BIOLOGICAL CONTROL OF THE COLORADO POTATO BEETLE LEPTINOTARSA DECEMLINEATA (COLEOPTERA: CHRYSOMELIDAE) IN QUEBEC BY AUGMENTATIVE RELEASES OF THE TWO-SPOTTED STINKBUG PERILLUS BIOCULATUS (HEMIPTERA: PENTATOMIDAE)

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.

HortScience ◽  
1994 ◽  
Vol 29 (4) ◽  
pp. 254e-254
Author(s):  
Conrad Cloutier

Tests in experimental plots over two seasons have shown that it is possible to obtain excellent control of eggs and larvae of the Colorado potato beetle (CPB) (Leptinotarsa decemlineata) under Quebec growing conditions by augmentative releases of a generalist predator, the twospotted stinkbug P. bioculatus. The stinkbugs were mass-reared on CPB eggs and larvae in the laboratory, and were released as second or third instar nymphs at the time of peak beetle oviposition. They were introduced manually at ratios of 2-4 predators : beetle egg mass in plots comprising ≈1000 `Kennebec' potato plants. Short-interval sampling after introduction indicated good rates of establishment and survival of the released P. bioculatus nymphs. Analysis of CPB egg recruitment and mortality indicated high rates of destruction of CPB eggs by the stinkbug. Egg destruction was followed by significant predation of late-instar bugs on CPB larvae, resulting in significant reductions of CPB prepupal and adult densities, and excellent foliage protection in treated plots compared to untreated controls. The results will be discussed with reference to traits of P. bioculatus that make it a good candidate for biocontrol of the CPB, and to problems yet to be resolved before augmentative releases of the predator can be used as an integrated pest management tactic in larger scale potato production.


HortScience ◽  
1995 ◽  
Vol 30 (4) ◽  
pp. 829C-829
Author(s):  
Simon Lachance ◽  
Conrad Cloutier

Predators and parasitoids used for biological control must possess good dispersal potential in order to ensure spatially uniform and cost-effective control. The rate of dispersal of Perillus bioculatus (F.) (Hemiptera: Pentatomidae), a predator of the Colorado potato beetle (Leptinotarsa decemlineata), was measured following central release in 0.025-ha potato plots. Factors influencing predator dispersal were also studied under controlled conditions in plant growth chambers. Temperature, predator size as affected by instar, and physiological age with respect to the completion of feeding during the intermolt stage were found to be significant factors. Predator density was also evaluated because of the strong tendency for this species to aggregate, thereby influencing dispersal. Results can be used to develop predictive models for inundative releases of P. bioculatus.


Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1464
Author(s):  
Maja Čačija ◽  
Renata Bažok ◽  
Majda Kolenc ◽  
Tena Bujas ◽  
Zrinka Drmić ◽  
...  

Colorado potato beetle (CPB) is an economic pest of potato that has developed resistance to all classes of chemical insecticides, thus requiring alternative control measures. As a potential solution, entomopathogenic nematodes (EPNs) have proven effective in suppressing this pest, but their efficacy against overwintering generations of CPB in Croatia has not been sufficiently researched. The aim of this two-year (2018–2019) field study was to determine the efficacy of Steinernema feltiae and Steinernema carpocapsae applied to overwintering CPB adults. EPNs were applied at three doses (7.5 mil./10 m2, 5.0 mil./10 m2 (the recommended dose) and 2.5 mil./10 m2) by watering the soil where the adults were overwintering. The first-year results were satisfactory for both EPNs: the efficacy of S. feltiae ranged from 79.03% to 100.00%, while the efficacy of S. carpocapsae ranged from 77.32% to 96.22%. In the second year, the highest efficacy (69.57%) was obtained using the recommended dose of S. feltiae. Although the results are not consistent across the two years of our study and suggest further research, they indicate that EPNs have great potential in controlling overwintering CPB generations to reduce first generation abundance and damage, and also to prevent the spread of new generations to surrounding potato growing areas.


1996 ◽  
Vol 21 (1) ◽  
pp. 144-145
Author(s):  
E.. McEnhill ◽  
E. Grafius ◽  
J. Sirota ◽  
C. Brunt ◽  
J. Ferrigan ◽  
...  

Abstract Fifteen insecticide treatments were tested at the MSU Montcalm Research Farm, in Entrican, MI, for their control of Colorado potato beetles (CPB). ‘Snowden’ potatoes were planted 12 inches apart with a 34 inch row spacing on 10 May. Treatments were replicated four times and assigned to plots in a RCB design. The plots measured 40 feet long and were three rows wide. There were at least two rows of bare ground between plots and five feet of untreated potatoes between plots in the same rows. The Admire and Mocap treatments were applied in furrow at planting. The first foliar treatment was applied, at 25% CPB hatch, on 18 June using a tractor-mounted sprayer (30 gal/acre, 40 psi). Subsequent first generation sprays were applied on 29 June and 7 July. Light rain occurred on 7 July before the insecticides had a chance to dry. Insecticide effectiveness was determined by counting the various stages of CPB on two randomly chosen plants from the middle row of each plot. Counts were done on 12 and 23 Jun and 3 and 12 July. Second generation methods were the same as for the first generation with sprays occuring on 19 July, 26 July and 2 Aug and counts on 18, 24 and 31 Jul. All plots other than the two Trigard treatments were sprayed with a maintenance spray of Imidan and PBO. Each plot was assessed for percent defoliation on 3 July and 9 August. The middle row of potatoes from each plot was harvested on 22 August, separated by size and weighed.


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.


Sign in / Sign up

Export Citation Format

Share Document