Aceratagallia curvata Oman

Description & Identification

Small, robust species. Length of male 2.90—3.20 mm., female 3.20—3.40 mm. (Nielson, 1968)General color light tan. Crown with two distinct black spots on anterior margin; pronotum light tan; elytra with light fuscous markings on veins.(Nielson, 1968)Pygofer in lateral aspect slightly longer than wide, caudal margin produced posteriorly at about middle to bluntly angled lobe; 10th segment with pair of long straight spines directed posteroventrad along inside of caudal submargin of pygofer; aedeagus in lateral aspect simple, apical half of shaft narrow, tubelike, slightly curved laterally at apex; gonopore terminal; style in dorsal aspect with distal third expanded along inner coarsely serrate margin and curved laterally, apex foot shaped; female 7th sternum in ventral aspect with caudal margin truncate and slightly notched at middle. (Nielson, 1968)This species is allied to obscura and can be separated by the apex of the style, which is curved laterally and expanded on its inner serrate margin.(Nielson 1968)

Biology & Ecology

This species is common on alfalfa throughout its range. Under the name 'Agallia uhleri” it was recorded as the most abundant species on alfalfa and injurious to several crops in California by DeLong and Davidson in 1931 (186). In Arizona it is the most important species attacking alfalfa and is present in alfalfa fields every month, with peak populations occurring in February, August, and November (Nielson and Currie 1962) [566]. In cage tests Nielson and Bleak in 1963 [565] found that damage to alfalfa seedlings was most severe during the first 5 days. Damage appeared to be caused largely by removal of plant sap, since little or no toxic effect was observed. Males caused 83 percent seedling mortality, females 61 percent, and the sexes combined 45 percent.I and my coworkers (unpublished data) completed a study of the life history and behavior of the species in the greenhouse at Mesa, Ariz. The results were as follows: Average period in days for precopulation was 3.5, preoviposition 1.5, egg 10.4, first instar 4.8, second instar 3.0, third instar 3.3, fourth instar 8.2, and fifth instar 5.1. The life cycle from egg to adult averaged 31.5 days. Adult longevity for males averaged 90 days and for females 97. Longevities of one female and one male were 240 and 304 days, respectively. The latter is the longest period ever recorded for the life of a single male leafhopper. (Nielson, 1968)

Worldwide Distribution

It is prevalent only in the Western United States. It has been collected or reported from Arizona, California, Nevada, Oregon, and Utah (Oman 1933) [576]. (Nielson, 1968)

Vector Status

Economic Crops

This species is a vector of the New York strain of potato yellow dwarf virus in the Eastern United States Transmission of this virus from crimson clover to crimson clover by curvata was first reported by Black in 1944 [81]. Specimens were collected from California for the tests in New Jersey. Details of the transmission experiments were not given. No evidence of transmission of other strains of potato yellow dwarf or other viruses by this species or confirmation of Black’s work by other workers has been reported.(Nielson 1968)

Plant Diseases