Insect avoidance

Siibsecpiently, biocontrol proved to be successful in controlling waterhyacinth plants (12), particularly when undertaken in conjunction with chemical control, though not all types of waterhyacinth plants responded similarly(c/. 13). Appreciating the differences in the uptake of metal ions by the plant types was a key to understanding their characteristics, especially size and insect avoidance. 

The environmental characteristics that seemed most logical to explain the ecotypes and their differences were based upon trace metals and their coordination chemistry There are at least two consequences of this hypothesis insect avoidance and trace-metal uptaUce (for use in the "polishing stages of sewage treatment) ... 

The proper choice and appHcation of an insecticide for pest control are predicated upon factors, eg, the life history and ecology of the pest, the relation of pest population to economic damage, the effect of the insecticide on the pest or its plant or animal host, related organisms in the ecosystem, and proper timing of the appHcation to prevent illegal residues at harvest and to avoid damaging of bees and other pollinating insects. 

Stage) and many other insects. Diatomaceous earth is a natural grade diatomite. It requires no warning label on the bag or container. However, the continual breathing of any dust should he absolutely avoided. 

The inner surface of a vial is treated with the insecticidal coating by introducing a measured volume, usually 5 or 10 ml., of standard solution or tissue extract and placing the vial in an air bath oven at 70° C. with care to avoid local overheating until the volume is reduced to about 1 ml. The vial is then removed and rolled by hand while the remaining solvent evaporates, care being taken to secure an even distribution over the sides and bottom. As soon as the vial is cool, the cover is put on with the open hole over the vial. Flies or other test insects may then be introduced as desired. 

Accessibility of the deposit to the insects by contact is the chief feature of the small vial method, but fumigant action cannot be eliminated entirely. In the case of DDT this has been found to be unimportant, for flies kept in the vials out of contact with the surface are not affected. But with 7-hexachlorocyclohexane or parathion there is a noticeable toxic effect. If the vials are stood upright, laid on the side, or hung upside down, there is a decrease in the mortality produced in the order given. The position on the side has been adopted because it avoids extremes and because practical use of an insecticide often involves limited but not accentuated ventilation. 

May require removal and destruction of infected plants. Incineration of impacted fields may be required. Consult local/state agricultural assistance office. Many fungi are easily spread by mechanical vectors (e.g., farm implements, track out, running water) and extreme care must be taken to avoid further contamination. Wear disposable protective coverall, disposable boot covers, and disposable gloves. Insects may also act as mechanical vectors for some plant fungi and, if appropriate, response activities must also include efforts to contain and eliminate these vectors. 

Sodium molybdate and other molybdenum compounds in toxic baits have potential for termite control (Brill et al. 1987). Baits containing 1000 mg Mo/kg were fatal to 99% of the termite Reticu-litermes flavipes in 48 days. After 8 to 10 days, termites became steel-gray in color, but appeared otherwise normal. Mortality began only after day 16. Termites did not avoid the poisoned bait, even at concentrations of 5000 mg Mo/kg. Yoshimura et al. (1987) reported similar results with another species of termite sodium molybdate killed 100% of the workers in a colony of Copotermes formo-sanus within 24 h after eating filter paper treated with a 5% solution. Some other species of insects — including fire ants (Solenopsis sp.) and various species of beetles and cockroaches — were not affected when exposed to baits containing 5000 mg Mo/kg for 48 days (Brill et al. 1987). 

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