Journal of Insect Science (2008) 8 (49), 21-22

From Pestinfo-Wiki
Jump to: navigation, search

N. Megha Parajulee, B. Ram Shrestha and C. Stanley Carroll (2008)
Intercrop movement of Lygus hesperus in the Texas High Plains: Potential for landscape level management
Journal of Insect Science 8 (49), 21-22
in P.B. Goodell and P.C. Ellsworth, organizers: Second International Lygus Symposium, Pacific Grove, California, April 15-19 2007
Abstract: Lygus hesperus (Knight) (Hemiptera: Miridae) is an economically important pest of various field crops. It is the dominant species within the Texas High Plains Lygus complex. The year-round availability of its potentially preferred host plants is one of the reasons for the occurrence of this pest throughout most of the year in the Texas High Plains. Because it is a highly polyphagous and mobile pest, it can exploit various field crops and weed hosts for its population development and maintenance. It has been recorded that L. hesperus can move from one host plant to another alternative host plant species when the primary host becomes unsuitable or less preferred. Thus, management of this pest is not feasible by simply managing a single crop, which leads to the need for landscape level management of this pest. Intensive surveys of all potential field crops and wild weed hosts of Lygus hesperus have been conducted for the Texas High Plains region which provides a listing of potential hosts, host-plant sequencing and indirect assessment of intercrop movement of this pest. Because alfalfa is a major host plant of L. hesperus in the Texas High Plains cotton production landscape, a two-year season long survey of roadside alfalfa and adjacent cotton was conducted at numerous locations in Lubbock County. A two-year field study was also conducted in selected weed and crop hosts to examine Lygus colonization preference. These two indirect assessments of Lygus movement suggested selected weed and crop hosts to examine Lygus colonization preference. These two indirect assessments of Lygus movement suggested alfalfa with cotton may largely determine the resulting intercrop movement of Lygus between cotton and non-cotton hosts. Therefore, if alfalfa is not managed properly it may serve as a source of Lygus for adjacent cotton. Physical marking and recapture studies have been reported for some other crops but the technique of physical marking with fluorescent dye is not efficient and cannot be used for field marking and landscape level monitoring of a Lygus population. The enzyme-linked immunosorbent assay (ELISA) has been successfully used for other insects for quantification of their intercrop movement. Therefore, we tested the ELISA technique to quantify cotton-alfalfa intercrop movement of L. hesperus. Seven animal origin proteins and one plant protein were tested for their suitability in ELISA based Lygus monitoring. The direct ELISA protocol has been optimized for two animal proteins for laboratory and field marking. Chicken egg albumin and bovine milk casein can be used for field marking in landscape level monitoring of intercrop movement of L. hesperus. A preliminary study conducted in 2006 under a low Lygus density regime showed that ELISA detection procedure satisfactorily quantified the inter- and intra-crop movement between alfalfa and cotton. ELISA detected that 1 out of 3 Lygus retrieved from cotton moved from adjacent alfalfa while 4 out of 85 Lygus retrieved from alfalfa showed positive response to markers from both alfalfa and cotton, indicating likely movement from alfalfa to cotton and back to alfalfa. More research is underway to examine the Lygus movement behavior at the landscape level.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Database assignments for author(s): Megha N. Parajulee

Research topic(s) for pests/diseases/weeds:
population dynamics/ epidemiology
environment - cropping system/rotation

Pest and/or beneficial records:

Beneficial Pest/Disease/Weed Crop/Product Country Quarant.

Lygus hesperus Alfalfa/lucerne (Medicago sativa) U.S.A. (mid S)
Lygus hesperus Cotton (Gossypium) U.S.A. (mid S)