Moses T. K. Kairo

Host Age Choice for Oviposition in Pauesia juniperorum (Hymenoptera: Braconidae: Aphidiinae) and its Effect on the Parasitoid's Biology and Host Population Growth

Pauesia juniperorum has been selected as a potential agent for the biological control of Cinara cupressivora, an important introduced pest of conifers in Africa. As part of the pre-introductory assessment studies, selection of different host age categories for oviposition was studied in choice and no choice experiments. The duration of development and adult size of parasitoid progeny developing in different host age categories were compared. The effects of parasitism on survival and reproduction of five categories of the apterous morph of the host ranging in age from 3-15 days was also studied. The age of hosts had a significant influence on the degree with which different categories were parasitized. Host defensive behaviour, which increased with age, influenced the outcome of attempts by the parasitoid to oviposit. The effect was greater in older hosts, but in young hosts their small size was more important in enabling aphids to escape parasitism. The duration of development decreased while adult size i...

Egg Parasitoids Attacking Cactoblastis cactorum (Lepidoptera: Pyralidae) in North Florida

ABSTRACT Interest in the natural enemies of Cactoblastis cactorum (Berg) has increased since the moth was found in Florida in 1989. Previous surveys for natural enemies in Argentina identified egg parasitoids in the family Trichogrammatidae as potentially important control agents of C. cactorum. A study was conducted in north Florida to identify and to assess occurrence of egg parasitoids attacking this invasive moth in its new homeland. Surveys undertaken at 6 locations in north Florida from Jul 2008 to Dec 2009 revealed that eggsticks of C. cactorum were attacked by egg parasitoids from the Trichogramma genus: T. pretiosum Riley, T. fuentesi Torre, and an additional unidentified Trichogramma species belonging to the T. pretiosum group. In order to assess the importance of these egg parasitoids, the fate of individual C. cactorum eggsticks was determined during weekly visits to each site. This assessment showed that the combined level of parasitism of C. cactorum eggsticks was very low with less than 0.2% of host eggs attacked at any one of the 6 sites. While parasitoids attacked smaller eggsticks, there was no correlation between the numbers of eggs in an eggstick attacked with increasing number of eggs/eggstick. Comparing the mean number of eggs/eggstick, there was no difference between the 3 flight periods of C. cactorum, but there was a difference between the 6 sites. Based on these results, the use of Trichogramma wasps as an inundative biological control agent, complementary to the Sterile Insect Technique application, is discussed.

Laboratory Biological Parameters of Trichogramma fuentesi (Hymenoptera: Trichogrammatidae), an Egg Parasitoid of Cactoblastis cactorum (Lepidoptera: Pyralidae)

ABSTRACT Trichogramma fuentesi Torre was identified attacking Cactoblastis cactorum (Berg), a serious pest of Opuntia spp. in North America, raising the possibility of using this egg parasitoid as an inundative biological control agent. Studies were conducted to assess the biological parameters of this parasitoid under laboratory conditions. Nutritive quality influence of the rearing supplement on the parasitoids longevity, mating, and age was evaluated based on the level of parasitism. The presence and type of food source had a positive impact on female longevity, and female parasitoids given a diet composed of pure honey lived the longest; an average of 11 d. Mated females parasitized a greater number of C. cactorum host eggs than did unmated females. Percent parasitism significantly decreased with female age. Two- to 3-day old female parasitoids had the highest level of parasitism. Two-day old host eggs were the optimal host egg age for parasitization by T. fuentesi. In the context of implementing an inundative biological control program against C. cactorum, two-day old mated and honey fed Trichogramma females should be released to increase level of control.

New Record of Hypogeococcus pungens (Hemiptera: Pseudococcidae) in the Dominican Republic with Comments on Specific Characters

The mealybug Hypogeococcus pungens Granara de Willink (Hemiptera: Pseudococcidae) is a new record for the Dominican Republic, based on specimens collected on 21 May 2010 from the ornamental plant Gomphrena globosa L. (Caryophyllales: Amaranthaceae), in Santo Domingo. La especie Hypogeococcus pungens Granara de Willink (Hemiptera: Pseudococcidae) fue encontrada el 21 de mayo del 2010 como un nuevo record para la Republica Dominicana, especimenes fueron colectados en Santo Domingo sobre la planta ornamental Gomphrena globosa L. (Caryophyllales: Amaranthaceae). View this article in BioOne

Host Specificity and Risk Assessment of Trichogramma fuentesi (Hymenoptera: Trichogrammatidae), a Potential Biological Agent of Cactoblastis cactorum (Lepidoptera: Pyralidae)

Abstract Cactoblastis cactorum (Berg) (Lepidoptera: Pyralidae) is a non-native moth attacking prickly pear cactus, Opuntia spp., in southeastern U.S. The insect is also an important threat to ecological systems and to native and endangered Opuntia spp. in southwestern USA. The egg parasitoid Trichogramma fuentesi Torre (Hymenoptera: Trichogrammatidae) was discovered attacking wild C. cactorum in Florida. To evaluate the potential effect of inundative releases of T. fuentesi against C. cactorum, the host searching behavior of T. fuentesi on C. cactorum eggs and host suitability of selected lepidopteran eggs were studied in the laboratory. Host suitability was studied on the native blue cactus moth, Melitara prodenialis Walker, and 6 selected species of butterfly eggs [Danaus plexippus (L.), Dryas iulia (Hübner), Junonia coenia (Hübner), Papilio glaucus (L.), Papilio polyxenes (F.), and Vanessa cardui (L.)] to assess the potential for non-target effects from T. fuentesi. The proportion of parasitism of the native cactus moth (M. prodenialis) was 98%; significantly higher than the non-native cactus moth, C. cactorum (11% average parasitism rate). The high proportion of parasitism for all native non-target species tested and the lowest proportion of parasitism for the exotic target species suggested that T. fuentesi not be considered for inundative releases in a biological control approach against C. cactorum.

Does Secondary Plant Metabolism Provide a Mechanism for Plant Defenses in the Tropical Soda Apple Solanum Viarum (Solanales: Solanaceae) against Spodoptera exigua and S. eridania (Lepidoptera: Noctuidae)?

Abstract Survival assays were conducted with beet armyworm Spodoptera exigua (Hübner) and southern armyworm S. eridania (Stoll) with tropical soda apple Solanum viarum Dunal, a relative of tomato. In addition, polyphenol oxidase (PPO) enzyme assays were conducted to determine if plant defense compounds are being produced by tropical soda apple in response to herbivory. Both S. exigua and S. eridania induced plant defenses in tropical soda apple. Significantly more S. exigua and S. eridania neonate larvae survived to 2nd instar on non-induced plants and artificial diet when compared with plants with induced defenses. Tropical soda apple plants fed on by S. exigua and S. eridania had significantly increased PPO activity.

Influence of sun and shade conditions on Gratiana boliviana (Coleoptera: Chrysomelidae) abundance and feeding activity on tropical soda apple (Solanaceae) under field conditions

Summary Tropical soda apple is a perennial invasive weed species that has become a serious problem in both agricultural and natural areas of the southeastern United States. A field survey was conducted at a ranch in Madison County, Florida, to assess the effect of sun and shade conditions on the abundance and feeding activity of Gratiana boliviana Spaeth (Coleoptera: Chrysomelidae) on tropical soda apple. The results revealed that beetle abundance and their feeding damage were greater on plants growing in full sun exposure than on plants growing in shaded habitat.

Notes on the Ovipositional Behavior of Trichogramma fuentesi (Hymenoptera: Trichogrammatidae), an Egg Parasitoid of Cactoblastis cactorum (Lepidoptera: Pyralidae)

Our study characterized host searching and oviposition ability of T. fuentesi . In general, female wasps walked to a C. cactorum egg, drummed over the surface, drilled into the chorion, and deposited an egg. Grooming and resting behaviors were observed infrequently and host feeding was never recorded. In a typical observation period of 60 min with eggs of the exotic C. cactorum , female parasitoids spent 16% of their time drumming, 4% drilling, and 8% egg laying into the selected host. Most of the oviposition behaviors happened in the first hour. Nuestro estudio caracterizo la busqueda de hospedero y la capacidad de oviposicion de Trichogramma fuentesi . En general, las avispas hembras caminaron hacia los huevos de Cactoblastis cactorum, pegaron sus antenas sobre la superficie de los huevos como un tambor (en tamboreo), perforaron el corion y depositaron su huevo adentro. Los comportamientos de aseo y de descanso fueron observados con poca frecuencia y la alimentacion sobre el hospedero no fue registrada. En un periodo de observacion tipica de 60 min con los huevos de la especie exotica C. cactorum , los parasitoides hembras pasaron el 16% de su tiempo en tamboreo, el 4% perforando y el 8% poniendo huevos dentro de los hospederos seleccionados. La mayoria del comportamiento de oviposicion ocurrio en la primera hora. View this article in BioOne

TROPICAL SODA APPLE (SOLANUM VIARUM) MEDIATED COMPETITION VIA INDUCED RESISTANCE: INTERACTION BETWEEN GRATIANA BOLIVIANA, SPODOPTERA EXIGUA AND FRANKLINIELLA OCCIDENTALIS 1

ABSTRACT Survival assays were conducted with beet armyworm (BAW), Spodoptera exigua (Hübner), a tortoise beetle, Gratiana bolivana Spaeth, and western flower thrips (WFT), Frankliniella occidentalis (Pergande), on tropical soda apple (TSA), Solanum viarum Dunal, a relative of tomato. Both S. exigua and G. boliviana seem to induce plant defenses in tropical soda apple. Significantly more S. exigua neonate larvae survived to second instar on non-induced plants and artificial diet when compared with plants with induced defenses. Our results further suggest that the induced response in TSA was systemic, since BAW neonates suffered higher mortality in induced plants despite not being in direct contact with the damaged part of the plant. Results suggested that feeding action of G. boliviana on TSA had no significant influence on WFT host choice.