A critical evaluation of host ranges of parasitoids of the subtribe Diabroticina (Coleoptera: Chrysomelidae: Galerucinae: Luperini) using field and laboratory host records

Abstract

The subtribe Diabroticina is a large group of New World Chrysomelidae that includes corn rootworms, cucumber beetles and other pests. Recent introductions of Diabrotica virgifera virgifera LeConte into Europe, and the development of resistances to current management practices of rootworms in the USA have increased interest in new sustainable options for managing those pests. The only parasitoids that have been shown to consistently target and develop inside the beetle adults are Centistes gasseni Shaw, Centistes diabroticae Gahan (both Hym.: Braconidae), and Celatoria diabroticae Shimer, Celatoria compressa (Wulp), Celatoria bosqi Blanchard, and Celatoria setosa Coquillett (all Diptera: Tachinidae). This review improves our understanding of the realised and potential host range of these known parasitoids by rectifying erroneous references in light of new host records and from laboratory host range tests. Based on this critical review, all tachinid and braconid species studied are considered to be specific at least to the level of subtribe, i.e. Diabroticina. Celatoria setosa, Celatoria diabroticae and C. bosqi, have a narrow realised and potential host range; the former is restricted to the genus Acalymma and the last two to the fucata and virgifera groups of the genus Diabrotica. The braconids Centistes gasseni and C. diabroticae are also specific. The realised host range of C. gasseni includes species in the Diabrotica fucata and virgifera groups; while its potential host range also includes Acalymma species. The realised and potential host range of Centistes diabroticae includes Acalymma species as well as species in the fucata and virgifera groups of Diabrotica. Celatoria compressa has the broadest realised range compared to the other species studied, since it was obtained from species in several genera of Diabroticina; and its potential host range may also include Old World Aulacophora species.

Ecology and Evolutionary History of Diabrotica Beetles—Overview and Update

“…Parasitic flies of the species Celatoria compressa Wulp (Diptera: Tachinidae) were reared from several species of Diabroticite beetles in Veracruz, Mexico [71]. Based on extensive field surveys in central Mexico [73], this fly species was later considered for classical biological control of D. v. virgifera in Europe [91,92]. The fly, however, cannot be considered a specialist on species in the genus Diabrotica.…”

A Sustainable Agricultural Future Relies on the Transition to Organic Agroecological Pest Management

“…In addition, use of non-preferred cucurbit cultivars can reduce beetle damage, and is effective at farm-scale [119]. Finally, a habitat for natural enemies could be provided [113], and the role of parasitoids could be better understood and promoted [120][121][122]. The example of cultural practices replacing the role that neonicotinoid insecticides occupy in conventional systems typifies sustainable alternative with lessened off-target effects that organic agroecological pest management strategies can provide.…”

Biology and Management of Pest Diabrotica Species in South America

“…In spite of the large number of species in the Diabrotica genus, and how widespread several of them are, only five species of parasitoids are known for the whole genus [94,95]. This is not the result of a lack of survey efforts, since many entomologists have surveyed for parasitoids and pathogens for many years throughout the Americas, and only one new species was detected in 60 years ( [94], and literature therein). The scarcity of parasitoids of adults in the genus has been hypothesized to be due to the accumulation of cucurbitacins in fatty tissues [96,97].…”

“…[98,99]. There are no references of predators or parasitoids of larvae of South American species of Diabrotica [94]. However, based on the wide range of predators detected for D. virgifera virgifera in North America [100,101], it is to be expected that there are egg and larval predators of South American Diabrotica as well, which are yet to be discovered.…”