control level was achieved for nymphs by 8 × 107 spores/ml. The LC50 values were obtained as 1.2 × 106 and 6.9 × 105 spores/ml for adults and nymphs, respectively. The present study suggests that the entomopathogenic fungus, L. longisporum could be considered as a potential candidate in biocontrol programs of C. pini. This is the first report on the pathogenicity of L. longisporum on C. pini.

Xenorhabdus nematophila and Photorhabdus luminescens are entomopathogenic bacterial symbionts that produce toxic proteins that can interfere with the immune system of insects. Herein, we show that outer membrane proteins (OMPs) could be involved as bacterial virulence factors. Purified totals OMPs of both bacterial species were injected into fifth instar larvae of Spodoptera exigua Hübner. Larvae were surveyed for cellular defenses fluctuations in total haemocyte counts (THC) and granulocyte percentage and for the humoral defenses protease, phospholipase A2 (PLA2), and phenoloxidase (PO) activities at specific time intervals. Changes in the expression of the three inducible antimicrobial peptides (AMPs), cecropin, attacin, and spodoptericin, were also measured. Larvae treated with OMPs of both bacterial species had more haemocytes than did the negative controls. OMPs of X. nematophila caused more haemocyte destruction than did the OMPs of P. luminescens. The OMPs of both bacterial species initially activated insect defensive enzymes post-injection, the degree of activation varying with enzyme type. The AMPs, attacin, cecropin, and spodoptericin were up-regulated by OMP injections compared with the normal larvae. The expression of these three AMPs was maximal at four hours post injection (hpi) with P. luminescens OMPs treatment. Expression of the three AMPs in X. nematophila treated insects was irregular and lower than in the P. luminescens OMPs treatment. These findings provide insights into the role of OMPs of entomopathogenic nematode bacterial symbionts in countering the physiological defenses of insects.

The tomato leaf miner, Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae), is a serious threat to tomato production in the world. Due to serious issues with insecticide resistance, there is a dire need for alternative control methods. Entomopathogenic nematodes (EPN) have potential for the biological control of T. absoluta. In the laboratory, we examined the effect of temperature, soil type, and exposure time on the efficacy of the EPN species Steinernema carpocapsae (Nematoda: Steinernematidae) and Heterorhabditis bacteriophora (Nematoda: Heterorhabditidae) against last-instar T. absoluta larvae. Both species caused high mortality in loamy sand (89%) and coco peat (93%) but not in sandy loam (17%). H. bacteriophora caused 92-96% mortality at 19, 25, and 31°C; S. carpocapsae caused 89-91% mortality at 25 and 31°C but only 76% at 19°C. Both species caused similar mortality levels after 65-min exposure; thereafter, mortality increased only with S. carpocapsae reaching high levels even at a low concentration. Both species infected larvae within leaf galleries. When applied to whole large tomato plants in the greenhouse, both species provided similar control levels (48-51%) at high pest densities. Both species could be incorporated as an effective alternative to synthetic insecticides into T. absoluta management programs in greenhouse tomato production. [ABSTRACT FROM AUTHOR]

Xenorhabdus nematophila is a symbiotic bacterium of the entomopathogenic nematode Steinernema carpocapsae (Weiser). It produces several toxic proteins which interfere with the immune system of insects. The current study shows that purified pilin protein could be a virulence trait of X. nematophila . The fifth instar larvae of Spodoptera exigua (Hübner) was injected with purified pilin. Changes in the cellular defenses in terms of total haemocyte counts and granulocyte percentage and humoral factors including total protease, phospholipase A 2 , and phenoloxidase activities (humoral defense) as well as the expression of the three main antimicrobial peptides attacin, cecropin, and spodoptericin were measured at specific times. The level of THC and granulocytes in larvae with different concentrations of pilin protein were less than the negative control. Also agglutination of haemocytes was observed 8–16 h post-injection. The pilin protein activated phenoloxidase in the initial hour post-injection, by 2 hpi, activity was stable. The activities of phospholipase A2 and protease activities reached maximum levels at 12 and 4 hpi, respectively, and then decreased. The expressions of attacin, cecropin, and spodoptericin in larvae treated with pilin protein were up-regulated above that of the normal sample. The overexpression of cecropin was greater than the other antimicrobial protein mRNA transcripts. The spodoptericin expression had an irregular trend while expressions of attacin and cecropin reached maximum levels at 4 hpi and then decreased. Generally, after the injection of pilin protein, the cellular and humoral immune system of S. exigua is activated but this toxin was able to inhibit them. This is the first report of the role of pilin protein when the bacterial symbiont of S. carpocapsae encounters the humoral defense of an insect. [ABSTRACT FROM AUTHOR]

Much effort has been focused on the development of microbial biopesticides composed of entomopathogenic fungi as alternatives to synthetic insecticides for pest management programs. The citrus mealybug, Planococcus citri Risso (Hemiptera: Pseudococcidae), is an important pest in greenhouses and on citrus plants globally. The current study isolated and characterized two species of entomopathogenic fungi, Lecanicillium longisporum (Petch) Zare & W. Gams and Lecanicillium lecanii (Zimmere). Their virulence at the second nymph and adult stages of P. citri were documented using mycosis with scanning electron microscopy. L. lecanii was found to be more effective at different citrus mealybug growth stages. Nymphal P. citri were more susceptible than adults to fungal infection. Susceptibility at all stages was dose dependent. The results of laboratory trials used for greenhouse tests. In a comparison of wheat, beet pulp paddy rice and rice bran as substrates for solid substrate fermentation, wheat produced the most conidia for the L. lecanii . For L. longisporum, however, was the most appropriate media. The results of this study indicate that the entomopathogenic fungi L. longisporum and L. lecanii are potentially useful biological control agents for the citrus mealybug. [ABSTRACT FROM AUTHOR]

Bacillus thuringiensis (Berliner) strains 344 and 1644 belonging to the CNPMS/Embrapa (Maize and Sorghum National Research Center) Microorganism Bank, located in Sete Lagoas, MG, showed to be highly efficient in controlling fall armyworm, Spodotpera frugiperda (J.E. Smith). Strains 344 and 1644 were isolated from soil samples originated from Iguassu Falls and Rolândia, respectively, Paraná State, Brazil. While strain 344 harbors cry1Ab, cry1B, cry1E and cry1Fb genes, strain 1644 showed cry1B, cry1C, and cry1D and cry1Fb genes. The strain 344 crystal has bipyramidal shape and showed LC50 equal to 8.21 x 106 spores/mL. Strain 1644 has cuboid crystal and showed LC50 equal to 2.07 x 106 spores/mL. Comparative analysis of protein profile, plasmid and amplification with primers ERIC allowed the differentiation of the evaluated strains.

Globally, Maruca vitrata (Geyer) is a serious yield constraint on food legumes including Yard-long bean (Vigna unguiculata subspecies sesquipedalis). However, there is a dearth of information on its damage potential, distribution and population dynamics in Yard-long beans. In the present study, the level of M. vitrata larval infestation on flowers and pods of Yard-long beans in Sri Lanka was determined with respect to three consecutive cropping seasons, Yala, Off and Maha. Results indicated that larval infestation and abundance varied with developmental stage of flowers and pods, cropping season and their combined interactive effects. Flowers of Yard-long beans were more prone to M. vitrata larval attack compared to pods. Abundance and level of infestation of M. vitrata varied with plant parts, having a ranking of flower buds (highest) > open flowers > mature pods > immature pods (lowest). Peak infestation was observed six and eight weeks after planting on flowers and pods, respectively. Among the three cropping seasons, M. vitrata infestation was found to be higher during Maha and Off seasons compared to Yala. The findings of this study contribute to the identified knowledge gap regarding the field biology of an acknowledged important pest, M. vitrata, in a previously understudied crop in Sri Lanka.

Dr. Rer. Nat. Alois M. Huger had a long and distinguished career at the Institut für biologische Schädlingsbekämpfung (Institute for Biological Pest Control) Darmstadt, Germany, where he became one of the world’s leading insect pathologists. He applied his experience and understanding of insect tissues and specialist skills in microscopy to diagnosis and elucidation of the pathology of insect diseases. During his career he discovered the Oryctes nudivirus and Bacillus thuringiensis subsp. tenebrionis , and was a member of teams unravelling amber disease in scarab beetles and the role of bacteria in parthenogenesis of parasitoids. He researched and described the life cycles of microsporidian and rickettsial pathogens of insects and was the first to describe the ultrastructure of a microsporidian spore. Dr. Huger carried out diagnosis of diseased insects over a period of 55 years and has left us with many publications and a database containing thousands of records for ongoing investigation. Working with multiple pathogens in different systems, Dr. Huger obtained an overview second to none in the complexities of insect/pathogen relationships and has been at the forefront of making these discoveries benefit humanity. He is a worthy recipient of the Founders’ Lecture Honoree Award, the highest honour of the Society for Invertebrate Pathology. [ABSTRACT FROM AUTHOR]

The carob moth (Ectomyelois ceratoniae) is the key pest of pomegranate, which causes a significant percentage of losses in pomegranate orchards and warehouses of Iran annually. The pest larvae are characterized by displaying a cryptic behavior within the fruit, which avoids most routine control techniques, especially chemical method. The low efficiency of traditional measurements and also the rich species diversity of natural enemies within the infested fruits highlight the necessity of exploring effective control methods, especially environmental friendly approaches. Entomopathogenic nematodes (EPNs) are a group of biological control agents that actively search for the host, including those in a cryptic habitat like the carob moth larvae within infested fruits. Here, we assumed that treatment of the infested and dropped fruits with EPNs may provide new insight into the management of the carob moth. Three species of EPNs, Steinernema feltiae, S. carpocapsae, and Heterorhabditis bacteriophora were selected and used in a series of in vitro and in vivo experiments. In preliminary assays, the EPNs species were used with different concentrations of infective juveniles (IJs) (0, 1, 5, 10, 25, and 50 IJ/larvae) in 2-cm diam. plates. The mortality rates of the laboratory tests were 79.75% and 76.5% for S. feltiae and S. carpocapsae, corresponded to LC50 value of 2.02 IJ/larva for S. feltiae and 2.05 IJ/larva for S. carpocapsae. On the contrary, H. bacteriophora demonstrated low virulence on the pest larvae in petri tests with a LC50 = 426.92 IJ/larva. Hence, both Steinernema species were selected for subsequent experiments. The penetration rate for S. feltiae and S. carpocapsae into the hemocoel of the pest was 43% and 31%, respectively, and the corresponding reproduction rate was 15,452 IJ/larva for S. feltiae and 18,456 IJ/larva for S. carpocapsae. The gathered data from those in vitro tests were used for a field assay. Different concentrations (5, 10, 50, 100, and 160 IJ/cm2 of the arena) of S. feltiae and S. carpocapsae were applied in the field test. The mean mortality results from the last test were 10.89% and 26.65% for S. feltiae and S. carpocapsae, respectively. Finally, we found that these low virulence rates of the nematodes were attributed to inhibitory/repellency effects of saprophytic fungi within the infested pomegranates, a usual status of the infested fruits in autumn or winter seasons. Future work on additional EPN populations more adapted to the extreme conditions of the pomegranate production area in Iran may provide sufficient evidence to continue the further investigation on the best EPN species populations and advanced formulations with high durability. [ABSTRACT FROM AUTHOR]

During a survey for natural enemies of the rosaceous longhorn beetle (RLHB), Osphranteria coerulescens, two isolates of entomopathogenic fungi (EPF) were found in Razavi Khorasan province of Iran. These isolates were determined to be of the species Beauveria bassiana and Metarhizium anisopliae using morphological characteristics and molecular analysis. Subsequently, the mycosis process of the isolates on larvae of RLHB was documented using scanning electron microscopy (SEM). In order to assess virulence of these indigenous isolates of EPF, a series of trials were conducted against RLHB larvae, pupae and adult stages. In laboratory bioassays the pest was susceptible to both EPF isolates, but the B. bassiana isolate caused significantly higher mortality than the M. anisopliae isolate in all life stages tested. In a semi-field trial EPF suspension containing 2.5 × 10 viable conidia per ml was sprayed directly against pest larvae beneath tree bark under two conditions: apricot branches covered with a polyvinyl cover and without cover. The B. bassiana isolate showed a higher infection rate than M. anisopliae and the cover had significant effect on larval mortality, ranging from 67 % for covered infested apricot branches to 31 % without cover in the B. bassiana treatments. Our findings revealed that polyvinyl covers were necessary to improve conidial persistence under field conditions. In a supplementary survey on the semi-mass production potential of the fungal conidia, the ability of B. bassiana and M. anisopliae to germinate was studied using three solid media. Sugar beet pulp provided the highest yield of conidia for both EPF species, and can be considered as an effective solid medium for fungal growth. These findings highlighted the potential of EPFs as biocontrol agents of O. coerulescens. [ABSTRACT FROM AUTHOR]

The present work describes the immune response of wireworm larvae, Agriotes lineatus (L.) (Coleoptera: Elateridae) when challenged with two species of entomopathogenic nematodes, Steinernema feltiae (Filipjev) (Strongyloidea: Steinernematidae) and Heterorhabditis bacteriophora (Poinar) (Rhabiditoidea: Heterorhabditidae). Two main immunological processes including cellular and humoral reactions have been addressed. Total haemocyte counts after infection with H. bacteriophora increased quickly in initial times, but decreased over time post-injection (at 12 and 16 h). Instead, haemocyte numbers after infection with S. feltiae was unchanged in the early stage, but significantly decreased until 16 h post-injection. Plasmatocytes and granulocytes showed more significant changes compared to other haemocytes. The encapsulation response to parasites was significantly different against two nematode species. Particularly, S. feltiae was almost unrecognized by host haemocytes (5.85 % of encapsulated parasites). Assays with H. bacteriophora showed 23.5 % of encapsulated nematodes. From 8 to 12 h after H. bacteriophora infection, an increase in phenoloxidase activity was detected, while in the larvae injected with S. feltiae the enzymatic activity decreased gradually reaching the lowest level 16 h post-injection. This is the first report on the modulation of immune response of wireworm larvae after infection with entomopathogenic nematodes. [ABSTRACT FROM AUTHOR]

In Brazil, the sugarcane borer, Diatraea saccharalis (Fabricius, 1794) (Lepidoptera: Crambidae), is controlled with massive releases of the hymenopteran parasitoid Cotesia flavipes Cam. (Hymenoptera: Braconidae); over 3 million hectares of sugarcane are treated annually with 18 billion parasitoids. In order to meet this demand, parasitoids are produced in D. saccharalis under laboratory conditions where a Nosema sp. is reported to be an important problem in mass rearing of the host. The goals for this work were to study the pathogenicity of the Nosema sp. and the progression of the disease in the host under laboratory conditions. The average median lethal time (LT 50 ) of Nosema sp. in first instar D. saccharalis varied from 9 ± 0.3 to 42 ± 2.3 days at concentration of 5 × 10 5 –0.5 spores/mm 3 artificial diet (10 7 –10 spores/μl). For third instar, the average of LT 50 ranged from 32 ± 0.7 to 37 ± 0.7 days at concentration of 5 × 10 5 –5 × 10 2 spores/mm 3 artificial diet (10 7 –10 4 spores/μl in saline). The concentration necessary to cause 50% mortality (LC 50 ) of first instar larvae was 5.6 (0.9–17.6) spores/μl and the estimated LC 50 for third instar larvae was 1,200 (200–4700) spores/μl. The impacts of Nosema sp. on D. saccharalis were analyzed for first instar larvae fed 0.5 spores/mm 3 artificial diet. Duration and viability of the larval and pupal stages, adult longevity, pupal weight and fertility life table were measured for offspring of mating pairs composed of infected females and uninfected males or infected males and uninfected females and compared to offspring of uninfected pairs. Nosema sp. infection resulted in adverse effects on all biological parameters measured except for the duration of the larval and pupal stages and the weight of the male pupae, which did not differ statistically between infected and uninfected groups. The intrinsic rates of growth ( r m ) were greater for uninfected pairs compared to pairs with either male or female infected. The growth rate of individual larvae produced by uninfected adults was 48.2% faster than of larval offspring of infected females and it was negative (−0.003) when males were infected. Our study confirms the negative impact of the Nosema sp. in mass rearing of D. saccharalis for parasitoid production but shows potential for use as a microbial control agent of the sugarcane borer. [ABSTRACT FROM AUTHOR]

The biological traits of the entomopathogenic nematodes (EPNs), Steinernema carpocapsae and Heterorhabditis bacteriophora, against the larvae of the leopard moth, Zeuzera pyrina were evaluated in the laboratory. The traits included pathogenicity, penetration potential as well as foraging behaviour. Plate assays were performed using a range of EPN concentrations (5, 10, 20, 50 and 100 infective juveniles (IJs) per larva). The LC50 values for S. carpocapsae and H. bacteriophora were 6.4 and 8.4 IJs larva-1 after 72 h. Both EPN species caused high mortality in branch experiments. Significantly higher mortality rates occurred in the larger larvae after exposure to S. carpocapsae. Both EPN species successfully penetrated the Z. pyrina larvae as well as larvae of Galleria mellonella L. (Lepidoptera: Galleridae).The proportional response of H. bacteriophora to host-associated cues was strongly higher than S. carpocapsae in Petri dishes containing agar 1, 12 and 24 h after EPN application. These results highlight the efficiency of EPNs for the control of Z. pyrina larvae. However, due to the cryptic habitat of Z. pyrina larvae in their galleries in the trees, field trails need to be conducted to further evaluate this potential. [ABSTRACT FROM AUTHOR]

Rose sawfly,Arge ochropus(Gmelin), is one of the most important pests of ornamental plants such as roses and wild rose bushes in Northern Iran. We investigated the interactions between the insecticides imidacloprid and the entomopathogenic nematodesHeterorhabditis bacteriophoraandSteinernema carpocapsaeas control agents of fifth-instar larvae in the laboratory. The larvae were very susceptible toS. carpocapsae(LC50: 21 infective juvenile per larva) andH. bacteriophora(LC50: 32). Combinations of two imidacloprid rates (LC30and LC50) and four rates of each nematode species (LC25–LC75) were tested. Combinations with the lower imidacloprid rate except for that with the highestH. bacteriophorarate caused higher mortality than both respective single-agent treatments. In combination with the higher imidacloprid rate, only one combination withH. bacteriophoraand two combinations withS. carpocapsaecaused higher mortality than both respective single-agent treatments. Interactions were generally stronger at the lower imidacloprid rate and were stronger forS. carpocapsae(synergistic in seven combinations, additive in one) than forH. bacteriophora(synergistic in two, additive in six). Synergistic imidacloprid-S. carpocapsaecombinations could be a useful tool for the control ofA. ochropuslarvae that would simultaneously control other common pests susceptible to imidacloprid. [ABSTRACT FROM PUBLISHER]

The haemocyte reactions of the white grub larvae Polyphylla adspersa to entomopathogenic nematodes (EPN), together with the host haemocyte types, have been studied. Six types of identified haemocytes included the prohaemocytes, granulocytes, plasmatocytes, oenocytoids, coagulocytes and spherulocytes. The granulocytes were :he dominant (65.2%) haemocyte type followed by the plasmatocytes (22.1 %). Both haemocyte types encapsulate EPN. White grub larvae and last larval stage of Galleria mellonella were individually infected with monoxenic Heterorhabditis bacteriophora or Steinernema glaseri. The maximum total haemocyte counts (THC) level of the white grub larvae against the nematode S. glaseri occurred at 12 h post-injection. In addition, by 8 h post-injection, the granulocyte and plasmatocyte levels decreased. The cell reactions of the grubs against H. bacteriophora in terms of THC and differential haemocyte counts and the encapsulation rate started earlier and were more pronounced than those against S. glaseri. The maximum percentage of the encapsulation observed in the white grub larvae against S. glaseri (27.3 ± 0.7%) and H. bacteriophora (36.5 ± 3.5%) occurred at 12 and 8 h post-injection, respectively. EPN-triggered encapsulation in P. adspersa larvae was more extensive than in G. mellonella larvae. [ABSTRACT FROM AUTHOR]

Rosaceae longhorned beetle, Osphranteria coerulescens, is an important pest of fruit trees that attacks all fruit trees belonging to the family Rosaceae in cold regions of Iran. The potential efficacy of two species of entomopathogenic nematodes (EPN), Heterorhabditis bacteriophora and Steinemema carpocapsae, against last instar larvae of this pest was tested under laboratory conditions. In plate assays, the larvae were susceptible to both EPN species but were more susceptible to S. carpocapsae (65.0-97.5% mortality) than H. bacteriophora (42.5-87.8%). Both nematode species were able to penetrate and reproduce within O. coerulescens larvae, but reproduction rate for H. bacteriophora was higher than those of S. carpocapsae; however, the penetration rate for S. carpocapsae was greater than H. bacteriophora. In a migration test on agar plate, S. carpocapsae showed negligible attraction to the pest or to Galleria mellonella cues. However, H. bacteriophora was strongly attracted to the sector of Petri dishes containing larvae. In a test using apricot tree branches, both species of EPN passed from mass frass of O. coerulescens larvae in the tip of the branches, penetrated into the larval galleries, and located and killed the larvae of O. coerulescens in their natural habitat deep inside the branches. Our findings provide the first insight into the biocontrol efficacy of EPN against O. coerulescens larvae, and highlight their potential for the control of this pest. Field experiments are needed to evaluate their potential under the environmental conditions in which rosaceae longhorned beetle larvae are found. [ABSTRACT FROM AUTHOR]

Abstract: Wolbachia is a widespread endosymbiont of insects with a diverse range of biological effects on its hosts. We studied the prevalence of Wolbachia in some important species of tephritids in Iran. Among different populations of five fruit fly species, Dacus ciliatus (cucurbit fly), Rhagoletis cerasi (cherry fruit fly), Ceratitis capitata (Mediterranean fruit fly), Myiopardalis pardalina (melon fly) and Carypomya vesuviana (jujube fly), two species, R. cerasi and C. vesuviana, showed infection with separate Wolbachia strains, namely wCer6 and wVes1, respectively. C. vesuviana is introduced here as a novel host for Wolbachia. Genotyping of Wolbachia strains in 12 populations of five fruit fly species, using multilocus sequence typing (MLST) and the wsp gene sequence showed the occurrence of two new strains as well as a new strain type (ST) belonging to the A supergroup. On the basis of the results of this study, 12 barcodes under five species of Iranian tephritids have been added to the database of DNA barcodes. Inter- and intra-specific differences among COI sequences showed a clear gap in barcoding among most fruit flies. [Copyright &y& Elsevier]

Entomopathogenic nematodes (EPNs) from the families Steinernematidae and Hererorhabditidae are considered excellent biological control agents against many insects that damage the roots of crops. In a regional survey, native EPNs were isolated, and laboratory and greenhouse experiments were conducted to determine the infectivity of EPNs against the cucurbit fly,Dacus ciliatusLoew (Diptera: Tephritidae). Preliminary experiments showed high virulence by a native strain ofHeterorhabditis bacteriophoraPoinar (Rhabditida: Heterorhabditidae) and a commercial strain ofSteinernema carpocapsaeWeiser (Rhabditida: Steinernematidae). These two strains were employed for further analysis while another native species,Steinernema feltiae, was excluded due to low virulence. In laboratory experiments, larvae and adult flies were susceptible to nematode infection, but both nematode species induced low mortality on pupae.S. carpocapsaehad a significantly lower LC50value against larvae thanH. bacteriophorain filter paper assays. Both species of EPNs were effective against adult flies butS. carpocapsaecaused higher adult mortality. When EPN species were applied to naturally infested fruit (150 and 300 IJs/cm2), the mortality rates ofD. ciliatuslarvae were 28% forS. carpocapsaeand 12% forH. bacteriophora. Both EPN strains successfully reproduced and emerged from larvae ofD. ciliates. In a greenhouse experiment,H. bacteriophoraandS. carpocapsaehad similar effects on fly larvae. Higher rates of larval mortality were observed in sandy loam and sand soils than in clay loam. The efficacy ofS. carpocapsaeandH. bacteriophorawas higher at 25 and 30°C than at 19°C. The results indicated thatS. carpocapsaehad the best potential as a biocontrol agent ofD. ciliatus, based on its higher virulence and better ability to locate the fly larvae within infected fruits. [ABSTRACT FROM AUTHOR]

The susceptibility of potato tuber moth, Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae) to native and commercial strains of entomopatho-genic nematodes (EPNs) was studied under laboratory conditions. Native strains of EPNs were collected from northeastern Iran and characterised as Steinernema feltiae and Heterorhabditis bacteriophora (FUM 7) using classic methods as well as analysis of internal transcribed spacer (ITS) and D2/D3 sequences of 28S genes. Plate assays were performed to evaluate the efficiency of five EPN strains belonging to four species including Steinernema carpocapsae (commercial strain), S. feltiae, Steinernem glaseri and H. bacteriophora (FUM 7 and commercial strains). This initial assessment with 0, 75, 150, 250, 375 and 500 IJs/ml concentrations showed that S. carpocapsae and H. bacteriophora caused the highest mortality in both larval and prepupal stages of P. operculella, PTM. Thereafter, these three strains (i.e. S. carpocapsae, H. bacteriophora FUM 7 and the commercial strains) were selected for complementary assays to determine the effects of soil type (loamy, loamy-sandy and sandy) on the virulence of EPNs against the second (L2) and fourth instar (L4) larvae as well as prepupa. A soil column assay was conducted using 500 and 2000 IJs in 2-ml distilled water. Mortality in the L2 larvae was not affected by the EPN strain or soil type, while there was a significant interactive effect of nematode strains and soil type on larval mortality. The results also showed that EPN strains have higher efficiency in lighter soils and caused higher mortality on early larvae than that in loamy soil. In L4 larvae, mortality of PTM was significantly influenced by nematode strain and applied concentrations of infective juveniles. The larval mortality induced by S. carpocapsae was higher than those caused either by a commercial or the FUM 7 strain of H. bacteriophora. Prepupa were the most susceptible stage. [ABSTRACT FROM AUTHOR]

Abstract: A major issue for mass rearing of insects concerns sanitary conditions and disease. Microsporidian infection (Nosema sp.) in laboratory colonies of Diatraea saccharalis (Fabr.) (Lepidoptera: Crambidae), used in producing the parasitoid, Cotesia flavipes Cameron (Hymenoptera: Braconidae), is representative of the problems faced by growers and industry. Although C. flavipes has been produced for several years in Brazil for biological control of D. saccharalis, we have only recently observed that the parasitoid becomes infected when developing inside hosts infected with Nosema sp. We assessed the effects of Nosema sp. on C. flavipes, including the ability to locate and select hosts, and evaluated pathogen transmission. Third instar larvae of D. saccharalis were inoculated with Nosema sp. spores at different concentrations and were parasitized when larvae reached fifth instar. Heavily infected D. saccharalis larvae did not support parasitism. Parasitoids that developed in infected D. saccharalis larvae exhibited increased duration of larval and pupal stages, decreased adult longevity and number of offspring, and reduced tibia size compared to parasitoids developing in uninfected D. saccharalis larvae. Infection by Nosema sp. reduced the ability of the C. flavipes parasitoid to distinguish between volatiles released by the sugarcane infested by healthy larvae and pure air. Uninfected parasitoids preferred plants infested with uninfected hosts. But infected C. flavipes did not differentiate between uninfected hosts and those infected with Nosema sp. The pathogen is transmitted from host to parasitoids and parasitoids to hosts. Pathogenic effects of the microsporidium in C. flavipes are sufficiently severe to justify disease management efforts, particularly considering the importance of C. flavipes as a biological control agent in sugarcane. [Copyright &y& Elsevier]

Abstract: The current state of knowledge regarding the effect of pesticides on insect immunity is reviewed here. A basic understanding of these interactions is needed for several reasons, including to improve methods for controlling pest insects in agricultural settings, for controlling insect vectors of human diseases, and for reducing mortality in beneficial insects. Bees are particularly vulnerable to sublethal pesticide exposures because they gather nectar and pollen, concentrating environmental toxins in their nests in the process. Pesticides do have effects on immunity. Organophosphates and some botanicals have been found to impact hemocyte number, differentiation, and thus affect phagocytosis. The phenoloxidase cascade and malanization have also been shown to be affected by several insecticides. Many synthetic insecticides increase oxidative stress, and this could have severe impacts on the production of some antimicrobial peptides in insects, but research is needed to determine the actual effects. Pesticides can also affect grooming behaviors, rendering insects more susceptible to disease. Despite laboratory data documenting pesticide/pathogen interactions, little field data is available at the population level. [Copyright &y& Elsevier]