Spatial and temporal dispersion of Doryctobracon areolatus (Szépligeti) (Hymenoptera: Braconidae) in orchards infested with Anastrepha fraterculus (Wiedemann) (Diptera: Tephritidae).

Doryctobracon areolatus (Szépligeti) is an endoparasitoid and promising fruit fly control agent. The objective of the study was to determine the spatial (horizontal and vertical) and temporal dispersion of D. areolatus in the field. To evaluate the horizontal and temporal dispersion, two peach orchards were selected. In each orchard, 50 points were marked at different distances from the central point, from where 4,100 couples of D. areolatus were released. Four hours after release, parasitism units (PU) (3 per point) were fixed to the trees at a height of 1.5 m from the ground. The PUs were composed of ripe apples artificially infested with second instar larvae of Anastrepha fraterculus (30 larvae/fruit). For the evaluation of vertical dispersion, in an olive orchard six points were selected (trees of ≈4 m in height). Each tree was divided into three heights in relation to the ground (1.17, 2.34, and 3.51 m). Doryctobracon areolatus was able to disperse horizontally at a distance >60 m from the release point. However, the highest parasitism rates [15-45% (area 1); 15-27% (area 2)] were observed up to 25 m. Higher percentages of parasitism and of recovered offspring occur in the first days after the release of the parasitoid (2 DAR). As for vertical dispersion, D. areolatus parasitized A. fraterculus larvae up to the highest attachment height of the evaluated PUs (3.51). The results showed the potential use of D. areolatus in the management of fruit flies in the field.

Search hours for food attractant by Anastrepha fraterculus and Ceratitis capitata (Diptera: Tephritidae) adults in guava orchards.

Anastrepha fraterculus (Wiedemann, 1830) and Ceratitis capitata (Wiedemann, 1824) are considered the main pests of Brazilian fruit production. Understanding the behavior of species is of great importance for the success of management strategies. This study was to determine the period and search time by attractive food for A. fraterculus and C. capitata adults by using three commercial food attractants: BioAnastrepha™ 5%; Isca Samaritá Tradicional™ 5% and Ceratrap™ 1.5%. The largest catches of A. fraterculus and C. capitata adults in McPhail traps occurred during the day between 6:30 am and 6:30 pm for both species. The BioAnastrepha™ food attractant provided the largest catches compared to Isca Samaritá Tradicional™ and Ceratrap™. In addition, there was a higher prevalence of capturing females than males, for both flies' species. The period of largest search activity for food attractant was observed from 12h:31 pm to 04:30 pm for A. fraterculus and C. capitata, time of greatest temperature on the day. The definition of the period of largest activity of A. fraterculus and C. capitata adults in the field helps in the elaboration of management strategies to be adopted.

Lethal and sublethal effects of toxic bait formulations on Doryctobracon areolatus (Hymenoptera: Braconidae) and implications for integrated fruit fly management.

The use of toxic baits has become one of the main methods of management of fruit flies in Brazil. The application of toxic baits may cause side effects on the native parasitoid Doryctobracon areolatus (Hymenoptera: Braconidae). Based on the results, formulations made from the food attractants 3% Biofruit, 1.5% Ceratrap, 1.25% Flyral, 3% Isca Samaritá, 3% Isca Samaritá Tradicional, and 7% sugarcane molasses associated with the Malathion 1000 EC and the ready-to-use toxic bait Gelsura (containing the active ingredient alpha-cypermethrin) were classified as harmful (class 4) to D. areolatus (mortality > 85% at 96 HAE). In contrast, for toxic baits formulated with insecticide phosmet, the mortality ranged from 38% to 72%, classified as slightly harmful or moderately harmful. However, when phosmet was added to the 3% Samaritá Tradicional bait, the mortality was only 3.9% (class 1-harmless), similar to the toxicity observed for the Success 0.02 CB ready-to-use bait (0.24 g a.i. spinosad/l) (<5% mortality). Although toxic baits were formulated with spinosyn-based insecticides, all toxic bait formulations were classified as harmless or slightly harmful (<50% mortality) to D. areolatus, with the exception of 1.5% Ceratrap + spinetoram and 7% Sugarcane molasses + spinosad (≈ 60% mortality-moderately harmful). In addition, these formulations did not show sublethal effects in reducing the parasitism and emergence rate of the F1 generation of D. areolatus in A. fraterculus larvae. The results serve as a basis for the correct use of toxic food baits without affecting the biological control.

Use of Preservatives in Vegetable Protein-Based Food Attractants for Monitoring Anastrepha fraterculus (Diptera: Tephritidae) in Peach Orchards.

Studies have demonstrated that the addition of preservatives mixed with food attractants have provided a more expressive attractiveness for fruit fly adults. The objective of the study was to evaluate the capture of Anastrepha fraterculus (Wiedemann, 1830) adults when the addition of borax and/or benzalkonium chloride preservative in BioAnastrephaTM and Isca Samaritá TradicionalTM food attractants compared to CeraTrapTM (control, no preservatives added) in peach orchards. As well as, verifying the effect over non-target insects. BioAnastrephaTM, Isca Samaritá TradicionalTM and CeraTrapTM attractants enabled the capture of A. fraterculus adults when used by themselves in McPhail traps. However, by adding borax and benzalkonium chloride, BioAnastrephaTM and Isca Samaritá TradicionalTM food attractants significantly increased the number of adults captured. Additionally, the number of A. fraterculus adults captured by BioAnastrephaTM attractant + borax was similar to CeraTrapTM attractant over time. Regarding non-target insects, the highest percentages of subjects captured belong to the Coleoptera (4.4 to 11%) and Diptera orders (24.1 to 34.6%) (Drosophilidae family). Nevertheless, insects from the Hymenoptera order [(Formicidae (0.14 to 0.96%), Vespidae (0.02 to 0.3%), and Apidae (0.04 to 0.9%)] families. Neuroptera (0.02 to 0.98%) and Lepidoptera (0.09 to 0.7%) were also captured, although those amounted to less than 1% of the A. fraterculus total. Adding borax and benzalkonium chloride to BioAnastrephaTM and Isca Samaritá TradicionalTM food attractants potentialize the effect of A. fraterculus capture in monitoring traps. Also, adding preservatives made attractants more durable, consequently, the need to replace attractants was not as frequent.