Interactions between citrus psylla,Trioza erytreae (Hem. Triozidae), and spiders in an unsprayed citrus orchard in the transvaal lowveld |
| |
Authors: | M A van den Berg Ansie S Dippenaar-Shoeman Valerie E Deacon Susan H Anderson |
| |
Institution: | (1) Citrus and Subtropical Fruit Research Institute, Private Bag X 11208, 1200 Nelspruit, South Africa;(2) Plant Protection Research Institute, Private Bag X 134, 0001 Pretoria, South Africa |
| |
Abstract: | During a two year survey, a total of 3,054 spiders represented by 21 families were sampled in an unsprayed citrus orchard
in the Transvaal Lowveld. Numerically the Salticidae was the dominant family (34.4%) followed by the Theridiidae (21.9%),
Thomisidae (11.9%), Araneidae (7.9%), Clubionidae (7.0%) and the Tetragnathidae (3.7%). Eighteen species of spiders were observed
to prey on citrus psylla,Trioza erytreae (Del Guercio) (Hemiptera: Triozidae), while six species trap nymphs and adults under their retreats and webs. There were
significant positive correlations between the weekly psylla populations and the weekly populations of web-building spiders
and wandering spiders present one to four weeks later but no significant correlation between the weekly spider populations
and the weekly psylla populations present one to five weeks later. This seems to indicate that while spiders are unable to
keep citrus psylla populations at acceptable low levels, they may contribute in reducing their numbers.
|
| |
Keywords: | Araneae citrus psylla spiders Trioza erytreae |
本文献已被 SpringerLink 等数据库收录! |
|