Acoustic Activity Cycles of Rhynchophorus ferrugineus (Coleoptera: Dryophthoridae) Early Instars After Beauveria bassiana (Hypocreales: Clavicipitaceae) Treatments

Acoustic Signal Applications in Detection and Management of Rhynchophorus spp. in Fruit-Crops and Ornamental Palms

“…The activity cycles in Jalinas et al (2017) were similar to those observed by Dosunmu et al (2014) in the activity of palmetto weevil larvae monitored in palm fronds over a 56 d period. Shade et al (1990) also observed cyclic molting activity during acoustic monitoring of Callosobruchus maculatus (F.) (Coleoptera: Chrysomelidae) larvae in cowpea seeds, Vigna unguiculata (L.) Walp (Fabaceae).…”

“…The "typical" pattern of movement and feeding activity includes 0.1 to 0.3 s trains of short, 1 to 10 ms impulses with broadband spectra produced by weak contacts of larvae scraping or sliding along a tunnel, or by snapping of wood fibers during feeding (Mankin et al 2011). Such trains, hereafter termed bursts, have been reported previously in studies where larvae and adults of a variety of different insect species had been recovered after recording (Mankin et al 2011), including palmetto weevil (Dosunmu et al 2014), red palm weevil (Jalinas et al 2015(Jalinas et al , 2017, and Oryctes elegans Prell (Coleoptera: Scarabaeidae), with or without red palm weevil recovered from the same tree (Mankin et al 2016a). In contrast to the commonly observed pattern, each 0.2 to 0.3 s squeal in Figure 1 begins with descending bands of 2 or more loud harmonics, which then are followed by the more typical trains (bursts) of short impulses with broadband spectra.…”

“…In the spectrogram, darker color indicates greater energy at the specified frequency and time. an important role in interpretation of insect acoustic activity patterns (Jalinas et al 2017). In this case, 15-d-old red palm weevil larvae were exposed to different B. bassiana treatments and placed into holes drilled into 5-yr-old Phoenix canariensis Chabaud (Arecaceae) palms.…”

“…For this report, we describe some of the physical, behavioral, and physiological causes of variability of red palm weevil acoustic activity and consider some of the methods developed to correctly interpret the variability. Our example of physical variability interpretation is a distinctive "squeal" sound frequently detected in field recordings from red palm weevil-infested palms (Rach et al 2013), but only rarely in laboratory or semi-field studies (Jalinas et al 2015(Jalinas et al , 2017. In addition, we discuss how future studies of early detection or biological control treatment efficacy may benefit from continued improvements in acoustic sensor and signal processing technology.…”

“…In studies reported at the 2016 International Congress of Entomology, acoustic technology was used to monitor the effects of different treatments of B. bassiana against red palm weevil larvae inside palm trees (Jalinas et al 2015(Jalinas et al , 2017. The monitoring of acoustic activity over time after treatment enabled estimation of B. bassiana treatment efficacy and red palm weevil mortality in situ.…”