Lethal effects of formulated essential oils on Phenacoccus solenopsis (Hem.: Pseudococcidae), under the laboratory and fields conditions

 In this research after formulating essential oils of Mentha longifolia, Mentha piperita and Oliveria decumbens, quality of the prepared formulations was studied according to the FAO standards. Then insecticidal efficacy of these compounds was investigated in comparison with Dayabon (Dayabon®) and acetamiprid (Mospilan®) against first instar nymphs and adults of Phenacoccus solenopsis in lab and field conditions. The LC50 values of formulated essential oils of M. longifolia, M. piperita, O. decumbens, Dayabon, Dayabon+ sesame oil and  acetamiprid on the adults and the nymphs of P. solenopsis were 164.55, 171.41, 195.92, 6177.85, 3316.58, 69.28 and 49.77, 55.13, 65.32, 4256.10, 2159.89 and 16.45 mg/l, 48h after treatment respectively. Field experiments were also conducted with four replications in a randomized complete block design. The numbers of P. solenopsis (nymph and adult) on branch samples were counted before treatment and 1, 3, 7 and 14 days after treatment. The field bioassay results showed that formulated essential oils had acceptable effects on developmental stages of P. solenopsis. Acetamiprid toxicity was higher than the other treatments but gradually reduced. The total results revealed that formulated essential oils were known as promising compounds in integrated management of this pest.