• Title/Summary/Keyword: larval growth

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Secondary Damage and Adult Emergence of Pine Bark Beetle (Blastophagus piniperda) in Tended Forests (숲 가꾸기 임지의 소나무좀 발생과 후식 피해)

  • Goo Kwan-Hyo;Lee Jeong-Hwan;Kim Jong-Kab
    • Korean Journal of Agricultural and Forest Meteorology
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    • v.7 no.4
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    • pp.258-264
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    • 2005
  • The objectives of this study were to study 1) emergence of pine bark beetles, 2) larval density in residual timber on Idlest land by each felling season, and 3) the secondary damage rates in the tended forest. Pine forest land which had undergone tending had a higher secondary damage ratio $(59.6\%)$ by pine bark beetles than forest land that was not tended $(2.8\%)$. The number of escape holes averaged 11.3 0.31 per $250 cm^2$ on the bark of leaf trees in the tended forest. The number of escape holes was higher in the Jinju site than in the Hamyang site. The larval habitat density of pine bark beetles as compared with each felling period was higher after mid-October than in forests tended early in October. Thus, forests should be tended before early October in order to prevent secondary damage from pine bark beetles. Secondary damage in the tended forest was higher in the upper part $(75.5\%)$ of the tree crown than in the lower part $(49.2\%)$. The damage was higher in terminal shoots $(80\%)$ than in lateral shoots $(48\%)$. Therefore, secondary damage by pine bark beetles can cause deterioration of the elongation growth of the forest trees. In conclusion, if by-products of tended pine forest forests are neglected, they will be utilized as a propagation site for pine bark beetles (Blastophagus piniperda L). The propagated adults will damage the tender shoots of the leaf trees and thus seriously limittheir elongation.

Enriched Rotifer Feeding Efficiency in the Walleye Pollock Theragra chalcogramma Depends on Larval Fatty Acid Composition (명태(Theragra chalcogramma) 자어의 지방산 조성에 따른 영양강화 로티퍼의 먹이효율)

  • Park, Jin-Chul;Hong, Woo-Seok;Seo, Joo-Young;Nam, Won Shik;Kwon, O-Nam
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.51 no.5
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    • pp.549-555
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    • 2018
  • The objectives of this study were to confirm the nutritional requirements and improve the survival of the walleye pollock Theragra chalcogramma, a cold seawater fish, by enrichment. We analyzed the fatty acids and amino acids of fertilized pollock eggs before hatching, just-hatched larvae, larvae that had absorbed only the yolk sac, and larvae starved for 2 days after yolk absorption. For the survival improvement experiment, we administered docosahexaenoic acid (DHA), eicosapentaenoic acid (EPA), and DHA-EPA enrichment. Fatty acid decreased DHA and EPA content. On the $30^{th}$ day, body growth was significantly greater in pollock given the EPA and DHA-EPA treatments (P<0.05). Larval survival at 20 and 30 days after hatching (DAH) was greatest under the DHA-EPA treatment (P<0.05). Survival was significantly lower under the EPA treatment at 10 DAH, but then increased to approach that seen under the EPA-DHA treatment (P<0.05). Therefore, we determined that reduced survival in hatchlings of high-mortality pollack could be improved by controlling EPA and DHA content during enrichment. We conclude that cold seawater fish must be given feed that meets their nutritional needs, which can be accomplished using newly manufactured enrichment products for the larvae of cold seawater fish, such as pollock.

Morphology and Distribution of the Minute Tubercles on the Skin Surface of Larvae in the Korean Endemic Bitterling, Acheilognathus somjinensis(Pisces, Cyprinidae), with Its Larval Growth

  • Park, Jong-Young;Oh, Min-Ki;Kim, Chi-Hong;Kang, Eon-Jong;Beon, Mu-Sup
    • Animal cells and systems
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    • v.12 no.4
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    • pp.297-304
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    • 2008
  • Morphology and distribution of the minute tubercles projected on the skin surface of larvae with its development were observed in the Korean bitterling, Acheilognathus somjinensis. The minute tubercles appeared to be two distinct morphologies, hemispheric or scaly and vestigial structures. Just after hatching, the epidermis of the larvae consists of a thin single cell layer having smaller basophilic flat or round-flattened basal cells. As the larvae grow, the epidermis contains more small flat cells and large epidermal cells which are round and hemispheric, or scaleshaped, called minute tubercles. They are distributed over the anterior part and most part of yolk sac, posterior region of yolk sac and the body region. Vestigial epidermal cells, another minute tubercle, occur only in the caudal fin-fold region, which they are shrunken and flattened, causing the cell boundary to be unclear. They increase in number and height from just to 5 days after hatching, but they become reduced as the larvae develop gradually. The required time for those disappearance was different each by regional body: at day 20 after hatching in the anteriormost part of yolk sac, and day 11 after hatching in the posterior part of yolk sac and the body, and day 21 after hatching in two regions such most part of the yolk sac and the caudal finfold regions.

Pathogenicity of Nuclear Polythedrosis Virus Isolated from the Tobacco Cutworm, Spodoptera litura (담배거세미나방 핵다각체병 바이러스의 병원성)

  • 임대중;박범석;진병래;최궤문;강석권
    • Korean journal of applied entomology
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    • v.27 no.4
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    • pp.219-224
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    • 1988
  • Rearing of Spodoptera litura fed on arfificial diet basically formulated with kindby bean powder was much promisible for production of S. litura nuclear polyhedrosis virus(SINPV) than that on kidney bean leaves. The $LC_{50}$ of SINPV against 3rd and 5th instar were $4.48{\times}10^{3}$ PIB/ml and $4.52{\times}10^{4}$ PIB/ml, respectively. The $LC_{50}${/TEX} of SINPV varied from 5.8 days to 7.7 days at higher inocula in the testes. The larval growth of 1st and 3rd instar larvae fed on virus were much delayed and the larval were killed within 4th instar in the former and within 5th instar in latter. S. litura larvae were very susceptible to multinucleocapsid nuclear polyhedsosis virus (MNPV) of Autographa californica, S. littoralis and Trichoplusia ni.

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Early Growth of Cultured Larval Haddock, Melanogrammus aeglefinus (Haddock, Melanogrammus aeglefinus 자어의 초기성장)

  • Park, In-Seok;Johnson, Stewart C.;Hur, Jun-Wook
    • Development and Reproduction
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    • v.10 no.4
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    • pp.271-275
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    • 2006
  • The objective of this study was to examine the early growth of haddock, Melanogrammus aeglefinus larvae from a series of reared specimens for provide information to developmental biology and more information on the aspect of aquaculture in the larvae of this species. Larvae were reared in the laboratory and sampled periodically for developmental study until 67 days after hatching. An increase in total length of fish indicated continuous growth, described by the growth expression of the type $TL=3.5374e^{0.0536X}(r^2=0.8759$, where TL is total length and X is at days after hatching) and $BW=0.0002e^{0.1858X}(r^2=0.8671$, where BW is body weight and X is at days after hatching), respectively. Pattern of body depth and pectoral fin length are instantaneous growth which expression of the type $BD=0.3545e^{0.0778X},\;r^2=0.9563$(where BD is body depth and X is at days after hatching) for body depth growth and the type $PL=0.0111e^{0.1591X},\;r^2=0.9194$(where PL is pectoral fin length and X is at days after hatching) for pectoral fin length growth. The relationship of body depth and total length expressed as $BD=0.2397X-0.5735(r^2=0.9957$, where BD is body depth and X is total length), and pectoral fin length and total length is $PL=0.1929X-1.3767(r^2=0.9882$, where PL is pectoral fin length and X is total length) pectoral fin length against body depth simultaneously recorded for juvenile haddock(PL=0.8117BD-0.9718, $r^2=0.9814$, where PL is pectoral fin length and BD is body depth). Relationship of body depth and body weight was expressed the type of $BD=-9.4734X^2+19.046X+1.3672,\;r^2=0.941$(where BD is body depth and X is body weight), and pectoral fin length and body weight expressed the type of $PL=6.379X^2+14.023X+0.3774,\;r^2=0.9494$(where PL is pectoral fin length and X is body weight). From this point view, growth characteristics of juvenile haddock in this experiment may be useful to establish a successful culture technique for rearing larval haddock.

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Ontogenetic Development of the Digestive System in Chub Mackerel Scomber japonicus Larvae and Juveniles

  • Park, Su-Jin;Lee, So-Gwang;Gwak, Woo-Seok
    • Fisheries and Aquatic Sciences
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    • v.18 no.3
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    • pp.301-309
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    • 2015
  • Chub mackerel, Scomber japonicus, larvae and juveniles were reared from hatching to 35 days after hatching (DAH), and the development of their digestive systems was histologically investigated. The larvae were initially fed on rotifers and Artemia nauplii starting around 19 DAH, and thereafter on Artemia nauplii, fish eggs, and a formulated feed mixture. The primitive digestive system differentiated at 3 DAH; the digestive tract was distinctively divided into the buccopharyngeal cavity, esophagus, stomach, air bladder, intestines, and rectum. The gastric gland and pyloric caeca first appeared at 5 and 7 DAH, respectively. The stomach was divided into cardiac, fundic, and pyloric regions in the preflexion phase. The number of gastric glands and pyloric caeca, as well as the volume of the gastric blind sac increased markedly, with development continuing into the juvenile stage. The precocious development of the digestive system during the larval period might be related to the early appearance of piscivory, which is able to support high growth potential. The organogenesis results obtained for this precocial species represent a useful tool to aid our understanding of the physiological requirements of larvae and juveniles to ensure optimal welfare and growth under aquaculture conditions, which will improve current rearing practices of this scombrid species.

Potential Usage of Food Waste as a Natural Fertilizer after Digestion by Hermetia illucens (Diptera: Stratiomyidae)

  • Choi, Young-Cheol;Choi, Ji-Young;Kim, Jong-Gill;Kim, Myung-Sook;Kim, Won-Tae;Park, Kwan-Ho;Bae, Sung-Woo;Jeong, Gil-Sang
    • International Journal of Industrial Entomology and Biomaterials
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    • v.19 no.1
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    • pp.171-174
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    • 2009
  • The black soldier fly larvae are able to decompose various organic wastes such as livestock manures and food wastes. We tested whether the quality of the insect derived compost, i.e. larval feces, was comparable to that of a commercial fertilizer. The results show that the chemical composition and the growth rate of cabbages grown on the insect derived compost are virtually identical to those on the commercial fertilizer. Therefore the insect derived compost will be an ideal substitute to commercial fertilizers.

Screening of Botanicals Against Root Knot Disease Complex in Mulberry (Morus indica L.)

  • Naik V. Nishitha;Sharma D.D.;Govindaiah Govindaiah;Chowdary N.B.;Mala V.R.
    • International Journal of Industrial Entomology and Biomaterials
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    • v.14 no.1
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    • pp.57-61
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    • 2007
  • For developing an integrated eco-friendly package against root knot disease complex of mulberry caused by the association of Meloidogyne incognita with Fusarium solani and F. oxysporum causing serious loss in terms of leaf yield and quality during cultivation, twenty botanical extracts at 5, 10 & 20% concentrations were screened under in vitro conditions. Among the extracts, Allium sativum followed by Lasownia inermis were found to be effective at 20% concentration against both the virulent fungi and nematode. Both the extracts reduced the mycelial growth of virulent fungi to an extent of 76-100%, inhibited the hatching of nematode eggs by 80-90% and 76-85% larval mortality over the control. The other extracts were found either moderately or poorly effective in reducing the growth of fungi, hatching of nematode eggs and enhancing the mortality of larvae. The two effective botanical extracts, which rated as strong inhibitors against both nematode and virulent fungi, can be utilized in developing an integrated ecofriendly technology for better management of root knot disease complex in mulberry.

The Effects of Elevated Carbon Dioxide in Seawater on the Early Life Stages of Black Sea Bream Acanthopagrus schlegelii (해수 중 이산화탄소의 증가가 감성돔( Acanthopagrus schlegelii)의 초기성장에 미치는 영향)

  • Shim, JeongHee;Kim, Kyungsu;Kim, Suam
    • Korean Journal of Fisheries and Aquatic Sciences
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    • v.46 no.6
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    • pp.862-867
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    • 2013
  • Since the industrial revolution, seawater has increased in temperature and acidity due to the increase in anthropogenic carbon dioxide in the atmosphere. To understand the effect of elevated $CO_2$ on the early life stages of fish, we reared fertilized eggs of black sea bream Acanthopagrus schlegelii under three $CO_2$ concentrations (400, 850 and 1550 ppm) for 3 weeks. The standard length and wet weight of black sea bream larvae declined with enhanced $CO_2$ concentration in the rearing water (P<0.05). However, chemical analysis using ICP-OES on internal tissues of black sea bream larvae indicated that the whole-body calcium concentration increased with $CO_2$ concentration in the rearing water. These conflicting results suggest that future experiments should examine the acid-base balance to investigate the formation of bone and otolith during larval growth.

Effects of RH 5849, an Ecdysone Agonist, against Feeding and Growth of Tobacco Cutworm(spodoptera litura Fabricius)Larvae (담배거세미나방(Spodoptera litura Fabricius) 유충의 섭식과 생장에 대한 곤충탈피호르몬길항제 RH 5849의 영향)

  • 박노중;장경수;조점래;조광연
    • Korean journal of applied entomology
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    • v.31 no.4
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    • pp.475-479
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    • 1992
  • The non-steroidal ecdysone agonist RH 5849 showed almost similar LC.o values( 18.1-26.5 ppm) at all stages of larval development of the tobacco cutworm, Spodoptera litura, when treated by a leaf-disk dipping method. The feeding-inhibition rate for the 4th instar larvae was dose-dependent, and simultaneously the weight gain of 3rd instar larvae ceased within 48 hour after feeding of the cabbage leafdisk dipped into RH 5849 4.2 ppm solution. The systemic larvicidal effect of RH 5849 was compared at cabbage and tobacco whole plant test. The $LC_{50}$ values below 20 ppm(mg/kg soil) was lasted for 15 days in cabbage, 30 days in tobacco respectively.

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