Identifying the predator complex of Homalodisca vitripennis (Hemiptera: Cicadellidae): a comparative study of the efficacy of an ELISA and PCR gut content assay

Abstract

A growing number of ecologists are using molecular gut content assays to qualitatively measure predation. The two most popular gut content assays are immunoassays employing pest-specific monoclonal antibodies (mAb) and polymerase chain reaction (PCR) assays employing pest-specific DNA. Here, we present results from the first study to simultaneously use both methods to identify predators of the glassy winged sharpshooter (GWSS), Homalodisca vitripennis (Germar) (Hemiptera: Cicadellidae). A total of 1,229 arthropod predators, representing 30 taxa, were collected from urban landscapes in central California and assayed first by means of enzyme-linked immunosorbent assay (ELISA) using a GWSS egg-specific mAb and then by PCR using a GWSS-specific DNA marker that amplifies a 197-base pair fragment of its cytochrome oxidase gene (subunit I). The gut content analyses revealed that GWSS remains were present in 15.5% of the predators examined, with 18% of the spiders and 11% of the insect predators testing positive. Common spider predators included members of the Salticidae, Clubionidae, Anyphaenidae, Miturgidae, and Corinnidae families. Common insect predators included lacewings (Neuroptera: Chrysopidae), praying mantis (Mantodea: Mantidae), ants (Hymenoptera: Formicidae), assassin bugs (Hemiptera: Reduviidae), and damsel bugs (Hemiptera: Nabidae). Comparison of the two assays indicated that they were not equally effective at detecting GWSS remains in predator guts. The advantages of combining the attributes of both types of assays to more precisely assess field predation and the pros and cons of each assay for mass-screening predators are discussed.

Background matching behaviour and pathogen acquisition: plant site preference does not predict the bacterial acquisition efficiency of vectors

“…Homalodisca vitripennis (Germar), for example, consumes between 10 and 100 times its dry body-weight hourly (see Redak et al 2004). During such lengthy feeding episodes sharpshooters are exposed to a range of visual predators including jumping spiders (Salticidae), assassin bugs (Hemiptera: Reduviidae), lizards (Lopez et al 2003;Suttle and Hoddle 2006;Fournier et al 2008), and potentially insectivorous birds (Burger et al 1999).…”

Molecular Markers Discriminate Closely Related Species <I>Encarsia diaspidicola</I> and <I>Encarsia berlesei</I> (Hymenoptera: Aphelinidae): Biocontrol Candidate Agents for White Peach Scale in Hawaii

“…In the current study, as in previous work with molecular predation studies (de Leó n et al 2006a, Fournier et al 2008, we demonstrated the importance of including an internal control (28S ampliÞca-tion) for these types of molecular marker assays. The internal controls become even more important when working with tiny insects, as in the current study.…”

“…To conÞrm for the presence of genomic DNA, ampliÞcation reactions were performed with 1 l of stock DNA and 28S primers at an annealing temperature of 65ЊC (forward, 5Ј-CCCTGTTGAGCTTGACTCTAGTCT-GGC-3Ј and reverse, 5Ј-AAGAGCCGACATCGAAG-GATC-3Ј) (Werren et al 1995) with 1.5 mM MgCl 2 and the ampliÞcation conditions described below. The 28S assay was also used as an internal control in subsequent PCR reactions to test for the presence of PCR inhibitors or failures (Pooler et al 1997, Vega et al 1993, de Leó n et al 2006a, Fournier et al 2008.…”

Molecular-genetic methods of the investigation of trophic relations hips in the agrocoenosis

“…При исследовании хищников цикады Homalodisca vitripenni ПЦР-анализ обходился в 7,5 дол-лара США на образец (стоимость праймеров не приво-дится), серологический анализ стоил 0,5 доллара США за образец, но на разработку антител потребовалось 12000 долларов США и год времени (Fournier et al, 2008). Там же приводится ссылка на исследователей, по-другому оценивающих ПЦР и серологический анализ (0,28 и 0,21 доллара соответственно) (Chen et al, 2000).…”