Dead Mites Research Articles

Selection and characterization of Beauveria spp. isolates to control the broad mite Polyphagotarsonemus latus (Banks, 1904) (Acari: Tarsonemidae).

This study was performed under laboratory conditions to identify isolates of the fungus Beauveria spp. that can control Polyphagotarsonemus latus in the greenhouse and field. Thirty Beauveria spp. isolates were tested by spraying 1 mL conidia (1 × 108 conidia/mL) on pepper leaf discs containing 15 mites. Evaluations were performed on the 3rd and 6th day post application by counting the number of dead mites. Vegetative growth and conidial production were measured from the selected isolates, and bioassays were conducted in the greenhouse on bean seedlings in plastic pots. The isolate Unioeste 53 was selected, and a conidial suspension (1 × 108 conidia/mL) was applied with a backpack sprayer. The evaluation consisted of pre- and post-treatment counts of the number of live mites on ten leaflets in both the plots treated with the fungus and control plots, and the same procedure was followed for the field experiment. In the laboratory, the Unioeste 53 isolate resulted in total and confirmed mortality rates of 70% and 57.7%, respectively. In the greenhouse, the population decreased by 76.71% by the 16th day after application. In the field, the population decreased by 66% by the 12th day after application, demonstrating the potential of this fungus for mite management.

Grooming behavior of Apis dorsata Fabricius, Thai commercial, and Primorsky honey bees (Apis mellifera Linnaeus) to the bee mite Euvarroa sinhai Delfinado & Baker

The purpose of this study was to determine grooming behavior efficacy of Apis dorsata, Thai commercial (A. mellifera, Italian honey bee hybrids), and Primorsky honey bees (A. mellifera) in killing the mite species Euvarroa sinhai. Ten A. dorsata, 15 Thai commercial and 15 Primorsky colonies were used to compare efficacy in their grooming behavior related to E. sinhai. Fallen E. sinhai from A. dorsata colonies was collected using a white plastic sheet (1.4×2 m), which was smeared by vegetative oil and placed 1m below each colony. The fallen E. sinhai on the plastic sheet were collected weekly until the colony was absconded. Dead E. sinhai from each colony of Thai commercial and Primorsky honey bees were collected by the use of mite collecting boards with wire screens. The boards were coated with a thin film of vegetable oil and maintained in the hives for periods of 7days until the end of the experiment (12months). Dead mites on the traps from A. dorsata, Thai commercial, and Primorsky colonies were retrieved by the use of a fine paint brush and examined for their injuries using a stereomicroscope at 40× magnification. Injuries obtained by the mites were classified as either injured legs only or injured both legs and body. The data on percent means of injured mites from colonies of the three bee types were analyzed using one-way ANOVA for a completely randomized design, and the means were compared using Duncan's new multiple range test. The results showed that A. dorsata workers had more efficient grooming behavior to kill E. sinhai than the Primorsky and Thai commercial bees, respectively. The percentage of injured mites in the A. dorsata debris (55.4±2.2%) was significantly higher (P=0.001, df=37) than that of the Thai commercial (18.6±1.6%) and Primorsky (41.4±2.1%) debris (percent mean±standard error), and the percentage of injured mites in the Primorsky debris was significantly higher than that of the Thai commercial debris. The percentage of mites that had severely injured both legs and body in the A. dorsata debris (42.0%) was higher than that of the Thai commercial (31.8%) and Primorsky (36.0%) debris. Mites that had injured legs only from the A. dorsata, Thai commercial, and Primorsky debris were 58.0%, 68.2%, and 64.0%, respectively.

Occurrence of Foreign Matter in Food: Applied Identification Method - Association of Official Agricultural Chemists (AOAC) and Food and Drug Administration (FDA)

Authors : E. C. Mattos, V. S. M. G. Daros, R. Dal Col, A. L. Nascimento Abstract : The aim of this study is to present the results of a retrospective survey on the foreign matter found in foods analyzed at the Adolfo Lutz Institute, from July 2001 to July 2015. All the analyses were conducted according to the official methods described on Association of Official Agricultural Chemists (AOAC) for the micro analytical procedures and Food and Drug Administration (FDA) for the macro analytical procedures. The results showed flours, cereals and derivatives such as baking and pasta products were the types of food where foreign matters were found more frequently followed by condiments and teas. Fragments of stored grains insects, its larvae, nets, excrement, dead mites and rodent excrement were the most foreign matter found in food. Besides, foreign matters that can cause a physical risk to the consumer’s health such as metal, stones, glass, wood were found but rarely. Miscellaneous (shell, sand, dirt and seeds) were also reported. There are a lot of extraneous materials that are considered unavoidable since are something inherent to the product itself, such as insect fragments in grains. In contrast, there are avoidable extraneous materials that are less tolerated because it is preventable with the Good Manufacturing Practice. The conclusion of this work is that although most extraneous materials found in food are considered unavoidable it is necessary to keep the Good Manufacturing Practice throughout the food processing as well as maintaining a constant surveillance of the production process in order to avoid accidents that may lead to occurrence of these extraneous materials in food.

Mange Caused by a NovelMicnemidocoptesMite in a Golden Eagle (Aquila chrysaetos)

A second-year, female golden eagle ( Aquila chrysaetos ) was live trapped in northern California because of severe feather loss and crusting of the skin on the head and legs. On physical examination, the bird was lethargic, dehydrated, and thin, with severe feather loss and diffuse hyperemia and crusting on the head, ventral wings, ventrum, dorsum, and pelvic limbs. Mites morphologically similar to Micnemidocoptes derooi were identified with scanning electron microscopy. The eagle was treated with ivermectin (0.4 mg/kg) once weekly for 7 weeks, as well as pyrethrin, meloxicam, ceftiofur crystalline free acid, and voriconazole. Although the eagle's condition improved, and live mites or eggs were not evident on skin scrapings at the time of completion of ivermectin treatment, evidence of dead mites and mite feces were present after the last dose of ivermectin. Two additional doses of ivermectin and 2 doses of topical selamectin (23 mg/kg) were administered 2 and 4 weeks apart, respectively. No mite eggs, feces, or adults were evident after treatment was completed. A second golden eagle found in the same region was also affected with this mite but died soon after presentation. This is the first report, to our knowledge, of successful treatment, as well as treatment with selamectin, of mites consistent with Micnemidocoptes species in any raptorial species.

Virus Status, Varroa Levels, and Survival of 20 Managed Honey Bee Colonies Monitored in Luxembourg Between the Summer of 2011 and the Spring of 2013

Abstract Twenty managed honey bee colonies, split between 5 apiaries with 4 hives each, were monitored between the summer of 2011 and spring of 2013. Living bees were sampled in July 2011, July 2012, and August 2012. Twenty-five, medium-aged bees, free of varroa mites, were pooled per colony and date, to form one sample. Unlike in France and Belgium, Chronic Bee Paralysis Virus (CBPV) has not been found in Luxembourg. Slow Bee Paralysis Virus (SBPV) and Israeli Acute Paralysis Virus (IAPV) levels were below detection limits. Traces of Kashmir Bee Virus (KBV) were amplified. Black Queen Cell Virus (BQCV), Varroa destructor Virus-1 (VDV-1), and SacBrood Virus (SBV) were detected in all samples and are reported from Luxembourg for the first time. Varroa destructor Macula- Like Virus (VdMLV), Deformed Wing Virus (DWV), and Acute Bee Paralysis Virus (ABPV) were detected at all locations, and in most but not all samples. There was a significant increase in VDV-1 and DWV levels within the observation period. A principal component analysis was unable to separate the bees of colonies that survived the following winter from bees that died, based on their virus contents in summer. The number of dead varroa mites found below colonies was elevated in colonies that died in the following winter. Significant positive relationships were found between the log-transformed virus levels of the bees and the log-transformed number of mites found below the colonies per week, for VDV-1 and DWV. Sacbrood virus levels were independent of varroa levels, suggesting a neutral or competitive relationship between this virus and varroa.

Brood removal influences fall of Varroa destructor in honey bee colonies

The hygienic removal of Apis mellifera brood infested with Varroa destructor disrupts the reproduction of the infesting mites, and exposes the foundress mites to potential removal from the colony by grooming. Using brood deliberately infested with marked mites, we investigated the association between the removal of mite-infested brood and the removal of exposed foundress mites in Italian (IHB) and Russian honey bee (RHB) colonies. Our results showed that RHB colonies removed more mite-infested brood in significantly less time (average = 87.9 ± 2.0% for 2.6 ± 0.1 days) than IHB colonies (average = 61.9 ± 7.3% for 3.2 ± 0.1 days or 19.3% per day). For the inoculated brood that was not removed, RHB colonies had lower proportions of brood cells containing: (a) live marked mites regardless of reproductive status (RHB = 4.4 ± 1.3%; IHB = 17.7 ± 5.9%); (b) dead marked mites (RHB = 1.1 ± 0.5%; IHB = 7.1 ± 2.2%); (c) lost introduced marked mites (RHB = 6.6 ± 1.6%; IHB = 13.3 ± 2.8%); and (d) reproductive marked mites (RHB = 8.3 ± 6.3%; IHB = 23.8 ± 6.9%) than IHB colonies did. These observations suggest that RHB colonies indiscriminately remove mite-infested brood regardless of mite status. Regarding trapped mites (i.e., those found below a modified queen excluder), the number of mite-infested brood cells removed positively correlated with the number of mites that were trapped in both honey bee stocks. The majority of the trapped mites fell during the first three days post mite inoculation, which coincided with the highest rates of brood removal. The highest proportions of trapped gravid foundress mites were also recorded during this time, when host bees were early in their development. The comparatively strong and rapid hygienic response of RHB to mite-infested brood and the associated removal of infesting foundresses are probably parts of a suite of factors responsible for suppressing V. destructor populations in RHB colonies.

Standardization and establishment of an in vitro culture of Blomia tropicalis toward technological development purposes

Standardization and establishment of an in vitro culture of Blomia tropicalis toward technological development purposes

A preliminary study of the acaricidal activity of clove oil, Eugenia caryophyllus

The search for more eco-friendly acaricides has prompted testing of medicinal plants from botanical sources. To evaluate the eradication of house dust mites (HDM), Dermatophagoides pteronyssinus, by direct contact using the essential clove oil (Eugenia caryophyllus). A pilot study was initiated to determine the killing power of clove oil. Synthetic fibers were immersed in 2% clove oil for 30 min, dried in a hot air oven at 60°C for 2 hrs after which 0.5 gm of HDMs were exposed to these coated fibers placed in the Siriraj Chamber (SC). Two additional long-term methods were employed. Ten mites were placed in the SC and 10 μl of clove oil was pipetted or sprayed onto them. These latter two procedures were each carried out for 3 consecutive days at 0, 1, 3 and 6 months. The solutions antimicrobial and antifungal properties were evaluated by exposing common bacteria and fungi to sterile filter disks impregnated with the mixture, and after overnight incubation, the disc diffusion method on nutrient agar was used. Ethyl alcohol served as the placebo. 99% and 81%, respectively, while the placebo mortality was <5%. The zone of inhibition indicated significant clearance for all the bacteria and fungi indicating greater biocidal activity when compared to the controls. SEMs revealed dead mites on the fibers. The effectiveness of pipetting and spraying was 99% and 81%, respectively, while the placebo mortality was <5%. The zone of inhibition indicated significant clearance for all the bacteria and fungi indicating greater biocidal activity when compared to the controls. Clove oil is a promising agent for killing dust mites with a potential use in dust-mite laden mattresses. Spraying diminishes in efficiency after 3 months.

Effect of Activated Charcoal Fibers on the Survival of the House Dust Mite, Dermatophagoides pteronyssinus: A Pilot Study

House dust mites produce potent allergens that exacerbate asthma in sensitized patients, whom are recommended to practice allergen avoidance within their home environment. We tested the effect of activated charcoal impregnated fibers on house dust mite survival. One hundred live adult house dust mites (Dermatophagoides pteronyssinus) were added to eight culture dishes preequilibrated at room temperature (n = 4) and 70% humidity (n = 4) containing house dust mite food and active charcoal fibers. At 10 minute intervals, live and dead house dust mites were counted. All house dust mites instantly attached to the activated charcoal fibers and started to shrink almost immediately. There were no live house dust mites present as early as 40 minutes in some dishes while after 190 minutes all house dust mites were dead. In conclusion, activated charcoal fibers, if incorporated into bedding items, have the potential to control house dust mites in the indoor environment.

Toxicidade de agroquímicos ao ácaro-da-leprose dos citros Brevipalpus phoenicis (Geijskes) e ao ácaro predador Neoseiulus californicus (McGregor) (Acari: Tenuipalpidae, Phytoseiidae)

O objetivo deste trabalho foi avaliar a toxicidade dos principais agroquímicos utilizados em citros em Brevipalpus phoenicis e Neoseiulus californicus, potencial predador de ácaros fitófagos na cultura. Os bioensaios foram realizados utilizando discos de folhas de laranjeira para N. californicus e frutos para B. phoenicis. Foram utilizadas 35 fêmeas adultas do ácaro predador e 50 fêmeas adultas do ácaro fitófago. Utilizaram-se 13 agroquímicos nas concentrações recomendadas para o controle do ácaro da leprose. As aplicações foram feitas por meio de torre de Potter, sendo realizadas quatro repetições para cada tratamento. As avaliações do número de ácaros vivos e mortos foram observadas 72 horas após a aplicação. Os bioensaios com espirodiclofeno e etoxazol foram realizados em ovos dos acarinos. Clorfenapir, e piridabem mostraram-se nocivos a N. californicus, causando mortalidades de 88,6 e 99%, respectivamente. Abamectina causou mortalidade de 62,1%, considerada elevada ao se comparar ao dinocape (2%), propargito (4,2%), enxofre (5%), fempropatrina (12,4%) e acrinatrina (22%). Cyflumetofen, óxido de fembutatina e deltametrina foram inócuos ao N. californicus. Espirodiclofeno não provocou inviabilidade de ovos e mortalidade nas larvas de N. californicus, contudo, etoxazole provocou 100% de mortalidade nas larvas do predador ao entrarem em contato como o resíduo do produto. Para B. phoenicis, abamectina, clorfenapir, dinocape, cyflumetofen, óxido de fembutatina, piridabem e propargito provocaram 100% de mortalidade. Fempropatrina (95%), acrinatrina (87%) e enxofre (76%) mostraram-se menos efetivos. O deltametrina não foi eficiente no controle do ácaro da leprose. Etoxazol e espirodiclofeno causaram inviabilidade em 100% dos ovos de B. phoenicis.

Toxic effect of a selection of medicinal plant products against the parasitic bee mite Varroa destructor

Varroa destructor is a dangerous pest directly for beekeeping and indirectly for crops that require insect pollination. Acaricides appeared to be effective against Varroa mite but their application within the hives contaminates the wax and honey. The problems associated with the use of acaricides proved considerable incentive to develop new treatment strategies and screening for potential acaricides to minimize these problems. Natural products might provide effective solution to the problem of varroatosis. In the present study, we tested medicinal plant extracts including Achillea millefolium, Artemisia sieberi, Mentha longifolia,Peganum harmala, Satureja sahandica, Teucrium polium and Thymus kotchyanus, andFerula assa-foetida resin against varroa mite. The mortality was counted after first and second weeks of treatment and total number of dead mites was recorded. All plant extracts and resin showed strong toxicity. However, F. assa- foetida resin and A. sieberi and T. kotschyanus extracts were stronger plant materials in the all tested times and displayed the highest number of mortality. These results demonstrated that tested plant extracts and resin can be suitable alternatives to conventional chemical substances. Key words: Honey bee, management, plant extracts, plant resin, Varroa destructor.

EFFECTIVENESS OF ESSENTIAL OILS OF MEDICINAL PLANTS AGAINST STORED PRODUCT MITE, SUIDASIA PONTIFICA OUDEMANS

Acaricidal activity of essential oils obtained from 28 selected medicinal plants against stored product mite, Suidasia pontifica Oudemans, was investigated using the dry film method. The bioassay was conducted in a glass tube, 0.4 cm in diameter, 3 cm long covered with fine nylon mesh on both ends. In preliminary tests, 1.0% (53 µg cm-2) of various essential oils and 95% ethanol used as control were evaluated. Each glass tube was treated internally with 20 µl essential oils. Observations were made at 24 h after treatment and the number of dead mites was recorded. At the dose of 1.0%, essential oils of clove (Syzygium aromaticum), cinnamon (Cinnamomum bejolghota), myrtle grass (Acorus calamus), betel vine (Piper betle), and turmeric (Curcuma longa) were highly toxic to S. pontifica with more than 70% mite mortality observed at 24 h. Dry film effect of essential oils at various concentrations (0, 0.05, 0.1, 0.5, 1.0 and 1.5% equaling to 0, 2.65, 5.3, 26.5, 53 and 79.5 µg cm-2, respectively) resulting in mite mortality observed at 24 h was used to establish LD50 values. Based upon 24 h LD50 values, the essential oil of cinnamon (fresh leaf) was the most toxic to the mite with high activity at 24.05 µg cm-2, followed by essential oils of clove (dried bud), myrtle grass, cinnamon (dried bark), clove (fresh leaf), turmeric and betel vine at 24.28, 28.34, 30.89, 33.67, 38.09 and 41.76 µg cm-2, respectively.

BartonellaquintanaTransmission from Mite to Family with High Socioeconomic Status

<i>Bartonella</i><i>quintana</i>Transmission from Mite to Family with High Socioeconomic Status

トマトの毛茸およびその滲出物がスワルスキーカブリダニの生存に及ぼす影響

We examined the effects of trichomes and the glandular trichome exudate on the survival of the predatory mite Amblyseius swirskii on young potted tomato plants. Removing the trichomes from the plant surface increased the survival rate from 0.8% (untreated plants) to 12.2% and decreased the mortality on plants from 63.3% ( untreated plants)to 0%. Almost all of the dead mites on untreated plants were observed adhering to the sticky secretions from trichome glands. To evaluate the toxicity of the secretions, we tested the effects of its main components (2-tridecanon and 2-undecanon) on A. swirskii by exposing mites to these chemicals for 48 h. All mites survived treatments with either of the chemical concentrations alone or a blend of these two chemicals. These results suggest that the main cause of the mortality of A. swirskii on tomatoes is not the toxicity of the secretions, but rather adhesion to the sticky secretions from the glandular trichomes.

Body size variability of Varroa destructor and its role in acaricide tolerance

Phenotypic plasticity has been defined as the ability of a genotype to produce different phenotypes when exposed to distinct environments throughout its ontogeny. Morphological variability of individuals is an example of this plasticity. Taking into account that several studies have reported a wide morphological variability in Varroa destructor populations, we evaluated if the body size plasticity of the parasite constituted a key factor able to modulate mites survival when they were exposed to a drug bioassays. Drug bioassays against mites were conducted using three different Syzygium aromaticum essential oil concentrations (0.5, 1, and 5 μl/capsule) and controls. After 4 h of exposition, mite mortality was registered. The width (WS) and length (LS) of the dorsal shield were measured in dead mites. General lineal models were carried to determine if V. destructor survival to acaricides was related to the explanatory variables. Data modelling confirmed that WS and LS variables, together with time interaction, were significantly related to V. destructor survival when the parasites were exposed to acaricides. The models proposed demonstrated that for the smaller S. aromaticum essential oil concentration, the larger the parasite body, the greater the probability that it remains alive at the end of the bioassay. Such relationship was inverse for the other two concentrations tested. Possible causes explaining the body size variability in V. destructor individuals were discussed.

Species list and habitat preference of Mesostigmata mites (Acari, Parasitiformes) in Latvia

This paper provides a review of the Mesostigmata mite material collected from 1992 up to 2009 in Latvia in a wide range of habitats: dead wood, Aphyllophorales fungi, forests, meadows, dune habitats, agricultural habitats, bogs, epiphytic mosses, and mites associated with Insecta and Vertebrata. A list of 368 Mesostigmata species of 27 families in Latvia with occurrence in different habitats is provided, which can be used as a future reference. According to occurrence among the habitats, the species are classified as generalist species, habitat specialist species or other species. About half of the species recorded were found to be specialist for a given habitat type. The highest proportion of habitat specialist species was found associated with the Vertebrata habitat. In total 39 species were recorded as generalist species; of them two (Parasitus kraepelini and Eviphis ostrinus) were recorded in 8 of the 10 habitat types. The highest number of generalist species was recorded in the Parasitidae (11 species), Aceosejidae (7 species) and Laelaptidae (5 species). Variation of the numbers of habitat specialist species within families among respective habitats was observed. Rhodacaridae and Laelaptidae had high number of specialist species in some habitat types. In total 32 rare species were recorded.

Molecular detection of establishment and geographical distribution of Brazilian isolates of Neozygites tanajoae, a fungus pathogenic to cassava green mite, in Benin (West Africa)

Diagnostic PCR with two specific primer pairs (NEOSSU and 8DDC) were used to monitor the establishment and geographical distribution of Brazilian isolates of Neozygites tanajoae Delalibera, Hajek and Humber (Entomophthorales: Neozygitaceae) released in Benin for the biological control of the cassava green mite, Mononychellus tanajoa (Bondar) (Acari: Tetranychidae). A total of 141 cassava fields were visited and samples of M. tanajoa suspected to be infected by N. tanajoae were collected in 60 fields distributed between the coastal Southern Forest Mosaic (SFM) and the Northern Guinea Savanna (NGS) zones of Benin, West Africa. Analysis of DNA samples of dead mites using the species specific NEOSSU primers revealed the presence of N. tanajoae in 46 fields. The second country specific pair of primers 8DDC revealed the presence of Brazilian isolates of N. tanajoae in 36 fields, representing 78.3% of fields positive for N. tanajoae. Brazilian isolates occurred from SFM to NGS zones in Benin, however, they were concentrated in fields located within former release zones (e.g. Department of Ouémé in the South and Borgou in the North). In contrast, the indigenous African isolates of N. tanajoae were evenly distributed in the sub-humid and humid savannah zones of the country. The mean infection rate of M. tanajoa with indigenous isolates of N. tanajoae was relatively low (5.3%) compared to Brazilian isolates (28%), indicating a higher biocontrol potential of the latter. This first post-release monitoring using PCR techniques showed that the Brazilian strains of N. tanajoae is well established in Benin and spread effectively in this area.

Treatment of canine‐generalized demodicosis: a blind, randomized clinical trial comparing the efficacy of Advocate®(Bayer Animal Health) with ivermectin

Advocate (moxidectin 2.5% + imidacloprid 10%) is a multiparasiticidal agent authorized for treating canine demodicosis in many countries. This blind, randomized clinical trial assessed the efficacy of Advocate at varying treatment intervals and compared it with that of oral ivermectin. Fifty dogs with generalized demodicosis were randomly assigned to one of four treatment groups: oral ivermectin (500 microg/kg once daily), Advocate applied at the authorized dose monthly (ADV1), every 2 weeks (ADV2) or weekly (ADV4). Each dog was evaluated every 4 weeks for 4 months or until negative scrapings at all sites resulted on two successive evaluations (parasitological cure). Miticidal efficacy was determined through deep skin scrapings taken from the same three sites on each occasion. Total numbers of live and dead adult mites, juveniles and eggs were determined. Thirty-five dogs completed the 4-month trial. Parasiticidal efficacy was assessed using several parameters including reduction in live adult mite counts. ancova analysis for this parameter confirmed that there were differences in efficacy among the treatment groups (P < 0.002). Tukey-Kramer all pairwise multiple comparison tests revealed that ADV4 was more effective than ADV1 (P = 0.016). Ivermectin was more effective than ADV1 (P = 0.003). Both ivermectin and ADV4 showed clinically substantial reductions in adult mite counts (89% for ADV4 and 98% for ivermectin). In conclusion, the efficacy of Advocate increased with the rate of application and weekly application may represent a new approach to the treatment of caninegeneralized demodicosis.

Responses to Varroa by honey bees with different levels of Varroa Sensitive Hygiene

SummaryMite resistance that we had earlier called suppression of mite reproduction (SMR) is a form of hygienic behaviour that we have named Varroa Sensitive Hygiene (VSH). With VSH, adult worker bees (Apis meiiifera) disrupt the reproduction of parasitic mites (Varroa destructor) by removing mite infested bee pupae from their cells. This study determines which brood cells are targeted by bees with VSH and which are not, and describes the relationship between brood removal and the sudden prevalence of sterile mites. We produced 26 colonies with different levels of VSH by backcrossing 14 queens from a high line, H (100% expression of VSH), and 12 queens from a low line, L (no VSH), to drones produced by an HL (high × low) queen. Because each of the 26 queens was mated to one drone, the resulting colonies were expected to represent the complete range of variability (0 to 100% of the alleles for VSH). To estimate brood removal, we measured mite populations in capped worker brood that was 0–3 days postcapping and again 7 days later when the cohort was aged 7–10 days postcapping. We correlated removal of mite-infested brood with the relative presence (at 7–10 days postcapping) of three classes of foundress mites: (1) viable: those with at least one daughter that could mature before emergence of the host bee; (2) nonviable: those with progeny but with no daughters that could reach maturity; and (3) no eggs: those with dead or nonovipositing foundress mites. As the rate of removal increased, both classes 1 and 2 showed significant declines, whereas class 3 was unchanged. Therefore, oviposition of the mite or something associated with mite oviposition provides the stimulus for bees with the VSH trait to remove mite infested pupae.

Molecular detection and differentiation of Brazilian and African isolates of the entomopathogen Neozygites tanajoae (Entomophthorales: Neozygitaceae) with PCR using specific primers

Neozygites tanajoae is an entomopathogenic fungus which has been used for biocontrol of the cassava green mite (Mononychellus tanajoa, CGM) in Africa. Establishment and dispersal of Brazilian isolates which have been introduced into some African countries in recent years to improve CGM control was followed with specific PCR assays. Two primer pairs, NEOSSU_F/NEOSSU_R and 8DDC_F/8DDC_R, were used to differentiate isolates collected from several locations in Brazil and from three countries in Africa, Benin, Ghana and Tanzania. The first primer pair enabled the species-specific detection of Neozygites tanajoae, while the second differentiated the Brazilian isolates from those of other geographical origin. PCR assays were designed for detection of fungal DNA in the matrix of dead infested mites since N. tanajoae is difficult to isolate and culture on selective artificial media. Our results show that all isolates (Brazilian and African) that sporulated on mummified mites were amplified with the first primer pair confirming their Neozygites tanajoae identity. The second pair amplified DNA from all the Brazilian isolates, but did not amplify any DNA samples from the African isolates. None of the two primers showed amplification neither from any of the non-sporulating mite extracts nor from the dead uninfected mites used as negative controls. We confirmed that the two primer pairs tested are suitable for the detection and differential identification of N. tanajoae isolates from Brazil and Africa and that they are useful to monitor the establishment and spread of the Brazilian isolates of N. tanajoae introduced into Benin or into other African countries for improvement of CGM biocontrol.