Sciothrips Cardamomi Research Articles

Field evaluation of Lecanicillium psalliotae and development of an integrated pest management strategy against Sciothrips cardamomi

Cardamom thrips, Sciothrips cardamomi Ramk. (Thysanoptera: Thripidae) cause huge economic losses to cardamom, Elettaria cardamomum (L.) Maton., a high-value spice crop, in all growing regions worldwide. To date, the pest is managed by synthetic pesticides, which results in harmful residues in the produce and also pose a serious threat to the environment. In our studies, we evaluated the biocontrol potential of a recently isolated entomopathogenic fungus, Lecanicillium psalliotae (Treschew) Zare & W. Gams (Ascomycota: Hypocreales) under field conditions for two years in two major cardamom growing states, Kerala and Karnataka in India. The results indicated that four rounds of soil application of the fungus granules reduced capsule damage by thrips significantly compared to control, whereas spray application of the fungus was ineffective. The compatibility of the fungus with commonly used pesticides in cardamom was tested under laboratory conditions and the fungus was found compatible with the pesticides, spinosad, fipronil and copper oxychloride. Further, we evaluated the fungus along with other management options such as application of recommended insecticide (quinalphos), reduced-risk insecticide (spinosad) and soil application of fungal entomopathogen (L. psalliotae) and in combination with insecticides for developing an integrated pest management (IPM) module for the management of the pest. The trials indicated that initial sanitization of the crop with either quinalphos or spinosad sprays followed by three rounds of soil application of the fungus or spray application of spinosad and soil application of L. psalliotae twice alternatively, reduced capsule damage by thrips significantly. Our findings offer a scope for integrated management of cardamom thrips with reduced risk to the environment. This is the first IPM schedule developed against this major pest of cardamom with biological control as a component.

Seasonal Incidence of Sciothrips Cardamomi Ramk. On M2 and M3 Varieties of Cardamom

Cardamom thrips Sciothrips cardamomi Ramk. is one of the important key pests of cardamom in hill and coastal zone of Karnataka. This study is on its seasonal incidence on varieties viz., M2 and M3 (M= Mudigere). It was observed that the mean incidence varied between 2.90 and 2.71 thrips/ leaf sheath during February-May; and on panicle, however, the incidence was more during September (2.63 and 2.53 thrips/ panicle, respectively). The correlation coefficients revealed a significant positive correlation with temperature and incidence in leaf sheath- in M2 (r = 0.571) and M3 (r = 0.636) varieties.

Plant morphological traits associated with field resistance to cardamom thrips (Sciothrips cardamomi) in cardamom (Elettaria cardamomum)

AbstractCardamom thrips (Sciothrips cardamomi) is a major insect pest of cardamom (Elettaria cardamomum) causing severe economic losses to the crop in all cardamom producing countries. The present control measures rely heavily on chemical insecticides, which in addition to increased input costs also lead to pesticide residues in the produce and environmental hazards. Although the crop is of high commercial value, limited efforts have been made to identify sources of resistance to this major pest. Exploiting sources of resistance along with integrated pest management tactics will help to reduce pesticide usage in this crop promoting sustainable production. The present study aimed at identifying sources of resistance against cardamom thrips and the associated plant morphological traits conferring resistance against the pest. Field screening of 180 cardamom germplasm accessions for 3 years at Appangala, Karnataka, India, resulted in identification of eight accessions resistant to cardamom thrips. Differences in panicle type and the nature of adherence of leaf sheath to the pseudostem explained a significant amount of the variance in resistance and therefore are likely to play a major role in conferring resistance against this pest. Multiple regression analysis of the different traits indicated that accessions with prostrate panicles having leaf sheath loosely adhered to the pseudostems were found to have significantly less thrips damage, when compared with other panicle and leaf sheath types. However, persistence of flower bract did not have a significant additive effect on imparting resistance against thrips. Metabolomic analysis of the accessions may provide further insight into the existence of supplementary biochemical mechanisms, if any, in imparting resistance. The identified traits and accessions can be exploited in future breeding programmes for developing thrips resistant cardamom varieties.

Management of cardamom borer, Conogethes punctiferalis Guenee and thrips, Sciothrips cardamomi Ramk using diafenthiuron and its residues in fresh and cured cardamom capsules

ABSTRACTCardamom is an important spice crops used all over the world as a flavoring agent of food materials. The productivity is limited by insect pests and thus effective insecticide which does not leave residues in the produce is the need of the hour. Diafenthiuron 50 WP @ 300 g a.i ha−1 was found effective in managing both the cardamom shoot and capsule borer, Conogethes punctiferalis Guenee and thrips, Sciothrips cardamomi Ramk and thus can be recommended for pest management. Cardamom capsules were collected from the plants that were sprayed with diafenthiuron at the recommended dose of 200 g a.i ha−1 and double the dose (400 g a.i ha−1), which were then analyzed under HPLC with a normal phase column. The diafenthiuron residue was below the detectable levels of 0.05 µg g−1 in the harvested produce (both fresh and cured) after twelve and fourteen days of spray. So, capsules can be harvested safely without any risk of insecticide residues 12 days after spraying of diafenthiuron and thus can be recommended for usage in cardamom plantations.

Multifarious plant growth promotion by an entomopathogenic fungus Lecanicillium psalliotae

An entomopathogenic fungus, Lecanicillium psalliotae strain IISR-EPF-02 previously found infectious to cardamom thrips, Sciothrips cardamomi promoted plant growth in cardamom, Elettaria cardamomum. The isolate exhibited direct plant growth promoting traits by production of indole-3-acetic acid and ammonia and by solubilizing inorganic phosphate and zinc. It also showed indirect plant growth promoting traits by producing siderophores and cell wall-degrading enzymes like, α-amylases, cellulases and proteases. In pot culture experiments, application of the fungus at the root zone of cardamom seedlings significantly increased shoot and root length, shoot and root biomass, number of secondary roots and leaves and leaf chlorophyll content compared to untreated plants. This is the first report on the plant growth promoting traits of this fungus. The entomopathogenic and multifarious growth promoting traits of L. psalliotae strain IISR-EPF-02 suggest that it has great potential for exploitation in sustainable agriculture.

Isolation and characterization of a Lecanicillium psalliotae isolate infecting cardamom thrips (Sciothrips cardamomi) in India

Cardamom thrips (Sciothrips cardamomi Ramk.) (Thysanoptera: Thripidae) cause serious economic loss to cardamom, Elettaria cardamomum (L.) Maton (Zingiberaceae). A fungus was isolated from cadavers of cardamom thrips collected during a survey in cardamom plantations of Wayanad District, Kerala, India and identified as Lecanicillium psalliotae (Treschew) Zare & W. Gams (Ascomycota: Hypocreales) based on morphological and molecular studies. Bio-assay studies with purified conidial suspension further confirmed the infectivity of the fungus to thrips. At the highest dose tested (1 × 107 conidia ml−1), up to 62.9 % mortality was recorded in the test population, ten days post inoculation. The fungal pathogenesis on adult thrips was documented by scanning electron microscopic studies. This is the first record of L. psalliotae in India and also a first report of a fungus infecting cardamom thrips.

Single strain infection of adult and larval cardamom thrips (Sciothrips cardamomi) by Wolbachia subgroup Con belonging to supergroup B in India

The presence of Wolbachia in cardamom thrips (Sciothrips cardamomi), a major insect pest of cardamom (Eletteria cardamomum) was detected by amplification of the fast evolving outer membrane protein coding gene wsp of the bacterium. Studies on the identity of Wolbachia showed infection with only subgroup Con belonging to supergroup B, and both male and female thrips were infected with the same Wolbachia subgroup. The incidence of Wolbachia infection varied from 15.0 to 87.8% in thrips collected from seven cardamom growing districts of different States in India. The overall infection rate was 53.5% with 57.1% male and 50.6% female populations infected with the bacterium. DNA sequencing and phylogenetic analysis revealed that all the Wolbachia isolates from thrips clustered together indicating that all thrips were infected by the same Wolbachia strain. This is the first ever report of Wolbachia infection in cardamom thrips and the possibility of using the bacterium as a tool in biological control of this important insect pest is discussed.

Efficacy of Neem Oil on Cardamom Thrips,Sciothrips cardamomiRamk., and Organoleptic Studies

The neem tree contains promising pest control substances which are effective against many pests. Oil extracted from neem seeds was used against cardamom thrips,Sciothrips cardamomi, a severe and economic pest of cardamom. Neem oil formulations, namely, Tamil Nadu Agricultural univeristy neem oil (TNAU NO) (acetic acid & citric acid), were found effective against the pest with a overall damage reduction of 30% after 14 days of treatment. The percent damage reduction in capsules over control after three consecutive sprays of TNAU NO(C) 2% and TNAU NO(A) 2% was 78.3 and 75.2 percent, respectively. The newly extracted and unformulated neem oil, though found inferior to the formulated one, still found to cause 50% and 70% reduction in damage caused by thrips at two and three rounds of sprays, making it useful in pest management. Organoleptic tests conducted on cardamom capsules sprayed with neem oil revealed no significant difference in taste, aroma, and overall acceptability of cow milk boiled with cardamom. Thus, TNAU NO (A and C) 2% was found effective against cardamom thrips with no adverse organoleptic properties and can be recommended.

Physical and biological compatibility of diafenthiuron with micro/macro nutrients fungicides and biocontrol agents used in cardamom

In the context of complex field problems, compatibility of an efficacious insecticide with other agrochemicals normally used in the field is essential. In this view diafenthiuron, a novel insecticide which inhibits ATP synthesis, used widely for pest management in cardamom, was tested for its compatibility with agrochemicals viz., fungicides and nutrients normally used in the crop. The results revealed that all the chemicals tested were physically and biologically compatible with diafenthiuron by means of physical stability and phytotoxicity ratings in the field. But the bioefficacy study on Conogethes punctiferalis in the laboratory and bioefficacy studies in the field against Sciothrips cardamomi reveal that diafenthiuron is incompatible and should not be sprayed along with fungicides like mancozeb and copper oxychloride. Another study on the compatibility of diafenthiuron with antagonistic microorganisms of plant pathogens viz., Trichoderma viride and Pseudomonas fluorescens revealed that diafenthiuron had some inhibitory effect on the mycelial growth of T. viride. Diafenthiuron did not affect the growth of P. fluorescens and thus can be used simultaneously for the control of insect pests and seed- and soil-borne diseases.

Identification and Screening of New Generation Insecticides against Cardamom Thrips (<i>Sciothrips cardamomi</i>) in Cardamom Cultivations in Sri Lanka

Two thrips species were identified from cardamom (Elettaria cardamomum) cultivations in Sri Lanka. They are the cardamom leaf thrips, Panchaetothrips indicus Bagnall (1912) and the cardamom thrips, Sciothrips cardamomi (Ramakrishna, 1935). Sciothrips cardamomi collected from Nuwara Eliya district is emerging as a devastating pest of cardamom (Elettaria cardamomum) in the district. Both adults and larvae damage panicles, flowers and capsules of cardamom. Injury to panicles leads to stunted growth, and damaged flowers fall prematurely. Affected tender capsules show scabby growth on the surface as they mature and hence have no market value. To manage this problem and as an immediate control measure, damage causing thrips were identified, damage estimated and seven new generation insecticides were screened at Kabragala Estate in Elamulla, Nuwara Eliya. The estimated direct pod damage was 91.7 ± 3.2%. Severely damaged pods showed significantly lower pod weight than undamaged pods. No significant difference in the pod weight was observed between undamaged pods and pods with less than 2/3 of scabby area. The insecticides Actara (thiamethoxam), Match (lufenuron), Regent (fipronil) and Calypso (thiacloprid) successfully reduced the pod damage while Matric (chromafenozide), Mimic (tebufenozide) and Mospilan (acetamiprid) did not reduce the damage percentage. But higher yields of 335.54 and 304.98 g/bush/harvest were obtained from the plots treated with Actara or Match respectively, in comparison to all other treatments. Therefore, either Actara or Match could be recommended for the management of S. cardamomi in cardamom plantations. Key words: Sciothrips cardamomi, Panchaetothrips indicus, Elettaria cardamomum doi: 10.4038/cjsbs.v37i2.501 Cey. J. Sci. (Bio. Sci.) 37 (2): 137-142, 2008

Honey bees of the cardamom ecosystem and the selective toxicity of diafenthiuron to four different bee species in the laboratory

SummaryBees are important pollinators necessary for fruit set in cardamom (Elettaria cardamomum). Apis cerana indica, Apis dorsata, Trigona iridipennis and Amegilla spp. were observed in cardamom plantations of south India. Since cardamom is attacked by an array of insect pests, synthetic insecticides were used in crop management. Diafenthiuron is one such insecticide found to be very effective against the cardamom borer, Conogethes punctiferalis and thrips, Sciothrips cardamomi. Most insecticides used in crop protection are reported to be hazardous to bees, so diafenthiuron was also tested for its toxicity to bees. Diafenthiuron was found to be slightly harmful to A. dorsata, A. cerana indica, A. foreaand moderately harmful to T. iridipennis. In particular, it was slightly to moderately toxic to bees on contact with treated surfaces in the laboratory. T. iridipennis and A. dorsata are found abundantly in the cardamom ecosystem and unfortunately highly susceptible to the insecticide. It was found that diafenthiuron is highly toxic when applied to the thorax of bees but it is less toxic on ingestion, i.e, contact toxicity is higher than oral toxicity. The labellum, the attractive part of the cardamom flower, where the bees land is not heavily exposed to pesticide sprays in the field because of its position and other reasons, so bees have a reduced chance of exposure to the pesticide in the field. Under critical situations, however, spraying of the chemical during peak bee activity should be avoided.

Excluding Pests from Red Ginger Flowers with Insecticides and Pollinating, Polyester, or Polyethylene Bags

Exclusion bags and pollinating bags were evaluated for efficacy against pests of red ginger,Alpinia purpurata (Vieill.) K. Schum. Exclusion bags made from spunbonded polyester or polyethylene floating row covers, and nonwoven polyethylene pollinating bags were secured to flowers with masking tape alone and in combination with foliar sprays of chlorpyrifos. Bagging flowers significantly reduced the mean percentage of flowers infested with ants, Pheidole megacephala (F.) and Technomlyrmex a/hipes (F. Smith), and banana aphids, Pentalonia nigroneroosa Coquerel. A single foliar application of chlorpyrifos reduced only the mean percentage of flowers infested with banana aphids. One foliar spray of chlorpyrifos before bagging flowers significantly reduced the mean percentage of flowers infested with ants, banana aphids, cotton aphids, Aphis gossypii Glover, and cardamom thrips, Sciothrips cardamomi (Ramakr). Eight, 16, and 49% of flowers harvested from spun bonded polyethylene, pollination, and spunbonded polyester bags, respectively, were mechanically injured or sunburned.

Pest Management Before Harvest and Insecticidal Dip After Harvest as a Systems Approach to Quarantine Security for Red Ginger

A systems approach consisting of insecticide application before harvest and use of an insecticidal dip after harvest provided quarantine security that eliminated all insect pests of red ginger, Alpinia purpurata (Vieill.) K. Schum., including the banana aphid, Penta Ionia nigronervosa Coquerel; cotton aphid, Aphis gossypii Glover; citrus mealybug, Plano coccus citri (Risso); obscure mealybug, Pseudococcus affinis (Maskell); longtailed mealybug, Pseudococcus longispinus (Targioni-Tozzetti); cardamom thrips, Sciothrips cardamomi (Ramakr); black earwig, Chelisoches Mario (F.); and an ant, Technomynnex albipes (F. Smith). Insecticide application consisted of chlorpyrifos 50 dry flowable (DF) applied to the foliage at 2-wk intervals, or chlorpyrifos 20 microencapsulated (MEC) applied as an insecticide barrier treatment. A 5-min dip with a combination of fluvalinate 2.0 flowable (F) and insecticidal soap (potassium salts of fatty acids) with agitation after harvest killed any remaining survivors as long as field populations had <6% mealybug infestation, <33% banana aphid infestation, and <70% cotton aphid infestation. These procedures plus a final inspection of flowers for live insects ensured pest-free ginger flowers that met quarantine security requirements.

Efficacy of Hydrogen Cyanide Fumigation as a Treatment for Pests of Hawaiian Cut Flowers and Foliage After Harvest

Efficacy of 30 min fumigations at 2,500, 3,700, and 4,600 ppm of hydrogen cyanide (HCN) was tested in the laboratory as a treatment against representative Hawaiian quarantine pests. Effective results were obtained for nymphs and adults of the banana aphid, Pentalonia nigroneroosa Coquerel, in red ginger flowers;an armored scale, Pseudaulacaspis cockerelli (Cooley), on oleander leaves; the green scale, Coccus viridis (Green), on ixora leaves; and nymphs of the coconut mealybug, Nipaecoccus nipae (Maskell), on palm. Other species of mealybugs and ants also were susceptible to the treatment, particularly at the highest concentration. Mostnymphs and adults of a thrips, Sciothrips cardamomi (Ramakrishna), in red ginger flowers survived all concentrations of fumigation. All adults of an orchid weevil, Orchidophilus aterrimus (Waterhouse), survived the treatment. The suitability of HCN fumigation is discussed.