Efficacy of certain chemical and safe alternative compounds on the cabbage aphid brevicoryne brassicae (Linnaeus)‎ and its associated parasitoid diaeretiella rapae (Mclntoch)‎ inhabiting cabbage plantations

الملخص EN

The study was conducted to evaluate the efficacy of two newly introduced European safe alternative compounds (Evure® and Karate® Zeon) versus two biocide compounds (Biosad 22% SC and Abamectin 1.8%EC), and the chemical compound (Melody 24%SC) against the cabbage aphid Brevicoryne brassicae (Linnaeus) inhabiting cabbage plantations during 2017/18 and 2018/19 cabbage growing seasons in Assiut, northern upper Egypt.

Impact of the tested compounds on the infestation levels and the yield income was evaluated.

Also, their side effect against the emergence of the aphid parasitoid Diaeretiella rapae (Mclntoch) was taken in consideration.

Data revealed that the newly introduced compound (Karate® Zeon) was the most effective compound on the population density of B.

brassicae during the entire period of study with 98.98% reduction in the pest numbers.

The other newly introduced compound (Evure®) reduced the pest numbers by less reduction percentage (94.20%), and ranked the second.

The chemical compound (Melody 24%SC) reduced the pest populations by 93.40% (less than both of the two newly introduced safe alternative compounds).

The biocide compounds (Abamectin 1.8% EC and Biosad 22% SC) presented 78.99 and 59.08% reduction in the pest populations and appeared as the least effective compounds.

Efficacy on the infestation levels and damaged (unmarketable) plants showed slight variation between the tested compounds (ranged between 47.46 -55.34 and 46.78-49.10%, respectively).

So, use of these compounds led to an increase in the marketable cabbage plants (yield income) by more than 50%.

Unfortunately the highest effective compound (Karate® Zeon) against cabbage aphid reduced the emerged parasitoid D.

rapae by 91.64%, and consequently could be has cautions as aphids control agent.

According to their acceptable effectiveness against B.

brassicae populations, infestation levels , unmarketable plants and low effectiveness against D.

rapae, it can be recommended to use the biocide compounds (Abamectin 1.8% EC and Biosad 22% SC) to manage the population density of cabbage aphids in the field by more than one application throughout one season