Cycloneda Munda Research Articles

Photoperiodic induction of adult reproductive diapause in the ladybird beetle Cycloneda munda (Coleoptera: Coccinellidae)

The developmental response and the induction and duration of adult hibernal diapause in a North American population of Cycloneda munda (Say) (collected at 38°N, 84.5°W) was determined by rearing individuals at four photoperiods (L:D 16:8, 14:10, 12:12, and 10:14) at 22°C. Preimaginal development of C. munda individuals was slower at L:D 10:14 than at three longer photoperiods. No C. munda females reared at L:D 16:8 entered diapause, 5% of females at L:D 14:10 were in diapause, whereas shorter photoperiods (L:D 12:12 and 10:14) induced diapause in 84% and 100% of females. Cycloneda munda females demonstrated a long-day response to photoperiod, similar to that observed in several other species of predaceous Coccinellidae that diapause as adults.

A window of opportunity: Subdominant predators can use suboptimal prey.

Introduced species have been linked to declines of native species through mechanisms including intraguild predation and exploitative competition. However, coexistence among species may be promoted by niche partitioning if native species can use resources that the invasive species cannot. Previous research has shown that some strains of the aphid Aphis craccivora are toxic to a competitively dominant invasive lady beetle, Harmonia axyridis. Our objective was to investigate whether these aphids might be an exploitable resource for other, subdominant, lady beetle species. We compared larval development rate, survival, and adult weight of five lady beetle species in no‐choice experiments with two different strains of A. craccivora, one of which is toxic to H. axyridis and one that is nontoxic. Two lady beetle species, Cycloneda munda and Coleomegilla maculata, were able to complete larval development when feeding on the aphid strain that is toxic to H. axyridis, experiencing only slight developmental delays relative to beetles feeding on the other aphid strain. One species, Coccinella septempunctata, also was able to complete larval development, but experienced a slight reduction in adult weight. The other two lady beetle species, Hippodamia convergens and Anatis labiculata, demonstrated generally low survivorship when consuming A. craccivora, regardless of aphid strain. All five species showed increased survival and/or development relative to H. axyridis on the “toxic” aphid strain. Our results suggest that this toxic trait may act as a narrow‐spectrum defense for the aphids, providing protection against only some lady beetle enemies. For other less‐susceptible lady beetles, these aphids have the potential to provide competitive release from the otherwise dominant H. axyridis.

Trap Height Affects Capture of Lady Beetles (Coleoptera: Coccinellidae) in Pecan Orchards.

There is scarce information regarding the vertical stratification of predaceous Coccinellidae in tall trees. Although numerous studies have been done in orchards and forests, very few studies have assessed the occurrence of predaceous Coccinellidae high in tree canopies. The objective of this study was to examine the abundance of Coccinellidae at different heights in mature pecan, Carya illinoinensis (Wangenh.) K. Koch, orchards with tall trees. From spring through late fall during 2013 and 2014, yellow pyramidal Tedders traps were suspended in the pecan canopy at 6.1 and 12.2 m, in addition to being placed on the ground (0 m). The exotic species Harmonia axyridis and Coccinella septempunctata accounted for a high percentage of trap capture during this study. Except for Olla v-nigrum, low numbers of native species (Hippodamia convergens, Coleomegilla maculata, Cycloneda munda, Scymnus spp., and Hyperaspis spp.) were captured. However, significantly more were captured in ground traps rather than in canopy traps with the exception of O. v-nigrum. Similar to most native species, significantly more C. septempunctata were captured in ground traps than canopy traps. This contrasts sharply with H. axyridis captured similarly at all trap heights. The ability to exploit resources across vertical strata, unlike many intraguild predators, may be an underestimated factor helping to explain the invasiveness of H. axyridis.

Coccinellid Predators of Aphid and Their Phylogenetic Analysis Using COI Gene Sequences

An extensive survey of aphid predatory Coccinellid beetles (Coleoptera: Coccinellidae) was conducted in Jahangirnagar University campus, Savar during October 2014 to March 2016. Total nine ladybird beetles viz, Adalia bipunctata, Coccinella septempunctata, Coccinella transversalis, Cycloneda munda, Harmonia axyridis, Hippodamia convergens, Micraspis discolor, Scymnus nebulosus, Sticholotis sp. were identified as predators of aphid. Among them, Micraspis discolor was most abundant predator. Biology and bio-control potential of M. discolor was studied in laboratory condition on bean infesting aphid (Aphis fabae). The maximum predation was 102±1.83 observed in 4th instar larvae of M. discolor. Along with biological study, phylogenetic relationship of ladybird beetles was constructed based on mitochondrial COI gene. Out of nine identified coccinellids, five species showed more conserve region than the rest in alignment. The interspecific genetic distance ranges for nine beetles were very low (0.15-0.24). Higher interspecific genetic diversity recorded for H. axyridis. The phylogenetic tree was created and analyzed using both Neighbour Joining and Maximum likelihood methods to define the origin and evolutionary relationships of the species. Molecular analysis demonstrated that evolution of these species has been occurred from a common ancestor. Such study of ladybird beetles would be helpful in biological control program of aphid pest. Int J Appl Sci Biotechnol, Vol 4(3): 408-416

Predator Fauna Associated with Oleander Aphids on Four Milkweed Species and the Effect of Those Host Plants on the Development and Fecundity ofCycloneda mundaandHarmonia axyridis

The oleander aphid, Aphis nerii Boyer de Fonscolombe, feeds on members of the Apocynaceae family, including several Asclepias species and Cynanchum laeve. Milkweeds alongside and within agricultural crops provide opportunities for natural enemies to encounter and feed upon A. nerii. The predator fauna associated with natural populations of A. nerii on four milkweed species was determined. The development and fecundity of two Coccinellidae species, Harmonia axyridis (Pallas) and Cycloneda munda (Say), were investigated in a laboratory. The development of fourth instar Coccinellidae when fed diets containing A. nerii from host plants having a low or high concentration of cardenolides was investigated. Immature beetle survival was generally poor and longevity was not significantly different when fed A. nerii from different host plant species, with similar survival patterns observed for first and fourth instar Coccinellidae larvae. Both H. axyridis and C. munda exhibited a reduced fecundity when fed A. nerii regardless of milkweed host species compared to beetle fecundity when fed a diet of Acyrthosiphon pisum. When provided with mixed diets, larvae consumed significantly more A. pisum than A. nerii. Larvae continued to accept A. nerii even after feeding on the aphid provoked emesis. Observations revealed that a fluid leaked from within wounded aphids temporarily or permanently immobilized lady beetle larvae. The unsuitability of A. nerii for lady beetles and the common association of milkweeds with agroecosystems raises concerns about the possible effects of feeding on this aphid by biological control agents.

Lady Beetle Composition and Abundance in Sweet Corn Bordered by Pasture, Buckwheat or Sunflower Companion Plantings

To determine the effect habitat management/border plantings have on beneficial insect diversity and abundance in agricultural crops, sweet corn, Zea mays L. ‘Garrison®’, was grown in replicated plots on Kentucky State University's Agricultural Research and Demonstration Farm. Each 25 m × 12 m plot was bordered on each length by a 2 m wide border of un-mowed pasture, buckwheat (Fagopyrum esculentum Moench), or dwarf sunflower (Heliathus annuus L. var. ‘Big Smile’). Yellow sticky traps 15 cm × 15 cm were used to capture lady beetles weekly through anthesis. Pink lady beetle, Coleomegilla maculata (DeGeer); Asian lady beetle, Harmonia axyridis (Pallas); spotless lady beetle, Cycloneda munda (Say); and seven spotted lady beetle, Coccinella septempunctata L. were caught in this study. The pink lady beetle was the most abundant species overall in all three borders and in the sweet corn plots with 79% and 94%, respectively. There were greater numbers of pink lady beetles in buckwheat (P < 0.00001) and sunflower (P = 0.0064) borders than pasture borders. However, there were no differences among populations of any of the lady beetle species in any of the sweet corn plots. Pink lady beetles were more numerous in sweet corn bordered by buckwheat (P ≤ 0.05), sunflower (P < 0.0001) and pasture borders (P ≤ 0.03) than in the borders themselves.

Incorporating a Sorghum Habitat for Enhancing Lady Beetles (Coleoptera: Coccinellidae) in Cotton

Lady beetles (Coleoptera: Coccinellidae) prey on insect pests in cotton. The objective of this 2 yr on-farm study was to document the impact of a grain sorghum trap crop on the density of Coccinellidae on nearby cotton.Scymnusspp.,Coccinella septempunctata(L.),Hippodamia convergensGuérin-Méneville,Harmonia axyridis(Pallas),Coleomegilla maculata(De Geer),Cycloneda munda(Say), andOlla v-nigrum(Mulsant) were found in sorghum over both years. Lady beetle compositions in sorghum and cotton and in yellow pyramidal traps were similar. For both years, density of lady beetles generally was higher on cotton with sorghum than on control cotton. Our results indicate that sorghum was a source of lady beetles in cotton, and thus incorporation of a sorghum habitat in farmscapes with cotton has great potential to enhance biocontrol of insect pests in cotton.

Susceptibility of endemic and exotic North American ladybirds (Coleoptera: Coccinellidae) to endemic fungal entomopathogens

We tested the laboratory susceptibility of four endemic and two exotic species of North American Coccinellidae to a single rate (2.5 × 10 5 conidia/ml) of Beauveria bassiana derived from different sources. The endemic species Olla v-nigrum, Cycloneda munda and Hippodamia convergens were susceptible to B. bassiana Isolate B which was originally isolated from O. v-nigrum and the rate assayed was known to represent the LC50 against O. v-nigrum. However, neither the endemic C. maculata nor the exotic species Harmonia axyridis and Coccinella septempunctata were susceptible to this isolate at this rate. Additionally, all species of endemic and exotic Coccinellidae used in these assays were resistant to B. bassiana strain GHA and BbAR1 at that rate. We discuss the implications of these results in regard to the establishment of exotic species in new habi tats.

Temporal detection of Cry1Ab-endotoxins in coccinellid predators from fields ofBacillus thuringiensiscorn

The area planted to genetically engineered crops has increased dramatically in the last ten years. This has generated many studies examining non-target effects of bioengineered plants expressing Bacillus thuringiensis endotoxins. To date, most have focused on population-level effects in the field or laboratory evaluation of specific plant-herbivore or plant-herbivore-predator trophic pathways. Using a post-mortem enzyme-linked immunosorbent assay, we examined the uptake of Cry1Ab-endotoxins by predatory coccinellids and the importance of anthesis to this trophic pathway. Adult Coleomegilla maculata, Harmonia axyridis, Cycloneda munda and Coccinella septempunctata contained low, but detectable, quantities of Bt-endotoxin when screened by ELISA. This was most evident in C. maculata, with 12.8% of 775 individuals testing positive for Cry1Ab-endotoxins. Interestingly, the presence of endotoxins in gut samples was not confined to periods around anthesis, but coccinellid adults tested positive two weeks before and up to ten weeks after pollen was shed, suggesting tri-trophic linkages in their food chain facilitates the transfer of endotoxins into higher-order predators. This contrasts with adult Coleomegilla maculata entering overwintering sites where Bt-endotoxins were not detected in gut samples, indicating low levels of persistence of Cry1Ab-endotoxins within coccinellid predators. This study enhances our understanding of complex interactions between transgenic crops and non-target food webs, but further research is required to quantify the significance of specific trophic linkages in the field.

Predation by Adult and Larval Lady Beetles (Coleoptera: Coccinellidae) on Initial Contact with Lady Beetle Eggs

Naïve adults and larvae of the native lady beetles Coleomegilla maculata (DeGeer), Cycloneda munda (Say), Hippodamia convergens Guérin-Méneville, Olla v-nigrum (Mulsant), and the exotic lady beetle Harmonia axyridis (Pallas) (Coleoptera: Coccinellidae) were tested for their initial response to eggs of these five lady beetle species and for egg consumption on first contact and after 3 h. Additionally, field-collected O. v-nigrum and H. axyridis adults were tested. C. maculata, H. axyridis, and O. v-nigrum adults responded similarly to all egg species on first contact. Higher numbers of C. munda adults did not eat C. maculata, H. convergens, and O. v-nigrum eggs on first contact compared with numbers that did eat C. munda and H. axyridis eggs. H. convergens adults always ate C. munda eggs but hardly ate H. axyridis eggs on first contact. Results showed that over the 3-h interval, egg predation by those predators feeding on first contact was always higher, except for adults and larvae of C. maculata, than for those that did not feed on first contact. Thus, acceptance of eggs on initial contact does impact egg survival. It is likely that eggs of all native species tested (i.e., C. maculata, C. munda, H. convergens, and O. v-nigrum), but not exotic H. axyridis eggs, are suitable food for C. maculata, H. convergens, and O. v-nigrum, whereas only C. munda eggs serve as suitable food for C. munda. In direct contrast, all egg species tested would likely serve as suitable food for the exotic H. axyridis.

CHANGES IN ABUNDANCE OF NATIVE AND ADVENTIVE COCCINELLIDAE (COLEOPTERA) IN ALFALFA FIELDS, IN NORTHERN NEW JERSEY (1993–2004) AND DELAWARE (1999–2004), U.S.A

Weekly and biweekly sweep net collections were made near Blairstown, New Jersey, and Newark, Delaware (both in the U.S.A.), for 12 and 6 consecutive years, respectively. At Blairstown, only one non-native coccinellid [Coccinella septempunctata (L.)] was common when this research was started in 1993, one [Propylea quatuordecimpunctata (L.)] had recently appeared, and two others [Harmonia axyridis (Pallas), Hippodamia variegata (Goeze)] were detected later during the 12-year study. All of these four species were adventive, having established themselves through commerce, three species at inland ports, and one near a coastal seaport. The most numerous adult lady beetles at both locations were two native species, Coleomegilla maculata (F.) and Hippodamia parenthesis (Say), and three adventive species, P. quatuordecimpunctata, C. septempunctata, and H. axyridis. Six species were occasionally swept at Blairstown - one adventive species (H. variegata) and five native species [Cycloneda munda (Say), Coccinella transversoguttata Mulsant, C. trifasciata Mulsant, Hippodamia convergens Guerin, and Brachiacantha ursina (F.)]. All but the last species were also found at Newark. Lady beetle numbers varied considerably from year to year at both locations, demonstrating that long-term (10 years or more) research is required to correctly identify population trends. No coccinellid species decreased during the 12-year study at Blairstown—indicating that the once-common H. convergens and several species of Coccinella had become rare before the study started in 1993, and before three of the four adventive lady beetles had become numerous. The previous establishment of exotic parasites, previously reported to have reduced pea aphid numbers, was likely indirectly responsible for decreasing coccinellid diversity in alfalfa. Competition by the adventive C. septempunctata may also have reduced some coccinellid species prior to 1993, but such data for the northeastern U.S.A. have not been published, to our knowledge.

Prevalence and association of the laboulbenialean fungus Hesperomyces virescens (Laboulbeniales: Laboulbeniaceae) on coccinellid hosts (Coleoptera: Coccinellidae) in Kentucky, USA

The laboulbenialean fungi occur throughout the world and are closely associated with a range of arthropods, including many coleopteran hosts. Throughout the summer of 2004, coccinellids were collected from a Bluegrass savanna woodland ecosys- tem, dominated by blue ash Fraxinus quadrangulata and Chinkapin Oak Quercus muehlenbergii, and the adults were examined for the presence of Hesperomyces virescens using binocular and scanning electron microscopy. Over 80% of adult Harmonia axyridis, a species previously reported as having a persistent association with the fungus, were infected. No significant differences were observed in incidence on male and female hosts, however, the distribution of fungus differed between sexes. Female H. axyridis had a greater percentage of infection on their elytron compared to other parts of their body whilst male infection was concentrated around their elytra, legs and abdomen. Although infection rates were significantly lower, we report, for the first time, the presence of this fungus on the hosts Cycloneda munda, Brachiacantha quadripunctata and Psyllobora vigintimaculata. This is the first study documenting the incidence of this insect-associated fungus with these native coccinellids of North America. In the samples collected from the Bluegrass savanna, two species (Coleomegilla maculata and Hyperaspis signata) were not infected by this fungus.

Impact of Transgenic &lt;I&gt;Bacillus thuringiensis&lt;/I&gt; Corn and Crop Phenology on Five Nontarget Arthropods

Large-scale Þeld studies were conducted to determine if temporal plantings of Bacillus thuringiensis (Berliner) (Bt) corn (event 176 and Bt11) would affect the seasonal abundance of the following generalist predators: Coleomegilla maculata DeGeer and Cycloneda munda (Say) (Coleoptera: Coccinellidae),Orius insidiosus (Say) (Heteroptera: Anthocoridae),Chrysoperla carnea Stephens (Neuroptera: Chrysopidae), and one specialist parasitoid, Macrocentrus cingulum Brischke (Hymenoptera: Braconidae). Adult populations were monitored using Pherocon AM yellow sticky traps at three locations in Iowa (1996 Ð1998). At each location, a split-plot design was used withBt and non-Bt corn as main plots and three planting dates as the split plots. Few differences in abundance were observed betweenBt and non-Bt corn for the generalist predators studied. However,M.cingulum, a specialist parasitoid of European corn borer, was signiÞcantly affected by the presence of Bt corn. Densities of adult M. cingulum were 29 Ð 60% lower in Bt corn compared with non-Bt corn. Regression analyses indicatedM.cingulum adults were preferentially recruited to and subsequently increased over time in the non-Bt corn treatments at each location within each year. SigniÞcant differences were observed among planting dates for all Þve species. Abundance effects from Bt corn on these natural enemies were not unexpected given the foraging and searching behaviors of different species and their varying levels of dependence on the presence of European corn borer.

Establishment of multicolored Asian lady beetle in Eastern North Carolina: seasonal abundance and crop exploitation within an agricultural landscape.

Seasonal abundance and cropexploitation of the multicolored Asian ladybeetle, Harmonia axyridis (Pallas)(Coccinellidae: Coleoptera), were identifiedduring its initial establishment in the easternNorth Carolina agroecosystem. Densities ofH. axyridis adults and larvae werecompared with densities of previouslyestablished predaceous coccinellids in wheat,potato, corn and soybean, which are thepredominant crops in this region. One-hundred-fifty whole plant samples werevisually inspected for coccinellid adults andlarvae in each crop on six farms every 7 to 14days. H. axyridis adults colonizedwheat, potato and corn, but reproduced only inwheat and potato. Soybean fields were notcolonized. The presence of H. axyridisin a crop was typically associated with anabundance of aphids, with the exception ofpotato, and no aphids were encountered insoybean. In addition to H. axyridis,four other lady beetle species, Coccinellaseptempunctata L., Coleomegilla maculata(DeGeer), Hippodamia convergens (Guerin)and Cycloneda munda L., were encounteredin the landscape. In wheat, potato and corn,densities of H. axyridis adults averagedthroughout the 1995 and 1996 seasons wereseven, ten and 28 times lower, respectively,than the season average density of the leastabundant species of previously established ladybeetle, whereas these densities averaged 82, 42and 356 times lower, respectively, than theaverage density of the most abundantestablished coccinellid species. H.axyridis is commonly encountered in theeastern North Carolina agricultural landscape,but its impact on the existing coccinellidassemblage cannot yet be determined. Theresults presented provide a baseline againstwhich the results of future studies can becompared to determine if H. axyridis isdisplacing established species.

Population Dynamics of Three Coccinellids in Flue-Cured Tobacco and Functional Response ofHippodamia convergens(Coleoptera: Coccinellidae) Feeding on Tobacco Aphids (Homoptera: Aphididae)

The seasonal abundance of 3 species of coccinellids was observed on flue-cured tobacco, Nicotiana tabacum L., during 1997 and 1998 in Tift County, GA. The most abundant coccinellid during both seasons was the convergent lady beetle, Hippodamia convergens Guerin-Meneville, which was present from mid-May, when tobacco aphids, Myzus nicotianae Blackman, colonized the crop, until late July when sampling ended. The sevenspotted lady beetle, Coccinella septempunctata L., and the multicolored Asian lady beetle, Harmonia axyridis (Pallas), were also observed. C. septempunctata was most abundant early in the season and maintained low population levels during June and July. Conversely, H. axyridis was absent in tobacco until late May and remained abundant until sampling was discontinued. Populations of H. convergens, H. axyridis, and C. septempunctata were linearly related to tobacco aphid populations during 1998. In functional response experiments, 4th-instar larvae and adult H. convergens exhibited a type II functional response to aphid density. Fourth-instar larvae had a higher search rate and a longer handling time than adult H. convergens. Two other coccinellid species were observed at low population densities on flue-cured tobacco, Coleomegilla maculata (Mulsant) and Cycloneda munda (Say). Collectively, coccinellids may be important biological control agents of tobacco aphids on Georgia flue-cured tobacco.

Arrival, Establishment, and Habitat Use of the Multicolored Asian Lady Beetle (Coleoptera: Coccinellidae) in a Michigan Landscape

A monitoring system established within an array of cultivated and uncultivated habitats was used to characterize the first 5 yr of establishment of the exotic multicolored Asian lady beetle, Harmonia axyridis (Pallas), in an agricultural landscape of southwestern Michigan. Population trends over time were summarized for 11 species of resident coccinellids before and after the arrival of H. axyridis . In addition, annual population increase, habitat utilization patterns, and within-season population fluctuation for H. axyridis were analyzed. H. axyridis became a dominant coccinellid species in the landscape 4 yr after its arrival. Adults of this species were found in all habitats monitored, including early secondary succession, poplar plantation, alfalfa, soybean, corn, and winter wheat. Significant population peaks were observed early and late in the season, depending on the habitat. Resident species that appear affected by the establishment of H. axyridis are Brachiacantha ursina (F.), Cycloneda munda (Say), and Chilocorus stigma (Say). However, to attribute the decline on the numbers of those species to H. axyridis will require further assessment.

Assessment of legume and nonlegume ground covers on Coleoptera: Coccinellidae density for low-input pecan management

AbstractAn annual legume cover crop was evaluated in pecan orchards to increase coccinellids that would reduce pecan aphids. Treatments were a ‘Dixie’ crimson clover and hairy vetch mixture and a grass sod. Coccinellids were abundant on the legume ground covers, but coccinellid density in the tree canopy was rarely affected by ground cover treatment. There were substantial differences between the coccinellid species collected from the legumes and from the trees. In Oklahoma, Olla v-nigrum (Mulsant) and Cycloneda munda (Say) were the main species in the trees, while Hippodamia convergens Guerin, Coccinella septempunctata L, and Coleomegilla maculata lengi Timberlake were dominant species in the legumes. In Georgia, Harmonia axyridis (Pallas) was the dominant species in the trees, and C. septempunctata in the legumes. Pecan aphids at two Oklahoma sites usually were not affected by cover crop treatment, but at the Georgia site, early-season aphids frequently were lower with a legume cover crop than with a grass sod. The accumulated effect of all aphid predators and parasitoids attracted to the legume aphids may have reduced the density of the pecan aphid.

Response of an Assemblage of Coccinellidae (Coleoptera) to a Diverse Agricultural Landscape

Changes in species assemblages of predatory coccinellids in response to landscape structure (habitat diversity and patchiness) was studied in a southern Michigan landscape during 1989–1990. Three sites with different mosaics of cultivated (alfalfa, corn, wheat) and uncultivated (deciduous, field succession) habitats were sampled for coccinellid species using yellow sticky traps. The landscape at each site was characterized using the Berger–Parker index for habitat diversity and a relative patchiness index for habitat fragmentation. Relative abundance, species richness, species dominance, and the Kendall coefficient were used to analyze and compare species assemblages among sites. Principal component analysis (PCA) was used to extract factor components per species and site scores, which were compared with landscape indices using the Pearson correlation coefficient. Thirteen species of coccinellids were captured during the 2 yr of weekly sampling. Of these species, Coccinella septempunctata (L.) was the dominant species in the landscape and was equally abundant in the 3 sites. Coleomegilla maculata lengi Timberlake was more abundant in the site that had a corn habitat, whereas Cycloneda munda (Say), Chilocorus stigma (Say), and Brachiacantha ursina (F.) were more abundant in the site that had a deciduous habitat. Overall, the site with a deciduous habitat had higher species richness. There were significant differences in species composition between the site with a deciduous habitat and the other 2 sites. Differences observed among sites were significantly correlated with the presence of uncultivated habitats in the landscape.

Survey of Lady Beetles (Coleoptera: Coccinellidae) in Sweet Corn Using Yellow Sticky Cards

Yellow cards coated with adhesive were used to survey for the presence, relative abundance and seasonal patterns of lady beetles in research and commercial fields of processing sweet corn in central and western New York in 1992 and 1993. The lady beetles species recorded, in order of abundance were: Coleomegilla maculata lengi Timberlake, Coccinella septempunctata L., Psyllobora vigintimaculata (Say), Hippodamia parenthesis (Say), Propylea quatuordecimpunctata (L.), Cycloneda munda (Say), Hippodamia glacialis glacialis (F.), Adalia bipunctata (L.), Coccinella trifasciata perplexa Mulsant, and Coccinella transversoguttata richardsoni Brown. Coleomegilla maculata lengi was in sufficient number to reflect seasonal patterns. Coleomegilla maculata lengi populations rapidly increased in early July, peaked in late July or early August and then rapidly declined. The timing of C. maculata lengi peak abundance was more closely related to day-of-year than to stage of crop development based on accumulated degree days from planting. The pattern of capture of C. maculata lengi at incremental distances into the field did not indicate colonization from the field edge.

PERENNIAL LEGUME GROUND COVERS INCREASE BENEFICIAL ARTHROPODS AND SUPPLY NITROGEN IN PECAN ORCHARDS

Perennial legumes ground covers were evaluated in pecan (Carya illinoinensis) orchards to supply nitrogen and increase beneficial arthropods. Ground covers were `Kenland' red clover (Trifolium pratense), `Louisiana S-1' white clover (Trifolium repens), a mixture of these two legumes, or bermuda grass (Cynodon dactylon), each in 5 ha plots. Nitrogen was applied at 0-200 kg·ha-1 N in 50 kg intervals to bermuda grass plots, and was omitted on the legumes. Aphids feeding on the legumes attracted lady beetles; however, lady beetle populations in the tree canopies were not affected by ground cover treatment. The most abundant lady beetle species in legumes were Coleomegilla maculata lengi (77%) and Coccinella septempunctata (13%); whereas, dominant species in tree canopies were Coleomegilla maculata lengi (33%). Olla v-nigrum (20%). Cycloneda munda (18%) and Coccinella septempunctata (15%). Several other beneficial arthropods were sampled in legumes and tree canopies. Aphid populations feeding on pecans were low (peak population ≈ 2 aphids/leaf), and not affected by ground cover treatment. Legumes supplied the equivalent of applying 68-156 kg·ha-1 N.