N. C. Leppla

Advances in insect rearing for research and pest management

The efficient production of large numbers of high-quality insects is a concern both for basic research and for the success of control programmes for pests of agricultural and medical significance. This volume provides a comprehensive overview of this important issue, identifying the major applications for insect-rearing technology. The chapters, international in scope, cover genetics and molecular biology; insect rearing and the development of bioengineered crops; nutrition, digestion and artificial diets; and the practical concerns of commercial insect rearing.

STRATEGIES FOR COLONIZATION AND MAINTENANCE OF THE MEDITERRANEAN FRUIT FLY

Colonies of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae) were established from field‐collected pupae and reared for 12 generations (G) using 3 different methods; given special care (C). eased from special care into mass rearing (E), and forced directly into mass rearing (F). The respective average numbers of viable pupae per ♀ increased from 1.5, 1.7, and 2.0 at G1 to 6.3, 6.6, and 8.5 at G12. The number of viable eggs per fertile ♀, though varying greatly depending on generation, never had an increasing or decreasing trend. Thus, since the fertility of individual ♀ ♀ remained relatively constant, improved yields were primarily due to an increase in the proportion of reproducing females. Furthermore, switching the E colony to the F regimen after G5 was as detrimental as initial colonization.

Identification of a sex pheromone produced by female velvetbean caterpillar moth

A sex pheromone produced by female velvetbean caterpillar moths,Anticarsia gemmatalis Hübner, that attracts conspecific males was isolated and identified as a blend of (Z,Z,Z)-3,6,9-eicosatriene and (Z,Z,Z)-3,6,9-heneicosatriene in a ratio of ca. 5∶3, respectively, when combined. The synthesized compounds elicited responses by velvetbean caterpillar moth males equivalent to those elicited by females in both laboratory wind tunnel bioassays and field trapping experiments.

Reproductive systems and the mechanics of copulation in Plecia nearctica Hardy (Diptera: Bibionidae)

Abstract In Plecia nearctica Hardy, sperm transfer is accomplished by means of spermatophore complex unique to the Bibionidae. Males possess well-developed accessory glands that establish and provision large bilobed spermatophores. The recipient female system is composed of a “pelvis-like” structure that envelops sinuous accessory glands, a bulbous bursa, and paired spermathecae attached to elongate ducts branching from the copulatory canal. After completion of two preliminary phases of copulation, coupling and clasping in three interlocking layers, semen is exchanged by extrusion of a filament from the distal spermatophore to the proximal bursa. Branches of the spermatophore filament also extend into the spermathecal ducts; however, the spermatophore proper remains in the male, and is expelled within seconds after disengagement.

Identification of a male-produced pheromone ofAnticarsia gemmatalis (Hübner) (Lepidoptera; Noctuidae) attractive to conspecific males

Observations in the laboratory and in the field indicated that maleAnticarsia gemmatalis (Hübner), the velvetbean caterpillar (VBC), are attracted to conspecific courting males. Male VBC subsequently were found to be attracted to extracts of male abdominal tips including the extrudable hairpencils. The active chemical in these extracts was identified as (Z,Z,Z)-3,6,9-heneicosatriene, which is also one of the major components of the female VBC sex pheromone. Male VBC in a wind tunnel and in the field exhibited a bimodal response distribution to a range of ratios of the (Z,Z,Z)-3,6,9-heneicosatriene and (Z,Z,Z)-3,6,9-eicosatriene, with one maximum at the pure heneicosatriene alone and the other at the 60∶40 female blend. This demonstrates that the male response to the male hairpencil component is distinct from that to the female sex pheromone.

Parasites Attacking Fall Armyworm Larvae, Spodoptera Frugiperda, in Late Planted Field Corn

Parasites emerged from larvae of the fall armyworm, Spodoptera frugiperda (J. E. Smith), collected from (1) under the husks of corn ears, (2) exposed surface areas of corn plants, and (3) broadleaf signalgrass, Brachiaria platyphylla (Griseb.) Nash. Mortality was highest among larvae collected from the signalgrass and lowest among those gathered from the surface areas of the corn plants. Eight species of parasites, representing the Braconidae, Eulophidae, Ichneumonidae, and Tachinidae were collected. Chelonus texanus Cresson caused the highest mortality followed by Meteorus autographae Muesebeck and Euplectrus platyhypenae Howard.

The role of parasitoid and predator production in technology transfer of field crop biological control

The immediate goals for improving natural enemy production are to reduce costs, increase efficacy and provide additional species for pest management. This paper describes expanding markets for natural enemies that are or could be produced commercially, gives operational and experimental examples of parasitoid and predator production for use in field crop biological control, defines some of the obstacles and makes recommendations for producing and using natural enemies. Additionally, it provides recent published guidance for implementing biological control in Integrated Pest Management.RésuméL’amélioration de la production en masse d’ennemis naturels implique en premier lieu une diminution des coûts, une augmentation de l’efficacité et le recours à de nouvelles espèces pour lutter contre les nuisibles. On décrit les débouchés commerciaux qui s’offrent maintenant aux ennemis naturels produits en masse ou susceptibles de l’être. Divers exemples de systèmes opérationnels et expérimentaux sont mentionnés, qui permettent de produire en masse les parasitoïdes et prédateurs destinés à la lutte biologique en cultures de plein champ. On évoque ensuite les principaux obstacles à surmonter et donne des recommandations concrètes quant à la production en masse et à l’utilisation d’ennemis naturels. Enfin, on montre à l’aide de cas récents comment la pratique de la lutte biologique s’insère dans le cadre de la protection intégrée

Circadian rhythms of the German cockroach (Dictyoptera: Blattellidae): Locomotion in response to different photoperiods and wavelengths of light

Abstract Male German cockroaches, Blattella germanica (L.), exposed to 12 h light-12 h dark, constant darkness and constant light in ultraviolet (u.v., 365 nm peak), blue green (495 nm peak) or white (about 400–1100 nm) light exhibited different rhythms and magnitudes of locomotion. All wavelengths induced a bimodal pattern of nocturnal activity in 12 h light-12 h dark, which was maintained as a free-running rhythm with a shorter period in constant darkness; activity was suppressed in constant light. Ultraviolet caused the greatest change in locomotion during transitions between photoperiods, but blue-green established a free-running rhythm that was maintained for longer. Since different sensory cells and perhaps pathways are involved in processing ultraviolet and blue-green light, ultraviolet could mediate direct responses to light stimuli and blue-green may regulate more complex behaviour.

MANAGEMENT OF PEST MOLE CRICKETS IN FLORIDA AND PUERTO RICO WITH A NEMATODE AND PARASITIC WASP

Abstract Non-indigenous invasive mole crickets, Scapteriscus vicinus Scudder (Orthoptera: Gryllotalpidae) in Florida and S. didactylus (Latreille) (the “changa”) in Puerto Rico, are being managed with an entomopathogenic nematode, Steinernema scapterisci (Nguyen and Smart) (Rhabditida: Steinernematidae), and a parasitic wasp, Larra bicolor L. (Hymenoptera: Sphecidae). Pest mole cricket populations have declined by 95% in north central Florida since these specialist natural enemies were released and established in the 1980s. Commercial production of the nematode was initiated, nearly 70 billion were applied in 34 Florida counties, and their establishment, spread, and impact on mole crickets were monitored. The infected mole crickets dispersed the nematode rapidly, so that within 6 months these parasites were present in most of the insects trapped in experimental pastures. Three years later, mole cricket populations were reduced to acceptable levels and the bahiagrass had recovered. The nematode was released for the first time in Puerto Rico during 2001 and has persisted; the wasp was introduced in the late 1930s. The geographical distribution of the wasp is being expanded in Florida and Puerto Rico by planting plots of Spermacoce verticillata (L.), a wildflower indigenous to Puerto Rico and widely distributed in southern Florida. Pastures, sod farms, golf courses, landscapes, and vegetable farms in Florida and Puerto Rico are benefiting from biological control of invasive mole crickets.

Comparison of Host-Seeking Behavior of the Filth Fly Pupal Parasitoids, Spalangia cameroni and Muscidifurax raptor (Hymenoptera: Pteromalidae)

ABSTRACT The pupal parasitoids, Spalangia cameroni Perkins and Muscidifurax raptor Girault and Sanders, can be purchased for biological control of house flies Musca domestica L. and stable flies Stomoxys calcitrans (L.) (Diptera: Muscidae). Little is known about the odors involved in host-seeking behavior of these two species, so odors associated with house flies were investigated in the laboratory using a Y-tube olfactometer. Odor stimuli from house fly host puparia, larvae, pine-shavings bedding with horse manure, and developing flies in the pine-shavings-manure substrate were evaluated in bioassays using the two pteromalid species. In choice tests, naïve female S. cameroni were strongly attracted to odor from the substrate containing house fly larvae and secondarily from the uninfested substrate and substrate with puparia versus humidified and purified air. This species also selected the substrate with larvae versus the substrate with the house fly puparia or uninfested substrate. Muscidifurax raptor was attracted to odor from the substrate containing puparia, washed puparia, and substrate with puparia removed. The data suggest that coexistence between the two pteromalid parasitoids, S. cameroni and M. raptor, might be promoted by different host-seeking behavior.