Oviposition inhibition

Experimental studies with southern armyworm larvae and thiocyanate — one of the in vivo cyanide metabolites — showed that 5000 mg thiocyanate/kg diet reduced pupation by 77%, completely inhibited oviposition, and reduced adult emergence by 80% (Brattsten et al. 1983), strongly suggesting that thiocyanate poisoning is the primary effect of high dietary cyanide levels in southern army worms. 

Mediterranean fruitfly, Ceratitis capitata females, acute single exposure of 150-155 Gy Inhibited oviposition 3... 

Birds that breed in cavities and reuse their nest sites often incorporate green parts of aromatic plants into their nests. Starlings, Sturnus vulgaris, prefer certain species of plants to others. House sparrows. Passer domesticus, incorporate neem (margosa) tree, Azadirachta indica, leaves into their nests. Extracts from neem leaves repel arthropods and inhibit oviposition (Sengupta, 1981). The aromatic plants are thought to fulfill an important function by keeping down populations of microbes in the birds nests (Mason and Clark, 1986). 

Contact and stomach action, not translocated in the plant. Inhibits moulting of nymphs and larvae, leading to death. Also suppresses oviposition by adults, treated insects lay sterile eggs... 

The crude ether extract significantly inhibited oviposition by the seed beetle, Callosobruchus maculatus (Bruchidae), on legume seeds and exhibited ovicidal and larvicidal action. Ofuya et al. (76). Oluwafemi and Taiwo (77) have recently shown that the toxigenic effects of crystalline aflatoxin B-1 produced by Aspergilus flams in cockerels, can be reversed by administration of alcoholic extract of the seeds ofM. myristica. 

Although none of the compounds tested were larvicidal against S. frugiperda. several compounds (mostly dithiocarbamates) inhibited reproduction of adults that survived the larval treatment. For example, adults that emerged from a larval medium, dosed with 32, 34, 35, 41. y, or 42 at 1 00 ppm, oviposited after mating, but eggs failed to hatch. In addition to preventing egg hatch,... 

Because of their ability to induce sterility in insects, hydrazine-derived compounds have long been of interest to us in our search for new reproduction inhibitors (1.-.4) In this context, we recently evalu = ated compound, ll-(2,4-dif luoropheny 1)-2-( 2-f luoro phenyl)-hydrazinecarboxamide (Figure 1), and found that it inhibited oviposition in house flies (Musca domestlea L.) when administered orally to adults. However, since infertility was accompanied by excessive adult mortality, failure to lay eggs was probably symptomatic of nonspecific toxic effects rather than effects directed at the reproduction pathway. 

Both basic and neutral fractions inhibited oviposition as 2 to 7 times less eggs were laid on treated paper strips than on untreated strips. 

Resistance of vTKM6f plants to SSB is probably due to the production of certain allomones which inhibit oviposition and disrupt the insect s growth and development. Some of these factors, such as compound A, have recently been identified and synthesized in collaboration with the Tropical Development Research Institute (formerly Tropical Products Institute), London (20). The allomones in the resistant TKM6 variety thus account for inhibition of SSB oviposition and for adverse effects on egg (embryonic), larval and pupal (post-embryonic) stages. On the other hand, nine wild rices (four . minuta J.S. Presl., four 0 officinalis Wall ex. Watt, and one (). punctata Kotschy ex. Steud.) had no compound A in their plant volatiles, but a few were still toxic to SSB (21). This confirms that allomones other than compound A may also be involved in SSB resistance. The role of nutritional factors in growth of SSB larvae remains yet to be studied. 

The ci and -DVT ols are ovipositional stimulants for A virescens (Table IV) and also inhibit the growth of wheat coleoptiles at 10 3 and 10 4 m. but because we have not yet separated the L and/3 isomers the relative biological properties of each isomer cannot be established. 

In Japan, to control greenhouse whitefly and cotton whitefly that infest vegetables and ornamentals in the greenhouse, a yellow plastic tape formulation containing pyriproxyfen was developed. The tape has been widely used as it can lower the population of whitefly for several months after installation, and the influence on natural enemies and pollinators is low, and so forth. The action mechanism in this system is that adults attracted by the yellow color touch the tape and take pyriproxyfen into the body. The hatching of oviposited eggs is strongly inhibited by ovicidal activity via adults [38, 39]. 

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