Abstract: This paper presents data referring to the external morphological characteristics, the biometrical measurements of species Brachycaudus helichrysi and Brachycaudus cardui. The researches have been carried out for a period of five years, 2005 - 2008 on the potato and 2016 in orchards from the experimental fields of the Didactic Station Timisoara and Varfurile, Arad County. The aptera of Brachycaudus helichrysi has a variable color ranging from brown to green and have a slight wax dusting. The body length is 1.6-2.1 mm. The winged adult of Brachycaudus helichrysi have an oval body, are smaller than aptera and have a length from 1.3 to 1.9 m and can be yellow, olive green, or pink. At the Brachycaudus helichrysii species the smallest length of the body established for aphids captured in Western zone of Romania was 1.30 mm, while the biggest was 1.90 mm. The average body length was 1.68 ± 0.18 mm. The length of the head and thorax was 0.95 mm and minimum length was 0.50 mm. The minimum width of head was 0.20 mm and the maximum width of head was 0.30 mm. The thorax width was minimum 0.40 mm and maximum 0.75 mm. The minimum length of the abdomen was 0.70 mm and minimum width was 0.50 mm, the maximum length of the abdomen was 1.15 mm and the maximum width was 0.90 mm. The wingless aphids of Brachycaudus cardui have an oval body and grow to a length from 1.8 to 2.5 mm. The alate aphids of Brachycaudus cardui have an oval body and grow to a length from 1.7 to 2.4 mm. At Brachycaudus cardui the smallest length of the body established for aphids captured in West Zone of Romania was 1.70 mm, while the biggest was 2.40 mm. The average body length was 2.07 ± 0.19 mm. The length of the head and thorax was 1.10 mm and minimum length was 0.65 mm. The minimum width of head was 0.20 mm and the maximum width of head was 0.40 mm. The thorax width was minimum 0.65 mm and maximum 0.95 mm. The length and width of the abdomen was 0.90 mm and minimum width was 0.70 mm, the maximum length of the abdomen was 1.10 mm and the maximum width was 0.70 mm.

Keywords: biometric measures, aphid, brachycaudus helichrysi, brachycaudus cardui

Presentation: oral