Biodiversity of Heteroptera in Puerto Rico: Part III. Conspectus of Pentatomomorpha: Aradoidea, Pyrrhocoroidea, Coreoidea, and Concluding Notes on Endemism and Biogeography

Superfamilies Aradoidea, Pyrrhocoroidea and Coreoidea from Puerto Rico are discussed as part of an updated account of Hemiptera: Heteroptera. In this final part, we present 48 species belonging to the three superfamilies, with six families known from Puerto Rico: Aradoidea: Aradidae (12); Pyrrhocoroidea: Largidae (1) and Pyrrhocoridae (3); and Coreoidea: Alydidae (5), Rhopalidae (7) and Coreidae (20). Taxonomic accounts presented here include synonymies, known distribution, lists of host plants and a listing of examined specimens. Taxonomical keys are also provided for the identification of all taxa included. Color plates for 43 species are included. Five species are new records for Puerto Rico: Brachyrhynchus membranaceus (F.), Leptoglossus confusus Alayo and Grillo, Eubule scutellata (Westwood), Mamurius cubanus Barber and Bruner, and Merocoris typhaeus (F.). Most species are widespread in the West Indies, with the largest number of island endemics in the Aradidae. A discussion of the origins, biodiversity, biogeography, and endemism of all Puerto Rican Pentatomomorpha is presented.

Fungal pathogens of mango (Mangifera indica L.) inflorescences

This is the first comprehensive study to identify fungal pathogens of mango (Mangifera indica L.) inflorescences in Puerto Rico. A total of 452 mango inflorescences were collected from four cultivars at seven developmental stages during two blooming seasons. Samples were gathered from the germplasm collection at the Agricultural Experiment Station of the University of Puerto Rico in Juana Díaz, Puerto Rico. Eight different symptoms were observed: cankers, flower abortion, powdery mildew, rachis necrotic lesions, rachis soft rot, tip blight, vascular wilt, and insect perforations with necrotic borders. Necrosis was the most prevalent symptom (47%), followed by powdery mildew (19%) and tip blight (6%). Symptoms of malformation were never observed in the field. Using a modified Horsfall and Barratt scale, data on all mango cultivars pooled from two blooming seasons showed that the full bloom stage, the last inflorescence developmental stage (G), displayed the highest mean disease severity (42.67%). This severity value was significantly higher than those of the other developmental stages evaluated (P<0.05). Early inflorescence developmental stages were asymptomatic or showed the lowest percentage of disease severity. An ANOVA was performed to compare disease severity among all mango cultivars regardless of developmental stage. Results showed that there were significant differences (P<0.05) between mean disease severity of cultivars ‘Parvin’ and ‘Haden’. Mean disease severity was higher in ‘Haden’ (20%) when compared to ‘Parvin’ (10.7%). There were no statistical differences in mean disease severity between cultivars ‘Irwin’, ‘Keitt’ and ‘Parvin’, or between ‘Irwin’, ‘Haden’ and ‘Keitt’. In addition to the powdery mildew caused by Pseudoidium anacardii, 26 genera of fungi, mainly of Ascomycetes, were identified from a total of 569 fungal isolates, from symptomatic and asymptomatic inflorescences. The most common fungi were: Diaporthe spp. (29%), followed by members of the Botryosphaeriaceae (16%), Curvularia spp. (11%) and Fusarium spp. (11%). Many fungal pathogens identified in this study were isolated from asymptomatic tissue, occurring as endophytes or latent pathogens: A. alternata, various members of the Botryosphaeriaceae, C. gloeosporioides complex, Cladosporium spp. and F. decemcellulare. Thus, the use of protectant fungicides will not be as effective as systemics in their control. Correct identification of fungal pathogens affecting mango inflorescences is important when quarantine regulations are applied. In addition, this information will facilitate the development of better management strategies in mango orchards.

Feeding systems and productive and physiological parameters of lambs raised under heat stress

The objective of this study was to determine physiological parameters (rectal temperature = RT, respiratory rate = RR, heart rate = HR) and production parameters (dry matter intake = DMI, water intake = WI, average daily weight gain = ADG, and feed conversion = FC) of crossbred and Katahdin lambs raised in rotational grazing of native pastures (NP) and in confinement under heat stress conditions. Nine crossbred lambs (average initial weight = 19.4 kg) were used and fed in a rotational grazing system for 70 days with occupation and rest periods of seven and 21 days, respectively. The lambs had daily access to the grazing area for four to six hours, grass hay and water ad libitum, a daily supplement of 100 g of commercial concentrate and a nutritional block. In the confined system, six lambs of the Katahdin breed (average initial weight = 27.3 kg) were used, and for 28 days these were fed total mixed rations (TMR) containing 30% grass hay, 15.4% soybean meal, 54.6% corn grain and a mineral block. The diet contained 14% Crude Protein (CP) and 66% Total Digestible Nutrients (TDN) and was formulated for an ADG of 200 g. The offered and rejected feed was quantified every day [4% body weight (BW)/dry matter basis (DMB)] to determine the DMI, and the volume of water offered and rejected to determine WI. To validate the stress conditions, the maximum environmental temperature and relative humidity were monitored to calculate the temperature and humidity index (THI), and the RT, HR and RR of the 15 lambs were determined. The lambs were weighed every seven days. In both experiments, the THI oscillated between 78 and 80. The lambs were under environmental heat stress conditions (THI x̅ = 79) during both studies. The averages of HR and RT in the grazing system were 118.0 beats per minute and 38.6° C, while the averages under the confinement system were 108.6 beats per minute and 39.4° C, respectively. The average RR (53.6 and 62.6 breaths per minute, in grazing and in confinement, respectively) was greater than the normal value considered for thermal comfort. Respiratory rate is the main mechanism used by lambs to dissipate heat. The heart rate also showed slightly higher values than those reported for animals in their comfort zone. However, the rectal temperature values were constant. As expected, crossbred lambs fed under grazing conditions with naturalized pastures (NP) had a low ADG (55.6 g). Nevertheless, Katahdin lambs fed in confinement with TMR had a DMI of 935.4 g/day (3.14% BW/DMB), a WI of 3.5 L/day, a FC of 4.74 and an ADG of 226.2 g. In conclusion, raising crossbred sheep in rotational grazing of NP without any type of agronomic management results in ADG that could not be considered viable in traditional production systems. The introduction of pure breeds and feeding them in confined systems with a TMR results in a pre-determined ADG (>200 g/day) and is an alternative that can be evaluated economically for its practical implementation.

Identifying interspecific lines of coffee resistant to Hemileia vastatrix Berk. et Br. and evaluating their adaptability to the coffee growing region of Puerto Rico

Thirteen lines from the coffee germplasm collection of the Adjuntas Agricultural Experiment Substation, lines T-5175 and T-8667 from Costa Rica, and four advanced multilines from the Portugal Research Center for Coffee Rust (CIFC; ‘Centro de Investigación de la Roya del Café de Portugal’) were evaluated for resistance to Hemileia vastatrix and their performance under coffee production conditions in Puerto Rico. The evaluations were conducted in the laboratory and on selected coffee farms. Lines of “Catimor” and “Sarchimor” types were selected based on their reaction to the rust pathogen and excellent agronomic characteristics and named ‘Frontón’ and ‘Limaní’, respectively. Incidence of black beans was examined in red, medium and green beans and was significantly higher in line T-5175, in plantings <300 meters above sea level, and in medium ripe and green fruits. Catimor lines from the CIFC were superior to the check ‘Caturra’ in fruit production and yield of green coffee.

Isolation of native entomopathogenic fungi with potential for control of the pepper weevil, Anthonomus eugenii Cano, in Puerto Rico

Entomopathogenic fungi were isolated parasitizing coffee borer beetle (Hypothenemus hampei Ferrari) and banana weevils (Cosmopolites sordidus Germar) in different parts of the island of Puerto Rico to be identified and examined for their pathogenicity on pepper weevil (Anthonomus eugenii Cano). Fungi were isolated and purified in acidulated potato dextroseagar (PDA) in the laboratory of the Plant Disease Clinic at the Agricultural Experiment Station, Juana Díaz. Seven fungal isolates were obtained from the municipality of Comerío, and one from the municipality of Adjuntas. Morphology, DNA sequences of different genetic regions of interest, and microsatellites were used for identification of fungal isolates. Two of the eight isolates were identified as Beauveria bassiana, three as Beauveria caledonica, two as Paecilomyces fumosorosea and one as Paecilomyces lilacinum. Pathogenicity tests were conducted in vitro using conidia suspension (1 x 106 conidia/mL). Insects were inoculated by immersion (10 sec) in the conidia suspension. Daily mortality data was taken (TL50, TL90) and the mean of the treatments were determined. All the fungal species were pathogenic to A. eugenii. The most effective treatments were: P. fumosorosea (Pae1) and B. bassiana (Bb1 & Bb3) with TL50 of 2.39, 2.53 and 2.56 days, respectively, while TL50 for the control was 6.56. A 100% mortality for treatments occurred between the fourth and sixth day compared to control, which reached it in 12 days. These isolates have the potential to be used on an integrated management program for the control of the pepper weevil.

Comparison of body dimensions between normal and double muscled Senepol heifers

Different body dimensions were compared between 16 normally muscled (NM) and 16 heterocygous double muscled (DM) Senepol heifers. Body weight (BW), withers height (WH), hip height (HH), thorarcic perimeter (TP), barrel (BA), shoulder to pin bone distance (SPD), and the internal pelvic width (PW), height (PH), and area (PA) were recorded in each heifer. Also included were the relationships of BW/body dimensions, except for dimensions PW and PH. Data were analyzed by the GLIMMIX and CORR procedures of SAS. The respective genotypes MN and DM did not differ (P>0.10) in BW (415 and 434 kg), WH (both 113 cm), HH (both 120 cm), TP (both 175 cm), B A (209 and 214 cm), B W/B A (1.99 and 2.03 kg/cm), SPD (both 147 cm), PW (both 13 cm), PA (212 and 220 cm2), and BW/PA (1.96 and 1.98 kg/cm2). However, DM heifers tended to present (P<0.10) higher values than NM heifers for BW/WH, BW/HH, BW/SPD, and PH by margins of 0.14 kg/cm, 0.15 kg/cm, 0.12 kg/cm, and 0.59 cm, respectively. Moreover, the BW/TP value was 0.09 kg/cm greater (P<0.05) in the DM than in NM heifers. The correlations between different pairs of body dimensions were lower in the DM than in the NM heifers. These results suggest that the enhanced musculature visually observed in DM heifers must be accompanied by hypotrophy of other body organs and tissues, but not including the pelvic region. This compensatory effect minimizes the posibility of observing differences in body dimensions in vivo between DM and NM heifers.