POPULATIONS OF TETRANYCHUS ATLANTICUS McG. (ACARINA: TETRANYCHIDAE) ON SOYBEAN SUPPLIED WITH VARIOUS LEVELS OF NITROGEN, PHOSPHORUS, AND POTASSIUM¹

Abstract

Populations of Tetranychus atlanticusMcGregor, on detached leaf discs from soybean plants in sand culture were greatly influenced by the amount of supplied nitrogen. Two nutrient formulae were used in which the balance of the ions were quite different. Increasing the nitrogen in either formula increased the population. The effects of supplied phosphorus or potassium seemed to depend on the interrelationship of ions in the nutrient solution.Varying the phosphorus concentration in one formula did not alter the number of progeny of this species. A much higher concentration of phosphorus than the standard level in the second formula resulted in a higher population. Differences in mite population resulting from various concentrations of potassium were not significant. The age of the soybean leaf, as indicated by its position on the plant, was found to influence the number of progeny of this species, with larger populations developing on the younger leaves.Studies of several phytophagous mites have indicated that the nutritional state of the host plant affects the mite population. Generally these studies have compared populations developing, under otherwise standardized conditions, on hosts supplied with various levels of nutrient ions. The mites involved were Tetranychus urticae Koch on the foliage of apple, cucumber, lima bean and tomato; Panonychus ulmi (Koch) on that of apple; and Bryobia praetiosa Koch on that of lima bean. In some cases a direct relationship was noted between the number of progeny and the level of nitrogen in the nutrient supplied to the host plant, while in other instances an opposite response was reported. In certain cases either deficient or excess phosphorus or potassium was reported to have an effect. The findings of these investigators will be discussed in connection with the results of our studies, which were conducted to determine what effect various levels of nitrogen, phosphorus, and potassium, supplied to soybean plants, would have on the production of progeny ~) Published as Miscellaneous paper No. 478 with the approval of the Director of the Delaware Agricultural Experiment Station, Publication 349 and Scientific Article 365 of the

Stabilization of the Rate of Nitrogen Accumulation by Larvae of the Cabbage Butterfly on Wild and Cultivated Food Plants

“…Rodriguez (1960) concluded that aphids, chinch bugs, lepidopterous larvae, scale insects, and mites all benefit either directly or indirectly from an increase in nitrogen in their food. This trend has been substantiated in more recent studies on mites (Cannon andConnell 1965, Storms 1969), aphids (van Emden 1966, Dixon 1970, lepidopterous larvae (SooHoo and Fraenkel 1966aand 1966b, Taylor and Bardner 1968, Feeny 1970, Schramm 1972, Wiseman et al 1973, Onuf 1976, bugs (McNeill 1973), and beetles (Taylor and Bardner 1968, Schramm 1972, Onuf 1976). These beneficial effects are variously manifested through increases in individual growth rate, longevity, fecundity, reproductive rate, andjor survivorship.…”

How Dietary Phosphorus Availability during Development Influences Condition and Life History Traits of the Cricket,Acheta domesticas

“…Aphids, chinch bugs, lepidopterous larvae and mites, for example, show increased growth rates, longevity and survival when they consume foods with elevated nitrogen content (Rodriguez 1960; Cannon and Connell 1965; Storms 1969; Soo Hoo and Fraenkel 1966; Van Emden 1966; Dixon 1970). …”

“…For decades, a mismatch in nitrogen content between insects and their food plants has been recognized to be a critical factor influencing herbivore success ( Slansky and Feeny 1977 ; McNeill and Southwood 1978 ; Mattson 1980 ; Denno and McClure 1983 ; Strong et al 1984 ; White 1993 ; Schindler and Eby 1997 ). Aphids, chinch bugs, lepidopterous larvae and mites, for example, show increased growth rates, longevity and survival when they consume foods with elevated nitrogen content ( Rodriguez 1960 ; Cannon and Connell 1965 ; Storms 1969 ; Soo Hoo and Fraenkel 1966 ; Van Emden 1966 ; Dixon 1970 ).…”

Arthropod Fauna Associated to Soybean in Croatia

“…Both species have similar thermal requirements but, T. atlanticus prefers extremely dry conditions [9]. Some differences were established in their response to host plant nutrient status [79]. The development of T. urticae is positively influenced by potassium content in the plant host, while T. atlanticus is positively influenced by content of phosphorus.…”