Pseudococcus viburni (obscure mealybug).

P. viburni, commonly known as obscure mealybug, is an unarmoured scale insect and a common pest in the UK, Netherlands, Australia, New Zealand, the French Riviera, Iran, California and Chile. It can affect a number of fruit and nursery plants including apples, tomatoes, orchids and cacti and cause substantial damage to fruit orchards and vineyards. The degree of polyphagy of P. viburni, combined with its numerous economically important host-plants, have meant that it began to be carried on infested plant material between countries from an early date. The species was first recorded outside South America, in France by Signoret (1875), and its subsequent spread followed the trade routes between Europe and the rest of the world; the species is still increasing its geographical range. While obscure mealybug does not spread widely by its own means, human transport of infested plant material disseminates it over long distances very effectively. It has successfully adapted to life in a variety of ecological conditions and in the higher latitudes where it cannot survive winter outdoors, it thrives in greenhouses (Schoen and Martin, 1999).

PREVALENCE ON THE INFESTATION OF FLEA BEETLE (Phyllotreta nigripes) AGAINST DIFFERENT VARIETIES OF MUNGBEAN

Mungbean is one of the important pulse crops in Bangladesh. More than 12 species of insect pests infest mungbean, among them flea beetle cause significant yield loss due to attack from seedling to vegetative stages. The experiment was conducted to find out tolerant and susceptible varieties of mungbean against flea beetle at the farmer’s field of Patuakhali, Bangladesh from January to April 2016. Results revealed that BARI Mung-4 had the lowest abundance of flea beetle while BINA Moog-7 and BARI Mung-6 had the highest flea beetle abundance. Among the tested all varieties, significantly the lowest number (1.33) of infested plant by flea beetle was recorded in BARI Mung-4 followed by BINA Moog-4 (1.51) and the highest number (2.54) of infested plant by flea beetle was in BARI Mung-6 followed by (2.42) BINA Moog-7. The lowest percentage of leaf area damaged was on BARI Mung-4 (5.37%) while the highest on BARI Mung-6 (11.33%). Population of flea beetle showed a positive correlation (R2= 0.019) with temperature and a negative correlation (R2= -0.01) with relative humidity. BARI Mung-6 produced highest yield while Patuakhali local Mung produced the lowest followed by BARI Mung-4. Among tested varieties BARI Mung-4 showed comparatively more tolerant against flea beetle and BARI Mung-6 produced maximum yield in spite of being susceptile to flea beetle.

PERKEMBANGAN PENGENDALIAN PENYAKIT VASCULAR STREAK DIEBACK PADA TANAMAN KAKAO / Current Research Progress and Strategy to Control Vascular Streak Dieback (VSD) Disease of Cacao

<p><em>Vascular streak dieback</em> (VSD) merupakan penyakit penting pada tanaman kakao. Penyakit ini telah berkembang luas di sentra produksi kakao di Indonesia dan menyebabkan kerugian 30-45% dari produksi. Luas serangan VSD di Indonesia pada tahun 2007 adalah 70.000 ha dengan kehilangan hasil sebesar Rp 405 643 680 000/tahun, dan kerugian terus meningkat dari tahun ke tahun. Tujuan dari revieu ini adalah menginformasikan tentang penyakit VSD dan perkembangan teknologi pengendaliannya. Penyakit VSD adalah penyakit pembuluh kayu yang menyerang tanaman kakao. Gejala serangan ditunjukkan oleh daun yang mengalami klorosis, gugur dan meranting, hingga akhirnya tanaman tidak berproduksi. Penyakit VSD disebabkan oleh cendawan <em>Ceratobasidium theobromae, </em>yang bersifat obligat parasit, tersebar melalui spora udara (basidiospora), melalui bahan tanam atau bibit kakao yang telah terinfeksi. Keberhasilan spora untuk berkecambah dan melakukan penetrasi jaringan daun sangat tergantung pada kondisi lingkungan. Karakteristik <em>C theobromae </em>yang sulit diperbanyak pada medium buatan menjadikan penelitian VSD sangat tergantung dengan kondisi inokulum di lapang. Komponen pengendalian yang telah dikembangkan berupa varietas atau klon kakao tahan VSD, aplikasi fungisida, agens hayati dan kultur teknis. Pengembangan kakao tahan VSD perlu disertai dengan pengembangan komponen teknologi pengendalian lainnya. Penanaman klon tahan VSD disertai dengan penerapan kultur teknis budidaya kakao yang tepat disertai aplikasi komponen pengendalian yang sesuai dianggap sebagai strategi untuk menekan penyebaran VSD yang efisien, efektif dan ramah lingkungan. .</p><p> </p><p align="center"><strong> </strong></p><p align="center">ABSTRACT</p><p>Vascular Streak Dieback (VSD) is a main disease in cacao. It has been widely spread in cacao producing centers in Indonesia which has caused 30-40% production loss. Infested plant showed symptoms such as clorosis on its leaves which then fall off and die back. eventually stop producing. VSD is caused by a obligate<em> </em>parasite<em> </em>fungus<em> </em><em>Ceratobasidium theobromae </em>, , spread through basidiospora, plant materials, or infected seedlings. Since this fungus is difficult to be cultured in artificial media causes the research on VSD highly depends on the availability of inoculum at the field The ability of spora to germinate and penetrate leaves tissue is determined by environment conditions. Components of control which have been developed are varieties or cacao clones, fungicide application, biocontrol agents, and technical culture. Developing VSD resistant cacao also necessitates the development of control technology components. Planting VSD resistant clones combines with sugested cultural practices are considered efficient and effective for controlling VSD as well as an environmental friendly control strategy.</p><p> </p>

Risk Assessment of Two Insecticides on Encarsia formosa, Parasitoid of Whitefly Bemisia tabaci

The assessment of acute toxicity to insect natural enemies is very important for insecticide selection used within integrated pest management (IPM). The acute toxicity of abamectin and imidacloprid against Encarsia formosa, a parasitoid of Bemisia tabaci, was investigated. Abamectin had a high toxicity risk to E. formosa, while imidacloprid showed a medium toxicity risk. When treated with the lethal concentration 30 (LC30) of abamectin, the dwelling time of E. formosa in B. tabaci infested-plant-area (IPA) was significantly lower than in non-infested plant areas (non-IPA). In addition, the frequency of E. formosa entering into the two areas was not significantly different in the LC10 and LC30 treatments. Within the IPA, LC10, and LC30 treatments decreased the dwelling time and entering frequency of parasitoid significantly. For imidacloprid treatments, E. formosa stayed a longer time in the non-IPA than in the IPA when treated with LC30. The frequency of E. formosa entering into the two areas was only slightly different in the LC1, LC10, and LC30 treatments. Within the IPA, LC10 and LC30 treatments were significantly decreased in the dwelling time and the entering frequency of E. formosa. The results indicate that abamectin and imidacloprid have high or medium acute toxicity against E. formosa and a negative sublethal effect on its searching behaviour.

Efficacy of three botanicals and a microbial derivatives acaricide (Abamectin) on the control of jute yellow mite, Polyphagotarsonemus latus (Bank)

Three botanical oils and of microbial derivatives an acaricide (Abamectin) were evaluated for their efficacy in controlling yellow mite Polyphagotarsonemus latus in the field laboratory of Entomology, Bangladesh Agricultural University, Mymensingh. The selected botanical oils viz. Neem oil, Mahogany oil and Karanja oil and the acaricide Ambush 1.8 EC were tested against jute yellow mite on standing jute plants of the experimental plots and assessed for their effect on the basis of population of the pest at 24, 48 and 72 hours after treatment and the reduction of yellow mite infested plant after 7 and 10 days of spraying. The acaricide Ambush 1.8 EC was highly effective showing reduction of 80.25% mite infested plant. Among the botanicals, Neem oil and Mahogany oil showed better efficacy and caused 60.55 % and 55.89 % reduction of mite infestation. Karanja oil was not found promising in controlling yellow mite of jute. Considering the effectiveness against the mite pest as well as the environmental safety, use of Neem and Mahogany oil and also the reduced risk acaricide, Ambush 1.8 EC might be suggested in the IPM of yellow mite.J. Bangladesh Agril. Univ. 14(1): 1-6, June 2016

Flaming to Reduce Inocula of the Boxwood Blight Pathogen, Cylindrocladium pseudonaviculatum, in Field Soil

Infested plant tissue can play a significant role in the epidemiology of boxwood blight in ornamental nursery systems. In an effort to reduce inoculum levels in an infested field in Carroll Co., Virginia, symptomatic plants were removed, collected into a pile, and destroyed by burning using a propane push flamer. The authors investigated whether soil flaming would be effective to reduce viable inocula of C. pseudonaviculatum in the upper layer of soil. Accepted for publication 4 October 2012. Published 26 October 2012.