scholarly journals Eriophyid Mites in Classical Biological Control of Weeds: Progress and Challenges

Insects ◽  
2021 ◽  
Vol 12 (6) ◽  
pp. 513
Author(s):  
Francesca Marini ◽  
Philip Weyl ◽  
Biljana Vidović ◽  
Radmila Petanović ◽  
Jeffrey Littlefield ◽  
...  
Keyword(s):  
Biological Control ◽  
Host Specificity ◽  
Biological Control Agent ◽  
Classical Biological Control ◽  
Control Agent ◽  
Alien Invasive Species ◽  
Biological Control Of Weeds ◽  
Control Programs ◽  
Eriophyid Mites ◽  
Nontarget Species

A classical biological control agent is an exotic host-specific natural enemy, which is intentionally introduced to obtain long-term control of an alien invasive species. Among the arthropods considered for this role, eriophyid mites are likely to possess the main attributes required: host specificity, efficacy, and long-lasting effects. However, so far, only a few species have been approved for release. Due to their microscopic size and the general lack of knowledge regarding their biology and behavior, working with eriophyids is particularly challenging. Furthermore, mites disperse in wind, and little is known about biotic and abiotic constraints to their population growth. All these aspects pose challenges that, if not properly dealt with, can make it particularly difficult to evaluate eriophyids as prospective biological control agents and jeopardize the general success of control programs. We identified some of the critical aspects of working with eriophyids in classical biological control of weeds and focused on how they have been or may be addressed. In particular, we analyzed the importance of accurate mite identification, the difficulties faced in the evaluation of their host specificity, risk assessment of nontarget species, their impact on the weed, and the final steps of mite release and post-release monitoring.

Predicting the Outcome of Biological Control

2001 ◽  
Author(s):  
Judith H. Myers
Keyword(s):  
Biological Control ◽  
Exotic Species ◽  
Natural Enemies ◽  
Biological Control Agent ◽  
Classical Biological Control ◽  
Control Agent ◽  
Biological Control Agents ◽  
Native Communities ◽  
Control Programs ◽  
Native Habitat

The movement of humans around the earth has been associated with an amazing redistribution of a variety of organisms to new continents and exotic islands. The natural biodiversity of native communities is threatened by new invasive species, and many of the most serious insect and weed pests are exotics. Classical biological control is one approach to dealing with nonindigenous species. If introduced species that lack natural enemies are competitively superior in exotic habitats, introducing some of their predators (herbivores), diseases, or parasitoids may reduce their population densities. Thus, the introduction of more exotic species may be necessary to reduce the competitive superiority of nonindigenous pests. The intentional introduction of insects as biological control agents provides an experimental arena in which adaptations and interactions among species may be tested. We can use biological control programs to explore such evolutionary questions as: What characteristics make a natural enemy a successful biological control agent? Does coevolution of herbivores and hosts or predators (parasitoids) and prey result in few species of natural enemies having the potential to be successful biological control agents? Do introduced natural enemies make unexpected host range shifts in new environments? Do exotic species lose their defense against specialized natural enemies after living for many generations without them? If coevolution is a common force in nature, we expect biological control interactions to demonstrate a dynamic interplay between hosts and their natural enemies. In this chapter, I consider biological control introductions to be experiments that might yield evidence on how adaptation molds the interactions between species and their natural enemies. I argue that the best biological control agents will be those to which the target hosts have not evolved resistance. Classical biological control is the movement of natural enemies from a native habitat to an exotic habitat where their host has become a pest. This approach to exotic pests has been practiced since the late 1800s, when Albert Koebele explored the native habitat of the cottony cushion scale, Icrya purchasi, in Australia and introduced Vadalia cardinalis beetles (see below) to control the cottony cushion scale on citrus in California. This control has continued to be a success.

Hybridization between Dactylopius tomentosus (Hemiptera: Dactylopiidae) biotypes and its effects on host specificity

2010 ◽  
Vol 100 (3) ◽  
pp. 331-338 ◽  
Author(s):  
C.W. Mathenge ◽  
P. Holford ◽  
J.H. Hoffmann ◽  
H.G. Zimmermann ◽  
R.N. Spooner-Hart ◽  
...  
Keyword(s):  
South Africa ◽  
Biological Control ◽  
Host Specificity ◽  
Biological Control Agent ◽  
Control Agent ◽  
Weed Species ◽  
Maternal Parent ◽  
Control Programs ◽  
Fitness Index ◽  
Biological Performance

AbstractDactylopius tomentosus is composed of biotypes adapted to different Cylindropuntia species. One biotype is an important biological control agent of C. imbricata in South Africa while another has the potential for the control of C. fulgida var. fulgida. These two weed species occur in sympatry in some areas of South Africa, so the introduction of the second biotype could result in hybridization, which, in turn, could impact on the biological control programs through altered host specificity and fitness of the hybrids. To anticipate what might happen, reciprocal crosses were made between the two biotypes, and the biological performance of the resultant hybrids was compared with that of each parental lineage on C. imbricata and C. f. var. fulgida. The biotypes interbred freely and reciprocally in the laboratory. Comparisons of crawler and adult female traits showed differences in performance that were dependent on the origin of the maternal and paternal genomes. However, when all traits were combined into a ‘fitness index’, both hybrids clearly outperformed the parental lineages. The increase in fitness shown by the hybrids over their maternal lineage was greater on the alternative host of the maternal parent than on the natural host of the maternal parent. Therefore, in areas where the two cacti occur in sympatry, hybridization between the biotypes is not expected to be detrimental to the biological control of either weed.

scholarly journals Limited host range in the idiobiont parasitoid Phymasticus coffea, a prospective biological control agent of the coffee pest Hypothenemus hampei in Hawaii

2021 ◽  
Author(s):  
Fazila Yousuf ◽  
Peter A. Follett ◽  
Conrad P. D. T. Gillett ◽  
David Honsberger ◽  
Lourdes Chamorro ◽  
...  
Keyword(s):  
Biological Control ◽  
Native Species ◽  
Biological Control Agent ◽  
Classical Biological Control ◽  
Environmental Safety ◽  
Control Agent ◽  
Hypothenemus Hampei ◽  
Parasitism Rate ◽  
Limited Host Range ◽  
Parasitoid Development

AbstractPhymastichus coffea LaSalle (Hymenoptera:Eulophidae) is an adult endoparasitoid of the coffee berry borer, Hypothenemus hampei (Ferrari) (Coleoptera:Curculionidae:Scolytinae), which has been introduced in many coffee producing countries as a biological control agent. To determine the effectiveness of P. coffea against H. hampei and environmental safety for release in Hawaii, we investigated the host selection and parasitism response of adult females to 43 different species of Coleoptera, including 23 Scolytinae (six Hypothenemus species and 17 others), and four additional Curculionidae. Non-target testing included Hawaiian endemic, exotic and beneficial coleopteran species. Using a no-choice laboratory bioassay, we demonstrated that P. coffea was only able to parasitize the target host H. hampei and four other adventive species of Hypothenemus: H. obscurus, H. seriatus, H. birmanus and H. crudiae. Hypothenemus hampei had the highest parasitism rate and shortest parasitoid development time of the five parasitized Hypothenemus spp. Parasitism and parasitoid emergence decreased with decreasing phylogenetic relatedness of the Hypothenemus spp. to H. hampei, and the most distantly related species, H. eruditus, was not parasitized. These results suggest that the risk of harmful non-target impacts is low because there are no native species of Hypothenemus in Hawaii, and P. coffea could be safely introduced for classical biological control of H. hampei in Hawaii.

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