Rapid isolation of high molecular weight DNA from single dry preserved adult beetle of Cryptolaemus montrouzieri for polymerase chain reaction (PCR) amplification

For studying genetic diversity in populations of predatory coccinellid, Cryptolaemus montrouzieri Mulsant (Coccinellidae: Coleoptera), our attempts to isolate high quality DNA from individual adult beetle using several previously reported protocols and even modifications were quite unsuccessful as the insect size was small and was preserved at -20°C as dry specimen. Here we describe a simple, rapid and efficient method of isolating high-quality intact genomic DNA with reduced protein contamination for polymerase chain reaction (PCR) amplification from a single, dry preserved specimen of adult Cryptolaemus. The procedure features macerating and mixing the single adult specimen of Cryptoalemus with cationic detergent cetyltrimethylammonium bromide (CTAB) in the homogenization buffer, two chloroform-isoamylalcohol extractions and an alcohol precipitation. RNA contamination was eliminated with RNAse treatment. The purity of DNA was high since the A260/A280 ratio ranged from 1.78 to 1.97. The isolated DNA was used as template for PCR, and the results were evaluated by comparing with different preserved samples.Key words: Rapid isolation, quality DNA, dry preserved specimens, Cryptolaemus montrouzieri

Evaluation of synthetic oviposition stimulants to enhance egg collection of the oriental fruit fly, Bactrocera dorsalis (Diptera: Tephritidae)

Tephritid flies are pests of horticultural importance throughout the globe. The oriental fruit fly, Bactrocera dorsalis (Hendel), is particularly feared because it attacks many commercial fruits and vegetables causing huge economic losses. The sterile insect technique (SIT) can be an effective, target-specific and economically feasible control method. However, implementation of SIT depends on mass production of high-quality insects. Production of superior quality eggs is of foremost importance in insect mass production. However, present protocols make use of fruit juices or fruit domes that attract saprophytic insects or microorganisms, reducing the quality of eggs. Furthermore, fermentation of juices is known to decrease oviposition efficiency, and daily sanitation of oviposition devices is required. Here, in a laboratory-scale study, we evaluate the effectiveness of four synthetic oviposition stimulants (OS) of B. dorsalis for egg production in dual choice tests, using oviposition devices similar to those used in mass rearing. Results indicated that γ-octalactone, benzothiazole, octen-3-ol and ethyl tiglate significantly increased egg laying compared to controls (water). Of these, γ-octalactone was particularly effective and elicited a 263-fold increase in oviposition on treated oviposition devices compared to control. Our findings demonstrate the potential of using OSs to improve the efficiency and cost effectiveness of mass production of B. dorsalis

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Not AvailableConsidering the quarantine importance of the red-banded mango caterpillar, Deanolis sublimbalis (Crambidae: Lepidoptera), studies were carried out to predict the impact of climate change on its geographical distribution using the ecological niche modeling. Predictions were made based on the analysis of the relationship between occurrence points of D. sublimbalis and the corresponding current and future climate data of the study area, which was retrieved from the worldclim database. Spatial analysis software DIVA-GIS was used for visualization of the maps. The maximum entropy algorithm provided reasonable estimates of the species range in respect of discrimination of suitable and unsuitable areas for its occurrence in both present and future climatic conditions. The model provided a good fit for species distribution with a high value of area under the curve (0.971). Jackknife test indicated temperature seasonality to be the most important bioclimatic variable determining the potential geographical distribution of D. sublimbalis. The model predicted higher suitability areas for the pest occurrence in eastern parts of Andhra Pradesh, coastal regions of Orissa, southern parts of West Bengal, and some parts of Tripura. In future climate scenarios of 2030, 2050, 2070, and 2080, model-predicted relative increase in its distribution. Prediction of likely changes in the pest distribution with climate change will be useful in formulating effective management strategies against mango fruit borer.Not Availabl