In this work, we present our results on the use of potassium alum as an environmentally
friendly insecticide. This compound has the potential to rid our homes, schools, hotels, restaurants, and
ships of cockroach infestations. This compound is environmentally friendly and has no hazardous effects
on plant, animal, or human ecosystems. Alum was approved for medical use a long time ago. In our laboratory,
we developed a novel method using potassium alum as an environmentally friendly insecticide to
kill the most common cockroach in the subtropical region, Periplaneta americana (L.). Adult and
nymph-staged cockroaches were left to feed on potassium alum per individual insect after a period
of food deprivation. The mortality was recorded as LT50. The younger nymphs the third and early fourth
instars died within 4 d of feeding after consuming an average of 0.3 mg per individual insect. Gravid females
were highly susceptible to alum toxicity and experienced a higher mortality rate, with an average of
3 mg per individual female. The oothecae of the normal untreated females were 8.1mm long and
4.13mm wide and weighed 94 mg. The eggs laid by the treated gravid females were underweight and exhibited
a dwarfism shape, and these eggs did not hatched if the females consumed the potassium alum
before laying eggs. The results revealed that the adult male and female cockroaches have to consume
1 mg and 2.7 mg, respectively, of potassium alum to kill 100% of them after 1 month of ingestion. The potassium
alum had to be ingested by the cockroaches to affect mortality. The effect of potassium alum was
attributed to chronic toxicity and not acute toxicity. The potential applications of this novel technique will
be discussed.
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