共查询到20条相似文献,搜索用时 0 毫秒
1.
2.
3.
Dr. J. Godula 《Cell and tissue research》1985,242(3):681-683
Summary The surface morphology of primary spermatocytes from testicular cysts of the last instar larvae of Spodoptera littoralis was examined by scanning electron microscopy (SEM). At this stage, each primary spermatocyte possesses four developing flagella, directed towards the lumen of the cyst. The identical length of flagella in all primary spermatocytes from a single cyst indicates that the initiation and rate of flagellar growth are synchronized. Some asynchrony can, however, be observed in the translocation of flagella to secondary spermatocytes during the first meiotic division. 相似文献
4.
5.
6.
《Insect Biochemistry》1987,17(6):877-881
Female pheromone gland extracts of Spodoptera littoralis were analyzed for pheromone precursors. Large amounts of fatty methyl esters were found and a positive relationship between the methyl esters and the pheromonal components was observed. The esters were identified on the basis of capillary gas chromatography, coupled gas chromatography with mass spectroscopy and dimethyl disulfide derivatization, and subsequent gas chromatography with mass spectrometry. The characteristic fatty esters of S. littoralis are methyl (Z)-9-tetradecenoate, (E)- and (Z)-11-tetradecenoate, (Z,E)-9,12-tetradecadienoate, (Z,E)-9,11-tetradecadienoate, and (Z)-11-hexadecenoate. The biosynthesis of the monosaturated acids involves probably the common E11 and Z11 desaturases and chain shortening. For the biosynthesis of the novel diene acids, we propose a second, specific desaturation of (Z)-9-tetradecenoate by an E11 desaturase to produce (Z,E)-9,11-tetradecadienoate or by an E12 desaturase to produce (Z,E)-9,12-tetradecadienoate. 相似文献
7.
8.
《Journal of Asia》2022,25(3):101956
The beet armyworm, Spodoptera exigua (Hübner, 1808) and the Egyptian cotton leafworm, S. littoralis (Boisduval, 1833), are amongst the most notorious agricultural pest species in Iran. Spodoptera exigua is considered a serious pest of different crops, whereas S. littoralis is known as an important pest of cotton.In this paper, the potential distribution areas of these species in Iran and the important climatic factors affecting their distribution were predicted using the MaxEnt model and the ArcGIS. The results indicate that the main environmental variables contributing to S. exigua’s distribution were precipitation of the coldest quarter (bio19), average wind speed in April (wind4), and annual precipitation (bio12). Also, minimum temperature of the coldest month (bio6), mean temperature of coldest quarter (bio11), altitude and average wind speed in May (wind5) were dominant climatic factors that affected the potential distribution of S. littoralis. These species overlapped in most parts of coastal areas in the southern and northern parts of Iran, with an average overlapping range of 33.2%. Considering their preferred host plants in Iran, it is necessary to strengthen biosurveillance programes and management of these two species in their suitable areas to prevent further invasion, which endangers agricultural security. 相似文献
9.
10.
Mohamad Ahmad Khedr 《Archives Of Phytopathology And Plant Protection》2016,49(5-6):95-110
In the research for alternative tools and botanical products to control Spodoptera littoralis (Boisduval) (Lepidoptera: Noctuidae). Sesamum indicum (L.) (Lamiales: Pedaliaceae) oil was assayed as an ovicide. The mortality increased with existence of fatty acids. Chemical analysis of S. indicum oil using GLC analysis showed palmitic acid as the major fatty acid (51.27%), while the major hydrocarbon and sterols were found to be heneicosane (58.63%) and β-sitosterol (2.60%), respectively. Generally, the values of LC50s indicated that one-day-old egg masses are more susceptible than three-day-old eggs. Also, the leaf dip technique is more efficient than the spraying one. Results showed several features of chorionic surface deformation treated with sesame and KZ oils than control using scanning electron microscopy. Meanwhile, the tested oils caused significant reduction in both total soluble protein and transaminase enzymes as compared to control. Additionally, the oils elongated the incubation period and larval duration than control. 相似文献
11.
Observations of oviposition behaviour by Chilo partellus revealed that antennae, ovipositor tip and possibly tarsi were all involved in the choice of oviposition site. Among a very large number of typical mechanoreceptor hairs on the tip of the ovipositor valves, two pairs of stouter, blunt-tipped hairs were discovered. These hairs alone took up silver nitrate stain and transmission electron microscope sections revealed that the hair shaft had a hollow lumen within which ran a group of four or five dendrites. It is concluded that these sensilla are contact chemoreceptors and they are positioned in such a way that, with the placing of each egg, they would contact the oviposition substrate. Similar hairs were found on the ovipositor of Spodoptera littoralis . It is suggested that the hairs may prevent oviposition on surfaces directly chemically harmful to the eggs. 相似文献
12.
13.
The effect of an optical brightener on the insecticidal activity of a Spodoptera littoralis (Boisduval) (Lepidoptera: Noctuidae) nucleopolyhedrovirus (SpliNPV) were examined in three instars of S. littoralis. LD50 values of the SpliNPV were reduced from 33 to <5, 73 to 5.7 and 342 321 to 288 412 occlusion bodies for second, third and fourth instars, respectively, by the addition of 1% Tinopal UNPA-GX. Relative potencies were >66, 12.8, and 1.2 for second-. third- and fourth-instar S. littoralis larvae, respectively. Relative mortality between the treatments with and without the brightener decreased from third- to fourth-stage larvae. In terms of speed of kill, the ST50 values of the baculovirus-infected larva were reduced from 210 to 159, 213 to 147, and 207 to 165 h for second-, third- and fourth-instar larvae, respectively, by the addition of the optical brightener at biologically equivalent doses. 相似文献
14.
An effective constant dose (55 μg) of precocene II (PII) was topically tested against the last three instars of Spodoptera littoralis (Boisd.) larvae. Application of PII induced morphogenetic abnormalities typical of juvenile hormone (JH) excess. The resultant imperfect insects included larval‐pupal mosaic and partial or severe cases of untanned pupae. The sixth‐instar larvae were more sensitive to PII administration than the two preceding instars. However, sensitivity of the last larval instar to PII varied with the timing of dose application relative to the developmental status of the larvae. Whereas the newly ecdysed (0‐day old) larvae were more sensitive, the older larvae of the same sixth‐instar showed sharp decrease in their sensitivity to PII with a concomitant increase of their age. Application of a single dose (5 μg) of JH I to PII pre‐treated larvae significantly (P < 0.001) reduced the production of imperfect insects where many PH‐treated larvae developed successfully to apparent normal pupae. Although a single dose of PII was more effective on S. littoralis larvae than repeated daily doses, the effectiveness of JHI‐therapy to PH pre‐treated larvae by repeated doses was less effective in producing perfect insects than JH‐therapy to PII pre‐treated larvae by single doses. The reversal of any of these by applied JHI is quite interesting but the mechanisms remain to be unraveled. 相似文献
15.
In the female genital system of Zygaena moths, an additional pair of accessory glands is present besides the Y-shaped sebaceous gland. The term 'Petersen's glands' is proposed for these organs. Anatomy, histology, histochemistry and cytology of Petersen's glands of Zygaena trifolii are described. The sac-like glands, situated in the extreme dorsocaudal part of the abdomen, can be divided into a purely secretory part consisting of acini with large pear-shaped gland cells and a reservoir part with combined secretory and storage function. The secretory cells of the acini are penetrated by long curved ductules or secretory end apparatuses having feltwork consisting of very fine filaments. The cytoplasm is characterized by abundance of smooth tubular endoplasmic reticulum (ATER) and the presence of peroxisomes. This cytoplasmic organization is in accordance with the chemical composition of the sticky secretion, which evidently consists completely of lipids. The ultrastructure of the epithelium lining the reservoir of the glands has both traits of secretory and of transporting epithelia. Besides contributing to the secretion, it may be involved in absorption of residual aqueous phase from the contents of the reservoir. 相似文献
16.
Larvae of Spodoptera littoralis and Galleria mellonella reared on standard laboratory food were used in experiments with metyrapone and azadirachtin. Metyrapone in S. littoralis caused high elevation of metabolic rate which resulted in a significant increase of body-mass. This phenomenon was associated with precocious transformation to pupal stage. The same results were obtained after application of azadirachtin or neem oil. Restriction of reproduction was also observed in S. littoralis . Both these compounds influenced body pigmentation: the treated larvae was light green or light gray. Synthesis of melanin was inhibited. In Galleria mellonella , the effect was not as prominent. 相似文献
17.
Naeem M. Eesa Hanaa El-Sherif Wael M. El-Sayed 《Invertebrate reproduction & development.》2017,61(1):27-33
The sensitivity of Spodoptera littoralis second and fourth instar larvae to the heavy metals cadmium (Cd) and lead (Pb) was investigated under laboratory conditions. Both Cd and Pb, even, at very low concentrations, had relatively high toxic effects on S. littoralis larvae. Cd was more toxic to S. littoralis larvae than Pb. In addition, the mean percentage feeding deterrence (FDI%) of Cd and Pb was concentration-dependent. The nutritional indices (consumption index, growth rate, efficiency of converted ingested and digested food, and approximate digestibility) of S. littoralis second and fourth instar larvae were more affected in Cd-treatments compared with those of Pb-treatments. Therefore, the presence of such heavy metals in the environment would exert an adverse impact on S. littoralis larvae and their development. 相似文献
18.
Mesbah HA Saad AS Mourad AK Taman FA Mohamed IB 《Communications in agricultural and applied biological sciences》2007,72(3):445-457
The naturally occurring phytoncidal chemical component of some plant- species are responsible for controlling and/or repelling insects from host plants. The use of natural products, readily available in the environment, to control the cotton leafworm, could be of help in reducing the need for applying the synthetic conventional insecticides . Moreover, crude vegetable oils application is quite safer to the non targets and the environment. The use of sex attractant pheromones as predicative tools to forecast pest population and their potential damage levels in specific crops, has significantly been limited because sex attractants are usually directed to one sex only. Thus, identification of plant constituents that attract S. littoralis Boisd. adults, especially females, and that directly affect their feeding or reproductive behaviour, would greatly expand opportunities for manipulation of the biological and environmental events that prevent the establishment, development, and dispersal of the insect-pest under study. Extracted Volatiles from certain parts of cotton plants, attracted both sexes of the cotton leafworm moths instead of attracting one sex only as the pheromones do. Plant flavonoids have been shown by many investigators to have an effect on insect behaviour, growth, and development. Quercetin is one of many bioflavonoids that exists in several fruits and vegetables. The Aim of the present work is to study in vivo the biochemical mode of action of quercetin as a synergist in combination with insecticides. The present results proved the synergistic effect of quercetin when combined with four insecticides, namely, profenofos (organophosphates), deltamethrin (pyrethroid), and tebufenozide et hexaflumuron as insect growth regulators against the studied insect-pest. Quercetin role as a synergist might be attributed to its ability to inhibit certain active oxidases, which may be responsible for in vivo detoxification of the intact insecticides when applied to insect larvae, through glutathione-S-transferase. 相似文献
19.
Lethal and sublethal effects of methoxyfenozide and spinosad on Spodoptera littoralis (Lepidoptera: Noctuidae) 总被引:1,自引:0,他引:1
Pineda S Schneider MI Smagghe G Martínez AM Del Estal P Viñuela E Valle J Budia F 《Journal of economic entomology》2007,100(3):773-780
Susceptibility to methoxyfenozide of Spodoptera littoralis (Boisduval) (Lepidoptera: Noctuidae) larvae was determined through exposure of neonate and fourth instars to dipped and sprayed pepper, Capsicum annum L., leaves. Methoxyfenozide and spinosad were tested against adults of this noctuid by oral, residual, and topical application. In larvae, we evaluated five (range, 0.001-10 mg active ingredient [AI] /liter) and six (range, 1-250 mg [AI] /liter) concentration levels by instars, respectively, by using two application methods at three different age leaf residues (0, 3, and 6 d after application). According to LC50 values, no significant differences were observed between the same age leaf residues of both application methods at 96 and 72 h after ingestion treatment on neonates and fourth instars, respectively. Nevertheless, toxicity of methoxyfenozide decreased significantly after time. For both application methods, the LC50 values of the first leaf residue (0 d after application) were significantly lower than those of 6-d-old residues. Furthermore, larval weight of fourth instars fed for 48 h with pepper, Capsicum annum L., leaves containing methoxyfenozide was significantly suppressed. Spinosad and methoxyfenozide reduced in a dose-dependent manner the fecundity and fertility of S. littoralis adults when treated oral and residually. Likewise, when methoxyfenozide was administered orally in three different adult crosses, the fecundity was strongly affected, independently of the treated sex. We conclude that the combination of lethal and sublethal effects of methoxy-fenozide and spinosad might exhibit significant effects on the population dynamics of S. littolaris. 相似文献
20.
Farag M Ahmed MH Yousef H Abdel-Rahman AA 《Zeitschrift für Naturforschung. C, Journal of biosciences》2011,66(3-4):129-135
A crude acetone extract and oil of ripe fruits from Melia azedarach L. were evaluated against the 2nd and 4th instar larvae of Spodoptera littoralis (Boisd.) (Lepidoptera: Noctuidae). Both oil and extract exhibited highly significant growth inhibition at all concentrations tested, while the oil of M. azedarach recorded higher insecticidal activity against both instars than the crude extract. GC-MS analysis of the oil revealed the presence of linoleic acid methyl ester, oleic acid methyl ester, and free oleic acid as the main components in addition to hexadecanol, palmitic acid, methyl esters of stearic acid and myristic acid. Fatty acids and their esters were not only the main constituents of essential oil from the ripe fruits of M. azedarach, but also mainly responsible for the insecticidal and growth inhibition activity against S. littoralis. 相似文献