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Ram Pal , V. S. Nagrare , M. Dayamma

Abstract

Liparis cordifolia is a cool growing terrestrial orchid distributed in Himalayan region. Small sized-plant, and its heart-shaped shining solitary leaf, long lasting elongating raceme and low light requirement during cultivation make it an attractive plant for indoor decoration. The growth and flowering behavior of this species under Darjeeling conditions are reported. The shoot bud arised in July and August from basal part of the pseudobulb and inflorescence emerged from the top of recently formed stem (pseudobulb) 23.8 days after initiation of shoot bud. The first flower bud opened in the last week of September to October, 15.12 days after emergence of flower buds. The raceme remained in flower for 54.18 days up to first week of December. The growth phase marked by emergence of ischolar_mains from the basal part of stem and swelling of pseudobulb in last week of November to first week of December. This phase lasted for 183.81 days. The plants proceeded to dormancy after senescence and drying of leaf in April and May. The data on morphological characters like pseudobulb length and width, leaf length and width, inflorescence length, raceme length, number of flowers are tabulated. Inflorescence length, raceme length and number of flowers were found to determine by length and width of previous years growth (pseudobulb). The various plant parts when compared with colour chart developed by Royal Horticulture Society showed different shades of green yellow colour. The leaves were found to have deepest (RHS 146 A, 146 B, and 147 A) and sepals and petals lightest green yellow color (RHS 145 C and 145 D).

Keywords

Growth and Flowering, Growth Cycle, Liparis cordifolia

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T. M. Aga ¹, V. J. Tambe ¹, V. S. Nagrare ², Bhausaheb Naikwadi ²

Affiliations
1 College of Agriculture, Maharaj Bag, Amravati Road, Nagpur-440 001, IN
2 Central Institute for Cotton Research (CICR), P. B. No. 2, Shankar Nagar P. O., Nagpur- 440 010, IN

Abstract

Aenasius arizonensis (Girault) ( = Aenasius bambawalei Hayat) (Hymenoptera: Encyrtidae), a solitary endoparasitoid of Phenacoccus solenopsis Tinsley, is a major invasive pest in several cotton growing countries around the globe. It has been recorded as an effective natural enemy of P. solenopsis. The biological characteristics of parasitoid were studied on P. solenopsis under laboratory conditions. The mean duration of development of A. arizonensis from oviposition to mummy formation was 5.9 ± 0.31 days for both male and female, while from mummy formation to adult emergence was 5.9 ± 0.31 and 7.3 ± 0.3 for male and female, respectively. The mean developmental period of male and female was 12.2 ± 0.33 and 14.2 ± 0.37 days, respectively. Males were short lived (16.3 ± 1.41 days) as compared to females (26.2 ± 1.72 days). Female started ovipositing on the day of emergence. The mean pre-oviposion, oviposition and post-oviposition periods were <1, 23.1 ± 1.66 and 3.1 ± 0.55 days, respectively. Mean daily and total fecundity in terms of number of parasitized host per female was 4.24 ± 0.2 and 100.5 ± 11.57, respectively. Sex ratio was skewed towards female and recorded as 1:2. Maximum percentage of parasitization occurred in adult host stage i.e. 90% followed by 3^rd, 2^nd, and 1^st instar nymph with 73.33%, 33.33% and 0 per cent, respectively. Among the three nymphal stages 3rd instar nymph was the most suitable stage for mass multiplication of parasitoid. Its successful utilization in mealybug management can be optimized by multiplying at this stage of host in the laboratory and thereafter inoculative release into the field. This report provides a detailed diagnostic description of A. arizonensis with illustration to facilitate easy identification & morphological differences between male & female along with the morphometric measurements of pupa & mummy.

Keywords

Aenasius arizonensis, Biology, Morphometrics, Host Stage Preference, Biological Control

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K. Shankarganesh ¹, V. S. Nagrare ², M. Amutha ¹, C. Selvi ¹, S. Bagyaraj ¹

Affiliations
1 ICAR-Central institute for Cotton Research (CICR), Regional Station, Coimbatore 641003, Tamil Nadu, IN
2 ICAR-CICR, Shankar Nagar, Nagpur 440010, Maharashtra, IN

Abstract

The present study evaluated the relative susceptibility of insecticides viz., imidacloprid, thiamethoxam, thiacloprid, flonicamid, clothianidin, diafenthiuron, spiromesifen, thiodicarb and chlorpyriphos against field collected population of Amrasca (S.) biguttula. Out of nine insecticides, maximum susceptibility was observed with thiamethoxam. The descending order of susceptibility was observed as thiamethoxam> thiacloprid> diafenthiuron> spiromesifen> imidacloprid> clothianidin> flonicamid> thiodicarb> chlorpyriphos. Based on the relative toxicity value it was observed that the insecticides such as chlorpyriphos, thiodicarb, flonicamid and clothianidin were 14.04, 12.01, 9.43 and 9.41x, respectively less toxic as compared to thiamethoxam. The detoxification enzyme assay revealed that the activity of esterase was high in thiamethoxam and thiacloprid exposed leafhopper, while cytochrome p450 activity was high in spiromesifen, thiamethoxam and thiacloprid exposed ones. Elevated level of esterase and cytochrome p450 in the insecticide exposed leafhoppers indicates the probability of insecticide resistance development.

Keywords

Cotton, Amrasca (Sundapteryx) biguttula, insecticides, resistance, susceptibility, detoxifying enzymes, cytochrome p450, esterases

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V. S. Nagrare ¹, Babasaheb B. Fand ¹, Rishi Kumar ², V. Chinna Babu Naik ¹, Kundan Bhure ¹, Bhausaheb Naikwadi ¹, Nandini Gokte-Narkhedkar ¹, V. N. Waghmare ¹

Affiliations
1 ICAR-Central Institute for Cotton Research (ICAR-CICR), Nagpur 440010, Maharashtra, IN
2 ICAR-Central Institute for Cotton Research (ICAR-CICR), Regional Station, Sirsa 125055, Haryana, IN

Abstract

Globally cotton is the most important natural fibre crop being cultivated commercially for domestic textile needs and export. Cotton plays an important role in India’s economy, occupies largest acreage and highest production in the world. In India, cotton is being grown in 10 major states divided in 3 distinct zones viz., north, central and south with varying climate and soil. Despite large acreage, cotton productivity in India is far below world average due to variety of reasons. Among them damage caused due to arthropod pests is vital. In this article authors have attempted through extensive literature survey, to provide up to date information on arthropod pests and their natural enemies associated with cotton crop in India. It is observed that, in India, cotton crop is attacked by 251 arthropod pest species (including insect and mites) belonging to 9 insect orders and 1 order from Acarina. Among these, about 12 species of insects are major pests causing significant losses to cotton crop while remaining species are either occasional, sporadic or minor in nature. Overall these pests cause economic damage to cotton crop in a range between 20-60 per cent. The major arthropod pests are sucking insects namely leafhopper Amrasca biguttula biguttula (Ishida), aphid Aphis gossypii Glover, thrips Thrips tabaci Lindeman., whitefly Bemisia tabaci (Gennadius), Cotton mealybug Phenacoccus solenopsis Tinsley, Papaya mealybug Paracoccus marginatus Williams and Granara de Willink, and Indian cotton mirid bug Creontiades biseratense (Distant). The bollworm complex is another major group of insects that attack cotton and comprises of American bollworm Helicoverpa armigera (Hubner), spotted bollworms Earias insulana (Boisduval), E. vitella (F.) and pink bollworm Pectinophora gossypiella (Saunders). Other pests like stem weevil Pempherulus affinis Faust and tobacco caterpillar Spodoptera litura F., are also categorized as major pests. A rich fauna of 368 natural enemies (including 174 species of predators and 194 species of parasitoids/parasites) play significant role as biological control agents to check arthropod pests in cotton ecosystems of India. In this review there is addition of 85 arthropod pests over previously reported 166 arthropod pests. This updated information on cotton pests and their important natural enemies may serve as an important guide to researchers and policy makers in carrying out potential pest risk assessment and devising appropriate management strategies for economically damaging cotton pests.

Keywords

Cotton, India, Cotton Ecosystem, Arthropod Pests, Fauna, Insects, Mites, Sucking Pests, Bollworms, Resurgence, Natural Enemies, Predators, Parasitoids.

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