Short communication: The preference and functional response of Sycanus aurantiacus (Hemiptera: Heteroptera: Reduviidae) on three prey types in laboratory conditions (original) (raw)
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Biological Control, 2004
Host plant-mediated orientation and oviposition by diamondback moth (DBM) Plutella xylostella (L.) (Lepidoptera: Yponomeutidae) and its predator Chrysoperla carnea Stephens (Neuroptera: Chrysopidae) were studied in response to four different brassica host plants: cabbage, (Brassica oleracea L. subsp. capitata), cauliflower (B. oleracea L. subsp. botrytis), kohlrabi (B. oleracea L. subsp. gongylodes), and broccoli (B. oleracea L. subsp. italica). Results from laboratory wind tunnel studies indicated that orientation of female DBM and C. carnea females towards cabbage and cauliflower was significantly greater than towards either broccoli or kohlrabi plants. However, DBM and C. carnea males did not orient towards any of the host plants. In no-choice tests, oviposition by DBM did not differ significantly among the test plants, while C. carnea layed significantly more eggs on cabbage, cauliflower, and broccoli than on kohlrabi. However, in free-choice tests, oviposition by DBM was significantly greater on cabbage, followed by cauliflower, broccoli, and kohlrabi, while C. carnea preferred to oviposit on cabbage and cauliflower, followed by broccoli and kohlrabi. The predation rates of DBM by C. carnea on kohlrabi and broccoli were not significantly different from one another, but were significantly higher than that on cabbage and cauliflower. When two types of plant, intact and injured, were available to adult DBM, female oviposition was significantly greater on injured plant leaves than on intact plants leaves. Similarly, C. carnea oviposition was significantly greater on injured plant leaves than on intact leaves. Implications regarding the possible role of green leaf volatiles in host selection/preference, as well as in tritropic interactions, are discussed.
Enperimental and Applied Acarology
The aims of this study were: (a) determine the prey stage preference of female Euseius hibisci (Chant) (Phytoseiidae) at constant densities of different stages of Tetranychus urticae Koch (Tetranychidae), (b) assess the functional response of the predator females to the varying densities of eggs, larvae, or protonymphs of T. urticae, and (c) estimate the functional response of E. hibisci when pollen of Ligustrum ovalifolium was present as well. We conducted experiments on excised pieces of strawberry leaf arenas (Fragaria ananassa) under laboratory conditions of 25 ± 2°C, 60 ± 5% RH and 12 h photophase. Our results indicated that the predator consumed significantly more prey eggs than other prey stages. Consumption of prey deutonymphs and adults was so low that they were excluded from the non-choice functional response experiments. The functional response on all food items was of type II. The two parameters of the functional response were estimated for each prey type by means of the adjusted non-linear regression model. The highest estimated value a¢ (instantaneous rate of discovery) and the lowest value of T h (handling time, including digestion) were found for the predator feeding on prey eggs, and a¢ was lowest and T h highest when fed protonymphs. Using the jack-knife method, the values for the functional response parameters were estimated. The values of a¢ and T h produced by the model were similar among all prey types except for the eggs, which were different. Using pollen simultaneously with prey larvae decreased the consumption of the latter over the full range of prey densities The suitability of this predator for biological control of T. urticae on strawberry is discussed.
AGRICULTURE UPDATE, 2017
The effective utilization of any biological control agent relies upon its comprehensive knowledge on bioecology, ecophysiology and behaviour. Hence, in the present study, the biology and predatory behaviour of third, fourth and fifth nymphal instars and adults of an assassin bug, Sycanuscollaris (Fabricius) to the larvae of rice meal moth, Corcyra cephalonica (Stainton) and leaf armyworm, Spodoptera litura (F.) was observed in the laboratory. The eggs were laid in clusters and cemented to each other and the surface of the plastic cylinder. The egg hatched after 11 to 15 days with each cluster having 15 to 70 eggs. Five nymphal instar stages were recorded. The mean longevity of each nymphal stage was 11.38±0.
Insect Science, 2010
Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae) is a voracious predator of soft-bodied insects such as juveniles of scale insects and the black scale Saissetia oleae (Olivier) (Hemiptera: Coccidae) is an important pest of several crops, such as the olive tree. However, the predatory efficiency of C. carnea on S. oleae has been unstudied yet. The present work aimed to study the functional response of larvae of C. carnea fed on S. oleae nymphs. In a controlled laboratory environment, increasing densities of S. oleae second and third nymph stages were offered to newly emerged specimens of the three larvae instars of C. carnea. After 24 h, the number of killed S. oleae was recorded and the functional response of C. carnea was assessed. The three larval stages of C. carnea displayed a type-II functional response, i.e., killed prey increased with higher S. oleae densities up to a maximum limited by the handling time. The attack rate did not significantly differ among the three instars while the maximum attack rate was significantly higher for the third instar. The handling time of the first larval instar of C. carnea was higher than that of the third instar. Our results demonstrated that S. oleae could act as a food resource for all larval stages of C. carnea. Furthermore, the third larval stage of the predator was the most efficient in reducing S. oleae densities. These results suggest that C. carnea larvae could contribute to S. oleae control in sustainable agriculture.
Functional response of a generalist insect predator to one of its prey species in the field
Journal of Animal Ecology, 2002
The shield beetle Cassida rubiginosa Müller (Coleoptera, Chrysomelidae) is one of the most prominent herbivores on creeping thistle, Cirsium arvense (L.) Scop. and is considered as a biological control agent against this weed. In order to investigate if augmented densities of this species could be sustained, predation on C. rubiginosa larvae was studied in the field with the aid of continuous video surveillance of individual prey during three seasons at two different study sites. 2. The paper wasp Polistes dominulus Christ (Hymenoptera, Vespidae) was responsible for 99·4% predation on C. rubiginosa larvae at both study sites. Prey densities were always reduced to a few individuals at the sites after a few days only. Thus, P. dominulus may annihilate the effect of augmentative releases of the beetle as a biocontrol agent. 3. P. dominulus showed no aggregation in patches of high host density (numerical response). The observed density dependence was attributed to the functional response of the wasp. 4. P. dominulus showed a Type III functional response. In mark-and-recapture experiments we found no indication that this type of functional response was the result of single wasps specializing on this particular prey type. 5. Type III functional responses in generalists can result by switching to prey species which become temporarily abundant. Since in a natural setting a mixture of prey species coexists in different abundance and which are differentially accepted by generalist predators, it is imperative to study their functional response in the field.
The reduviine assassin bug, Acanthaspis pedestris Stål is a predator of diverse insect pests. In the present study, the functional response of fourth and fifth nymphal instars and adult males and females of Acanthaspis pedestris Stål to the laboratory prey, the larvae of rice meal moth, Corcyra cephalonica (Stainton) and the natural prey the termite, Odontotermes obesus Rambur was studied. The life stages of A. pedestris responded to the increasing prey density of both the species by killing more number of prey than prey killed at lower prey densities and exhibited Holling's type II curvilinear responses. The searching time decreased as the prey density was increased in both prey species. The predation rate showed a steep rise from 1 to 16 prey densities. The maximum predations presented by 'k' values were always found restricted to the higher prey density. Attack ratios decreased as the prey density increased in the chosen prey species. Negative correlations were obtained between the prey density of both the species and the handling time, the recovery time and the searching time of the predator. Though a curvilinear type II relationships were found between the number of prey killed and the prey density in the life stages of A. pedestris fed with both the prey, the natural prey O. obesus promoted functional response parameters such as number of prey killed, attack rate and searching time and prolonged the handling time and the recovery time than the laboratory prey C. cephalonica. Hence, it is concluded that the life stages of A. pedestris more positively responded to its natural prey, O. obesus than to C. cephalonica.
Pakistan Journal of Zoology, 2016
Functional response study of Chrysoperla carnea Stephen (Neuroptera: Chrysopidae) larval instars fed on cabbage aphid, Brevicoryne brassicae (Linnaeus) was carried out under laboratory conditions at 28±1oC, with 65±5% R.H and 16:8 L: D photoperiod. The prey densities used for 1st instar larvae were 10, 15, 20, 25 and 30 (2nd – 3rd) nymphal instar aphids, while for 2nd instar larvae the used prey densities were 10, 20, 30, 40 and 50 and for 3rd instar larvae the used prey densities were 15, 30, 45, 60 and 75 aphids. Results showed that increase in the prey density resulted in increased consumption of prey up to certain limit in the 1st, 2nd as well as in the 3rd larval instar stage of C. carnea. The recorded highest consumed prey number were 22, 24 and 45 for the highest prey densities of 30, 50 and 75 in the 1st, 2nd and 3rd larval instar stage of C. carnea. Same trend was also recorded for searching, handling and resting time in all the three larval instar stage of C. carnea. The p...
Egyptian Journal of Biological Pest Control
Background Scaeva pyrastri (L.) (Diptera: Syrphidae) is a large-size Palaearctic region syrphid fly. The larval stage of S. pyrastri is aphidophagous in nature, while the adults are efficient pollinators of various crops. Therefore, this study was carried out to investigate the predation efficacy, biology and population growth parameters of S. pyrastri on the cabbage aphid, Brevicoryne brassicae (L.) (Hemiptera: Aphididae) as prey using age–stage-specific two-sex fertility table. Results The results showed that the mean total larval development duration was 8.31 days and the pre-adult stage was 19.82 ± 0.25 days long. In the adult stage, the mean longevity of female (18.57 ± 0.37 days) was longer than that of the male (15.50 ± 0.17 days). The adult pre-ovipositional, ovipositional and post-ovipositional periods were 4.25 ± 0.25, 8.50 ± 0.46 and 3.25 ± 0.31 days, respectively, and the mean female’s fecundity was 37.75 ± 1.16 eggs per female. The two-sex fertility table indicated that...