N. S. Azad Thakur

Host Plants Alter the Reproductive Behavior of Pieris brassicae Lepidoptera Pieridae and its Solitary Larval Endo-Parasitoid, Hyposoter ebeninus Hymenoptera Ichneumonidae in a Cruciferous Ecosystem

ABSTRACT The behavior of most destructive pest of cabbage, Pieris brassicae and that of its potential parasitoid, Hyposoter ebeninus, were studied under the influence of 4 common Brassica host plantspecies, cabbage, broccoli, cauliflower and knol-kohl. These host plant species were found to have considerable influence on egg distribution and leaf surface preference for oviposition and pupation. The number of egg masses was highest on knol-khol; however, the number of eggs per mass was highest on cabbage. Similarly, larval incidence was also highest on cabbage throughout the season, indicating that cabbage is the most preferred host. Natural parasitism on P. brassicae larvae by Hyposoter ebeninus was higher on knol-khol and cabbage. The weight of the third instar parasitized caterpillars was the highest on cabbage, suggesting that cabbage is the most favorable of these 4 hosts of P. brassicae for mass rearing of H. ebeninus. The development time of H. ebeninus was also shortest for cabbagereared larvae. Also the cocoon weight of the parasitoid was significantly higher when its host larvae were reared on cabbage. Overall from this study it can be concluded that, of the host plants evaluated, cabbage was preferred for oviposition by P. brassicae and its parasitoid. In addition, cabbage was found to be the best host plant for producing excellent quality H. ebeninus parasitoids.

Complete mitochondrial genome sequence of a phytophagous ladybird beetle, Henosepilachna pusillanima (Mulsant) (Coleoptera: Coccinellidae).

Abstract Ladybird beetles are generally considered as agriculturally beneficial insects, but the ladybird beetles in the coleopteran subfamily Epilachninae are phytophagous and major plant feeding pest species which causes severe economic losses to cucurbitaceous and solanaceous crops. Henosepilachna pusillanima (Mulsant) is one of the important pest species of ladybird beetle. In this report, we sequenced and characterized the complete mitochondrial genome of H. pusillanima. For sequencing of the complete mitochondrial genome, we used the Ion Torrent sequencing platform. The complete circular mitochondrial genome of the H. pusillanima was determined to be 16,216 bp long. There were totally 13 protein coding genes, 22 transfer RNA, 2 ribosomal RNA and a control (A + T-rich) region estimated to be 1690 bp. The gene arrangement and orientations of assembled mitogenome were identical to the reported predatory ladybird beetle Coccinella septempunctata L. This is the first completely sequenced coleopteran mitochondrial genome from the beetle subfamily Epilachninae from India. Data generated in this study will benefit future comparative genomics studies for understanding the evolutionary relationships between predatory and phytophagous coccinellid beetles.

Utility of ITS1 as a molecular tool for reliable identification of Henosepilachna pusillanima and H. septima (Coleoptera: Coccinellidae)

A majority species of the ladybird beetles are generally considered as beneficial insects, but the Coleopteran subfamily Epilachninae has major plant-feeding ladybird beetles. Therefore, these beetles are considered economically most important pests within the beetle groups (Li and Cook 1961). Both grubs and adults of Epilachninae cause serious economic loss to the crops and in some cases posing threat to successful cultivation of crops like potato in India (Ratul and Misra 1979). Within the subfamily Epilachninae, many species of the genus Henosepilachna Li feed on either cucurbitaceous or solanaceous plants (Katakura et al. 1992). Besides causing economic loss to the crops they are also responsible for pollen transfer in cucurbit ecosystem (Das et al. 2009). The taxonomy of the species belonging to the genusHenosepilachna remains confusing because of its wide variation in the external appearance/morphological characters which resulted in the misidentification of species in this genus (Naz et al. 2012). For example in literature,Henosepilachna pusillanima (Mulsant) has been known as H. dodecastigma or even by other names (Katakura 1988). However, H. pusillanima has now been accepted as a synonym of H. dodecastigma (Wiedemann) (Dharmaretnam 2002). The existences of intraspecific variations in these species also complicated the reliable identification process (Dharmaretnam 2002). Both H. septima (Dieke) and H. pusillanima feed on cucurbitaceous plants concurrently and cause severe economic losses in Japan (Nakano and Katakura 1999), India (Mahalya and Jesudasan 1996) and other parts of the world. Interestingly, H. septima superficially resembles H. pusillanima in size and colouration (Kapur 1967). Moreover, H. pusillanima is also morphologically similar to another cucurbit feeder, H. boisduvali (Mulsant) which has similar body

Arge xanthogaster (Hymenoptera: Argidae): A New Threat to Rose Plants in Meghalaya, India

Abstract The sawfly, Arge xanthogaster (Cameron) (Hymenoptera: Argidae), has recently emerged as a major pest of roses (Rosa spp. L; Rosales: Rosaceae) in Meghalaya and causes around 80% damage to wild and cultivated rose plants. This is a first report of A. xanthogaster as a pest of roses in India. Adults cause ovipositional injuries (split shoots) and larval feeding often results in complete defoliation. The species is multivoltine. Studies on its life history in new habitat are given. Since this species belongs to a species complex of Arge in which species are difficult to distinguish, an attempt was made to develop a DNA barcode based on standard barcoding gene cytochrome oxidase I (COI) of the mitochondrial DNA of this species.

An appraisal of pre-harvest rodent damage in major crops of north-eastern Himalaya, India

Pre-harvest crop damage caused by rodents was assessed during bamboo flowering phase (2005–2007) in two major states of north-eastern Himalaya. In Meghalaya, rodent damage in upland paddy, lowland paddy, maize, pine apple and groundnut was found to be 14.33, 16.31, 13.69, 17.36 and 16.02%, respectively. Relatively higher damage was recorded in Mizoram, where jhum rice and maize losses were 42.7–46% and 23.41–47.65%, respectively. In other crops, rodent injuries on oil palm were more severe (up to 75%) in many locations. Moreover, damage was observed to be variable in two states and also in different districts of the Mizoram. Furthermore, rodents were found to produce more damage at the maturity stage of crops; therefore, accordingly their management strategies could be manipulated during outbreak period.

Genetic characterization of Bactrocera fruit flies (Diptera: Tephritidae) from Northeastern India based on DNA barcodes

Abstract The Northeastern region of India, one of the mega biodiversity hot spots has enormous potential for the production of fruits and vegetables. Fruit flies of the genus Bactrocera Macquart are important pests of fruits and vegetables, and one of the limiting factors in successful production of these commodities. The relationship among some of the species is unclear due to their high molecular and morphological similarities. Moreover, due to the significant morphological resemblance between fruit fly species, reliable identification is very difficult task. We genetically characterized 10 fruit fly species of the genus Bactrocera by using standard DNA barcoding region of COI gene. The characterization and identification of eight species were straight forward. This study was unable to establish the molecular identity of Bactrocera sp. 2. Within the 547 bp region of partial COI gene, there were 157 variable sites of which 110 sites were parsimony informative, 153 were synonymous substitutions and 4 were non-synonymous substitutions. The estimate of genetic divergence among the ten species was in the range of 0–21.9% and the pairwise genetic distance of Bactrocera. (Bactrocera) dorsalis (Hendel) with B. (B.) carambolae was only 0.7%. Phylogenetic analysis formed separate clades for fruit and vegetable infesting fruit flies. B. (B.) aethriobasis Hardy, B. (B.) thailandica and B. (B.) tuberculata (Bezzi) have been reported for the first time from the Northeastern India. The information generated from this study would certainly have implications for pest management, taxonomy, quarantine and trade.

Sexual Dimorphism in Pseudonemorphus versteegi (Ritsema) (Coleoptera: Cerambycidae), Citrus Trunk Borerω

ABSTRACT The citrus trunk borer, Pseudonemorphus versteegi (Ritsema) (Coleoptera: Cerambycidae), is the most destructive pest of citrus in the entire northeastern Himalayan region of India. Adult beetles are stout, large in size, measuring 18.0 to 33.3 mm in length with bluish white elytra and 11-segmented filiform antennae. The antennae are 2.71 and 1.61 times longer than the lengths of the bodies of male and female beetles, respectively. These studies reveal and detail sexual dimorphism characters in adult of Pseudonemorphus versteegi.