Cylindropuntia Species Research Articles

The successful biological control of Cylindropuntia fulgida var. mamillata (A. Schott ex Engelm.) Backeb. (Cactaceae) (coral or boxing glove cactus) at two field sites in Queensland, Australia

Cylindropuntia fulgida var. mamillata (A. Schott ex Engelm.) Backeb. (Cactaceae) (coral or boxing glove cactus) is one of eight invasive species of Cylindropuntia in Australia that have been targeted for biological control. The ‘cholla’ lineage of Dactylopius tomentosus (Lamarck) (Hemiptera: Dactylopiidae) was first released in South Africa in 2008. This lineage is the second of a series of host-specific cochineal insects to be released to control Cylindropuntia species in Australia and was selected to target C. fulgida var. mamillata. Approval to field release this lineage was granted in November 2015 and the cochineal was first released at Leander Station, near Longreach, Queensland in March 2016 and at Booligar Station, near Hebel, Queensland in April 2016. An intensive monitoring program was undertaken at both sites to evaluate the establishment, rate and direction of spread and impact of the D. tomentosus ‘cholla’ lineage on C. fulgida var. mamillata. The cochineal established very well at Leander Station but needed to be re-released at Booligar Station following heavy rain and flooding soon after the first release. Once established, populations of the cochineal at both sites built up very quickly and spread with the prevailing winds, infesting 100% of plants at each of the monitoring sites within 14 months of release. The impact on plants was substantial, with 95% of plants dying at Leander Station within 19 months of the cochineal being released. At Booligar Station, about 98% of plants had died within 18 months of the second cochineal release. Of the plants that were still alive, all had been severely damaged by the cochineal and were showing signs of poor health. These results and observations at other release sites, both in Australia and South Africa, suggest D. tomentosus ‘cholla’ lineage should be an effective agent for the control of C. fulgida var. mamillata.

Characterization of the morphometry, germination process, phytochemicals, and antioxidant capacity of seeds of three species of the genus Cylindropuntia (Cactacea) of Chihuahua state

Cylindropuntia is a genus of cylindrical cacti found in northern Mexico. This study aimed to describe the fruit and seed morphometry, characterize the germination process, as well as determine the seed phytochemicals in three species of the genus Cylindropuntia from the state of Chihuahua in México: C. imbricata, C. spinosior, and C. leptocaulis. To measure the morphometric parameters, 20 fruits and 20 seeds from each fruit were used for each specie. For the characterization of the germination process, two scarification treatments were applied, and the germination was allowed for 42 days. Different parameters of the germination process were calculated as the germination percentage, mean germination time, germination speed, and mean germination speed. The concentration of reducing sugars, total phenols, tannins, flavonoids, antioxidant activity (DPPH and FRAP), and protein content were determined from seeds under basal conditions. Results revealed significant differences (p ? 0.05) for morphometric parameters in the fruit and seed of the three species examined, showing C. imbricata the highest values in both tissues, followed by those obtained for C. spinosior and C. leptocaulis, respectively. The germination percentage was higher in C. leptocaulis (13.3%), although achieved in a longer mean germination time (27.7 days), facing C. spinosior that presented the lowest values for the germination percentage (3.3%), mean germination time (4.6 days), and germination speed index (0.024 days). Seeds from C. leptocaulis showed the highest values for reducing sugar content (31.82 mg glucose·g?1 of dry weight) and the antioxidant activity determined by DPPH (26.37 mg CE·g?1of dry weight), whereas C. spinosior seeds showed the highest ones for the total phenols content (3.08 mg GAE·g?1 of dry weight) and the antioxidant activity determined by FRAP (11.7 mmol TE·g?1 dry weight). Besides, C. imbricata showed the highest value in the protein content (5.6 mg protein·g?1). This study provides the first data on seed phytochemicals and information on the germination process of these three species of Cylindropuntia, showing differences among them in the diverse parameters measured.

Exceptional biological control of two varieties of Cylindropuntia fulgida (Cactaceae) in South Africa using a recently-identified different biotype of the cochineal insect, Dactylopius tomentosus (Dactylopiidae)

The cactus Cylindropuntia fulgida (Engelm.) F.M. Knuth., from Mexico and southwestern USA, invades conservation and pasture land in the arid regions of South Africa. Mechanical and chemical control, and attempts at biological control, have been ongoing since the early 1970 s but, until recently, with little success. Two distinct morphological varieties of C. fulgida are recognized in South Africa, viz. Cylindropuntia fulgida var. fulgida Engelm. (‘chain-fruit cholla’) and Cylindropuntia fulgida var. mamillata (Schott ex Engelm.) Backeb. forma monstrosa Coult (‘boxing-glove cactus’). In 2008, a specific biotype - the ‘cholla’ biotype - of the cochineal insect, Dactylopius tomentosus (Lamark), that was obtained from Cylindropuntia cholla (F.A.C. Weber) F.M.Knuth in Baja California Sur in Mexico, was released on C. fulgida var. fulgida, and later, in 2011, on C. fulgida var. mamillata in South Africa. It has brought these cactus weeds under remarkably effective biological control. We assess the efficacy of biological control for the two morphological varieties of C. fulgida in South Africa. In the Northern Cape province, D. tomentosus ‘cholla’ effectively controls detached cladodes and small, rooted plants of chain-fruit cholla, but, following rain, old plants repeatedly coppice and regrow from their woody trunks. Hand-felling and stacking of cochineal-weakened C. fulgida var. fulgida plants killed them within 1–2 years. Cylindropuntia fulgida var. mamillata is under exceptionally effective biological control wherever D. tomentosus ‘cholla’ has been released. At two sites in the Northern Cape province that were monitored, approximately 90% of the plants died during the first ten months after release, while practically all were dead another 7 months later. The ‘cholla’ biotype of D. tomentosus has been supplied to Australia for use against various invasive Cylindropuntia species in that country.

The host range of four new biotypes of Dactylopius tomentosus (Hemiptera: Dactylopiidae) from southern USA and their potential as biological control agents of Cylindropuntia spp. (Cactaceae) in Australia: Part II

ABSTRACTEight Cylindropuntia species have naturalised in Australia and pose serious economic, environmental and social impacts. The host range of four additional biotypes of D. tomentosus from southern USA was investigated. Feeding and development were restricted to the genus Cylindropuntia. However, they showed differences in specificity within this genus and some biotypes discriminated between the provenances of Cylindropuntia rosea and Cylindropuntia tunicata. Efficacy trials were conducted to determine whether populations of each biotype could be sustained on the naturalised Cylindropuntia species and if these populations could retard the growth or kill these plants. The ‘acanthocarpa’ biotype offers potential control of C. rosea (Lorne Station), while the ‘cylindropuntia sp.’ biotype shows great potential to control C. rosea (Grawin). The ‘cylindropuntia sp.’ biotype also had a high impact on Cylindropuntia kleiniae and Cylindropuntia imbricata, and a moderate impact on Cylindropuntia leptocaulis and Cylindropuntia prolifera. The ‘acanthocarpa × echinocarpa’ biotype had its greatest impact on C. tunicata (Grawin), killing this plant in 18 weeks. A fourth biotype, ‘leptocaulis’, was damaging to some species, but was less effective than the other biotypes. Cylindropuntia spinosior is the only naturalised species in Australia where no effective biocontrol agent has been found.

The host range of three biotypes of Dactylopius tomentosus (Lamarck) (Hemiptera: Dactylopiidae) and their potential as biological control agents of Cylindropuntia spp. (Cactaceae) in Australia

The host range of two newly imported biotypes of Dactylopius tomentosus and their potential as biological control agents of Cylindropuntia spp. were investigated. A third biotype (‘imbricata’) of D. tomentosus previously released in Australia to control C. imbricata was also screened to determine if it will feed on other species of Cylindropuntia occurring in Australia. Efficacy trials were conducted to evaluate the ability of the biotypes to retard the growth or kill those plant species supporting development of four or more individuals in the host test trials. The host range of the three biotypes of D. tomentosus was restricted to the genus Cylindropuntia. However, the biotypes showed varying degrees of specificity within this genus. The ‘imbricata’ biotype was the only biotype to develop on Australian C. rosea provenances, albeit with a range of developmental success on all C. rosea provenances tested. The Spanish provenance supported the highest development success followed by Grawin (NSW), Lorne Station (NSW) while the least preferred was the Mexican provenance. The ‘rosea’ and ‘cholla’ biotypes were unsuitable candidates to control C. rosea in Australia. However, the efficacy trials showed that the ‘cholla’ biotype had a high impact on four of the eight naturalised Cylindropuntia species in Australia. This biotype established rapidly and the sustained feeding of one fecund female and her progeny killed potted plants of C. imbricata and C. fulgida at week 18. This biotype has the potential to be an effective agent against C. fulgida, C. imbricata, C. kleiniae and C. tunicata and, as a consequence, an application seeking its release in Australia has been lodged.

Genetic variation amongst biotypes of Dactylopius tomentosus

The tomentose cochineal scale insect, Dactylopius tomentosus (Lamarck) (Hemiptera: Dactylopiidae), is an important biological control agent against invasive species of Cylindropuntia (Caryophyllales: Cactaceae). Recent studies have demonstrated that this scale is composed of host-affiliated biotypes with differential host specificity and fitness on particular host species. We investigated genetic variation and phylogenetic relationships among D. tomentosus biotypes and provenances to examine the possibility that genetic diversity may be related to their host-use pattern, and whether their phylogenetic relationships would give insights into taxonomic relatedness of their host plants. Nucleotide sequence comparison was accomplished using sequences of the mitochondrial cytochrome c oxidase I (COI) gene. Sequences of individuals from the same host plant within a region were identical and characterized by a unique haplotype. Individuals belonging to the same biotype but from different regions had similar haplotypes. However, haplotypes were not shared between different biotypes. Phylogenetic analysis grouped the monophyletic D. tomentosus into 3 well-resolved clades of biotypes. The phylogenetic relationships and clustering of biotypes corresponded with known taxonomic relatedness of their hosts. Two biotypes, Fulgida and Mamillata, tested positive for Wolbachia (α-Proteobacteria), a common endosymbiont of insects. The Wolbachia sequences were serendipitously detected by using insect-specific COI DNA barcoding primers and are most similar to Wolbachia Supergroup F strains. This study is the first molecular characterization of cochineal biotypes that, together with Wolbachia sequences, contribute to the better identification of the biotypes of cochineal insects and to the biological control of cacti using host-specific biotypes of the scale.

Recruiting mechanisms of Cylindropuntia leptocaulis (Cactaceae) in the Southern Chihuahuan Desert

Sexual reproduction and vegetative propagation require the establishment of morphologically diverse reproductive structures (seedlings and stem segments). This study assesses both types of Cylindropuntia leptocaulis recruitment in two microenvironments protected from herbivory (in open space and under the canopy of Larrea tridentata) and with two soil types (collected below L. tridentata canopy and from open space).An observational study revealed that sexual establishment was very limited (only 8 juveniles/ha were found), while clonal establishment was more frequent (59 juveniles/ha); both types of propagule were found only under shrub canopy.Field experiments showed that, as in other Cylindropuntia species but contrasting with findings for Opuntia species, seeds germinated and seedlings survived under nurse plants as well as in open space, but they grew faster in the former environment. Faster growth under canopy shade provides better chances of successful recruitment to later life-cycle stages. Stem segments never established in open space, requiring the shade of nurse plants. This may be due to physiological constraints imposed by their small volume. In synthesis, the results indicate that clonal propagation is the most important recruitment mechanism in C. leptocaulis populations, and that it takes places under shrub canopy.

Is Cylindropuntia ×fosbergii (Cactaceae) a Hybrid?

The Mason Valley cholla, Cylindropuntia ×fosbergii (C. B. Wolf) Rebman, M.A. Baker & Pinkava, is the putative hybrid of C. bigelovii (Engelm.) F. M. Knuth and some other species of Cylindropuntia. We used AFLPs to screen chollas of the Anza-Borrego Desert in southern California to test this hypothesis of hybrid origin and identify the parental species involved. Other species scrutinized as potential parents include C. echinocarpa (Engelm. & J. M. Bigelow) F. M. Knuth, C. ganderi (C. B. Wolf) Rebman & Pinkava, C. californica var. parkeri (J. M. Coulter) Pinkava, and C. wolfii (L. D. Benson) M.A. Baker. Patterns of band sharing clearly testify to the close relationship between C. ×fosbergii and C. bigelovii. None of the other species screened came close to that level of similarity. Moreover, the numbers of total loci and unique loci in C. ×fosbergii do not meet the expectations of a hybrid taxon. We propose the alternative hypothesis that C. ×fosbergii is the sister species of C. bigelovii.

Determination of biotypes of Dactylopius tomentosus (Hemiptera: Dactylopiidae) and insights into the taxonomic relationships of their hosts, Cylindropuntia spp.

Host specialization to form biotypes is common among phytophagous insects, and it has been hypothesised that biotypes of Dactylopius tomentosus L. (Hemiptera: Dactylopiidae) occur. D. tomentosus is an important biological control agent for Cylindropuntia cacti when they occur as weeds. Additionally, there is uncertainty surrounding the taxonomic status of some species of Cylindropuntia. This study aimed to confirm the existence of D. tomentosus biotypes and to assess whether host specialization can help to resolve this systematic uncertainty. For this study, the host specificity and performance of ten provenances of D. tomentosus collected from C. cholla, C. fulgida var. fulgida, C. imbricata, C. f. var. mamillata, C. rosea and C. tunicata and reared on C. cholla, C. fulgida var. fulgida, C. imbricata and C. rosea were investigated. Five life-history parameters were measured including: crawler development time and survival, female development time, and the weight and number of eggs produced by females. Results revealed significant variation in host specificity with provenances either thriving, surviving or dying on the different hosts, thus demonstrating the existence of biotypes. Also, host specificity was related to host species and not to the geographic locality from which either the host or provenance was sourced. These findings suggest that the characteristics of Cylindropuntia species may differ sufficiently, there by presenting different selection pressures that induce and sustain distinct biotypes of D. tomentosus. The observed host use patterns of the biotypes separated the plant species into two groups that accorded with known phylogenetic relationships among Cylindropuntia species, suggesting that biotypes can be used to elucidate their taxonomic relatedness. Besides advancing our knowledge of the ecology and evolution of D. tomentosus, these novel findings have important implications for the biological control of Cylindropuntia species.

Distinguishing suitable biotypes ofDactylopius tomentosus(Hemiptera: Dactylopiidae) for biological control ofCylindropuntia fulgidavar.fulgida(Caryophyllales: Cactaceae) in South Africa

Cylindropuntia fulgida (Engelmann) F.M. Knuth var. fulgida (Engelmann) F.M. Knuth (Cff) (Caryophyllales: Cactaceae) is native to Mexico and Arizona and was introduced into South Africa for ornamental purposes. It subsequently became highly invasive, necessitating control. The cochineal insect, Dactylopius tomentosus (Lamarck) (Hemiptera: Dactylopiidae), was selected as a potential biological control agent based on its restricted host range among Cylindropuntia species and previous success in controlling C. imbricata (DC.) F. Knuth (Ci). Eight D. tomentosus provenances (Cholla, Cholla E, Fulgida, Mamillata, Imbricata, Tunicata U, Tunicata V and Rosea) from Cylindropuntia species in their native ranges were reared on Cff, whilst Cholla and Imbricata were also reared on Ci. Large differences were found in the development and survival of crawlers, and in the reproductive capacity of females. Three subjective categories of provenance interaction with host plants were identified based on a fitness index (FI) calculated from data relating to crawler survival, female development time and fecundity: (i) thriving (FI > or = 1) - insects had shorter developmental times, high crawler survival and highly fecund females (Cholla); (ii) surviving (FI<1 but >0) - insects had extended development times, low crawler survival and low fecundity (Imbricata, Fulgida and Mamillata); and (iii) dying (FI = 0) - insects died before or at the second instar (Rosea, Tunicata U and Tunicata V). Cholla, therefore, is highly suitable for biological control of Cff in South Africa. In addition, Cholla thrived on Cff but only survived on Ci whilst, in contrast, Imbricata thrived on Ci but only survived on Cff. This differential ability of provenances to thrive or survive on different host plants demonstrated that host adapted biotypes of D. tomentosus exist; therefore, biotypes should be taken into account when considering this species as a biological control agent of cactus weeds.

Forces Necessary for Mechanical Failure of Terminal Joints of Several Species of Cylindropuntia and Opuntia (Cactaceae)

EVANS, L. S. (Laboratory of Plant Morphogenesis, Biological Sciences Research Laboratories, Manhattan College, the Bronx, NY 10471), Z. KAHN-JETTER (Department of Mechanical Engineering, Manhattan College, the Bronx, NY 10471) AND S. BUTWELL (Laboratory of Plant Morphogenesis, Biological Sciences Research Laboratories, Manhattan College, the Bronx, NY 10471). Forces necessary for mechanical failure of terminal joints of several species of Cylindropuntia and Opuntia (Cactaceae). J. Torrey Bot. Soc. 131: 311-319. 2004.The number (plant height) and arrangement of stem segments of the nearly 200 species of Cylindropuntia and Opuntia depend upon mechanical stresses at joints between stem segments in relation to the amount of internal components in joints that withstand joint failure. Stress tests were performed on terminal joints (joints between terminal and sub-terminal stem segments) of five species of Cylindropuntia and Opuntia. For these five cactus species, moment of inertia, maximum bending stress at failure, and bending moment at joint failure values ranged from 0.22 to 50.9 10-9 m4, 1060 to 12200 kPa, and 0.45 to 2.39 N-m, respectively. Results of this study show that terminal joints with larger bending stresses prior to experimentation withstood larger stresses imposed during stress testing. This result indicates that joints are 'pre-stressed' and have a finite level of resistance when they develop naturally on the plant. Results show that maximum bending stresses at failure [breaking strengthslope of M / (I/c)] were higher for tensile than for compressive portions of terminal joints and joint angle deflections changed more for compressive joint portions than for tensile joint portions during stress testing. The high resistance to bending for tensile portions corresponded to a larger total area of lignified xylem cells (the preponderant wood cells) in tensile portions of terminal joints. We conclude that the mechanical properties of tensile portions are not similar to compressive portions of terminal joints. Moreover, the breaking strength of joints was positively correlated with the amounts of lignified cells in joints. Overall, the results imply that each terminal joint for a cactus species has an innate resistance to failure (ability to withstand a specific level of mechanical stress) that is established during the natural development of the joint.

Relationships between Number of Stem Segments on Longest Stems, Retention of Terminal Stem Segments and Establishment of Detached Terminal Stem Segments for 25 Species of Cylindropuntia and Opuntia (Cactaceae)

of detached terminal segments that become established for 25 cactus species. We hypothesized that cactus species with more segments per stem should require more force to remove terminal segments. Regression analyses of mean maximum stress at failure of terminal joints versus mean number of segments for the species tested gave a line equation of y = 380x + 1350 with a regression coefficient of 0.85. We hypothesized that cactus species with few segments per stem for adult plants should have good establishment of detached terminal stem segments while species with many segments on adult plants should have low levels of establishment of detached terminal segments. Regression analyses of mean establishment of terminal segments as a function of mean number of segments gave a line equation of y = - 1.73x + 80.6 with a regression coefficient of 0.77. In contrast, plant height was not related to either maximum normal stress at failure or segment establishment. We conclude that number of stem segments on longest stems of plants was a good predictor of force necessary to remove terminal segments. Number of stem segments was also a good predictor of rooting and establishment of terminal segments. Overall, the data of this study show that Cylindropuntia and Opuntia species with large numbers of stem segments along each stem rely mostly on sexual reproduction for procreation while species with fewer stem segments rely mostly on asexual reproduction via rooting of detached stem segments.