The development of an electronic aphid-counter

Abstract

SummaryVarious methods of estimating aphid populations are discussed and their limitations are noted.Details are given of the' construction and operation of an electronic counter by means of which normal colonies of aphids can be counted with a repeatability of ± 3%. It is essentially an instrument for use in the laboratory, where a stable power supply is normally available.

Control of the cabbage aphid (Brevicoryne brassicaeL.) with some systemic materials

“…The cabbage aphid problem in Canterbury has been briefly outlined by Lowe (1958). Because of the part played by seed-crops in carrying the overwintering population into the spring period, it is desirable that a reliable form of chemical control be available during the early spring period.…”

APHlD SAMPLING IN SUGAR BEET

“…The instars could be further separated by repeating the process with the two fractions, by using a longer column or more viscous liquids or by use of an upward current through the cylinder. The method could aid in determining the age-structure of a population, perhaps coupled with a counting device of the type described by Lowe and Dromgoole (1958). The sampling error between the numbers of aphids on different groups of plants was estimated by collecting 100 pairs of adjacent plants at regular intervals along a line of traverse of a beet field, and placing each plant of a pair in one of two polythene bags.…”

“…The instars could be further separated by repeating the process with the two fractions, by using a longer column or more viscous liquids or by use of an upward current through the cylinder. The method could aid in determining the age-structure of a population, perhaps coupled with a counting device of the type described by Lowe and Dromgoole (1958). 101 lOCM 88MESH/|N.…”

Chemical control of the cabbage aphid (Brevicoryne brassicaeL.)

“…The cabbage aphid problem in Canterbury and the control of spring populations on seed-crops with systemic materials have both been outlined by Lowe (1958aLowe ( , h, 1960).…”