Rice-feeding insects and selected natural enemies in West Africa: Biology, ecology, identification

FOREWORD • ACKNOWLEDGMENTS • INTRODUCTION • RICE IN AFRICA • RICE-FEEDING INSECTS • CLIMATIC ZONES AND RICE ECOSYSTEMS AS HABITATS • CONSTRAINTS TO RICE PRODUCTION • SPECIES IN WEST AFRICA • DIRECT DAMAGE • ROLE IN DISEASE TRANSMISSION BIOLOGY AND ECOLOGY OF RICE-FEEDING INSECTS ROOT FEEDERS : Mole crickets, Gryllotalpa africana Palisot de Beauvois; Orthoptera: Gryllotalpidae • Root aphids, Tetraneura nigriabdominalis (Sasaki); Hemiptera (suborder Homoptera): Aphididae • Termites, Macrotermes, Microtermes, and Trinervitermes spp.; Isoptera: Termitidae • Black beetles, Heteronychus mosambicus Peringuey (= H. oryzae Britton); Coleoptera: Scarabaeidae: Dynastinae • Rice water weevils, Afroryzophilus djibai Lyal; Coleoptera: Curculionidae • STEM BORERS : Stalk-eyed fly, Diopsis longicornis Macquart; Diptera: Diopsidae • Stalk-eyed fly, Diopsis apicalis Dalman; Diptera: Diopsidae • Stem borer, Pachylophus beckeri Curran; Diptera: Chloropidae • African striped rice borer, Chilo zacconius Bleszynski; Lepidoptera: Pyralidae • African white borer, Maliarpha separatella Ragonot; Lepidoptera: Pyralidae • Scirpophaga spp.; Lepidoptera: Pyralidae • African pink borers, Sesamia calamistis Hampson and S. nonagrioides botanephaga Tams and Bowden; Lepidoptera: Noctuidae AFRICAN RICE GALL MIDGE : Orseolia oryzivora Harris and Gagne; Diptera: Cecidomyiidae LEAFHOPPERS AND PLANTHOPPERS : Green leafhoppers, Nephotettix afer Ghauri and Nephotettix modulatus Melichar; Hemiptera: Cicadellidae • White rice leafhoppers, Cofana spectra (Distant) and C. unimaculata (Signoret); Hemiptera: Cicadellidae • White-winged planthopper, Nisia nervosa (Motschulsky); Hemiptera: Meenoplidae • Brown planthopper, Nilaparvata maeander Fennah; Hemiptera: Delphacidae • Rice delphacid, Tagosodes cubanus (Crawford); Hemiptera: Delphacidae • Spittlebugs, Locris maculata maculata Fabricius and L. rubra Fabricius; Hemiptera: Cercopidae FOLIAGE FEEDERS : Rice caseworm, Nymphula depunctalis (Guenée); Lepidoptera: Pyralidae • Rice leaffolders, Marasmia trapezalis (Guenée); Lepidoptera: Pyralidae • Green-horned caterpillar, Melanitis leda ismene Cramer; Lepidoptera: Satyridae • African rice hispids; Coleoptera: Chrysomelidae Flea beetles, Chaetocnema spp.; Coleoptera: Chrysomelidae • Ladybird beetle, Chnootriba similis (Mulsant); Coleoptera: Coccinellidae • Leaf miner, Cerodontha orbitona (Spencer); Diptera: Agromyzidae • Rice whorl maggot, Hydrellia prosternalis Deeming; Diptera: Ephydridae • Rice grasshoppers : Short-horned grasshoppers, Hieroglyphus daganensis; Orthoptera: Acrididae • Short-horned grasshoppers, Oxya spp.; Orthoptera: Acrididae • Meadow grasshoppers, Conocephalus spp.; Orthoptera: Tettigoniidae • Variegated grasshopper, Zonocerus variegatus (L.); Orthoptera: Pyrgomorphidae • Whitefly, Aleurocybotus indicus David and Subramaniam; Hemiptera: Aleyrodidae • Spider mites, Oligonychus pratensis Banks, O. senegalensis Gutierrez and Etienne, Tetranychus neocaledonicus Andre; Acari: Tetranychidae INSECTS THAT ATTACK PANICLES : Earwigs, Diaperasticus erythrocephalus (Olivier); Dermaptera: Forficulidae • Blister beetles; Coleoptera: Meloidae • Panicle thrips, Haplothrips spp.; Thysanoptera: Phlaeothripidae • Stink bugs, Aspavia spp.; Hemiptera: Pentatomidae • Green stink bugs, Nezara viridula (L.); Hemiptera: Pentatomidae • Alydid bugs, Stenocoris spp., Mirperus spp. • and Riptortus; Hemiptera: Alydidae • Cotton stainers, Dysdercus spp.; Hemiptera: Pyrrhocoridae NATURAL ENEMIES OF WEST AFRICAN RICE-FEEDING INSECTS : INVENTORY OF NATURAL ENEMIES OF WEST AFRICAN RICE-FEEDING INSECTS: Predators • Parasitoids AN ILLUSTRATED KEY TO THE IDENTIFICATION OF SELECTED WEST AFRICAN RICE INSECTS AND SPIDERS: SECTION I: ORDERS BASED ON ADULTS • SECTION II: INSECTS • SECTION III: SPIDERS REFERENCES SUBJECT INDEX FOR THE BIOLOGY AND ECOLOGY AND NATURAL ENEMIES SECTION

Designing standardized and optimized surveys to assess invertebrate biodiversity in tropical irrigated rice using structured inventory and species richness models

Insect pest management depends on simple, rapid, and reliable sampling methods that should also be standardized and optimized. We tested structured inventory, community characterization, and sampling optimization approaches on the invertebrate fauna of Philippine irrigated rice, undisrupted by pesticides, using seven field methods and species richness models. Canopy and floodwater invertebrates were intensively and repetitively sampled from 600 quadrats (0.1-m2 planar area) over dry and wet cropping seasons in one field at the International Rice Research Institute in the Philippines. In the canopy, pooled counts from D-Vac and plant dissections (PD) on the same rice hills (absolute methodology) were compared with three other methods (i.e., FARMCOP, Blower-Vac, sweep-net), while, in the floodwater, the area collector (absolute methodology) was compared with three other methods (i.e., FARMCOP, Blower-Vac, strainer-net). Overall, 25 and 50% of the observed richness of canopy and floodwater taxa, respectively, were caught by all four methods. Estimated inventory completeness for the canopy and floodwater averaged 82 and 98%, respectively, after all methods were pooled. To maximize observed richness, optimization results for the canopy recommended allocating the highest sampling effort to D-Vac and PD, followed by the Blower-Vac, whereas the area collector should be assigned the highest sampling effort in the floodwater, followed by the strainer-net or Blower-Vac. Our results suggest that structured inventory and species richness models are useful tools for setting optimization criteria and stopping rules for sampling crop-invertebrate assemblages based on inventory completeness and for enabling more informative biodiversity comparisons. © The Authors 2016

Diversity and biocontrol potential of dominant ants associated with the cacao mirid bug, Helopeltis bakeri poppius (Hemiptera: Miridae) in a selected cacao farm in Sto. Tomas, Batangas, Philippines

The ants associated with cacao (Theobroma cacao L.) suspected as predators of the cacao mirid bug, Helopeltis bakeri Poppius were surveyed using four collecting methods, namely: (1) beating the canopy; (2) handpicking; (3) pitfall trapping, and (4) ground surface food-baiting in regularly pruned trees and weeded farm (site 1) and irregularly pruned trees and weedy farm (site 2) in Santo Tomas, Batangas, Philippines during the month of January 2018. A total of 2,072 ant individuals (1,019 in site 1 and 1,053 in site 2) belonging to 13 species in 13 genera under four subfamilies were recorded. These are Myrmicinae with 1,182 individuals (57.04%) in five species represented by Solenopis geminata Fabricius 1804; Tetramorium sp.; Carebara diversa Jerdon 1851; Pheidole sp. and Crematogaster sp.; Formicinae with 793 individuals (38.27%) in four species-Nylanderia sp.; Oecophylla smaragdina Fabricius 1775; Anoplolepis gracilipes F. Smith 1857 and Polyrhachis sp.; Dolichoderinae with three individuals (0.15%) in Tapinoma melanocephalum Fabricius 1793, and Ponerinae with 94 individuals (4.54%) in three species-Odontoponera denticulata F. Smith 1858; Odontomachus simillimus F. Smith 1858, and Leptogenys sp. Of all taxa, C. diversa and O. smaragdina were most preponderant, followed by Crematogaster and Odontoponera in the second group; whereas, Anoplolepis, Pheidole, Nylanderia and Solenopsis were the least preponderant. Our findings showed that Shannon-Weaver function of diversity (H’) was slightly higher in weedy and irregularly pruned farm (H’=1.18) compared to the weeded and regularly pruned one (H’=1.08). On the other hand, alpha diversity (α) index showed diversity highest in soil (α =1.9) \u3e trunk (α =1.7) \u3e foliage area (0.6). Sorensen’s Coefficient index (CI) of similarity of ant species was high (0.86) denoting that at least nine taxa are common in the same orchard irrespective of farmers practice. A new scoring system was developed based on ant’s attraction to food baits. Of all taxa, only O. smaragdina and Solenopsis geminata preyed on the cacao mirid bug and demonstrated potential use as biological control agents in cacao farms. © Rushing Water Publishers Ltd. 2018

Diversity and functional guild composition of rice leaffolder [cnaphalocrocis medinalis (Guenee), lepidoptera: Pyralidae] natural enemies in irrigated super hybrid rice and non-rice habitats in China

The rice leaffolder, Cnaphalocrocis medinalis (Guenee) is a key insect pest of irrigated super hybrid rice in China. Its pool of natural enemies revealed 24 species of parasitic Hymenoptera belonging to 17 genera under 7 families in Wuyishan City, Fujian Province, East China. Four species of Trichogramma were the most dominant parasitoids attacking the eggs. Two braconids, Cotesia cypris (Nixon) and Cardiochiles philippinensis Ashmead were the most common larval parasitoids while the ichneumonids occur in low numbers. On the other hand, 119 species of predators - spiders, odonatans, dipterans, ants and mirid bug complimented the parasitic Hymenoptera. Of all the natural enemies, the predatory spiders (Araneae) present in both the super hybrid rice and non-rice habitats totalled 2,787 individuals and only 60 predatory insects were found. The spiders were 50.4x and 41.6x more preponderant than the predatory insects in both habitats, respectively. The super hybrid rice had 1,664 spider individuals belonging to 38 species under 11 families while the non-rice habitats recorded 1,123 individuals representing 84 species under 16 families. These findings served as the first documentation of all parasitoids and predatory natural enemies of rice leaf folder in China based on collections from the irrigated super hybrid rice and surrounding non-rice habitats in Wuyishan City, East China. ©Rushing Water Publishers Ltd. 2016

LIVING WITH THE ENEMY: JUMPING SPIDERS THAT MIMIC WEAVER ANTS

Volume: 33Start Page: 813End Page: 81

Comperiella calauanica sp. n. (Hymenoptera: Encyrtidae), an endoparasitoid of the invasive coconut scale, Aspidiotus rigidus Reyne (Hemiptera: Diaspididae) on Luzon Island, Philippines

Comperiella calaztanica sp. n., an encyrtid endoparasitoid of coconut scale insect, Aspidiotus rigidus Reyne discovered in Calauan, Laguna, Philippines is described and illustrated. This highly invasive armoured scale insect is a devastating pest of coconut trees including seedlings in three provinces on Luzon Island, namely: Batangas, Laguna and Quezon. A key to the species of Comperiella reported in the Philippines is also provided. The endoparasitoid is a promising biological control agent in the regulation of the coconut scale insect populations in the field. Survey results showed that parasitism by C. calauanica sp. n. on A. rigidus colonies in the affected areas ranged from 65-92% in the third quarter of 2014

Effects of

Endotoxins from Bacillus thuringiensis (Bt) produced in transgenic pest-resistant Bt crops are generally not toxic to predatory and parasitic arthropods. However, elimination of Bt-susceptible prey and hosts in Bt crops could reduce predator and parasitoid abundance and thereby disrupt biological control of other herbivorous pests. Here we report results of a field study evaluating the effects of Bt sprays on non-target terrestrial herbivore and natural enemy assemblages from three rice (Oryza sativa L.) fields on Luzon Island, Philippines. Because of restrictions on field-testing of transgenic rice, Bt sprays were used to remove foliage-feeding lepidopteran larvae that would be targeted by Bt rice. Data from a 546-taxa Philippines-wide food web, matched abundance plots, species accumulation curves, time-series analysis, and ecostatistical tests for species richness and ranked abundance were used to compare different subsets of non-target herbivores, predators, and parasitoids in Bt sprayed and water-sprayed (control) plots. For whole communities of terrestrial predators and parasitoids, Bt sprays altered parasitoid richness in 3 of 3 sites and predator richness in 1 of 3 sites, as measured by rarefaction (in half of these cases, richness was greater in Bt plots), while Spearman tests on ranked abundances showed that correlations, although significantly positive between all treatment pairs, were stronger for predators than for parasitoids, suggesting that parasitoid complexes may have been more sensitive than predators to the effects of Bt sprays. Species accumulation curves and time-series analyses of population trends revealed no evidence that Bt sprays altered the overall buildup of predator or parasitoid communities or population trajectories of non-target herbivores (planthoppers and leafhoppers) nor was evidence found for bottom-up effects in total abundances of non-target species identified in the food web from the addition of spores in the Bt spray formulation. When the same methods were applied to natural enemies (predators and parasitoids) of foliage-feeding lepidopteran and non-lepidopteran (homopteran, hemipteran and dipteran) herbivores, significant differences between treatments were detected in 7 of 12 cases. However, no treatment differences were found in mean abundances of these natural enemies, either in time-series plots or in total (seasonal) abundance. Analysis of guild-level trajectories revealed population behavior and treatment differences that could not be predicted in whole-community studies of predators and parasitoids. A more conclusive test of the impact of Bt rice will require field experiments with transgenic plants, conducted in a range of Asian environments, and over multiple cropping seasons

Life history and host plant assessment of the cacao mirid bug Helopeltis bakeri poppius (Hemiptera: Miridae)

Helopeltis bakeri Poppius is a major insect pest of cacao, Theobroma cacao L. in the Philippines. It is one of the four Helopeltis species endemic to the Philippines, easily recognizable for its sexual dimorphism. Up to date, no developmental biology and host plant list have been recorded for H. bakeri. Here, we report its life history, conduct surveys, and present potential host plant species. Biological characteristics of H. bakeri reared on Ipomea batatas (L.) Poir. shoots were observed in the laboratory at 27±1 °C, 59 to 73% RH, and L12:D12. Five nymphal stages were recorded. Egg incubation period was 7.49±0.43 days, and the duration of each of the fve developmental stages was 3.11±0.53, 1.51±0.37, 2.07±0.11, 4.40±0.32 and 4.45±0.17 days, respectively. Adult longevity was not signifcantly diferent between both sexes. We also provided morphological descriptions and measurements of the immature stages to aid proper nymphal identifcation of H. bakeri. No choice tests and feld observations revealed four potential host plants, i.e., Chromolaena odorata (L.) R King & H Robinson, Cucumis sativus L., Hibiscus rosasinensis L., and Psidium guajava L., and two plants, i.e., Polyscias scutellaria (Burm. f.) Fosb. and Ipomea batatas (L.) Poir with confrmed host association. The information gathered on the life history, and host plant associations of H. bakeri would help decide the appropriate pest management strategy for controlling the population of this insect pest in the country’s cacao-growing areas