Aphid

Blackman and Eastop (2000) listed six aphid species from Jerusalem artichoke (compared to 21 species from sunflower) Macrosiphum euphorbiae Thomas, Protrama penecaeca Stroyan, Trama troglodytes von Heyden, Uroleucon compositae Theobald, Uroleucon gobonis Matsumura, and Uroleucon helianthicola Olive. They do not cause serious damage to either the above- or belowground plant parts. 

penecaeca is a very large aphid (3.8 to 5.0 mm), dirty grayish white in color, which has been recorded on the roots of H. tuberosus in northern India (Blackman and Eastop, 2000 Verma, 1969). 

troglodytes is a large, plump white aphid found on the roots of Jerusalem artichoke and other Helianthus spp. it is invariably attended by ants. This species occurs in Europe, western Siberia, Central Asia, and Japan (Blackman and Eastop, 2000 Eastop, 1953). 

compositae is a medium- to large-sized aphid (1.9 to 4.1 mm), broadly spindle shaped and shiny dark red to almost black in color. It colonizes the flower stems and leaf mid-ribs of plants in the family Compositae, including Jerusalem artichoke. It is widely distributed in Africa and on the Indian subcontinent and has also been found in South America (Brazil, Surinam), several Pacific Islands, Taiwan, and Sicily. No sexual forms have been recorded. Taxonomically, it is difficult to separate from the East Asian species U. gobonis, and it may represent an anholocyclic race of that species (Blackman and Eastop, 2000 Eastop, 1958). 

gobonis is similar in size and appearance to U. compositae, dark greenish to black in color, and found on flower stems and the underside of leaves of Compositae in the Far East (Korea, Mongolia, China, Japan, and Taiwan). Holocyclic (annual sexual phase) and anholocyclic (entirely parthenogenic) life cycles have been recorded (Blackman and Eastop, 2000 Takahashi, 1923). 

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In agriculture, the average benefit/cost ratio from insecticide use ranges from 3 to 5 return for every 1 invested by the farmer(s). There are many examples where the return is much greater. In California, treatment of sugarbeets with granular phorate systemic insecticide to control the aphid and... 

Imidocloprid [105827-78-9] l-[(6-chloro-3-pytidinyl)methyl]-N-nitro-2-imida2ohdininiine (4) (bp 137—144°C, vp 0.2 )J.Pa at 20°C) is soluble to 0.51 g/L. It is a synthetic nicotinoid with both contact and systematic activity against aphids, leafhoppers, whiteflies, and other sucking insects. The rat LD qS are 424 male, 475 female (oral), and 5000 (dermal) mg/kg. 

Nicotine is used as a contact insecticide for aphids attacking fmits, vegetables, and ornamentals, and as a fumigant for greenhouse plants and poultry mites. Nicotine sulfate is safer and more convenient to handle and the free alkaloid is rapidly Hberated by the addition of soap, hydrated lime, or ammonium hydroxide to the spray solution. Nicotine sprays commonly contain 0.05—0.06% nicotine, and nicotine dusts, 1—2% nicotine. 

Methoprene and hydroprene are first-generation juvenoids that iacorporate minor stmctural optimisation of neotenin to increase persistence. Methoprene, 1-isopropyl (E,E)-ll-methoxy-3,7,ll-tnmethyl dodecadi-2,4-enoate (129) (bp 100 C/6.7 Pa, vp 3.5 mPa at 25°C), is soluble ia water to 1.4 mg/L. The rat oral LD q is >34,000 mg/kg. Methoprene has been used as a mosquito larvicide, ia baits for ant control, and as a catde feed-through treatment for horn fly control. Hydroprene, methyl (H,H)-3,7,ll-trimethyl-dodecadi-2,4-enoate (130) (bp 174°C at 2.5 kPa, vp 2.5 mPa at 25°C), is soluble ia water to 0.54 mg/L. The rat oral LD q is >34,000 mg/kg. Hydroprene is especially effective against aphids and cockroaches. 

Sodium selenate has been used on a small scale in commercial greenhouses, primarily for growing carnations and chrysanthemums. It is transformed by the plants into volatile selenides, which repel red spiders, mites, thrips, and aphids (see Insect control technology). Sodium selenite is not intended for crops which could ultimately be used as food for humans or domestic animals. 

The edible parts of parsnips (Pastimea sativa L.), which have been consumed for centuries by humans without causing any obvious harm, were found to contain a chemical of insecticidal and strong synergistic nature (1). The insecticidal constituent, present at about 200 p.p.m., was isolated and identified as 5-allyl-l-methoxy-2, 3-methylenedioxybenzene or myristicin. Its toxicity to various insects [vinegar flies, houseflies, Mediterranean fruit flies, mosquito larvae, Mexican bean beetles, and pea aphids] was established and compared with pyrethrum and aldrin (Tables I and II). The knockdown effect, although definite, was not as great as that of pyrethrum. In tests... 

There are marked species differences in A-esterase activity. Birds have very low, often undetectable, levels of activity in plasma toward paraoxon, diazoxon, pirimi-phos-methyl oxon, and chlorpyrifos oxon (Brealey et al. 1980, Mackness et al. 1987, Walker et al. 1991 Figure 2.10). Mammals have much higher plasma A-esterase activities to all of these substrates. The toxicological implications of this are discussed in Chapter 10. Some species of insects have no measurable A-esterase activity, even in strains that have resistance to OPs (Mackness et al. 1982, Walker 1994). These include the peach potato aphid (Myzus persicae Devonshire 1991) and the... 

Metabolic resistance may be the consequence of the appearance of a novel gene on the resistant strain, which is not present in the general population it may also be due to the presence of multiple copies of a gene in different strains or clones as in the example of OP resistance in the peach potato aphid mentioned earlier. 

Rodriguez, A. E., Tingey, W. M. and Mutschler, M. A. 1993. Acylsugars of Lycopersicon pennellii deter settling and feeding of the green peach aphid (Homoptera Aphidae). J. Econ. Entomol. 86 34-49. 

Associations between endosymbiotic bacteria and the Homoptera, Blattaria, and Coleoptera are common. One of the best known is that between Biicli-nera and the aphids (149,150). Both partners are obligate and mutualistic symbionts, and the aphids cannot survive without the bacteria (150). Buclmera, in fact. 

P. Baumann, L. Baumann, C.-Y. Lai, and D. Rouhbakhsh, Genetics, physiology and evolutionary relationships of the genus Buchnera intracellular symbionts of aphids, Annii. Rev. Microbiol. 49 55 (1995). 

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