Dysdercus Koenigii Research Articles

TOXICITY AND MORPHOGENETIC EFFECTS OF DIFFERENT BOTANICALS ON RED COTTON BUG DYSDERCUS KOENIGII FAB. (HEMIPTERA : PYRRHOCORIDAE) IN NORTH EASTERN HILL (NEH) REGION OF INDIA

ABSTRACT Toxicity and morphogenetic effects of various botanicals was evaluated against third instar nymphs of Dysdercus koenigii by two bioessay techniques viz., dry film and seed dip methods. Anonin was found to be most toxic and econeem least toxic to the nymphs of D.koenigii. The descending order of toxicity of different botanicals for dry film method was anonin > imidacloprid > karanjin > achook > ecomeem, whereas by seed dip method the order was anonin > imidacloprid > achook > karanjin > econeem. All the botanical insecticides initiated dose dependent changes, resulting in delayed metamorphosis with abnormal wing development, no moulting and finally death within 24 - 48 h after treatements. Thus, the toxicity levels of various botanicals would serve as ready reckoner for the selection of various plant - based products for the management of red cotton bugs on okra and other crops in the NEH region.

Influence of transgenic cotton on the relative abundance and damage by target and non-target insect pests under different protection regimes in India

Effectiveness of transgenic cottons with Bacillus thuringiensis ( Bt) cry1Ac gene along with non-transgenic commercial cultivars of Gossypium hirsutum and G. arboreum for the management of cotton bollworm, Helicoverpa armigera was evaluated at the research farm, International Crops Research Institute for the Semi-Arid Tropics, Patancheru, Andhra Pradesh, India. In general, there were no significant differences in oviposition between the transgenic and the non-transgenic cultivars under protected and unprotected conditions. The larval numbers were significantly lower on the transgenic hybrids during the 2004 rainy season under high infestation, but the differences in larval density between the transgenic and non-transgenic hybrids during 2002 and 2003 seasons under low levels of infestation were quite small. Bollworm damage in squares and bolls was significantly lower in the transgenic hybrids than in the non-transgenic ones, although there were a few exceptions. Differences in seed cotton yield between the transgenic and the non-transgenic hybrids were not significant under unprotected conditions at moderate levels of infestation during the 2002 and 2003 cropping seasons (except in the case of Mech 184). However, significant differences in seed cotton yield were observed during the 2004 cropping season under heavy bollworm infestation. Seed cotton yield of the first picking in transgenic hybrids was significantly greater than that of the non-transgenic counterparts. Transgenic hybrids suffered low shoot damage by spotted bollworm, Earias vittella. However, there were no differences between the transgenic and non-transgenic hybrids in their relative susceptibility to cotton jassid, Amrasca biguttula biguttula and serpentine leaf miner, Liriomyza trifolii, white fly, Bemisia tabaci, green bug, Nezara viridula, ash weevil, Myllocerus undecimpustulatus, and red cotton bug, Dysdercus koenigii. With a few exceptions, the bollworm damage and seed cotton yield of the G. arboreum varieties Aravinda and MDL 2450, and the G. hirsutum variety L 604 was not significantly different than that of the transgenic hybrids, and these varieties were also resistant to cotton jassid. The results suggested that it would be useful to combine transgenic resistance to H. armigera with plant characteristics conferring resistance to the target or non-target insect pests in the region in order to realize the full potential of transgenic plants for sustainable crop production.

Stage- and sex-dependent changes in the lipid profile of Dysdercus koenigii (Heteroptera: Pyrrhocoridae) during development

Lipids were extracted from the plasma and gonads of fourth and fifth instars and adults of Dysdercus koenigii (Heteroptera: Pyrrhocoridae). Thin layer chromatography of the extracts revealed fractions of free fatty acids (FFA), monoglycerides (MG), diglycerides (DG), triglycerides (TG), phospholipids (PL), free cholesterol (FC) and esterified cholesterol (EC). There were distinct differences in the lipid profiles within sexes for both tissues during development. Phospholipid from female plasma showed significant fluctuation during development, while that from males remained constant. In female gonads, PL levels increased significantly from the fouth instar to the fifth instar. Monoglycerides were detected only in adult male plasma and adult female gonads, at very low levels. Plasma DG in males was found to increase significantly during development. Maximum gonadal DG was recorded in male fourth instars and female fifth instars. Triglycerides in female plasma declined from the fourth instar to the adult stage. In contrast, TG in gonads increased significantly in the fifth instar of both sexes. Plasma FFA of both sexes fluctuated during development. Free cholesterol was detected only in adult male plasma. Plasma EC increased from the fourth instar to the adult stage in males, and it was highest in gonads of fifth instars of both sexes.

Chemosterilant activity of naturally occurring quinones and their analogues in the red cotton bug, Dysdercus koenigii (Het., Pyrrhocoridae)

The chemosterilant activity of two naturally occurring napthaquinones, plumbagin from Plumbago sp. and juglone from Juglans regia has been evaluated using the red cotton bug Dysdercus koenigii. Their activity were compared with synthetic napthaquinones, menadione, two benzoquinones, 2,6‐dimethyl and 2,3,6‐trimethylbenzoquinone and a hydroquinone 2,6‐dimethylhydroquinone. As far as the authors are aware, the present investigation is the first systematic attempt to investigate the effects of quinones on different aspects of reproduction, namely mating behaviour, fecundity and fertility. All the above types of quinones have revealed adverse effects on the reproduction of D. koenigii, which were topically treated as 1‐day‐old adults with different doses of the compounds depending on their 50% lethality (LD50) values. Analysis of the data revealed a highly statistically significant reduction in the number of eggs, their hatching and further development up to the final instar stage. The sterility index increased with the increase in the dose of any of the above compounds and was highest when both sexes were treated. Among the natural products, juglone induced more sterilizing effects than plumbagin at 5–10 μg/insect. Menadione caused sterility at a very low dose such as 0.5 μg. Of the two benzoquinones, the dimethylbenzoquinone acted at a much lower dose.

Insect growth regulatory activity of naturally occurring quinones and their derivatives in Dysdercus koenigii Fabr. (Hem., Pyrrhocoridae)

Plumbagin, a naphthoquinone occurring in the plants belonging to Plumbago sp. is known to have insect growth disrupting activities. In the present study, a comparative evaluation of bioactivities of related naphthoquinones, juglone and menadione and benzoquinones, 2,6‐dimethylbenzoquinone and 2,3,6‐trimethylbenzoquinone along with 2,6‐dimethylhydroquinone have been undertaken using Dysdercus koenigii. The LD50 values of the compounds showed wide variation. Although all the test compounds disrupted the normal growth at sublethal doses, 2,6‐dimethylbenzoquinone and menadione showed activity at low doses.

Insect growth regulatory activity of naturally occurring quinones and their derivatives in Dysdercus koenigii Fabr. (Hem., Pyrrhocoridae)

Insect growth regulatory activity of naturally occurring quinones and their derivatives in Dysdercus koenigii Fabr. (Hem., Pyrrhocoridae)

Isolation, characterization and insect growth inhibitory activity of major turmeric constituents and their derivatives against Schistocerca gregaria (Forsk) and Dysdercus koenigii (Walk)

Curcuminoids, the major colouring constituents of Curcuma longa (turmeric) rhizome powder, comprise mainly three closely related curcumins (I, II and III). A simple method has been devised for their efficient extraction and separation. Their structures have been confirmed by 1H NMR spectroscopy and unique mass fragmentation pattern. Curcumin-I, the major constituent has been converted to five alkyl ether derivatives, which have been tested along with the parent compounds and other extractives for insect growth inhibitory activity against Schistocerca gregaria and Dysdercus koenigii nymphs. At 20 µg per nymph, benzene extract and dibutyl curcumin-I were the most active (60% inhibition) against S gregaria, whereas at 50 µg per nymph these substances exhibited moderate growth-inhibitory activity (45%) against D koenigii nymphs. At these concentrations, turmeric oil caused 50–60% nymphal mortality in both test insects. The insect control activity of most of the turmeric products was comparable to or better than that of a commercial neem formulation. © 2000 Society of Chemical Industry

Role of juvenile hormone in the synthesis and sequestration of vitellogenins in the red cotton stainer, Dysdercus koenigii (Heteroptera: Pyrrhocoridae).

Investigations were carried out to determine the role of juvenile hormone (JH) and 20-hydroxy ecdysone in the synthesis and uptake of vitellogenins, which were earlier identified, purified and characterised, in Dysdercus koenigii. The concentration(s) of vitellogenin(s) in fat body, haemolymph and that of vitellin(s) in ovary were significantly lower after chemical allatectomy at eclosion. In addition, at 70 h after emergence, chemical allatectomy reduced ovarian vitellin concentration, but vitellogenin levels remained normal in the fat body and haemolymph. The haemolymph vitellogenins were not incorporated into oocytes in such insects. Administration of JH-III at 20 h after allatectomy restored vitellogenin levels in the fat body and haemolymph, but the ovary failed to incorporate the available vitellogenins from haemolymph in such insects. However, when JH-III was administered twice, one at 20 h and then at 70 h after allatectomy, vitellogenin concentrations in fat body and haemolymph and also vitellin concentrations in ovary approached control levels. It is suggested that JH has two separate roles, one in vitellogenin synthesis and the other in uptake. 20-hydroxy ecdysone had no apparent role in either vitellogenin synthesis or uptake in D. koenigii.

Isolation, characterization and insect growth inhibitory activity of major turmeric constituents and their derivatives againstSchistocerca gregaria (Forsk) andDysdercus koenigii (Walk)

Curcuminoids, the major colouring constituents of Curcuma longa (turmeric) rhizome powder, comprise mainly three closely related curcumins (I, II and III). A simple method has been devised for their efficient extraction and separation. Their structures have been confirmed by 1H NMR spectroscopy and unique mass fragmentation pattern. Curcumin-I, the major constituent has been converted to five alkyl ether derivatives, which have been tested along with the parent compounds and other extractives for insect growth inhibitory activity against Schistocerca gregaria and Dysdercus koenigii nymphs. At 20 µg per nymph, benzene extract and dibutyl curcumin-I were the most active (60% inhibition) against S gregaria, whereas at 50 µg per nymph these substances exhibited moderate growth-inhibitory activity (45%) against D koenigii nymphs. At these concentrations, turmeric oil caused 50–60% nymphal mortality in both test insects. The insect control activity of most of the turmeric products was comparable to or better than that of a commercial neem formulation. © 2000 Society of Chemical Industry

Vitellins and vitellogenins of Dysdercus koenigii (Heteroptera: Pyrrhocoridae) — identification, purification and temporal pattern

Two vitellins, VtA and VtB, were purified from the eggs of Dysdercus koenigii by gel filtration and ion exchange chromatography. VtA and VtB have molecular weights of 290 and 260 kDa, respectively. Both Vts are glycolipoproteinaceous in nature. VtA is composed of three polypeptides of M r 116, 92 and 62 kDa while VtB contained an additional subunit of M r 40 kDa. All subunits except the 116-kDa subunit are glycolipopolypeptides. Polyclonal antibody raised against VtA (anti-VtA antibody) cross-reacted with VtB and also with vitellogenic haemolymph and ovaries and pre-vitellogenic fat bodies, but not with haemolymph from either adult male, fifth instar female, or pre-vitellogenic females demonstrating sex and stage specificity of the Vts. Immunoblots in the presence of anti-VtA revealed two proteins (of 290 and 260 kDa) in both vitellogenic haemolymph and pre-vitellogenic fat bodies that are recognised as D. koenigii Vgs. In newly emerged females, Vgs appeared on day 1 in fat bodies and on day 3 in haemolymph and ovaries. Vg concentration was maximum on day 2 in fat body, day 4 in haemolymph and day 7 in ovary. Although the biochemical and temporal characteristics of these proteins show similarity to some hemipterans, they are strikingly dissimilar with those of a very closely related species.

Toxic, Growth-Inhibitory and Antifeedant Activity of Gliricidia sepium Jacq. Leaf Extract against Dysdercus koenigii Fabricius, Achaea janata Linnaeus and Spodoptera litura Fabricius

Evaluations of toxicity, antifeedant, growth-regulatory activity of the methanol extract of Gliricidia sepium leaves were carried out against Dysdercus koenigii Fabr. (Heteroptera: Pyrrhocoridae), Achaea janata Linn, and Spodoptera litura Fab., (both Lepidoptera: Noctuidae). Topical application of 100–300 μg of the extract to different stages of the test insects resulted in dose-dependent effects including larval-pupal intermediates and deformed adults. The highest tested dosage (300 μg/μl) resulted in reduced survival rate and morphological abnormalities. At certain doses a strong antifeedant activity was evident against the lepidopteran insects.

Effect of Artemisia annua oil on development and reproduction of Dysdercus koenigii F. (Hem., Pyrrhocoridae)

The effect of topical application of Artemisia annua oil on the development and reproduction of Dysdercus koenigii was studied. On the basis of 48 h mortality, the LD50 for fifth instar nymphs was 0.48 μl/nymph. The treated nymphs showed 2 days delay in development, and also produced intermediates. The treatment decreased haemolymph protein concentration and disturbed its electrophoretic protein pattern. The adults which emerged from treated nymphs showed poor ovary development. There was a greater median neurosecretory activity in the treated insects compared with control insects till day 6 of adult life.

The effects of exposing eggs of four cotton insect pests to volatiles of Allium sativum (Liliaceae)

AbstractExposure of freshly laid eggs (<24 h old) of Earias vittella Fabricius (Lepidoptera: Noctuidae) and Dysdercus koenigii (Fabricius) (Hemiptera: Pyrrhocoridae) to volatiles from bulbs of Allium sativum significantly reduced their hatchability. Eggs of Spodoptera litura (Fabricius) (Noctuidae) treated likewise, failed to hatch. Eggs of Helicoverpa armigera (Hübner) (Noctuidae) were more tolerant and showed only a slight decrease in mortality. None of the immature stages of D. koenigii and H. armigera and only 30% of those of E. vittella that hatched from treated eggs managed to complete their metamorphosis. A few larvae of H. armigera developed to the pupal stage but their pupal weights were markedly low. These findings are interpreted as the chronic effects of volatiles affecting larvae/nymphs following developmental defects sustained during embryonic development. The known chief constituents such as allicin, 2-propene sulfenic acid, 2-propene thiol, propylene, thioacrolein and ajoene present in the volatiles were presumed to be responsible for the adverse consequences reported here.

Toxicity of plumbagin and juglone to the eggs of the cotton stainer, Dysdercus koenigii

AbstractToxicity of two plumbaginoids viz., plumbagin and juglone to the eggs of the cotton stainer, Dysdercus koenigii was studied by a residual film technique. Of these two, plumbagin showed the higher toxicity against different‐age eggs with LC50 ranging from 0.0044 to 0.0066%. Eggs showed low susceptibility in the middle of embryogenesis. The toxicity of plumbaginoids, especially plumbagin, is discussed in relation to mode of action and prospects of its use as an ovicide in control of the insect.

Antimicrobial and insecticidal activity of an aquatic algachara zeylanicaklein ex willd

This paper describes the antimicrobial, ovicidal and insecticidal properties of a petroleum ether extract (PEX) of Chara zeylanica Klein ex Willd. and its fractions (P1 to P19) obtained through the application of various fractionation methods. Some of these fractions, after purification and chemical characterization, showed that they were either hydrocarbons or fatty acids. The PEX showed antimicrobial property against 12 out of 29 microbes tested. Only 15 fractions of PEX exhibited microbicidal activity. Some fractions retained that lethal activity even for a period of six months. The P11 had the broadest antimicrobial spectrum. The dermatophyte, Candida albicans, was the most susceptible microbe. The ovicidal effect of some of the fractions of PEX on the eggs of Dysdercus koenigii was significant. The P7a induced maximum sterility and reduced average facundity significantly in the cotton pest.

Postembryonic Development and Reproduction inDysdercus koenigii(F.) (Heteroptera: Pyrrhocoridae) on Exposure to Eucalyptus Oil Volatiles

Exposure of differently-aged (3, 5, 10 or 15 days) nymphs of Dysdercus Koenigii to eucalyptus oil vapours for a brief period once during rearing (2, 3, 4 or 5 hours) respectively), variously affect...

Biology and genetics of orange mutant of the cotton stainer, Dysdercus koenigii

The occurrence of an orange body coloured mutant, governed by a single somatic recessive gene of the cotton stainer, Dysdercus koenigii is reported. Both the strains did not show any quantitative difference in growth, development and reproductive biology. Males of the orange mutant lacked any special preference for females of orange mutant. Inheritance of the orange mutant in mixed population showed its relative stability at about 21% from F2 to F8 generations. The utility of the orange mutant for studies on population genetics and dynamics of the cotton stainer is discussed.

Plumbagin-induced ultrastructural haemocytic response of Dysdercus koenigii F.

The phytochemical ptumbagin, isolated from Plumbago zeylanica L., was applied in 2 and 5 μl doses of 0.1 % concentration on the surface of Dysdercus koenigii F. adults and its effect on the haemocytes of the bug, studied by transmission electron microscopy. All the five haemocyte types viz. the prohaemocyte, plasmatocy te, granular haemocyte, oenocytoid, and the adipohaemocy te are affected within a period of 24–48 hr.The effect begins with an acute state of vacuolization of the cells and a gradual destruction of the organelles, followed by dissolution of the plasma membrane and passing out of the internal organelles, like the mitochondria and the endoplasmic reticulum. This phenomenon is responsible for a consistent elimination of the haemocytes from the blood, leading to lowering of the resistance and mortality of the insects.

Eucalyptus oil odour treatment effects on biochemistry of some tissues of female nymphs/adults of Dysdercus koenigii

Eucalyptus oil vapour treatment provided toDysdercus koenigii female individuals as virgin adults or during their fifth instar nymphal life led to a fall in the total protein content accompanied by a rise in the free amino acid titre of haemoiymph and fat body. However, the level of total lipids in these two tissues under such condition varied in that a decrease and an increase were recorded in haemoiymph and fat body respectively. In the ovary of this adult female, the amounts of total proteins and lipids were low, while the value for total free amino acids was high. The implications of all these findings are discussed chiefly in relation to transport, synthesis and degradation of biochemical constituents in the three tested tissues.

Conessine as a larval growth inhibitor, sterilant, and antifeedant from Holarrhena antidysenterica Wall

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.