Emergence of New Potential Insect Pests of Date Palm: Could Climate Change Be the Reason?

Four insect species were reported as new potential pests of date palm in recent years. They are sorghum chafer (Pachnoda interrupta), the rose chafer (Potosia opaca), the sericine chafer beetle (Maladera insanablis), and the South American palm borer (Pysandisia archon). The first three species belong to the order Coleoptera and the family Scarabaeidae, while the fourth species is a lepidopteran of the family Castniidae. The injury as well as the economic damage caused by the four species on date palm need to be quantified. Due to climate change and anthropogenic activities, the date palm pest complex is expected to change in the future. To the author's knowledge, this article provides the first report of sorghum chafer as a pest damaging date palm fruit.

Field Level Auto-inoculation of Sorghum chafer, Pachnoda interrupta (Olivier) (Coleoptera: Scarabaedae) with Metarhizium anisopliae based Microbial Bio-control Agents using Locally Affordable Traps

Sorghum chafer,<em>Pachnoda interrupta</em>, is the most serious pest of sorghum in Ethiopia destroying the entire fields at the milk stage and causing up to 100% yield loss. Current control methods entirely depend on direct spraying and baiting with insecticides which does not provide long lasting control. Efficient biological control agents such as entomopathogenic fungi that can control the pest in the breeding sites need to be developed. Traps equipped with auto-inoculation devices are important alternative methods to spread entomopathogens into insect pest populations. Field studies on fungal auto-inoculation trap development from locally available materials conducted over three feeding and two mating seasons of <em>P. interrupta</em> resulted in two efficient auto-inoculation traps (AIT1 and AIT2) baited with a five compounds blend lure which were not significantly different in catch performance with the standard Japanese beetle trap. Two selected virulent isolates of <em>Metarhizium anisopliae</em> (PPRC51 and PPRC2) were tested for field efficacy using these two designs of locally affordable auto-inoculation traps loaded with 1gm of dry conidia. Using AIT1, PPRC51 and PPRC2 induced 41% and 40% field mortality respectively, on <em>P. interrupta</em> adults under high temperature and low relative humidity conditions, while highest field viability of the two isolates five days after application was 36 % and 40 % for PPRC51 and PPRC2, respectively. Based on the catch performance, field efficacy and viability data observed, the two AIT’s are recommended for further development to be used with PPRC51 and PPRC2 for augmentation biological control in the pest’s natural habitat as a component of integrated pest management against <em>P. interrupta</em>

Metarhizium sp. isolated from dead Pachnoda interrupta (Coleoptera: Scarabaeidae) as a potential entomopathogenic fungus for the pest insect: proof-of-concept for autodissemination

Sustainable pest management requires the use of ecosystem-friendly control options (e.g. entomopathogens) coupled with target-specific application methods. Here we investigate the susceptibility of the sorghum chafer (Pachnoda interrupta, Olivier) toMetarhiziumsp., isolated from deadP. interruptaunder field conditions over several years. Target-specific trapping was achieved using Japanese beetle traps or locally made autoinoculation devices, with methyl salicylate or banana as an attractant. Of the attracted and infected beetles, 49% mortality was achieved during October 2005 and 71% during July 2006, while the corresponding mortality in control treatments was 13 and 5%, respectively. We further confirmed that the mortality of the beetles was due to the fungal treatment as 50 and 80% of the dead beetles showed mycosis, respectively. The performance of the pathogen was also investigated in an autodissemination device in 2008 and 2009, where the beetles that were attracted passed through an inoculation chamber. Of the attracted and infected beetles in the autodissemination device, 58.5% (October) and 90.9% (July) were dead within 15 days after treatment. Control mortality was only 3 and 2%, respectively. The potential for horizontal transmission was investigated, where 47% (October) and 59% (July) of the beetles exposed to the pathogen through horizontal transmission were killed. The pathogen was found to be viable for more than 3 days in the field. Our results show thatMetarhiziumsp. has potential as a biological control agent, and for achieving autodissemination using the target pest as the vector.