Aphids effects

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. 

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... 

Crawford, L.A., I.D. Hodkinson, and N.W. Lepp. 1990. The effects of feeding by the black bean aphid Aphis fabae Scap. (Homoptera Aphididae) on copper and cadmium accumulation in broad bean (Viciafaba L.). Environ. Geochem. Health 12 245-251. 

Esfenvalerate Summer Cereal 2 app at 7.5 g a.i./ha and 15 g a.i./ha No significant effects on Carabids and Staphylinid beetles and short-lived effects on Lycosidae, Dipterans, and Aphids Recovery after 3 weeks... 

It can also be made by nitrating diethyl phenyl phosphate below 0°. It is a red oil, almost insoluble in water, and Schrader found it effective against aphids, while Ball and Allen1 proved it active against the housefly, milkweed bug and cockroach. Later work showed it active against the two-spotted spider mite. 

The presence of aphids, Toxoptera graminum (Rondani) and Macrosiphum granarium (Kirby), on wheat during March and April has caused considerable alarm to wheat farmers in central Mexico. It has been found, however, that in the majority of cases the aphids do not represent a serious economic problem. Naturally occurring predators are able to reduce the aphid populations rapidly. For cases in which this natural biological control is not effective it has been found that benzene hexachloride (BHC) applied as a dust gives good control of these pests. 

An illustration of the variable responses to nicotine concerns aphids. In an experiment, 2 per cent of an insect population died or became moribund when exposed to 0.0001 M nicotine solution, 48 per cent were affected when the concentration was 0.0025 M, and 98.5 per cent when the concentration was 0.012 M. The concentrations of nicotine required to affect all the insects alike varied more than 120-fold.21 The pharmacology of nicotine as studied in mammals is notably complex and unpredictable, partly because many sites of action are involved. Its effect on different human individuals is also diverse, but it has not been adequately investigated, particularly in view of the fairly well established fact that amblyopia and Buerger s disease occur in relatively rare cases directly because of its use.22... 

Many types of soaps have been used to kill, dislodge or repel certain garden pests. They vary greatly in effectiveness and in toxicity to plants. They are frequently effective against thrips and other small, soft-bodied insects such as aphids, mealybugs and whiteflies. Their disadvantages are that they are expensive and they need to be reapplied frequently, possibly every three or four days. 

Analyses of the volatiles released by females of the peach aphid Tube-rocephalus momonis showed two sex pheromone components that were identified as (4a5,75,7ai )-nepetalactone and (4a5,75, 7ai )-nepetalactol, in a ratio of 4 1. The most effective blend for trapping males was found to be 85 15 nepetalactone to nepetalactol respectively. In addition to T. momonis, over 20 other species of aphids were also caught. 

Females of the potato aphid Macrosiphum euphorbiae produced (17 , aS, IS, 7 7 )-nepetalactol and (4a5, 75, 7a7 )-nepetalactone in ratios that varied with age from 4 1 to 2 1. Males did not respond to either of the components when presented alone. However, the 5 1 ratio, which proved quite attractive in lab tests, was not as effective during three years of field trials. ... 

Bultman TL et al.. Effects of fungal endophyte isolate on performance and preference of bird cherry-oat aphid, Environ Entomol 35 1690—1695, 2006. 

In this paper we summarize our work on the role of indole alkaloids and hydroxamic acids on the resistance of cereals to aphids. In addition, we describe the effects of water stress on susceptibility of barley to aphids. 

Effect of water stress on susceptibility of barley to aphids. Barley seedlings were subjected to water stress. These plants accumulated among other compounds proline and glycine-betaine (Table IV). Also, the more stressed plants were the most susceptible to aphids. The cultivar used in this experiment lacked gramine. However, when a gramine-containing cultivar was used gramine concentration was not affected by water stress. 

To test if some stress compounds had beneficial effects on aphids proline, choline and glycine-betaine were incorporated into artificial diets. Proline and choline appeared to decrease survival of aphids, while glycine-betaine did not (Table V). Moreover, glycine-betaine caused a drastic increase in aphid reproduction. Thus, the increased susceptibility to aphids of water stressed plants may be partially due to the higher content of glycine-betaine. 

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