Toxicities of Insecticidal Toxic Baits to Control Ceratitis capitata (Diptera: Tephritidae): Implications for Field Management

Ceratitis capitata (Wiedemann, 1824) is a significant insect pest of fruits produced worldwide and is capable of causing direct and indirect damage to fruit. Chemical control is the most frequently used management strategy, mainly involving organophosphate insecticides. However, the frequent use of this chemical group has resulted in unacceptable chemical residues on fruits. In this study, the toxicity of 18 insecticides was evaluated in adults and larvae of C. capitata in a laboratory. The organophosphate insecticides chlorpyrifos (Lorsban 480BR), phosmet (Imidan 500WP), and malathion (Malathion 1000EC); the spinosyns spinetoram (Delegate 250WG) and spinosad (Tracer); and the pyrethroid alpha-cypermethrin (Fastac 100SC) caused high mortality (>80%) in C. capitata adults in topical application bioassays and by ingestion when mixed with Biofruit 5% food lures. However, the insecticides chlorfenapyr (Pirate), spinetoram and chlorpyrifos produced a significant reduction in larval infestation of the fruits (67, 74, and 84% larval mortality, respectively). Insecticides based on spinosyns, alpha-cypermethrin, and cyantraniliprole are alternatives that can replace organophosphates in the management of C. capitata in the field.

Toxicities and Residual Effect of Spinosad and Alpha-Cypermethrin-Based Baits to Replace Malathion for Ceratitis capitata (Diptera: Tephritidae) Control

Ceratitis capitata (Wiedemann, 1824) is the main insect pest of fruits worldwide. The objective of this study was to evaluate the toxicity and residual effects of the ready-to-use toxic baits Success 0.02CB (0.24 g of active ingredient [a.i.] per liter of spinosad) and Gelsura (6 g of a.i./liter of alpha-cypermethrin) and to compare them with other food lures containing spinosad and malathion mixed with hydrolyzed protein (Biofruit 5% and Flyral 1.25%), Anamed without dilution or sugarcane molasses (7%) against adult C. capitata in laboratory and greenhouse trials. Ceratitis capitata adults were highly susceptible to all toxic bait formulations (mortality > 80%) until 96 h after exposure. The lowest LT50 (hours) of toxic baits were 2.32 (Gelsura at 4,000 mg/liter), 4.26 (Gelsura at 2,000 mg/liter), 4.28 (Anamed + malathion) and 4.89 (sugarcane molasses + malathion), while formulations containing spinosad (Biofruit, Flyral, Anamed and Success 0.02CB) showed LT50 of approximately 11 h. Without rain, Gelsura (2,000 mg/liter) and all spinosad formulations provided mortality superior to 80% 14 d after application. Gelsura and Anamed + spinosad showed higher resistance to a 5-mm simulated rain, similar to Anamed + malathion, while the other formulations had its efficacy decreased. All toxic baits were effective on adult C. capitata in residual experiments without rain while Anamed + spinosad caused high adult mortality after 5 to 25 mm rains. Gelsura and Anamed + spinosad can be used to replace toxic baits containing malathion for C. capitata population management.

Concentration and lethal time of toxic baits based on spinosyns on Ceratitis capitata and Diachasmimorpha longicaudata 1

ABSTRACT The use of toxic baits with spinosyns (spinosad and spinetoram), along with the parasitoid Diachasmimorpha longicaudata, is a sustainable alternative for the management of Ceratitis capitata. This study aimed to evaluate the lethal concentration (LC) and lethal time (LT) of spinosad and spinetoram, associated with the food lures sugarcane molasses at 7 %, Biofruit at 3 %, Ceratrap® at 1.5 %, Flyral® at 1.25 %, Isca Samaritá® and Samaritá Tradicional® at 3 %, on C. capitata, under laboratory conditions, as well as their effect, at the concentration of 96 mg L-1, on D. longicaudata. For the lethal time data, mortality was assessed at 2, 4, 6, 8, 10, 12, 14, 16, 18, 20, 22, 24, 36, 48, 60, 72, 84 and 96 h after the exposure to the toxic baits. The lowest lethal concentrations (LC50 and LC95), to spinetoram (0.5 mg L-1 and 3.7 mg L-1, respectively) and spinosad (0.8 mg L-1 and 7.8 mg L-1, respectively), corresponded to the association with Samaritá Tradicional® at 3 %. The lowest lethal time (TL50), in hours, for the spinosad insecticide, corresponded to the formulation containing Biofruit at 3 % (6.6), and, to spinetoram, Samaritá Tradicional® at 3 % (7.9). For D. longicaudata, the formulations that caused the lowest mortality corresponded to the association of Biofruit® at 3 % with spinosad (4.7 %) and Samaritá Tradicional® at 3 % with espinetoram (3.5 %). The toxic baits formulated with spinosad and espinetoram, associated with Isca Samaritá® at 3 %, caused a mortality rate of more than 60 % to the parasitoid D. longicaudata.

Detection of Volatile Constituents from Food Lures by Tephritid Fruit Flies

Tephritid fruit flies require protein for sexual and gonotrophic development. Food-based lures are therefore widely used in strategies to detect and control fruit flies in the Tephritidae family. However, these baits are attractive to a broad range of insect species. We therefore sought to identify volatiles detected by the fly antennae, with the goal to compose lures that more specifically target tephritids. Using gas chromatography-coupled electroantennographic detection (GC-EAD) we screened for antennal responses of four important tephritid species to volatile compounds from five commercially available protein-based baits. Antennal active compounds were reconstituted in synthetic blends for each species and used in behavioral assays. These species-based blends were attractive in olfactometer experiments, as was a blend composed of all antennally active compounds from all the four species we observed (tested only in Bactrocera dorsalis, Hendel). Pilot field tests indicate that the blends need to be further evaluated and optimized under field conditions.

Toxicity and residual effects of toxic baits with spinosyns on the South American fruit fly

The objective of this work was to assess the lethal concentration and lethal time (LC and LT) of spinosad and spinetoram, combined with different food lures, and their residual effects on South American fruit fly (Anastrepha fraterculus). The toxic baits were offered in eight concentrations (2, 6, 14, 35, 84, 204, 495, and 1,200 mg L-1), combined with the following food lures: 7% sugarcane molasses, 3% Biofruit, 1.5% CeraTrap, 1.25% Flyral, 3% Samaritá Bait, and 3% Samaritá Tradicional; diluted food lures in water were used as controls. The residual effect of the formulations at 96 mg L-1 concentration were evaluated for 21 days and were compared with that of the commercial bait Success 0.02 CB. Both insecticides were toxic to adults of A. fraterculus, and mortality varied with the food lure used. The LC50and LT50ranged from 15.19 to 318.86 mg L-1and from 11.43 to 85.93 hours, respectively. Spinosad was 2 to 36 times as toxic as spinetoram when combined with different hydrolyzed proteins. Toxic baits formulated with spinosad and spinetoram (96 mg L-1) caused mortality equivalent to the one by Success 0.02 CB (90.2%), when assessed on the day of application. Toxic baits formulated with 3% Biofruit + spinosad and 3% Samaritá Bait + spinetoram are effective for managingA. fraterculusand provide up to seven days of residual effect in the absence of rain; however, only Success 0.02 CB caused more than 80% mortality for up to 21 days.

Monitoring Resistance to Spinosad in the Melon Fly (Bactrocera cucurbitae) in Hawaii and Taiwan

Spinosad is a natural insecticide with desirable qualities, and it is widely used as an alternative to organophosphates for control of pests such as the melon fly,Bactrocera cucurbitae(Coquillett). To monitor the potential for development of resistance, information about the current levels of tolerance to spinosad in melon fly populations were established in this study. Spinosad tolerance bioassays were conducted using both topical applications and feeding methods on flies from field populations with extensive exposure to spinosad as well as from collections with little or no prior exposure. Increased levels of resistance were observed in flies from the field populations. Also, higher dosages were generally required to achieve specific levels of mortality using topical applications compared to the feeding method, but these levels were all lower than those used for many organophosphate-based food lures. Our information is important for maintaining effective programs for melon fly management using spinosad.