Gut Contents Of Predators Research Articles

Detection of secondary predation by PCR analyses of the gut contents of invertebrate generalist predators

Predation by generalist predators is difficult to study in the field because of the complex effects of positive and negative interactions within and between predator species and guilds. Predation can be monitored by molecular means, through identification of prey DNA within predators. However, polymerase chain reaction (PCR) amplification of prey DNA from predators cannot discriminate between primary and secondary predation (hyperpredation), in which one predator feeds on another that has recently eaten the target prey. Here we quantify, for the first time, the potential error caused by detection of prey DNA following secondary predation, using an aphid-spider-carabid model. First, the aphid Sitobion avenae was fed to the spider Tenuiphantes tenuis and the carabid Pterostichus melanarius, and the postconsumption detection periods, for prey DNA within predators, were calculated. Aphids were then fed to spiders and the spiders to carabids. Aphid DNA was detected in the predators using primers that amplified 245- and 110-bp fragments of the mitochondrial cytochrome oxidase I gene. Fragment size and predator sex had no significant effect on detection periods. Secondary predation could be detected for up to 8 h, when carabids fed on spiders immediately after the latter had consumed aphids. Beetles tested positive up to 4 h after eating spiders that had digested their aphid prey for 4 h. Clearly, the extreme sensitivity of PCR makes detection of secondary predation more likely, and the only reliable answer in future may be to use PCR to identify, in parallel, instances of intraguild predation.

Use of a gut content ELISA to detect whitefly predator feeding activity after field exposure to different insecticide treatments1

A 2-year commercial-scale study was conducted to qualitatively evaluate the effect of different insecticide treatment regimes on the predator complex attacking Bemisia tabaci (Gennadius) in cotton. In 1996 three insecticide regimes were compared: a rotation of conventional broad-spectrum insecticides or one of two different regimes based on the initial use of the insect growth regulators (IGRs), buprofezin and pyriproxyfen. In 1997 the same three regimes plus an untreated control were compared; split-plots were sprayed once for Lygus hesperus Knight control using a broad-spectrum insecticide. Relative feeding activity for each predator species was compared between treatment regimes by analyzing the gut contents of predators for the presence of whitefly remains using a whitefly-specific enzyme-linked immunosorbent assay (ELISA). The ELISA results were combined with predator density data to obtain a qualitative pesticide impact index for each predator group. In total, we analyzed the gut contents of 32 262 field-collected predators, representing nine different taxa. Of these, Pseudatomocelis seriatus (Reuter), Spanagonicus albofasciatus (Reuter), and spiders consisting primarily of Misumenops celer (Hentz) are shown to be whitefly predators for the first time. Predator populations were usually reduced in plots that received applications of broad-spectrum insecticides for B. tabaci and L. hesperus control, but there were few treatment differences in the proportions of predators containing whitefly remains in their guts. However, the feeding activity of certain predator species in fields sprayed with broad spectrum insecticides was significantly reduced compared with those in IGR-based and control treatments. Overall, insecticide regimes using IGRs were less lethal to the whitefly predator complex than regimes consisting of only conventional, broad-spectrum insecticides, but differences in predator feeding activity on whitefly between the various insecticide treatment regimes were minimal.

Detection of scavenged material in the guts of predators using monoclonal antibodies: a significant source of error in measurement of predation?

Molecular detection systems used to analyse the gut contents of invertebrate predators have enhanced our understanding of trophic interactions, but do not distinguish between the methods of consumption. Many predators regularly scavenge, which could have profound implications for quantitative analyses of the dynamics of predation. We report the first quantified assessment of the potential error caused by scavenging in post-mortem measurements of predation in a slug-carabid system. An anti-slug monoclonal antibody was able to detect antigens from decayed slugs after surprisingly long periods, significantly longer on relatively sterile peat than on natural soil. On soil the half-life of antibody-detectable slug proteins was 8.2 days while on peat it was 11.5 days. When slugs that had decayed on soil for 100 h were fed to the carabid predator Pterostichus melanarius, slug proteins could still be identified after 6 h (but not 12 h) digestion. Fresh and decayed slug was eaten in equal quantities by the beetles suggesting no aversion to the latter. The results suggest that significant errors may be caused by scavenging leading to inaccurate interpretation of predation rates in the field.

Rapid screening of invertebrate predators for multiple prey DNA targets

DNA-based techniques are providing valuable new approaches to tracking predator-prey interactions. The gut contents of invertebrate predators can be analysed using species-specific primers to amplify prey DNA to confirm trophic links. The problem is that each predator needs to be analysed with primers for the tens of potential prey available at a field site, even though the mean number of species detected in each gut may be as few as one or two. Conducting all these PCRs (polymerase chain reactions) is a lengthy process, and effectively precludes the analysis of the hundreds of predators that might be required for a meaningful ecological study. We report a rapid, more sensitive and practical approach. Multiplex PCRs, incorporating fluorescent markers, were found to be effective at amplifying degraded DNA from predators' guts and could amplify mitochondrial DNA fragments from 10+ species simultaneously without 'drop outs'. The combined PCR products were then separated by size on polyacrylamide gels on an ABI377 sequencer. New primers to detect the remains of aphids, earthworms, weevils and molluscs in the guts of carabid predators were developed and characterized. The multiplex-sequencer approach was then applied to field-caught beetles, some of which contained DNA from as many as four different prey at once. The main prey detected in the beetles proved to be earthworms and molluscs, although aphids and weevils were also consumed. The potential of this system for use in food-web research is discussed.

Synchronized hatch and its ecological significance in rainbow smelt Osmerus mordax in St. Mary's Bay, Newfoundland

Early life history stages in most marine animals are subject to high mortality through predation, starvation, and dispersal. Accordingly, the potential exists for the selection of behavioral mechanisms that reduce mortality. We examined the ecological significance of synchronization in hatch and the initiation of larval drift in rainbow smelt, Osmerus mordax, populations in St. Mary's Bay, Newfoundland. Larval abundances from six 24‐h ring net surveys (2‐h intervals) in Colinet and Salmonier Rivers during 2002/2003 suggest synchronized hatch following dusk (~2200 h). Monitoring of egg hatching in situ confirmed synchrony was at hatch and notemergence. Larval abundance showed no relationship with temperature or flow rates, and the consistency in hatch pattern suggested a light/dark cue. In experimental manipulations in which eggs were exposed to light and dark conditions for 2‐h periods, hatch percentages were up to five times higher (p < 0.005) in dark treatments. We hypothesized that the linkage of hatch to low light levels represents a mechanism to avoid elevated larval predation in daylight conditions. Egg predation determined from predator gut content analysis suggested that extreme predation risk from small (<20 cm) salmonids peaked during the day, prior to dusk, and was lowest during night (2200–0400 h). Microcosm experiments demonstrated that newly hatched larvae exposed to predators in dark conditionsdid not change in number, but mortality averaged 60% in light conditions. Our results suggest that predation pressure during the early life history of aquatic organisms might play a strong role in the optimization of aquatic life histories.

A multiple ELISA system for simultaneously monitoring intercrop movement and feeding activity of mass-released insect predators

We combined two protein-marking enzyme-linked immunosorbent assays (ELISA) with a predator gut content ELISA to monitor the movement and feeding activity of commercially-purchased Hippodamia convergens Guèrin-Mèneville (Coleoptera: Coccinellidae) under realistic field conditions during two field seasons in central Arizona. The protein-marking ELISAs were used to differentiate released H. convergens from the native beetles. Commercially purchased beetles marked with rabbit immunoglobulin G (IgG) were released into cotton fields and chicken IgG marked beetles were released into adjacent cantaloupe fields. Results showed that the total native beetle abundance in each crop was about the same size. The recovery rates after 15 days for the released beetles were less than 1.0% over all the releases, indicating that they dispersed readily from the release site. Of the recaptured beetles containing rabbit IgG (cotton), 82.2% were recovered in cotton and 11.8% moved to cantaloupe. Of those containing chicken IgG (cantaloupe), 66.5% were recovered in cantaloupe and 33.5% moved to cotton. A predator gut content ELISA was used to determine if there were differences in the frequency of predation of released versus indigenous H. convergens on the silverleaf whitefly, Bemisia argentifolii Bellows & Perring (Homoptera: Aleyrodidae). The proportion of beetles containing whitefly antigens was always higher for the released beetles than for their native counterparts. Our results demonstrate an approach to combine protein marking and predator gut content ELISAs that allows the simultaneous comparison of feeding and intercrop movement of native and commercially-obtained biological control agents.

Detection of Japanese flounder-specific DNA from gut contents of potential predators in the field

: Predation by invertebrates may be one of the major factors influencing the mortality of released flounder juveniles in the field. We developed a polymerase chain reaction (PCR)-based technique for the detection of Japanese flounder material from the gut contents of potential predators in the field. The PCR primers used here are flounder specific and encompass a 153 bp region from the right domain of the mitochondrial control region. With these oligonucleotide primers, PCR reactions yielded specific amplification products from the gut contents of some putative predators, including Matuta lunaris, Portunus gladiator, Sepioteuthis lessoniana, Suggrundus meerdervoorti, Platycephalus sp. and Rhyncopelates oxyrhynchus. Many animals with gut contents of unidentified fish material showed indication of predation on the flounder after release of hatchery reared flounder juveniles. The technique developed in the present study is useful not only for the survey of predation on the flounder by known species, but also for the search for novel potential predatory species in the field.

SPIDER PREDATION: SPECIES-SPECIFIC IDENTIFICATION OF GUT CONTENTS BY POLYMERASE CHAIN REACTION

We extend detection of arthropod predator gut contents by polymerase chain reaction (PCR), heretofore restricted to insect predators, to spiders. Single individuals of the corn lead aphid, Rhopalosiphum maidis, were detected in the guts of spiderlings of Oxyopes salticus up to 12 h after feeding; individuals of the congeneric bird cherry oat aphid, R. padi, were not detected. Unfed O. salticus and Misumenops sp. were also negative.

Can multiple-copy sequences of prey DNA be detected amongst the gut contents of invertebrate predators?

The first experiments to clearly demonstrate that DNA techniques might be used to detect predator-prey interactions between arthropods are reported. The accurate modelling of such interactions has depended until now upon a mixture of laboratory experiments, population monitoring and biochemical tests. The latter involve gut-content analyses, and have most recently depended upon the development of prey-specific monoclonal antibodies. Although these are excellent for detecting predation on a target prey, they are impractical for analysing the prey range of a particular predator. Molecular detection depends upon the ability of DNA to resist digestion in the predator gut and of the polymerase chain reaction (PCR) to amplify prey-specific DNA from semidigested material. As a first step, experiments using carabid beetles, Pterostichus cupreus L., as predators and mosquitoes as prey are reported. The target sequences were fully characterized multiple-copy esterase genes from two laboratory strains of Culex quinquefasciatus Say. Although DNA was extracted from homogenates of whole beetles (minus appendages), a 146 bp product could be amplified from both mosquito strains digested in the beetle gut for 28 h. The larger, 263 bp product was detectable for 28 h in one mosquito strain, but could not be amplified after 5 h from the other. Whether the beetles had eaten one mosquito or six, digested for zero or 28 h, the prey were equally detectable. Having demonstrated that shorter, multiple-copy sequences survive digestion for a considerable period in the gut of a predator, the opportunity exists to develop new detection systems for studying predation in the field.

Variation in the Efficacy of Several Predator Gut Content Immunoassays

Abstract Five different immunoassay formats were examined for their ability to detect a minute quantity of prey remains in predator guts. The convergent lady beetle, Hippodamia convergens Guerin-Meneville, that had consumed either one or five pink bollworm, Pectinophora gossypiella (Saunders), eggs was evaluated by the following immunoassays: three variations of enzyme-linked immunosorbent assay (ELISA), a dot blot, and a Western blot. Sandwich ELISA, dot blot, and Western blot were the most sensitive immunoassays based on the proportion of individual predators scoring positive for prey remains. The direct ELISA and indirect ELISA were ineffective at detecting prey in the predators. The advantages and disadvantages of each immunoassay format are discussed.

Immunological Examinations of Species Variability in Predator Gut Content Assays: Effect of Predator:Prey Protein Ratio on Immunoassay Sensitivity

In qualitative predator gut content immunoassays, sensitivity of an immunoassay is important for determining whether a predator contains a targeted prey antigen. If the immunoassay employed is insensitive, the probability of obtaining a false-negative reaction is high. The sensitivity of an indirect enzyme-linked immunosorbent assay (ELISA) developed to detect pink bollworm, Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae), egg(s) in whole body homogenized predators varied in efficacy between species. Specifically, the indirect ELISA was more effective at detecting egg antigen in small predators than in large predators. In this study, we examined the effect that the predator:prey protein ratio has on the sensitivity of an indirect ELISA. Our results suggest that when assaying whole body homogenized predators, care must be taken not to overload an ELISA microplate with nontarget(predator)proteins.Predatorsamplesshould be diluted to less than 125 mg of total protein per sample. Any protein concentration above 125 mg per ELISA microplate well will likely result in an ELISA false-negative reaction. In another experiment, we compared the efficacy of an indirect ELISA with a dot blot immunoassay. Adults of Hippodamia convergens Guerin-Meneville (Coleoptera: Coccineliidae) that had eaten one pink bollworm egg were homogenized in variable dilutions of phosphate-buffered saline (PBS) and each sample was analyzed for pink bollworm egg antigen using both immunoassays. The dot blot immunoassay was more reliable than the indirect ELISA for detecting minute traces of egg antigen in the samples. Generally, the volume of PBS that the H. convergens were homogenized in had little effect on the qualitative outcome of the dot blot. However, the indirect ELISA was more effective when H. convergens was homogenized in a larger volume of PBS. This suggests that the efficacy of an indirect ELISA can be improved for large, protein-rich predators by grinding them in a larger volume of PBS, thus minimizing the total protein in a given sample. r 1997 Academic Press

Measuring the Sensitivity of an Indirect Predator Gut Content ELISA: Detectability of Prey Remains in Relation to Predator Species, Temperature, Time, and Meal Size

The gut contents of three species of insect predators that were fed either a variable or a fixed number of pink bollworm eggs but held at variable time and temperature regimes were assayed by an indirect enzyme-linked immunosorbent assay (ELISA). The sensitivity and efficacy of the monoclonal antibody-based ELISA was dependent on the predator species examined. Small predators were more immunoresponsive to the ELISA than large predators. Furthermore, the assay sensitivity was dependent on the number of prey consumed, elapsed time after feeding, and temperature at which the predators were held. The smaller predator species retained recognizable traces of prey remains for longer periods than larger predator species. The ELISA efficacy decreased with increasing ambient temperature. A series of regression equations have been developed to estimate the median detection interval of prey in a predator's gut that takes into account the predator species examined, the quantity of prey consumed, and ambient after-meal temperature.

An immunological study of predation on hatchery-reared, juvenile red drum ( Sciaenops ocellatus, Linnaeus): description of an ELISA and predator-prey studies in nature

This report is a continuation of an on-going study to develop immunological methods for eventual use in determining the predation mortality of newly released, hatchery-reared red drum ( Sciaenops ocellatus, Linnaeus). Using a specific goat antiserum produced to a purified 80 kDa red drum glycoprotein, we detected the glycoprotein routinely in soluble extracts of red drum by Western blots. To supplement the immunoblotting, we proceeded to develop a highly sensitive and specific ELISA (enzyme-linked immunosorbent assay). The major problem in developing the ELISA was defining conditions to eliminate a natural inhibitor in soluble extracts of red drum that prevented the 80 kDa protein from binding to microtiter plates. The technical difficulties for a successful ELISA were resolved by adjusting extracts to pH 4.7 and 0.3 M NaCl, based on conditions developed for purification of the 80 kDa protein on a cationic-exchange gel by fast protein liquid chromatography (FPLC). The defined parameters eliminated the inhibition and resulted in optimal binding of the glycoprotein to the polymer surface of plates for ELISA. Approximately 10 h after the release of tens of thousands of red drum fingerlings at two sites in Biscayne Bay, FL, USA, a center-bag haul seine was used to sample the fish and capture predators. Two species, Sphyraena barracuda (Walbaum), great barracuda, and Strongylura notata (Poey), redfin needlefish, were the major predators. ELISA and Western blots were used to identify visually difficult or unidentifiable Sciaenops ocellatus in gut contents of the predators. Based on nine samples from seven Strongylura notata, and 10 samples from eight Sphyraena barracuda, 100% of the samples were identified as red drum in the needlefish and 50% in the great barracuda. These studies confirm the feasibility of using immunological methods to identify otherwise unidentifiable prey in gut contents of predators in nature.

Immunological approaches to the detection of predation upon New Zealand Flatworms (Tricladida: Terricola): Problems caused by shared epitopes with slugs (Mollusca: Pulmonata)

Abstract The geographical distribution and rate of spread of the earthworm predator Artioposthia triangulata (Dendy), a planarian flatworm accidentally introduced to Britain from New Zealand, is thought to be influenced primarily by ecoclimatic factors. However, anomalies in the expected distribution pattern and population dynamics may be caused in part by predation, and therefore the possibility of using antibodies to detect flatworm remains amongst the gut contents of potential predators was investigated. Cross‐reactivity between an anti‐flatworm polyclonal antiserum and slugs was effectively eliminated by absorption against slug proteins. Similar cross‐reactivity between certain anti‐slug monoclonal antibodies, and flatworms, was also found, indicating similar protein sequences or epitopes. The possibility that these reactions were caused by an immunoglobulin‐binding protein within the flatworms, or endogenous peroxidases affecting ELISA results, was eliminated. Possible evolutionary explanations for such cross‐reactivity are discussed. These results strongly support the need to use fully characterized flatworm‐specific monoclonal antibodies for predation studies in the field, to quantify the role of predation in flatworm population dynamics and to identify potentially useful biological control agents.

Estimating the predatory impact of gelatinous zooplankton

We propose a new approach to assess the predatory impact of gelatinous zooplankton on their prey, in which information from field samples and laboratory experiments allows us to estimate predator ingestion rates from analyses of predator gut contents. The feasibility of this approach was tested in laboratory experiments with the ctenophore Pleurobrachia bachei feeding on adult stages of the copepods Pseudocalanus newmani and Acartia longiremis. We developed a simple model of predator ingestion-egestion dynamics. The model assumes that predator clearance rates, F, and instantaneous egestion rates, c, are constant over the range of prey concentrations appropriate to the field study. A series of experiments was designed to test the validity of these assumptions and to estimate values of the parameters F and E for Pleurobrachia feeding on Pseudocalanus and Acartia. Results from these experiments indicate that the above assumptions are reasonable for these predator-prey pairs until prey concentrations exceed 60,000 prey m- 3. Ingestion rates are shown to be proportional to predator gut contents, with the slope of the relationship providing an estimate of the instantaneous egestion rate. Provided that the model assumptions are met, this approach can be used to estimate the predatory impact of other planktivorous predators on more complex prey assemblages.

An immunological study of predation on hatchery-reared, juvenile red drum ( Sciaenops ocellatus): preparation and assays of a “red drum-specific” protein for predator-prey experiments

This immunological study is part of a program to test the feasibility of artificial stock enhancement using hatchery-reared red drum ( Sciaenops ocellatus) (L.) and specifically to determine the predation mortality of newly released fish. Initially, a polyvalent antiserum was produced in a goat by multiple injections of a soluble red drum extract. In comparative experiments with soluble extracts of 12 different fishes and three different invertebrates found in the same environment, using sodium dodecyl sulfate-polyacrylamide gel electrophoresis and the goat polyvalent anti-serum for Western blots, an 80 kDa “red drum specific” protein was selected that was absent from the other species. The protein was present as two isoforms in fingerlings, but as one protein in older fish. The protein was purified by ammonium sulfate fractionation, and column chromatography with the Fast Protein Liquid Chromatography system. A second goat was immunized with the highly purified red drum 80 kDa protein to obtain a specific antiserum for immunoassays. Cross-reactivity in Western blots with pre-immune and immune goat sera and unrelated fish proteins was removed from the sera by solid phase adsorption. The adsorbed goat anti-80 kDa glycoprotein serum was used in predator-prey studies to identify partially digested-visually unrecognizable red drum. In controlled laboratory feeding experiments, the 80 kDa protein was detected in Western blots of stomach contents after 1 and 2 h of digestion, but not after 4 h. Western blots after 2 h showed immunoreactive breakdown products from the 80 kDa protein in stomach contents. The methods with the red drum protein appear applicable to any fish for specific identification in predator gut contents by immunological procedures.

Drifting mesocosms: the influence of gelatinous zooplankton on mortality of bay anchovy, Anchoa mitchilli, eggs and yolk-sac larvae

A mesocosm system was developed to be deployed from a research vessel and set adrift with its enclosed plankton, including fish eggs, larvae, and gelatinous predators. The system consists of an array of mesocosms that are 1 m diameter, 5 m long, and 3.2 m3 capacity, and which are constructed of 20-μm porosity dacron. Deployment and harvesting procedures are described. The mesocosms "capture" a sample of the water column and provide an assay method to examine planktonic processes in experiments of a few hours' to a few days' duration. Mortality rates of bay anchovy, Anchoa mitchilli, eggs and yolk-sac larvae were estimated from drifting mesocosm experiments in 1989 and 1991. Overall mean instantaneous rates were 0.073 h−1 for eggs and 0.051 h−1 for larvae, indicating that 95% of a cohort had died within 2 days of hatching. Egg and larval mortality rates were variable due to the variability in the initial numbers of captured eggs and larvae and to the complex mix of predator sizes and biovolumes that were enclosed in different deployments. An attempt (only partially successful) was made to relate observed mortalities to the abundance of two enclosed gelatinous predators, a ctenophore Mnemiopsis leidyi and a scyphomedusan Chrysaora quinquecirrha. The mesocosm results are compared with those from an encounter model that predicts predation mortality. The results are also compared with synoptic ichthyoplankton surveys and an analysis of predator gut contents, which provide independent estimates of egg/larvae mortality and their consumption by gelatinous predators. The drifting mesocosm methods holds promise and, with modifications of experimental design, can be a valuable tool to study zooplankton population processes, including those of early life stages of marine estuarine fishes.

A new method for immunologically marking prey and its use in predation studies

We introduce a new method for immunologically examining predator gut contents. It differs from previously described gut content analyses because it does not require the development of prey-specific antibody probes. Instead, insect prey were marked with a readily available antigen, rabbit immunoglobulin G (IgG). We then assayed predators that had fed on IgG labeled prey with an enzyme-linked immunosorbent assay (ELISA) using goat anti-rabbit IgG. Of the predator species that fed on the IgG labeled prey, 98.8% of those with chewing mouthparts scored positive for IgG 1 h after feeding. Our prey-labeling ELISA was less efficient for detecting IgG prey remains in predators with piercing/sucking mouthparts. Only 29.5% of these individuals scored positive for rabbit IgG in their guts 1 h after feeding. An additional study was conducted to measure the retention time of IgG-labeled prey in the guts of two species of predators with chewing mouthparts. Results from this experiment showed that the retention time varied depending on the predator and prey species examined. Results from these studies indicate that this marking technique could have widespread use for analyzing the gut contents of predators with chewing mouthparts, but it has limited application for those predators with piercing/sucking mouthparts.

Development of a monoclonal antibody to detect predation of the sweetpotato whitefly, Bemisia tabaci

AbstractWe have developed an enzyme‐linked immunosorbent assay (ELISA) for detection of whitefly antigen in the guts of predaceous arthropods based on a monoclonal antibody (MAb) produced in response to Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae) egg antigen. We observed positive antigen‐antibody reactions with the egg and the adult female stages of certain whitefly species and not with others. This MAb did not cross‐react with any of the whitefly nymphs or adult males we tested. Moreover, this MAb did not cross‐react with the various life stages of other insect species we examined. This immunologically‐based technique to identify whitefly egg facilitates examinations of predator gut contents in the field. Such a specific and sensitive whitefly egg immunoassay will expedite the characterization of the B. tabaci predator complex in the southwestern United States.

New Approach To Mark Insects for Feeding and Dispersal Studies

This study examines the feasibility of marking Lygus hesperus Knight adults externally by submersion in rabbit immunoglobulin G(IgG) solution. Rabbit IgG retention time was measured in the laboratory on insects submerged in an IgG solution. We marked insects with rabbit IgG and ran an enzyme-linked immunosorbent assay (ELISA) with its complementary antibody (antirabbit IgG). We concurrently ran an ELISA assay using the same samples against an egg-specific L. hesperus monoclonal antibody (MAb)to measure the presence of L. hesperus egg antigen in the insect. A previously developed egg-specific MAb to L. hesperus enabled us to assay simultaneously adult females (which possess the egg antigen) and adult males for the presence of L. hesperus egg antigen. This combination of techniques will enable us to examine the gut contents of potential predators of L. hesperus eggs or adult females using whole body macerates while simultaneously evaluating the efficiency of lab-reared predators for augmentative biological control.