Showing papers on "Spodoptera litura published in 1989"
TL;DR: Clerodane diterpenoid compounds from Teucrium (Labiatae) were assayed for antifeedant activity against larvae of Spodoptera littoralis and Heliothis armigera.
90 citations
TL;DR: The response of various stages of S. litura to temperatures under constant laboratory conditions was similar to that under field conditions and the upper developmental threshold temperature of all stages was 37°C; 40°C was lethal.
Abstract: Developmental thresholds and thermal requirements for different stages of Spodoptera litura (F.) fed on groundnut leaves were determined under constant laboratory conditions and in the field. An average of 64 degree-days (DD) above a threshold of 8°C was required from oviposition to egg hatch; the larval period required 303 DD and pupal stage 155 DD above a 10°C threshold; females needed 29 DD above a 10.8°C threshold from emergence to oviposition. Fifth and sixth instars accounted for about 50%of the total larval requirement under laboratory and field conditions. The response of various stages of S. litura to temperatures under constant laboratory conditions was similar to that under field conditions. The upper developmental threshold temperature of all stages was 37°C; 40°C was lethal.
41 citations
01 Sep 1989
25 citations
TL;DR: Mass-labelling experiments with selectively deuterated palmitic acids demonstrate that Δ-11 desaturation of this acid is part of the biosynthetic pathway of the female sex pheromone blend of Spodoptera littoralis.
21 citations
Journal Article•
17 citations
TL;DR: Seven coumarin derivatives have been isolated from the n-hexane and methanol extracts of aerial parts of Atalantia racemosa Wight and Arn and tested for antifeedant activity against Spodoptera litura F. larvae, where xanthotoxin is the most active and luvangetin is moderately active, while xanthyletin and racemosin are active only at higher concentrations.
Abstract: Seven coumarin derivatives have been isolated from the n-hexane and methanol extracts of aerial parts of Atalantia racemosa Wight and Arn. (Rutaceae) and tested for antifeedant activity against Spodoptera litura F. larvae. Among these, xanthotoxin is the most active and luvangetin is moderately active, while xanthyletin and racemosin are active only at higher concentrations. Rutarin, rutaretin, and umbelliferone failed to cause feeding inhibition even at a concentration of 1000 ppm. Antifeedant activities of 17 other structurally related coumarins have also been studied, to establish structure-activity relations
15 citations
TL;DR: Conessine, the steroidal alkaloid of Holarrhena untidysenterica Wall, possesses a wide range of activities against four insect species viz.
Abstract: Conessine, the steroidal alkaloid of Holarrhena antidysenterica Wall, possesses a wide range of activities against four insect species viz. Aedes aegypti, Dysdercus koenigii, Spodoptera litura and Pieris brassicae. In D. koenigii the compound inhibits the egg hatching of treated adults and nymphs. In Ae. aegypti the larval developmental periods are extended, resulting in a high mortality rate. Such effects are produced at very low dosages of 0.5 to lOppm. Antifeedant activity is observed against larvae of S. litura and P. brassicae at concentrations of 0.005 to 0.2 % of conessine.
14 citations
01 Jan 1989
13 citations
01 Nov 1989
TL;DR: Dietary concentration of rutin up to 1% wet weight had no adverse effect on the weight gain, nutritional indices, and efficiency of conversion of assimilated and ingested food when fed to early V instar larvae over a period of 48 h.
Abstract: Rutin (quercitin-3-β-D-rutinoside) a widely occurring plant glycoside affects neonate survival and inhibits early larval growth of the tobacco leaf eating caterpillar,Spodoptera litura (F) when added to an artificial diet for this insect. Dietary concentration of rutin up to 1% wet weight had no adverse effect on the weight gain, nutritional indices (approximate digestibility, efficiency of conversion of assimilated and ingested food) when fed to early V instar larvae over a period of 48 h. Rutin was excreted unchanged and the overall amount excreted was ≈50%. Neonate larvae reared on control diet till early V instar and subsequently fed on high doses (0·1 to 1%) of rutin did not exhibit any increase in the mid-gut carboxylesterase activity. Similar rearing on sublethal doses (0·01 to 0·1%) of rutin, followed by feeding of a high dose (1%), resulted in significant increase in the midgut carboxylesterase activity of V instar larvae.
13 citations
TL;DR: The sporeendotoxin complex of this strain, designated as HD‐635‐S‐1987, is proposed as a reference standard for bioassays against Spodoptera spp.
Abstract: The marked resistance of Spodoptera spp. to endotoxins of Bacillus thuringiensis including the well recognized standards HD‐1–1971 and HD‐1‐S‐1980 has necessitated the search for a new active strain that can be used as a standard reference in the bioassays of these lepidopterous insects. The high activity of B. thuringiensis var. entomocidus HD‐635 vs. Spodoptera littoralis and S. exigua was found to fulfill these requirements. The sporeendotoxin complex of this strain, designated as HD‐635‐S‐1987, is proposed as a reference standard for bioassays against Spodoptera spp. and is assigned arbitrarily the value of 10,000 iu/mg. Potencies of an active strain, i.e. B. thuringiensis var. aizawai HD‐133 and of a low‐active preparation, i.e. HD‐1‐S‐1980 were carried out in reference to the newly proposed standard. Comparative studies revealed the possible reduction of bioassay period to 4 days as time saving and for a priori judgement on the activity of certain bioinsecticide preparations derived from B....
11 citations
TL;DR: In this paper, five isolates of three entomogenous fungi were bioassayed for their infectivity to second instar larvae of Spodoptera litura Fab. by spraying the host larvae with the conidial suspension in the laboratory.
Abstract: Five isolates of three entomogenous fungi were bioassayed for their infectivity to second instar larvae of Spodoptera litura Fab. by spraying the host larvae with the conidial suspension in the laboratory. Of them, Beauveria bassiana (Bals.) Vuill. (Bapatla isolate) was found to be the most virulent recording the lowest LC 50 of 19.90 × 10 5 conidia ml -1 . Tbe LC 50 values of the Bangalore and New Delhi isolates of B. bassiana, Paecilomyces fumosoroseus (Wize) Brown and Smith and P. farinosus (Holm ex Gray) Brown and Smith ranged from 5.55 × l0 8 to 5.58 × 10 9 conidia ml -1 , Bioassay of second, third and fourth instar larvae of S. litura for their susceptibility to Bapatla isolate or B. bassiana showed that susceptibility decreased with increase in age of the larvae in terms of both LC 50 and LT 50 .
Journal Article•
TL;DR: 1) ハスモンヨトウ幼虫の加害がアズキの収量および品質に与える影響を,摘葉試験と飼育幼 虫の摂食量から検討し,
Abstract: 1) ハスモンヨトウ幼虫の加害がアズキの収量および品質に与える影響を,摘葉試験と飼育幼虫のアズキ葉摂食量から検討し,被害許容水準を推定した。2) アズキの莢数および収量は摘葉程度が大きくなるほど減少した。この傾向は摘葉時期が遅くなるほど顕著であった。早期の摘葉では莢数および子実肥大は確保されたが,晩期の摘葉では着莢数,多粒莢率および100粒重が減少した。3) 幼虫1頭当りの平均摂食葉面積は2039cm2で,全体の82%を終齢期に摂食した。摂食面積と収量指数との関係から被害許容水準を株当り老齢幼虫数では約2頭と推定した。4) 9月前半期は幼虫による葉の摂食が旺盛で,分散後に花や子実への加害が認められ,開花盛期から莢伸長期と重なるため,この時期の防除はとくに重要である。
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TL;DR: In S. litura testicular growth during the last larval instar and early pupal stage is associated with significant increase in DNA, RNA and protein contents and 20-HE injection in ligated late last instars increases the testicular weight and protein content.
Abstract: In S. litura testicular growth during the last larval instar and early pupal stage is associated with significant increase in DNA, RNA and protein contents. DNA synthesis is stimulated by 20-hydroxyecdysone (20-HE) in the penultimate instar testes. 20-HE injection in ligated late last instars increases the testicular weight and protein content. Accessory reproductive gland (ARG) development takes place during the mid and late pupal stages. Protein synthesis in the pharate adult ARG is stimulated by 20-HE. Juvenile hormone has no effect on ARG protein synthesis.
TL;DR: Treatment of second instar larvae of Heliothis armigera and Spodoptera litura F increased their susceptibility to endosulfan, monocrotophos, fenvalerate and Cypermethrin and the LC50 of these insecticides to both the species of larvae were lowered when treated with B.t.
Abstract: Laboratory bioassay tests showed that Bacillus thuringiensis (B.t.) (Bactospeine) treatment of second instar larvae of Heliothis armigera (Hbn.) and Spodoptera litura F. increased their susceptibility to endosulfan, monocrotophos, fenvalerate and Cypermethrin. The LC50 of these insecticides to both the species of larvae were lowered when treated with B.t. Comparison of susceptibility ratios showed that the increased susceptibility to insecticides was more in H. armigera than in S. litura larvae. Les epreuves de bioassay au laboratoire ont montre que la sensibilite aux endosulfan, fenvalerate, monocrotophos et cypermethrine est augmente aux larves d’Heliothis armigera et Spodoptera litura lorsque leurs larves du deuxieme stade sont inocule par le Bacillus thuringiensis (B.t.) (Bactospeine). On les a inocule en les permettant a nourrir pour 24 h sur les feuilles de Poischiche (Cicer arietinum) et de ricin (Ricinus communis) traites par une suspension du B.t. dans l’eau distillee a 300 mg/l. Les valeurs de LC50 de ces produits phytosanitaires aux tous les deux especes des larves ont abaisses lorsqu’ elles sont etaient inoculees avec le B.t. La comparaison des rapports de la sensibilite a montre que la sensibilite induit par le B.t. aux produits phytosanitaires a ete davantage aux larves d’Heliothis armigera que de S. litura.
01 Nov 1989
TL;DR: The histology and ultrastructure of the adult testis of Spodoptera litura are studied using light microscopy and electron microscopy for the continued occurrence of spermatogenesis in theAdult testes.
Abstract: The histology and ultrastructure of the adult testis ofSpodoptera litura are studied using light microscopy and electron microscopy. Maturing spermatocytes, spermatids and their conditions within the testes are described. The continued occurrence of spermatogenesis in the adult testes has been traced and reported.
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