Classical and augmentative biological control against ... - IOBC-WPRS

Chapter 3
Pathogens and Nematodes as candidate for ClBCA
The particular cases of pathogens and nematodes have been recently reviewed by Hajek and
co-workers (62, 63 3 ). Our own survey indicates that half of the papers actually deal with
entomopathogenic fungi. Six pest species were identified including two mites (Aceria
guerreronis and Mononychellus tanajoa) and two insects (Aphis gossypii and Coptotermes
formosanus). However, except for the evaluation of Neozygites species against M. tanajoa
(14, 39, 42, 43), other attempts seem to be rather limited. With regard to the catalogue of
Hajek et al.(62), two other cases of entomopathogen fungi were missed in our own survey.
These are the introductions of Entomophaga maigmaiga and Metarhizium anisopliae, against
respectively the Lymantria dispar and the Curculionidae Otiorynchus nodosus for which the
sources of Hajek and coworkers were mainly personal communications. The rather limited
use of entomopathogenic fungi in ClBC was also confirmed by the review of Shah and
Pell(156). The use of viruses as biocontrol agent for ClBC against arthropod pests were only
documented fort three cases that are the Lepidoptera species Anticarsia gemmatalis (48, 127)
and Lymantria dispar (16) and the Coleoptera Oryctes rhinoceros (81). Microspodia as
candidate for ClBC were reported in only two studies (25, 165). The sole case of the use of
nematodes is the study of Hurley et al. (79) who studied the extension of the use of parasitic
nematode Deladenus siricidicola against the woodwasp Sirex noctilio.
Predatory arthropods as candidate for ClBCA
The literature about predatory arthropods is dominated by four case-studies. The first one is
the classical biocontrol of the cassava green mites M. tanajoa by Typhlodromalus aripo and,
to a lesser extent, T. manihoti. All these studies are the extension of a very large classical
biocontrol programme at a continental scale; two main issues were addressed during the
recent decade that are the introduction and field evaluation of T. aripo in Mozambique and
Malawi (125, 194) and the ecological interactions with other species (14, 124, 193) or
plants(55). The second case-study is those of the predatory ladybird Harmonia axyridis (19,
90, 91, 137). The main concern of these publications is nevertheless not the Research and
Development in ClBC but rather the risks of non-intended effects and geographic spray of
this insect that is now considered as a world-wide invasive species. Another case of the use of
ladybird is those of Cryptolaemus montrouzieri and Scymnus coccivora which have been
successfully used to control the hibiscus mealybug Maconellicoccus hirsutus (51, 86, 103)
which is the extension of a worldwide use of these species. The fourth main case-study is the
classical biocontrol programme of Prostephanus truncatus, a serious pest of stored maize
beetle using Teretrius (formerly Teretriosa) nigrescens (73, 169, 170). The lasts reported uses
of predatory arthropods as candidate for ClBC were those of the Coleoptera Laricobius
nigrinus against the adelgid Adelges tsugae (197) and the phytoseid Neoseiulus baraki
against the coconut mite A. guerreronis (119). Contrary to other cases which were the
continuity of older programmes, these two studies are associated with new BCA inventories
undertaken during the last ten years - see respectively (196) and(99).
Insect parasitoids as BCA
Related journals papers and categorization of the studies
In total, 125 publications were used for this analysis. Only 14% were associated to
proceedings of meetings or other supports than journals. 43 different journals were identified
but 50% of the publications were published only by five: Biological Control (21%),
BioControl (8%), Biocontrol Science and Technology (7%), Florida Entomologist (7%) and
3 within this Chapter, numbers in parentheses refer to references listed in Appendix 9
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