Virulence of entomopathogenic nematodes (Rhabditida: Steinernematidae and Heterorhabditidae) for the control of Diabrotica speciosa germar (coleoptera: chrysomelidae)

Abstract

Entomopathogenic nematodes (EPNs) are used in biological control of soil insects and show promise in the control of D. speciosa. The objective of this work was to evaluate the potential of native and exotic entomopathogenic nematode isolates in the control of D. speciosa under laboratory and greenhouse conditions. Results showed that all of EPNs caused larval mortality. The most virulent were Heterorhabditis sp. RSC01 (94%), Steinernema glaseri (84%), Heterorhabditis sp. JPM04 (82%) and Heterorhabditis amazonensis RSC05 (78%). There was no effect of the Heterorhabditis sp. RSC01 and S. glaseri isolates on eggs.The maximum mortality of D. speciosa larvae by Heterorhabditis sp. RSC01 was observed at a concentration of 300 IJ/ insect, while by S. glaseri observed the highest mortality at the concentration of 200 IJ/ insect. The Heterorhabditis sp. RSC01 isolate caused over 80% pupal mortality at a concentration of 250 IJ/insect. The virulence of Heterorhabditis sp. RSC01 and S. glaseri was affected by temperature. The Heterorhabditis sp. RSC01 isolate caused reduction in larva survival under greenhouse conditions at all of the tested concentrations and there was no difference in mortality among different concentrations of infectid juveniles.

A Deep Learning-Based Approach for the Detection of Infested Soybean Leaves

“…Diabrotica speciosa, also called green cow or patriot, has been detected in most crops in South America. In Brazil, the adult pest is considered an important pest infesting some extensive crops, such as soybeans [26], [27]. The pest that prefers the softer leaves and damages plants by eating small round holes in the leaf or making incisions on the leaf edges [12].…”

Biology and Management of Pest Diabrotica Species in South America

“…Similar results have been obtained for South American species. In Brazil, the microbial control of D. speciosa larvae with entomopathogenic fungi or nematodes is considered to have great potential because the soil is a relatively stable environment in terms of temperature and humidity, especially in no-till farming [ 111 ]. Argentine strains of M. anisopliae and B. bassiana killed third instars of D. speciosa in the laboratory [ 112 ].…”

Studies on entomopathogenic nematodes in Brazil: past and future

“…Laboratory and greenhouse Santos et al [25] Sugar cane borer Fowler [47] evaluated soil samples of 1,532 locations, adding mole crickets of the genera Scapteriscus and Neocurtilla (Orthoptera: Gryllotalpidae) as insect bait, and obtained 18 isolates of S. feltiae and 13 isolates of Heterorhabditis spp. Some authors suggested that those Steinernema isolates may have been misidentified, and in fact they could be Steinernema scapterisci, later described by Nguyen & Smart [48] in 1990.…”

“…In Brazil, this type of application has proved to be effective to control pests on different crops. In greenhouse experiments, the application of aqueous suspensions has been found to be effective against Conotrachelus psidii Marshall (Coleoptera: Curculionidae) (guava weevil) [13] , Mahanarva spectabilis (Distant) (Hemiptera: Cercopidae) (spittlebug) [86] , Diabrotica speciosa (Germar) (leaf beetle) [25] , Sphenophorus levis Vaurie (Coleoptera: Curculionidae) (sugarcane weevil) [16] and Dysmicoccus texensis (Tinsley) (Hemiptera, Pseudococcidae) [19] . With respect to field trials, good results have been obtained against M. fimbriolata (sugarcane root spittlebug) [11] , C. psidii [13] , Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) (fruit fly), Anastrepha fraterculus (Wied.)…”