Mite Damage Research Articles

Entomopathogenic fungi as potential biocontrol agents of the ecto-parasitic mite, Varroa destructor, and their effect on the immune response of honey bees (Apis mellifera L.)

Three isolates of each of the entomopathogenic fungi, Metarhizium anisopliae, Beauveria bassiana and Clonostachys rosea, were assessed for their pathogenicity to the honey bee parasitic mite, Varroa destructor. The fungi were applied to varroa mites by immersing them in a spore solution, and then the inoculated mites were placed on honey bee brood inside capped cells. At 7days post inoculation (dpi), the three fungi caused significant varroa mortality compared to non-inoculated mites. In brood treated only with varroa mites, expression of the honey bee genes, hymenoptaecin and poly U binding factor 68 Kd (pUf68), decreased over time, while expression of blue cheese (BlCh) and single minded (SiMd) was not affected. In brood inoculated directly only with M. anisopliae or B. bassiana, the emerged adults showed reduced weight indicating infection by the fungi, which was confirmed by observation of hyphae in the brood. Fungal infection of the brood resulted in increased expression of hymenoptaecin, pUf68 and BlCh, but not SiMd. In brood treated with varroa mites that had been inoculated with the fungi, expression of hymenoptaecin, pUf68 and BlCh, but not SiMd, was even more up-regulated. While varroa mites can suppress gene expression in honey bee brood, varroa mites infected with entomopathogenic fungi induced their expression. This may be due to a low level of fungal infection of the bee, which negated the immunosuppression by the mites. Therefore, entomopathogenic fungi could reduce varroa mite damage to honey bee brood by both infecting the parasite and preventing varroa-associated suppression of honey bee immunity.

Farmers' perception of coconut mite damage and crop diversification alternatives in the coastal belt of Tanzania

This article analysed farmers' perceptions of the effects of coconut mite in their livelihood and assessed crop diversification as a copping strategy for reduced coconut production. A socio-economic model of farmers' decisions on intercropping as an indicator for overall crop diversity was developed. The study was conducted between November 2009 and March 2010 in five districts in Tanzania, which were selected on the basis of the coconut's economic importance, using structured questionnaires which were administered to 200 household heads. Respondents were categorized in three groups – resource-poor farmers (43% of sample), medium-level farmers (50%) and well-off farmers (7%) according to six criteria. More than 80% of farmers were aware of the negative effects of the coconut mite. The result further indicated that the damaged nuts cause a loss of more than 30% of the cash income from coconut. Intercropping coconut with cassava, maize, cashew nut, sorghum and pineapples were the alternatives used by farmers to cope with declining coconut production caused by coconut mite and lethal yellowing disease. Land ownership and size, income from crops, non-farm income and family size were the main factors that influenced the farmer's decision to diversify crops. Although farmers diversify their cropping systems in order to be self-reliant, there is still a need to promote policies and programmes that will address coconut production constraints such pests and diseases such as rehabilitation of old plantations.

Spectral monitoring of two-spotted spider mite damage to pepper leaves

Two-spotted spider mites (TSSM; Tetranychus urticae Koch) cause significant damage to crops and yields, in the field as well as in greenhouses. By feeding, TSSM destroy chloroplast-containing cells; this damage can be spectrally detected in the reflectance of the visible and near-infrared regions. This study focuses on hyperspectral reflectance data of greenhouse pepper (Capsicum annuum) leaves, obtained by integrated sphere. The reflectance data were transformed into vegetation indices allowing early TSSM damage detection by separation between leaf damage levels. One-way analysis of variance of coupled damage levels was applied to each of the vegetation indices. We concluded that early identification of TSSM greenhouse pepper leaf damage can be obtained by multispectral means. Furthermore, the proposed methods may identify the damage on the upper side of the leaves although the TSSM feed on the underside of leaves.

Genotypic variability and relationships between mite infestation levels, mite damage, grooming intensity, and removal of Varroa destructor mites in selected strains of worker honey bees (Apis mellifera L.)

The objective of this study was to demonstrate genotypic variability and analyze the relationships between the infestation levels of the parasitic mite Varroa destructor in honey bee (Apis mellifera) colonies, the rate of damage of fallen mites, and the intensity with which bees of different genotypes groom themselves to remove mites from their bodies. Sets of paired genotypes that are presumably susceptible and resistant to the varroa mite were compared at the colony level for number of mites falling on sticky papers and for proportion of damaged mites. They were also compared at the individual level for intensity of grooming and mite removal success. Bees from the “resistant” colonies had lower mite population rates (up to 15 fold) and higher percentages of damaged mites (up to 9 fold) than bees from the “susceptible” genotypes. At the individual level, bees from the “resistant” genotypes performed significantly more instances of intense grooming (up to 4 fold), and a significantly higher number of mites were dislodged from the bees’ bodies by intense grooming than by light grooming (up to 7 fold) in all genotypes. The odds of mite removal were high and significant for all “resistant” genotypes when compared with the “susceptible” genotypes. The results of this study strongly suggest that grooming behavior and the intensity with which bees perform it, is an important component in the resistance of some honey bee genotypes to the growth of varroa mite populations. The implications of these results are discussed.

Damage level of the two-spotted spider mite Tetranychus urticae Koch (acari: tetranychidae) in soybeans

Among phytophagous spider mites, the two-spotted spider mite Tetranychus urticae Koch, 1836 is one of the most important agricultural pests, not only because of the damage it causes, but also because it has a wide host range, infesting many commercial crops such as leafy greens, cotton, beans, and soybeans, among others. This study was carried out in a greenhouse of the Faculdade de Ciências Agrárias (FCA) of the Universidade Federal da Grande Dourados (UFGD), located in the city of Dourados, state of Mato Grosso do Sul. The experiment was arranged in a randomized block design with 5 treatments and 4 replicates. The treatments consisted of 5 levels in percentage of chlorotic symptoms (indicating mite damage): 0%, 25%, 50%, 75%, and 100%. All of the characteristics evaluated, except for number of pods per plant, the number of seeds per plant, the total weight (productivity), and the weight of 1000 seeds, were significantly influenced by the different levels of chlorotic symptoms. The economic damage level for the two-spotted spider mite Tetranychus urticae, according to the equation y = 66.63-0.51 x, based on the price of US$ 11.00 per bag of soybeans and a control cost of US$ 16.00, would be 15.80% chlorotic symptoms. At a price of US$ 29.00 per bag with the same control cost, the economic damage level would be 13% of chlorotic symptoms.

<p><strong>Impact of the date of transplanting on population dynamics of the rice sheath mite, </strong><strong><em>Steneotarsonemus spinki </em></strong><strong>Smiley (Acari: Tarsonemidae), on the rice cultivar IET-4786 in the Gangetic Plains ofWest Bengal, India*</strong></p>

West Bengal is one of the main rice producing Indian states, where about 14 million t are produced in 6.2 million ha. In recent years, the rice sheath mite, Steneotarsonemus spinki Smiley, has been one of the most destructive mite pests of this crop in the Bengal Basin, especially in the wet season. It colonizes the leaf sheath, causing chaffy and sterile grains and brownish patches on the affected plant parts.An experiment was conducted to study the impact of five different dates of transplanting (at seven day intervals) of rice cultivar IET-4786 on mite density and crop yield. The study was conducted from July to November 2007 in Kalyani, West Bengal. Rice sheath mite population increased gradually, reaching the maximum level on September 25 on plants of the first three planting dates, and on October 5, on plants of the last two planting dates. The result revealed that peak incidence of mite occurred at the ripening stage of the first three planting dates, but significantly higher number of mite population and damage symptoms in all plants were observed in the last two planting dates, at the panicle emerging to flowering stage. Poor yield was obtained from plants of the last planting date, which could be due to the sheath mite attack.

<p><strong>Coconut destiny after the invasion of </strong><strong><em>Aceria guerreronis </em></strong><strong>(Acari: Eriophyidae) in India*</strong></p>

The coconut mite, Aceria guerreronis Keifer, has emerged as a common menace to most of the coconut plantations in India. After its first upsurge in Kerala at the end of the 1990´s, the mite has spread to many states in southern and northern India, causing considerable damage. Coconut provides one third of the agricultural income in the regions in which it is grown and more than 10 million people are dependent on this cash crop directly or indirectly through coconut-based industries like coir, copra, oil, honey, furniture, handicrafts, beverages, bakery products and so on. The economic instability of the coconut farming community and the people employed in coconut-based industries rank the highest order. A critical assessment of the various problems created by A. guerreronis in the agricultural economy of India is presented in order to supplement data on crop loss through nut malformation, nut fall, loss in fibre and copra. Varietal differences in susceptibility of the plant and future strategies in terms of management practices for an early control of the mite are discussed, and suggestions for future activities to alleviate mite damage are presented.

Interaction between Phaseolus plants and two strains of Kanzawa spider mites

Kanzawa spider mites, Tetranychus kanzawai, are polyphagous herbivores that feed on various plant families including legumes. Lima bean leaves infested by T. kanzawai emit a specific blend of volatiles. We found that two strains of spider mites were able to induce different blends of volatile to lima bean plants infested by either strain. Here we describe the genetic properties of the two strains and the responses of lima bean plants to the mite damage in terms of expression of defensive genes, emission of herbivore-induced plant volatiles, and phenotypic response of lima bean and other legume leaves (leaf color).

Occurrence and distribution of cassava pests and diseases in Rwanda

A survey was conducted in 2007 to obtain information on the distribution, incidence and severity of cassava pests and diseases in Rwanda, and determine how these parameters relate with cassava varieties and intercropping. Local (unimproved) cultivars predominated in most farmers’ fields (over 83%) and 78% of the fields were intercropped. Cassava green mite, Mononychellus tanajoa and cassava whitefly, Bemisia tabaci, were the most abundant pests. Within-field incidence of green mite averaged 42% but damage was mild (average score of 2.3 on a scale of 5). Typhlodromalus aripo, the mite predator of green mite, was found in 28% of the fields surveyed, with a mean incidence of 5.7% within fields. The mean number of B. tabaci whitefly adults on the apical five leaves was 0.92 whereas the mean number of whitefly nymphs on a middle leaf was 5.2. Incidence of cassava mosaic disease within sites averaged 33.2%. Cutting infection accounted for 66% of infected plants but the relative contribution of cutting and whitefly infection varied among the major varieties. Mite damage as well as mosaic disease incidence and severity were higher on local varieties. However, whitefly populations were higher on improved varieties. Intercropping was associated with lower pest populations and disease incidence and severity.

Varietal Resistance of Okra against Two Spotted Spider Mite, Tetranychus urticae

The present investigation was undertaken to evaluate the okra germplasm and identify the potential sources of two spotted spider mite resistance that can be exploited for the improvement of commercial okra. Based on the mean mite population and damage score six entries out of the 58 entries namely Kasturi bhendi, (R), Dharmapuri local (MR), Parbani Kranti (MR), Pusa Sawani (MR), COBhH1 (MR) and Mahyco 10 (S) with varied levels of resistance were identified.

곤봉가루응애(Tyrophagus similis)에 의한 시설재배 시금치 피해

친환경 시설재배 시금치에서 생장점 부위를 가해하는 응애를 채집하여 곤봉가루응해(Tyrophagus similis Volgin, 1949)로 동정되었다 곤봉가루응애에 의한 시금치의 피해는 주로 생장점부근의 어린잎에서 나타나는데 곤봉가루응애의 크기가 0.5 nm 정도로 매우 작아 농민들이 육안으로 해충을 확인하기는 매우 어렵다. 본 연구에서는 우리나라에서 처음으로 확인된 곤봉가루응애에 의한 시금치 피해에 대해 보고하고 응애의 형태 및 피해증상에 대한 정보를 제공하고자 한다. A mite damage was observed in spinach (Spinacia oleracea L.) under organic culture greenhouses. The mite was identified as Tyrophagus similis Volgin, 1949. It was very difficult for the farmers to diagnose the mite damage because of its tiny size about 0.5 nm in length. And the symptom was not clear at the early growth stage of the spinach because the mite mainly attack the very young leaves. In this study, we first report the spinach damages by T. similis in Korea. Informations on the mite morphology and the spinach damage symptoms are provided for the diagnosis.

Genetic variation in jasmonic acid- and spider mite-induced plant volatile emission of cucumber accessions and attraction of the predator Phytoseiulus persimilis.

Cucumber plants (Cucumis sativus L.) respond to spider–mite (Tetranychus urticae) damage with the release of specific volatiles that are exploited by predatory mites, the natural enemies of the spider mites, to locate their prey. The production of volatiles also can be induced by exposing plants to the plant hormone jasmonic acid. We analyzed volatile emissions from 15 cucumber accessions upon herbivory by spider mites and upon exposure to jasmonic acid using gas chromatography—mass spectrometry. Upon induction, cucumber plants emitted over 24 different compounds, and the blend of induced volatiles consisted predominantly of terpenoids. The total amount of volatiles was higher in plants treated with jasmonic acid than in those infested with spider mites, with (E)-4,8-dimethyl-1,3,7-nonatriene, (E,E)-α-farnesene, and (E)-β-ocimene as the most abundant compounds in all accessions in both treatments. Significant variation among the accessions was found for the 24 major volatile compounds. The accessions differed strongly in total amount of volatiles emitted, and displayed very different odor profiles. Principal component analysis performed on the relative quantities of particular compounds within the blend revealed clusters of highly correlated volatiles, which is suggestive of common metabolic pathways. A number of cucumber accessions also were tested for their attractiveness to Phytoseiulus persimilis, a specialist predator of spider mites. Differences in the attraction of predatory mites by the various accessions correlated to differences in the individual chemical profiles of these accessions. The presence of genetic variation in induced plant volatile emission in cucumber shows that it is possible to breed for cucumber varieties that are more attractive to predatory mites and other biological control agents.

Plant–eriophyoid mite interactions: cellular biochemistry and metabolic responses induced in mite-injured plants. Part I

This review is a comprehensive study of recent advances related to cytological, biochemical and physiological changes induced in plants in response to eriophyoid mite attack. It has been shown that responses of host plants to eriophyoids are variable. Most of the variability is due to individual eriophyoid mite-plant interactions. Usually, the direction and intensity of changes in eriophyoid-infested plant organs depend on mite genotype, density, or the feeding period, and are strongly differentiated relative to host plant species, cultivar, age and location. Although the mechanisms of changes elicited by eriophyoid mites within plants are not fully understood, in many cases the qualitative and quantitative biochemical status of mite-infested plants are known to affect the performance of consecutive herbivorous arthropods. In future, elucidation of the pathways from eriophyoid mite damage to plant gene activation will be necessary to clarify plant responses and to explain variation in plant tissue damage at the feeding and adjacent sites.

Natural Enemies of Honey Bees <i>Apis Cerana</i> F and Associated Problems in Beekeeping in Kaski, W Nepal.

A study was conducted at the southern belt of Kaski District during August 2003 to July 2004 to identify natural enemies of honey bee Apis cerana Fab. and associated problems in beekeeping. Four species of wasps viz: Vespa velutina, V. bicolor, V. tropica and V. basalis were observed preying on Apis cerana. Six species of Ants were collected from hive attacking honey bees viz Componatus sp, Sima sp, Monomorium sp, Myrmica sp and two unidentified. Four species of spider viz Palatar indicus, Ariope areuta and the other two belonging to family Theridae and Araneidae were collected from the hives. Two species of Birds, Green bee- Eater and Drongo; One species of Beetle, One Chalcid (Antrocephalus sp) were identified.The disease Thaisac brood, Mite, Wax Moth and pesticide damage, deforestation, absconding of bees, lack of technical knowledge were important problems for apiculture in study area. Key words: Apis cerana F; Enemies; Pesticide; Absconding; Kaski Journal of Natural History MuseumVol. 24, 2009Page: 89-95

Local dispersion and damage of Corymbia citriodora subsp. variegata (Myrtaceae) regrowth by eriophyid mites (Acari: Eriophyoidea)

Eriophyid mites (Acari: Eriophyoidea: Eriophyidae: Rhombacus sp. and Acalox ptychocarpi Keifer) are recently-emerged pests of commercial eucalypt plantations in subtropical Australia. They cause severe blistering, necrosis and leaf loss to Corymbia citriodora subsp. variegata (F. Muell.) K.D. Hill & L.A.S. Johnson, one of the region’s most important hardwood plantation species. In this study we examine the progression, incidence and severity of these damage symptoms. We also measure within-branch colonisation by mites to identify dispersive stages, and estimate the relative abundance of the two co-occurring species.Rhombacus sp., an undescribed species, was numerically dominant, accounting for over 90 % of all adult mites. Adults were the dispersive stage, moving mostly within branches, but 12 % of recruitment onto new leaves occurred on previously uninfested branches. Damage incidence and severity were correlated, while older leaves had more damage than younger leaves. “Patch-type” damage was less frequent but was associated with higher mite numbers and damage scores than “spot-type” damage, while leaf discoloration symptoms related mostly to leaf age.

Evaluation of a Sib-mated Population of Buddleja davidii ‘White Bouquet’ × Buddleja indica Hybrids

Abstract A hybridization experiment to sib-cross a population of B. davidii Franch. ‘White Bouquet’ × B. indica Lam. hybrids was initiated in 2004 to generate a larger population of such hybrids to assess landscape potential. Large populations from the sib-mated B. davidii ‘White Bouquet’ × B. indica hybrids can be generated. The population was initially assessed for growth habit, leaf size, floriferousness, seed morphology, and winter hardiness. Susceptibility to spider mite damage was also noted in the population. Although these hybrids have desirable traits such as non-dehiscent fruit and ornamental foliage, further hybridization is needed to address undesirable traits such as sparse growth and flowering along with spider mite susceptibility.

Remote sensing of spider mite damage in California peach orchards

Remote sensing techniques can decrease pest monitoring costs in orchards. To evaluate the feasibility of detecting spider mite damage in orchards, we measured visible and near infrared reflectance of 1153 leaves and 392 canopies in 11 peach orchards in California. Pairs of significant wavelengths, identified by Partial Least Squares regression, were combined into normalized difference indices. These and 9 previously published indices were evaluated for correlation with mite damage.Eight spectral regions for leaves and two regions for canopies (at blue and red wavelengths) were significantly correlated with mite damage. These findings were tested by calculating normalized difference indices from the Red and Blue bands of six multispectral aerial images.Index values were linearly correlated with mite damage (R2=0.47), allowing identification of mite hotspots in orchards. However, better standardization of aerial imagery and accounting for perturbing environmental factors will be necessary for making this technique applicable for early mite detection.

Controlling Varroa destructor (Acari: Varroidae) in honeybee Apis mellifera (Hymenoptera: Apidae) colonies by using Thymovar® and BeeVital®

This study was carried out to determine the effects of Thymovar® and BeeVital® on reducing Varroa mite (Varroa destructor) damage in honey bee (Apis mellifera L.) colonies in spring season. Average percentage of Varroa infestation level was determined as 24.27 on adult workers before the treatments. The drugs were applied two times on 25 September and 16 October 2006. Average percentage of Varroa infestation levels were determined as 5.18%, 10.78% and 35.45% after the first application, 1.90%, 7.05% and 61.15% after the second application in Thymovar®, BeeVital® and control groups, respectively. Average efficacies of Thymovar® and BeeVital® were found to be 96.91% and 88.66%, respectively. Difference between drug efficacies on Varroa mite was found significant (P<0.01). There was no queen, brood and adult honeybee mortality in all group colonies during the research.

Twospotted Spider Mite Population Level, Distribution, and Damage on Ivy Geranium in Response to Different Nitrogen and Phosphorus Fertilization Regimes

The influence of plant nutrition on arthropod pests has often been studied by comparing plants provided suboptimal nutrients with those provided sufficient or luxurious nutrients, but such results have limited applicability to commercially produced crops because nitrogen (N) and phosphorus (P) are almost never limiting in greenhouse production. We conducted a series of experiments with ivy geranium, Pelargonium peltatum (L.) L'Hŕ. ex Aiton 'Amethyst 96' to determine the response of twospotted spider mite, Tetranychus urticae Koch (Acarina: Tetranychidae), to six combinations of N (8 or 24 mM) and P (0.32, 0.64, or 1.28 mM) that reflected commercial production practices. All six combinations resulted in saleable plants when plants were free of spider mites, but tissue N and P concentrations among fertilizer combinations were different. On mite-infested plants, no difference in mite numbers or plant damage was found in response to N fertilization rates. Phosphorus had no effect on mite population level until week 8, at which time plants fertilized with 0.64 mM P had slightly more mites than plants fertilized with 0.32 mM. However, overall quality and dry weight of plants fertilized by 0.32 mM P was lower than that of 0.64 and 1.28 mM, which suggests that ivy geranium plants fertilized with the higher P rates may better compensate for mite feeding damage. Positive correlations were found between within-plant distribution of mites and the corresponding tissue N and P concentrations in three foliage strata, suggesting that tissue nutrient content may influence mite selection of feeding sites.

Twospotted Spider Mite Population Level, Distribution, and Damage on Ivy Geranium in Response to Different Nitrogen and Phosphorus Fertilization Regimes

Twospotted Spider Mite Population Level, Distribution, and Damage on Ivy Geranium in Response to Different Nitrogen and Phosphorus Fertilization Regimes