Biology, Impact and Preliminary Host-specificity Testing of the Rust Fungus, Uromyces salsolae , a Potential Biological Control Agent for Salsola kali in the USA

Additional retrospective testing of the gum leaf skeletoniser (Uraba lugens) biological control agent Cotesia urabae was conducted against the endemic moth Celama parvitis Although this native was included in host specificity testing before EPA approved the parasitoids release this work aimed to increase the sample size to better assess the potential risk posed The effect that different periods of host deprivation and prior oviposition experience had on the parasitoids readiness to attack was examined in a sequence of nochoice tests No parasitoids emerged from the 52 of larvae that survived to pupation thus confirming C parvitis as a nonhost Dissections of larvae that died during laboratory rearing revealed that 63 had contained a parasitoid but no C urabae parasitoid larvae developed beyond the second instar Significant differences were found in the attack times according to the parasitoids deprivation levels (age) and it was also observed that the duration until first attack significantly decreased after each nontarget presentation

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Biological and Host Range Characteristics of Lysathia flavipes (Coleoptera: Chrysomelidae), a Candidate Biological Control Agent of Invasive Ludwigia spp. (Onagraceae) in the USA

Insects ◽

10.3390/insects12050471 ◽

2021 ◽

Vol 12 (5) ◽

pp. 471

Author(s):

Angelica M. Reddy ◽

Paul D. Pratt ◽

Brenda J. Grewell ◽

Nathan E. Harms ◽

Ximena Cibils-Stewart ◽

...

Keyword(s):

Biological Control ◽

Host Range ◽

Plant Species ◽

Biocontrol Agent ◽

Biological Control Agent ◽

Control Agent ◽

Native Plant ◽

Native Plant Species ◽

The Usa ◽

Physical And Chemical

Exotic water primroses (Ludwigia spp.) are aggressive invaders in aquatic ecosystems worldwide. To date, management of exotic Ludwigia spp. has been limited to physical and chemical control methods. Biological control provides an alternative approach for the management of invasive Ludwigia spp. but little is known regarding the natural enemies of these exotic plants. Herein the biology and host range of Lysathia flavipes (Boheman), a herbivorous beetle associated with Ludwigia spp. in Argentina and Uruguay, was studied to determine its suitability as a biocontrol agent for multiple closely related target weeds in the USA. The beetle matures from egg to adult in 19.9 ± 1.4 days at 25 °C; females lived 86.3 ± 35.6 days and laid 1510.6 ± 543.4 eggs over their lifespans. No-choice development and oviposition tests were conducted using four Ludwigia species and seven native plant species. Lysathia flavipes showed little discrimination between plant species: larvae aggressively fed and completed development, and the resulting females (F1 generation) oviposited viable eggs on most plant species regardless of origin. These results indicate that L. flavipes is not sufficiently host-specific for further consideration as a biocontrol agent of exotic Ludwigia spp. in the USA and further testing is not warranted.

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