Engineering the biological control of the Colorado potato beetle with the predatory stink bug Perillus bioculatus

2006 ◽  
Author(s):  
Yannick de Ladurantaye ◽  
Mohamed Khelifi ◽  
Conrad Cloutier ◽  
Thomas A. Coudron
1995 ◽  
Vol 127 (2) ◽  
pp. 195-212 ◽  
Author(s):  
Conrad Cloutier ◽  
France Bauduin

AbstractField plot tests during two seasons show that augmentative releases of Perillus bioculatus can control first-generation eggs and larvae of the Colorado potato beetle (CPB) under Quebec short-season conditions. Stinkbugs mass-reared on CPB were introduced manually as 2nd- and 3rd-stage nymphs during spring oviposition of the beetle at densities of one nymph per 50–225 CPB eggs recruited per plant, in 0.025-ha plots. Sampling at intervals of 1–3 days measured predator establishment, CPB egg and larval mortality, and foliage protection level. Direct observations were used to document predator-prey relationships and to determine weather conditions favourable to P. bioculatus.In the 1 st-year test, with predators released over all plants within plots, CPB control was compared among: (1) stinkbugs alone, (2) the bioinsecticide Bacillus thuringiensis (BT) as Trident™, (3) a combination of both control alternatives, and (4) no protection against the CPB. BT and stinkbugs, both alone and in combination, produced significant control as measured by percentage reductions in prepupal drop to the ground, new adult emergence, and foliage protection. Only treatments involving P. bioculatus reduced CPB egg eclosion which was the key control factor; it is strongly correlated with overall control level.In the 2nd-year test, predators were released in a central area comprising only 25% of all plants within plots. Predator and CPB egg mass densities were manipulated to produce predator: prey ratios of 0:1, 0:2, 1.5:2, 1.5:1, 3:2, and 3:1, representing average ratios of 0, 1.5,or 3 P. bioculatus per plant, and 1 or 2 CPB egg masses per plant at release time. As expected, central release produced complex interactions between control, and predator and prey densities. High beetle density slowed predator emigration from the centre, more so at low predator density than at high predator density. Predators moved more quickly within the same row than across rows. CPB eggs were destroyed in large numbers in both years but in 1993, final control correlated with larval rather than egg predation. A maximum 80% reduction in prepupal drop to the ground was obtained at the 3:1 predator:prey ratio (1 P. bioculatus:95 CPB eggs recruited per plant).The results prove the efficacy of P. bioculatus for biological control of first-generation L. decemlineata populations, at densities resulting in approximately 300 eggs laid per plant during spring oviposition in the study area. Despite low natural populations of P. bioculatus and unclear prospects for commercial availability at reasonable cost, it is evident that stinkbug releases have potential as a non-chemical control measure within an IPM program in Quebec potato production.


1999 ◽  
Vol 131 (4) ◽  
pp. 521-538 ◽  
Author(s):  
Christine Noronha ◽  
Conrad Cloutier

AbstractPitfall and screen traps were used around potato Solanum tuberosum L. (Solanaceae) plots to detect directional patterns of prediapause (two seasons) and postdiapause (one season) movement in a univoltine population of the Colorado potato beetle, Leptinotarsa decemlineata (Say), from Quebec. Prediapause beetles were sampled for diapause readiness using a feeding–digging test. In 1994, a plot left unprotected from the beetle (moderately defoliated) was monitored. In 1995, movement around a plot left unprotected from the beetle (severely defoliated) was compared to that from a plot protected (only lightly defoliated) by inundative release of the potato beetle predator Perillus bioculatus Say (Hemiptera: Pentatomidae). Movement frequency by postdiapause beetles in spring 1995 was low compared with 1994 prediapause movement, especially on the ground. Low-frequency flying persisted over several weeks of postdiapause beetle oviposition, with only a brief period of directionality. Flight movement by satiated prediapause beetles in August 1994 and 1995 was strongly directional, being oriented toward the closest forest border east of the plots, where sampling confirmed overwintering. In both years, satiated prediapause beetles also emigrated by walking, but mostly from densely populated and defoliated plots. Newly emerged (unsatiated) prediapause beetles emigrated en masse from severely defoliated plants, and did so exclusively by walking. Directional walking contrasted with directional flying in being predominantly oriented south-westward to northwestward, suggesting cueing on the sun position during warm hours of the day.


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