৪৯তম বিসিএস ⎯ প্রাণিবিদ্যা [৫৯১]

Hosts include domestic or wild animals and people. The virus develops and multiplies inside the mosquito. The infected mosquito then transmits the virus through its saliva when it bites another, uninfected host. By passing on the virus, the mosquito acts as a “vector” of the disease.

Malaria parasites are transmitted to human hosts by female mosquitoes of the genus Anopheles. A diverse group of Anopheles (30 to 40 species) serves as vectors of human disease

Dengue viruses are spread to people through the bites of infected Aedes species mosquitoes (Ae. aegypti or Ae. albopictus). These are the same types of mosquitoes that spread Zika and chikungunya viruses

The mosquito must take its blood meal during the period of viremia, when the infected person has high levels of the dengue virus in the blood. Once the virus enters the mosquito's system in the blood meal, the virus spreads through the mosquito's body over a period of eight to twelve days.

diseases transmitted by mosquito 
  
- Dengue
- Chikungunya
- Malaria
- Zika
- West nile
- Eastern equine encephalitis
- La Crosse encephalitis
- Elephantiasis
- Jamestown Canyon e

Rajshahi silk is the name given to the silk products produced in Rajshahi, Bangladesh. It is famous because it is a high quality fabric used for clothing, especially for saris. In 2021, it was given geographical indication status as a product of Bangladesh

Apiculture is the science of raising or maintaining colonies of bees and their hives

বাংলাদেশে মৌমাছির প্রধানত তিনটি প্রজাতি আছে। যথা : Apis indica, Apis dorsata ও Apis florea. বাংলাদেশের জন্য Apis indicaবাণিজ্যিকভাবে গুরুত্বপূর্ণ ও কাঠের বাক্সে অর্থাৎ কৃত্রিমভাবে এদের প্রতিপালন করা যায়। Apis dorsata বন্য প্রকৃতির, জঙ্গল কিংবা বাড়ির চারদিকের বড় বড় গাছে এদের চাক দেখতে পাওয়া যায়

Apis mellifera  ( সাধারণত ইউরোপীয় অন্ধকার মৌমাছি নামে পরিচিত) হল পশ্চিমা মধু মৌমাছির একটি উপ-প্রজাতি , যা মধ্য এশিয়ায় বিকশিত হয়েছে , যার উৎপত্তিস্থল তিয়েন শান পর্বতমালা  এবং পরবর্তীতে 9,000 খ্রিস্টপূর্বাব্দের শেষ বরফ যুগের পরে পূর্ব এবং তারপর উত্তর ইউরোপে স্থানান্তরিত হয়। এর মূল পরিসর রাশিয়ার দক্ষিণ ইউরাল অঞ্চলের অন্তর্ভুক্ত ছিল এবং উত্তর ইউরোপ এবং পিরেনিস পর্যন্ত বিস্তৃত ছিল। তারা Apis mellifera- এর 'M' বংশের দুটি সদস্যের মধ্যে একটি , অন্যটি পশ্চিম চীনে।  ঐতিহ্যগতভাবে তাদের কালো জার্মান মৌমাছি বলা হত , যদিও এখন জার্মানিতে তাদের বিপন্ন বলে মনে করা হয়।  তবে আজকাল তাদের নামকরণের সম্ভাবনা বেশি, যেমন ব্রিটিশ কালো মৌমাছি, নেটিভ আইরিশ মধু মৌমাছি, কর্নিশ কালো মৌমাছি এবং নর্ডিক বাদামী মৌমাছি, যদিও তারা সকলেই একই উপ-প্রজাতি, স্থানীয় মৌমাছি পালনকারীরা প্রায়শই "নেটিভ" শব্দটি ব্যবহার করেন, এমনকি যেখানে মৌমাছি একটি বিদেশী প্রজাতি হিসেবে পরিচিত।

Crops benefited by bee pollination.
Fruits and nuts: Almond, apple, apricot, peach, strawberry, citrus and litchi.
Vegetable and Vegetable seed crops: Cabbage, cauliflower, carrot, coriander, cucumber, melon, onion, pumpkin, radish and turnip.
Oil seed crops: Sunflower, niger, rape seed, mustard, safflower, gingelly.

Pollinators improve the quality and quantity of farmers' crop yields. If a plant has been well pollinated, it will produce larger, tastier, and more uniform fruits. They are an essential part of a successful harvest; farmers will rent bees from beekeepers to help pollinate their crops

মৌচাক হলো মৌমাছির আবাসস্থল। এটি তৈরী হয় মোম জাতীয় পদার্থ দিয়ে। মৌচাকে ক্ষদ্র ক্ষুদ্র ষড়ভূজ প্রকোষ্ঠ থাকে। মৌমাছি এসব প্রকোষ্ঠে মধু সঞ্চয় করে।

The queen is the mother of the hive. There is only one queen and each day she has to lay the 1000 or so eggs that will develop into new honeybees. Her strong pheromones (body smells) keep the colony working together and prevent the worker bees from trying to lay eggs.

Decline causes like overfishing, use of illegal fishing gear, siltation, katha fishing, and abstraction of water for irrigation, catching of fry and brood fishes, lack of connection of beel with Banar river and absence of proper beel management policy were observed as major threats for fish diversity.

Econometric analysis of fish catch records demonstrated that salinity changes differentially affect the availability of fish species with varying salinity tolerances, reflecting the interplay of species-specific salinity aversion and fishers' adaptive strategies to optimize profitable catches.

Pollution can affect aquatic organisms in a number of ways, including decreasing the amount of dissolved oxygen, changing the pH of the water, and introducing toxic chemicals. These alterations can be lethal to different aquatic organisms, and might cause large-scale mortalities.

The primary malaria vectors in Bangladesh are a group of Anopheles species, with Anopheles vagus being identified as the predominant vector in recent years, alongside others like Anopheles baimaii, Anopheles philippinensis, Anopheles sundaicus, and Anopheles minimus. Other Anopheles species such as A. aconitus, A. annularis, A. maculatus, A. karwari, A. barbirostris, and A. nigerrimus have also been incriminated as playing a role in malaria transmission, especially during outbreaks or in specific geographic areas. 

The most effective personal protection measure against malaria-carrying mosquitoes in Bangladesh is to sleep under an insecticide-treated bed net (ITN), a core strategy recommended by the World Health Organization (WHO) to prevent malaria transmission and protect against bites, especially during active hours of dawn and dusk.  

In Bangladesh, biological methods for controlling mosquito larvae include using larvivorous fish like mosquitofish (Gambusia) or indigenous larvivorous fish, and Bti bacteria (Bacillus thuringiensis israelensis) as a larvicide. Predatory insects like dragonfly larvae and incorporating natural predators such as certain birds and bats into the environment also contribute to Integrated Aedes Management (IAM), a holistic approach to mosquito control. 

Common methods for reducing mosquito breeding sites in Bangladesh involve eliminating stagnant water sources, such as cleaning gutters and emptying containers, and improving waste management through proper disposal of garbage. Community-wide approaches, including public awareness campaigns and community clean-up drives to remove potential breeding grounds in public areas, are also essential. Biological controls, like introducing predatory fish or bacterial agents such as Bacillus thuringiensis israelensis (Bti) into waterways, are also used.  

Commonly used insecticides in Bangladesh for mosquito control include organophosphates like Pirimiphos-methyl and Temephos for larvicidal and adult control, and pyrethroids for adult mosquito control through methods like fogging and household products (coils, mats). Other insecticides used include microbials such as Bacillus thuringiensis israelensis (Bti) and insect growth regulators (IGRs) like pyriproxyfen, which are also used for larvicidal purposes. 

Indoor residual spraying involves coating the walls and other surfaces of the house with an effective residual insecticide, where mosquito vectors are known to rest. The insecticide will kill adult mosquitoes that come in contact with these treated surfaces for several months

In Bangladesh, commonly used natural mosquito-repellent plants include Neem (Azadirachta indica), Tulsi (Ocimum sanctum), lemongrass (Cymbopogon spp.), mint (Mentha spp.), and marigolds (Tagetes spp.), which are utilized through various methods like planting them around homes, using their leaves in water or steam, or extracting their essential oils for use in repellents and coils.  

Community awareness is vital for mosquito control in Bangladesh by empowering people to eliminate mosquito breeding grounds and prevent mosquito bites. Effective campaigns utilizing social media, religious institutions, and educational programs can educate communities on Dengue prevention and sanitation. This participatory engagement fosters social ownership and ensures sustainable practices, which are critical for tackling mosquito-borne diseases like dengue

In Bangladesh, insecticide-treated nets (ITNs) function by creating a physical barrier and repelling or killing mosquitoes, thereby reducing the risk of malaria transmission by protecting individuals and decreasing the overall mosquito population. When widely used, ITNs significantly lower the number of malaria cases, including uncomplicated Plasmodium falciparum infections, and decrease mortality rates, helping to control the spread of the disease within communities. 

The High Court of Bangladesh recently ordered Dhaka's city corporations to take immediate and effective measures to control mosquitoes, particularly the Aedes mosquito responsible for spreading dengue and chikungunya. This order, issued on June 23, 2025, also requires the corporations' Chief Executive Officers to submit a report to the court within two months detailing the actions taken and demanding that the government explain its failure to control mosquito-borne diseases

The major stem borer species infesting rice in Bangladesh is the Yellow Stem Borer (Scirpophaga incertulas).  
According to multiple sources, including Banglapedia, research articles, and agricultural websites, the yellow stem borer is considered the most prevalent rice stem borer species in Bangladesh, causing significant damage to the crop throughout its growth stages. 

The main damage symptom caused by the Brown Planthopper (BPH) on rice plants is called "hopper burn," characterized by a rapid yellowing, browning, and eventual drying of patches of plants in the field. This occurs as both adult and nymph BPH insects suck sap from the plant's stems, leading to wilting and plant death. Other symptoms include stunted growth, reduced grain yield, and the growth of sooty mold on the excreted honeydew.

Rice hispa mainly affects the leaves of the rice plant, causing white streaks or patches as both the adult beetles and larvae feed on the green tissues. Adults scrape the upper surface of the leaves, creating white streaks, while larvae burrow into the leaves and mine between the epidermal layers. In severe cases, this damage leads to the leaves turning yellow and withering.  

The jute hairy caterpillar, Spilosoma obliqua, and the jute semilooper, Anomis sabulifera, are two of the most destructive insect pests in Bangladesh, causing significant leaf damage, while the jute stem weevil (Apion corchori) degrades fiber quality by creating holes in the stem. Other major pests include the yellow mite (Polyphagotarsonemus latus) and the field cricket (Brachytrypes portentosus)

Ash weevils cause damage to jute plants through two main methods: adult weevils feeding on leaves and causing marginal notching, while their subterranean grubs feed on roots, leading to wilting, drying, and death of the plants. The grubs damage the roots, making the plants easy to pull from the soil, and the overall damage can reduce the plant's yield. 

In Bangladesh, several borer insects commonly attack sugarcane, with the stem borer (Chilo tumidicostalis) beingidentified as the most serious and destructive pest that damages the buds and stems. Other common borer pests that affect sugarcane in Bangladesh include: 
Early shoot borer (Chilo infuscatellus): This pest is particularly damaging to young sugarcane plants.
Top shoot borer (Scirpophaga excerptalis):  Infestation by this borer can cause stunted growth, the wilting of the top leaves, and the formation of "dead heart" shoots
Rootstock borer (Emmalocera depressella): This borer attacks the base of the plant, including the rootstock and buds.
Internode borer (Chilo sacchariphagus indicus): It drills into the cane's internodes, decreasing the stalk weight and juice quality.

The common symptom of sugarcane shoot borer infestation is dead hearts in young plants, where the central whorl of leaves dries up, and the affected shoot can be easily pulled out. Infested tissues also emit a foul, offensive odor. In older plants, the central shoot can weaken and die, and sometimes the tops may break off. 

The main groups of sap-sucking insect pests affecting sugarcane in Bangladesh include aphids (like the sugarcane woolly aphid) and leafhoppers (like the sugarcane pyrilla), both of which extract vital sap and secrete honeydew, leading to reduced crop yield and quality. Other sap-suckers like mealybugs and scale insects also cause significant damage by consuming plant sap. 

IPM- INTEGRATED PEST MANAGEMENT 

Scirpophaga incertulas, the yellow stem borer or rice yellow stem borer, is a species of moth of the family Crambidae. It was described by Francis Walker in 1863. It is found in Afghanistan, Nepal, north-eastern India, Sri Lanka, Bangladesh, Myanmar, Vietnam, Thailand, Malaysia, Singapore, Sumatra, Java, Borneo, Sumba, Sulawesi, the Philippines, Taiwan, China and Japan

Brown planthoppers damage rice plants by sucking out sap, which causes plants to wilt, yellow, and dry up, a condition called "hopperburn". High-density infestations can lead to significant yield loss, and the insects also spread damaging viruses like rice ragged stunt virus and rice grassy stunt virus. Additionally, their excreted waste, called "honeydew," promotes sooty mold growth, further harming the plant

An Integrated Pest Management (IPM) approach combining cultural, biological, and chemical controls is the most effective strategy against the yellow stem borer in rice. This method minimizes environmental impact and prevents the development of insecticide resistance, unlike relying solely on chemical sprays
Biological control
Using natural enemies is an environmentally friendly method to control borer populations. Parasitic wasps: Release the egg parasitoid Trichogramma japonicum at weekly intervals during the egg-laying period.
Biopesticides: Apply formulations of the bacteria Bacillus thuringiensis to reduce borer populations, as it affects the larvae.
Natural predators: Encourage natural predators such as spiders, wasps, and beetles, which feed on yellow stem borer eggs and larvae.

The Jute Hairy Caterpillar (Spilarctia obliqua) primarily affects the foliage of the jute plant, causing leaf skeletonization and defoliation. Young caterpillars feed on the lower epidermis, while older, more damaging larvae consume entire leaf tissues, leaving only the ribs. This severe damage to the leaves leads to poor plant growth, stunted development, and a significant reduction in fiber yield

Damage symptoms: Adult weevil causes marginal notching on leaves while the grub feeds on roots causing wilting of plants. 
The nature of damage caused by ash weevils on jute plants primarily affects the stem and leaves, ultimately reducing the quality and yield of the fiber. The jute stem weevil (Apion corchori) is the most significant species that damages jute crops

Common methods for controlling Jute Hairy Caterpillar include biological control using Spilosoma obliqua nucleopolyhedrosis virus (SpobNPV) or Bacillus thuringiensis (Bt), neem-based botanical insecticides like neem leaf extract, chemical control with synthetic pesticides like Diazinon, and cultural practices such as crop rotation, ploughing, and encouraging natural predators.   
Biological Control
Nucleopolyhedrosis Virus (NPV): SpobNPV is a promising bio-control agent used to control the caterpillar.  
Bacillus thuringiensis (Bt): Commercially available formulations of Bt are effective against the larvae of the jute hairy caterpillar.  
Botanical and Chemical Control
Neem Products: 
Neem-based products, such as neem leaf extract, are effective and eco-friendly alternatives to chemical pesticides.  
Synthetic Pesticides: 
Chemical insecticides like Diazinon 60 EC are effective when insect populations exceed the economic threshold level. However, their repeated use can lead to resistance in the pest.  
Cultural Control
Hand Picking: 
Removing and destroying infested leaves is an environmentally friendly method, especially for early-stage infestations.  
Crop Rotation: 
Practicing suitable crop rotation helps to manage the pest population.  
Ploughing: 
Ploughing the field after harvesting helps in destroying the overwintering stages of the pest.  
Natural Enemies: 
Encouraging insectivorous birds and parasitoids like Protapanteles obliquae can naturally control the population. 

Sugarcane Top Borer (S. excerptalis) larvae damage sugarcane by boring into the midrib of leaves and the growing point of shoots, causing symptoms like "dead hearts" (withered central leaves), "bunchy tops" (proliferation of lateral shoots), and often stunt growth, reducing the plant's overall productivity. Unlike other borers, they feed on the plant's growing tissue rather than tunneling into the stalk

যেসব মথ বছরে দু বার ডিম পাড়ে তাদেরকে দ্বিচক্রী  বা বাই ভল্টাইন বলে । 

আখের ডগা ছিদ্রকারী পোকা দমনের একটি সাধারণ নিয়ন্ত্রণ ব্যবস্থা হলো সমন্বিত বালাই ব্যবস্থাপনা অনুসরণ করা, যার মধ্যে রয়েছে আক্রান্ত ডগা সংগ্রহ করে ধ্বংস করা এবং পরজীবী পোকা (যেমন ট্রাইকোগ্রামা) ব্যবহার করা। পোকার আক্রমণ বেশি হলে ক্লোরোট্রানিলিপ্রল, ফিপ্রোনিল বা কুইনালফস-জাতীয় কীটনাশক ব্যবহার করা যেতে পারে, তবে এটি সমন্বিত বালাই ব্যবস্থাপনা (IPM) এর অংশ হিসেবে করতে হবে।   
জৈবিক ও যান্ত্রিক নিয়ন্ত্রণ
আক্রান্ত ডগা ধ্বংস করা: 
আক্রান্ত ডগাগুলো কেটে ফেলে নষ্ট করে ফেললে পোকার বংশবিস্তার রোধ করা যায়।  
পরজীবী পোকার ব্যবহার: 
ট্রাইকোগ্রামা নামক পরজীবী বোলতা বা সোলেনোপসিস ইনভিকটা নামক লাল পিঁপড়ের মতো শিকারী পোকা ব্যবহার করে পোকার ডিমের সংখ্যা কমানো যায়।  
রাসায়নিক নিয়ন্ত্রণ
কীটনাশকের ব্যবহার: 
যদি জৈবিক ও যান্ত্রিক পদ্ধতিতে পোকা নিয়ন্ত্রণ করা না যায়, তবে ক্লোরোট্রানিলিপ্রল (যেমন, ভিরতাকো), ফিপ্রোনিল, অথবা কুইনালফস-জাতীয় কীটনাশক ব্যবহার করা যেতে পারে।  
সঠিক ব্যবহার: 
কীটনাশক ব্যবহারের সময় অবশ্যই সতর্কতা অবলম্বন করতে হবে। ঔষধ স্প্রে করার বিস্তারিত তথ্য ও সঠিক ডোজ জানতে স্থানীয় কৃষি সম্প্রসারণ কর্মকর্তার পরামর্শ নিতে পারেন।  
অন্যান্য ব্যবস্থা  
আগাছা পরিষ্কার করা: 
ফসলের জমিতে আগাছা মুক্ত রাখা পোকার আক্রমণ কমাতে সাহায্য করে।
মোথা পুড়িয়ে ফেলা: 
আখ কাটার পর অবশিষ্ট মোথাগুলো তুলে ফেলে পুড়িয়ে ফেললে পোকা দমন করা যায়।

Trichogramma is an effective biological control agent used against sugarcane borers.  
Explanation: Trichogramma is a small parasitic wasp that lays its eggs inside the eggs of other insects, like sugarcane borers, effectively killing them before they hatch. 

মুগা সিল্ক 'অ্যান্থেরিয়া অ্যাসামেনসিস (Antheraea assamensis)' নামক এক ধরনের পোকা থেকে পাওয়া যায়। এটি সোম, সোয়ালু এবং দিঘলতি সহ বিভিন্ন গাছের পাতা খেয়ে থাকে এবং এই পোকা থেকেই সোনালী রঙের প্রাকৃতিক রেশম পাওয়া যায়

Pebrine is a devastating, infectious parasitic disease of silkworms and other caterpillars, caused by the microsporidian parasite Nosema bombycis. It leads to irregular development, loss of appetite, and the appearance of black pepper-like spots on the infected worms' bodies, which can cause significant economic losses in the silk industry. There is no known cure for pebrine, so disease detection and preventing further dissemination are crucial, with Louis Pasteur's investigations in the mid-19th century helping to reveal its cause.  

তসর পোকার বৈজ্ঞানিক নাম অ্যান্থেরিয়া মাইলিট্টা (Antheraea mylitta)। এটি এক ধরনের বন্য রেশম পোকা, যা থেকে তসর রেশম তৈরি হয়, যেমনটি উইকিপিডিয়াতে উল্লেখ করা হয়েছে

Univoltine refers to an organism, such as an insect, that produces only one brood or generation of offspring per year. This term is part of the concept of voltinism, which describes the number of generations produced in a specific time period, typically a year. Examples of univoltine species include many butterflies, such as the orange-tip butterfly in the UK, and some mason bees

ফেরোমন (Pheromone) হলো একটি রাসায়নিক পদার্থ যা একটি জীব একই প্রজাতির অন্য সদস্যদের সাথে যোগাযোগের জন্য নির্গত করে। এই সংকেতগুলো প্রস্রাব, ত্বক বা মলের মাধ্যমে নির্গত হতে পারে এবং একটি নির্দিষ্ট রাসায়নিক প্রতিক্রিয়া সৃষ্টি করে, যা জীবের আচরণ বা শারীরবৃত্তীয় প্রক্রিয়াকে প্রভাবিত করে