Photo-Selective Nets and Pest Control: Searching Behavior of the Codling Moth Parasitoid Mastrus ridens (Hymenoptera: Ichneumonidae) under Varying Light Quantity and Quality Conditions

Abstract

Photo-selective nets (PSN) are used to manipulate the physiology of fruit crops. Besides their advantages to the crop, PSN potentially affect insect pests and their natural enemies. We aimed to assess the effects of these production systems on the searching behavior of the codling moth parasitoid, Mastrus ridens. We hypothesized that PSN and black standard nets (SN) affect the behavior of the parasitoid by delaying host localization and reducing parasitism. Laboratory experiments were carried out in closed cages under four treatment conditions: black SN, pearl PSN, red PSN, and no PSN as control (uncovered cages). Our results showed that the host localization of M. ridens was delayed under black SN and enhanced by pearl and red PSN. The PSN and the black SN did not affect the parasitism levels. In addition, the initial behavior of the parasitoid during the first 30 min of the bioassays was not affected by treatments. However, females spent most of the time walking around the arena, grooming, or resting, regardless of the color of the net. Parasitism was not affected under the PSN or the black SN; however, this must be verified in field conditions.

Apple Production under Protective Netting Systems

“…Other more recent works demonstrate the potential of using photoselective colored nets in the biological management of the codling moth in apple orchards. In this case, the parasitoid capacity of the moth larva was affected by the color of the nets; females found their host faster under red and pearl nets when compared to black nets [57]. In recent years, new photoselective net materials have been incorporated with the specific purpose of controlling sunburn on apple orchards through the reduction of light transmission in the UV and IR spectra, which are based on combined colored pearl-gray, blue-gray, and pearl-blue nets (Figure 7); its use in commercial apple orchards allowed reducing sun damage in fruits with an effectiveness of 49%, 45%, and 33% in the "Granny Smith," "Cripps Pink," and "Fuji" cultivars, respectively, and in relation to the use black netting [17].…”