Effect of Diflubenzuron and Diflubenzuron in Combination with Neem Oil on the Life Stages and Developmental Periods of Rice Weevil, Sitophilus oryzae (L.)
Effect of diflubenzuron (DFB) and diflubenzuron in combination with neem oil (NO) on the life stages and developmental periods of rice weevil, Sitophilus oryzae (L.) was studied. The fresh polished rice and egg, larva and pupa infested rice were treated with DFB and DFB-NO at four different doses viz. 2-, 4-, 8- and 16 mg/kg and 2+2.25-, 4+2.25-, 8+2.25- and 16 mg/kg+2.25ml/kg, respectively.
Ramshagar dighi not an actually sea, but also it’s a big pond known as Ramshagor dhighi. Ramshagar dighi is the largest man made pond (Dighi, Bengali meaning) sited at Tajpur village in Dinajpur. Ramshagar dighi is only 8 km south from Dinajpur Town. It bears some exceptional historical events of national heritage. Ramshagar dighi was excavated by Raja Ram Nath, who dug it in time of the eve of battle of Palashi. Raja Ram Nath begun to dig out the Tank or Dhighi on the basis of ‘Food for Work’ system. About 1.5 millions of labors work in there to excavate the biggest pond of Bangladesh. Ram Nath spends an amount of Taka 30,000 in his time. Most of the historians believe that Ramshagar dighi was created during the 1750 to 1755 AD.
The study was conducted to collect and identify the ectoparasites and endoparasites of Channa punctatus (Bloch, 1793) from different water bodies of Rajshahi district during June 2011 to April 2012. Samples were collected from different fish markets and in some cases directly from fishermen of Rajshahi city. A total of 373 fishes were examined during the study period of which 251 fishes (67.29%) were infected. Organ wise distribution, monthly, seasonally, sex and length groups wise fluctuation of prevalence, abundance and mean intensity of parasites were studied. A total of 8 different parasitic genera were collected from the host fishes. Among them 5 were ectoparasites and 3 were endoparasites. Of these five ectoparasites one was protozoan Trichodina pediculatus, and two monogenic parasites Dactylogyrus vastator and Gyrodactylus elegans, one annelid was Hirudu medicenalis and one crustacean Argulus foliaceus. Three endoparasites were Ascaridia sp. nematodes one trematodes Genarchopsis sp and acanthocephalan pallisentis sp. Highest parasitic infestations were found in intestine, second highest was found in gill and the lowest was found in skin and stomach. Parasitic infestation fluctuated from months to months. Highest parasitic infestation was found in November and the lowest in June. The host fishes showed highest prevalence value and highest abundance value in autumn season. The host fishes showed their lowest prevalence and abundance value in winter season. Parasitic infestation was found to vary with size groups and sex groups. It was noted that the hosts of intermediate length and weight groups were found to be more infected than smaller and larger length group. Females were more infested than the males.
An investigation was carried out in three upzilas such as Puthia Upazila, Natore Upazila and Singra Upazila under Rajshahi division from May 2011 to February 2012 to assess the fisheries resources, present culture technique and socio-economic condition of fish farmers in the study area. A total 10 different water resources (ponds, khash Ponds, rivers Beels, floodplains, canals, vestates, boropits, paddy fields and pens) fond in the study area Ponds is the main fish production source among the resources. Above 47% fish production of total fish production of three upazilas cames from ponds. Carp fish culture of pond in the study area was mainly practiced with 3 native carps (Labeo rohita, Catla catla, Cirrhinus mrigala) and sexotic carps (Hypophthalmichthys molitrix, Cyprinus carpio, Ctenopharyngodon idellus, Puntius teri, Aristichthys nobilis). Farmers in the study area selected cultivable species by considering growth rate, market demand, price and availability of fry fish. They practice culture system in the pond and followed some management technique in pre-stocking management, stocking management and post stocking management. The socio-economic status of the fish farmers was not so good. Most of the fisherman is Muslim under study area. About 91.95% fisherman is Muslim in Singra Upazila. It is the highest percentage among three Upazila. Educational status of the majority of fish farmer class (I-IX). ‘About 25% to 31% fish farmer were illiterate and few graduate fishermen also found in the study area. About 40% to 55% fish farmer live in semipaka house. The ratio percentage of male and female fisher farmers was 1:0.046. A number of problems associated with fish farming faced by the fish farmer were also identified during the study period.
This is a protozoan parasite. Body dorsoventrally flattened. Dorsal surface convex and ventral surface flat. Several paralle, arching rows of cilia on ventral surface. Oral basket protrusible, conspicuous, opening on anterior part of ventral surface. Length 21.3 – 41.7 µm and width 13.3 — 38.6 µm. The disease caused by Chilodonella sp. called Chilodoneliasis.